[gcc.git] / gcc / c-common.c

/* Subroutines shared by all languages that are variants of C.
   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000
   Free Software Foundation, Inc.

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.h"
#include "tree.h"
#include "flags.h"
#include "toplev.h"
#include "output.h"
#include "c-pragma.h"
#include "rtl.h"
#include "ggc.h"
#include "expr.h"
#include "c-common.h"
#include "tm_p.h"
#include "intl.h"
#include "diagnostic.h"

#if USE_CPPLIB
#include "cpplib.h"
cpp_reader  parse_in;
#endif

#undef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE TYPE_PRECISION (wchar_type_node)

/* The following symbols are subsumed in the c_global_trees array, and
   listed here individually for documentation purposes.

   INTEGER_TYPE and REAL_TYPE nodes for the standard data types.

        tree short_integer_type_node;
        tree long_integer_type_node;
        tree long_long_integer_type_node;

        tree short_unsigned_type_node;
        tree long_unsigned_type_node;
        tree long_long_unsigned_type_node;

        tree boolean_type_node;
        tree boolean_false_node;
        tree boolean_true_node;

        tree ptrdiff_type_node;

        tree unsigned_char_type_node;
        tree signed_char_type_node;
        tree wchar_type_node;
        tree signed_wchar_type_node;
        tree unsigned_wchar_type_node;

        tree float_type_node;
        tree double_type_node;
        tree long_double_type_node;

        tree complex_integer_type_node;
        tree complex_float_type_node;
        tree complex_double_type_node;
        tree complex_long_double_type_node;

        tree intQI_type_node;
        tree intHI_type_node;
        tree intSI_type_node;
        tree intDI_type_node;
        tree intTI_type_node;

        tree unsigned_intQI_type_node;
        tree unsigned_intHI_type_node;
        tree unsigned_intSI_type_node;
        tree unsigned_intDI_type_node;
        tree unsigned_intTI_type_node;

        tree widest_integer_literal_type_node;
        tree widest_unsigned_literal_type_node;

   Nodes for types `void *' and `const void *'.

        tree ptr_type_node, const_ptr_type_node;

   Nodes for types `char *' and `const char *'.

        tree string_type_node, const_string_type_node;

   Type `char[SOMENUMBER]'.
   Used when an array of char is needed and the size is irrelevant.

        tree char_array_type_node;

   Type `int[SOMENUMBER]' or something like it.
   Used when an array of int needed and the size is irrelevant.

        tree int_array_type_node;

   Type `wchar_t[SOMENUMBER]' or something like it.
   Used when a wide string literal is created.

        tree wchar_array_type_node;

   Type `int ()' -- used for implicit declaration of functions.

        tree default_function_type;

   Function types `int (int)', etc.

        tree int_ftype_int;
        tree void_ftype;
        tree void_ftype_ptr;
        tree int_ftype_int;
        tree ptr_ftype_sizetype;

   A VOID_TYPE node, packaged in a TREE_LIST.

        tree void_list_node;

  The identifiers __FUNCTION__, __PRETTY_FUNCTION__, and __func__.

        tree function_id_node;
        tree pretty_function_id_node;
        tree func_id_node;

*/

tree c_global_trees[CTI_MAX];

/* The elements of `ridpointers' are identifier nodes for the reserved
   type names and storage classes.  It is indexed by a RID_... value.  */
tree *ridpointers;

tree (*make_fname_decl)                PARAMS ((tree, const char *, int));

/* If non-NULL, the address of a language-specific function that
   returns 1 for language-specific statement codes.  */
int (*lang_statement_code_p)           PARAMS ((enum tree_code));

/* If non-NULL, the address of a language-specific function that takes
   any action required right before expand_function_end is called.  */
void (*lang_expand_function_end)       PARAMS ((void));

/* Nonzero means the expression being parsed will never be evaluated.
   This is a count, since unevaluated expressions can nest.  */
int skip_evaluation;

enum attrs {A_PACKED, A_NOCOMMON, A_COMMON, A_NORETURN, A_CONST, A_T_UNION,
            A_NO_CHECK_MEMORY_USAGE, A_NO_INSTRUMENT_FUNCTION,
            A_CONSTRUCTOR, A_DESTRUCTOR, A_MODE, A_SECTION, A_ALIGNED,
            A_UNUSED, A_FORMAT, A_FORMAT_ARG, A_WEAK, A_ALIAS, A_MALLOC,
            A_NO_LIMIT_STACK, A_PURE};

enum format_type { printf_format_type, scanf_format_type,
                   strftime_format_type };

static void add_attribute               PARAMS ((enum attrs, const char *,
                                                 int, int, int));
static void init_attributes             PARAMS ((void));
static void record_function_format      PARAMS ((tree, tree, enum format_type,
                                                 int, int));
static void record_international_format PARAMS ((tree, tree, int));
static int default_valid_lang_attribute PARAMS ((tree, tree, tree, tree));

/* Keep a stack of if statements.  We record the number of compound
   statements seen up to the if keyword, as well as the line number
   and file of the if.  If a potentially ambiguous else is seen, that
   fact is recorded; the warning is issued when we can be sure that
   the enclosing if statement does not have an else branch.  */
typedef struct
{
  int compstmt_count;
  int line;
  const char *file;
  int needs_warning;
  tree if_stmt;
} if_elt;

static if_elt *if_stack;

/* Amount of space in the if statement stack.  */
static int if_stack_space = 0;

/* Stack pointer.  */
static int if_stack_pointer = 0;

/* Record the start of an if-then, and record the start of it
   for ambiguous else detection.  */

void
c_expand_start_cond (cond, compstmt_count)
     tree cond;
     int compstmt_count;
{
  tree if_stmt;

  /* Make sure there is enough space on the stack.  */
  if (if_stack_space == 0)
    {
      if_stack_space = 10;
      if_stack = (if_elt *)xmalloc (10 * sizeof (if_elt));
    }
  else if (if_stack_space == if_stack_pointer)
    {
      if_stack_space += 10;
      if_stack = (if_elt *)xrealloc (if_stack, if_stack_space * sizeof (if_elt));
    }

  if_stmt = build_stmt (IF_STMT, NULL_TREE, NULL_TREE, NULL_TREE);
  IF_COND (if_stmt) = cond;
  add_stmt (if_stmt);

  /* Record this if statement.  */
  if_stack[if_stack_pointer].compstmt_count = compstmt_count;
  if_stack[if_stack_pointer].file = input_filename;
  if_stack[if_stack_pointer].line = lineno;
  if_stack[if_stack_pointer].needs_warning = 0;
  if_stack[if_stack_pointer].if_stmt = if_stmt;
  if_stack_pointer++;
}

/* Called after the then-clause for an if-statement is processed.  */

void
c_finish_then ()
{
  tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
  RECHAIN_STMTS (if_stmt, THEN_CLAUSE (if_stmt));
}

/* Record the end of an if-then.  Optionally warn if a nested
   if statement had an ambiguous else clause.  */

void
c_expand_end_cond ()
{
  if_stack_pointer--;
  if (if_stack[if_stack_pointer].needs_warning)
    warning_with_file_and_line (if_stack[if_stack_pointer].file,
                                if_stack[if_stack_pointer].line,
                                "suggest explicit braces to avoid ambiguous `else'");
  last_expr_type = NULL_TREE;
}

/* Called between the then-clause and the else-clause
   of an if-then-else.  */

void
c_expand_start_else ()
{
  /* An ambiguous else warning must be generated for the enclosing if
     statement, unless we see an else branch for that one, too.  */
  if (warn_parentheses
      && if_stack_pointer > 1
      && (if_stack[if_stack_pointer - 1].compstmt_count
          == if_stack[if_stack_pointer - 2].compstmt_count))
    if_stack[if_stack_pointer - 2].needs_warning = 1;

  /* Even if a nested if statement had an else branch, it can't be
     ambiguous if this one also has an else.  So don't warn in that
     case.  Also don't warn for any if statements nested in this else.  */
  if_stack[if_stack_pointer - 1].needs_warning = 0;
  if_stack[if_stack_pointer - 1].compstmt_count--;
}

/* Called after the else-clause for an if-statement is processed.  */

void
c_finish_else ()
{
  tree if_stmt = if_stack[if_stack_pointer - 1].if_stmt;
  RECHAIN_STMTS (if_stmt, ELSE_CLAUSE (if_stmt));
}

/* Make bindings for __FUNCTION__, __PRETTY_FUNCTION__, and __func__.  */

void
declare_function_name ()
{
  const char *name, *printable_name;

  if (current_function_decl == NULL)
    {
      name = "";
      printable_name = "top level";
    }
  else
    {
      /* Allow functions to be nameless (such as artificial ones).  */
      if (DECL_NAME (current_function_decl))
        name = IDENTIFIER_POINTER (DECL_NAME (current_function_decl));
      else
        name = "";
      printable_name = (*decl_printable_name) (current_function_decl, 2);

      /* ISO C99 defines __func__, which is a variable, not a string
         constant, and which is not a defined symbol at file scope.  */
      (*make_fname_decl) (func_id_node, name, 0);
    }
  
  (*make_fname_decl) (function_id_node, name, 0);
  (*make_fname_decl) (pretty_function_id_node, printable_name, 1);
}

/* Given a chain of STRING_CST nodes,
   concatenate them into one STRING_CST
   and give it a suitable array-of-chars data type.  */

tree
combine_strings (strings)
     tree strings;
{
  register tree value, t;
  register int length = 1;
  int wide_length = 0;
  int wide_flag = 0;
  int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
  int nchars;
  const int nchars_max = flag_isoc99 ? 4095 : 509;

  if (TREE_CHAIN (strings))
    {
      /* More than one in the chain, so concatenate.  */
      register char *p, *q;

      /* Don't include the \0 at the end of each substring,
         except for the last one.
         Count wide strings and ordinary strings separately.  */
      for (t = strings; t; t = TREE_CHAIN (t))
        {
          if (TREE_TYPE (t) == wchar_array_type_node)
            {
              wide_length += (TREE_STRING_LENGTH (t) - wchar_bytes);
              wide_flag = 1;
            }
          else
            length += (TREE_STRING_LENGTH (t) - 1);
        }

      /* If anything is wide, the non-wides will be converted,
         which makes them take more space.  */
      if (wide_flag)
        length = length * wchar_bytes + wide_length;

      p = ggc_alloc_string (NULL, length);

      /* Copy the individual strings into the new combined string.
         If the combined string is wide, convert the chars to ints
         for any individual strings that are not wide.  */

      q = p;
      for (t = strings; t; t = TREE_CHAIN (t))
        {
          int len = (TREE_STRING_LENGTH (t)
                     - ((TREE_TYPE (t) == wchar_array_type_node)
                        ? wchar_bytes : 1));
          if ((TREE_TYPE (t) == wchar_array_type_node) == wide_flag)
            {
              memcpy (q, TREE_STRING_POINTER (t), len);
              q += len;
            }
          else
            {
              int i;
              for (i = 0; i < len; i++)
                {
                  if (WCHAR_TYPE_SIZE == HOST_BITS_PER_SHORT)
                    ((short *) q)[i] = TREE_STRING_POINTER (t)[i];
                  else
                    ((int *) q)[i] = TREE_STRING_POINTER (t)[i];
                }
              q += len * wchar_bytes;
            }
        }
      if (wide_flag)
        {
          int i;
          for (i = 0; i < wchar_bytes; i++)
            *q++ = 0;
        }
      else
        *q = 0;

      value = make_node (STRING_CST);
      TREE_STRING_POINTER (value) = p;
      TREE_STRING_LENGTH (value) = length;
    }
  else
    {
      value = strings;
      length = TREE_STRING_LENGTH (value);
      if (TREE_TYPE (value) == wchar_array_type_node)
        wide_flag = 1;
    }

  /* Compute the number of elements, for the array type.  */
  nchars = wide_flag ? length / wchar_bytes : length;

  if (pedantic && nchars > nchars_max)
    pedwarn ("string length `%d' is greater than the minimum length `%d' ISO C%d is required to support",
             nchars, nchars_max, flag_isoc99 ? 99 : 89);

  /* Create the array type for the string constant.
     -Wwrite-strings says make the string constant an array of const char
     so that copying it to a non-const pointer will get a warning.
     For C++, this is the standard behavior.  */
  if (flag_const_strings
      && (! flag_traditional  && ! flag_writable_strings))
    {
      tree elements
        = build_type_variant (wide_flag ? wchar_type_node : char_type_node,
                              1, 0);
      TREE_TYPE (value)
        = build_array_type (elements,
                            build_index_type (build_int_2 (nchars - 1, 0)));
    }
  else
    TREE_TYPE (value)
      = build_array_type (wide_flag ? wchar_type_node : char_type_node,
                          build_index_type (build_int_2 (nchars - 1, 0)));

  TREE_CONSTANT (value) = 1;
  TREE_READONLY (value) = ! flag_writable_strings;
  TREE_STATIC (value) = 1;
  return value;
}
\f
/* To speed up processing of attributes, we maintain an array of
   IDENTIFIER_NODES and the corresponding attribute types.  */

/* Array to hold attribute information.  */

static struct {enum attrs id; tree name; int min, max, decl_req;} attrtab[50];

static int attrtab_idx = 0;

/* Add an entry to the attribute table above.  */

static void
add_attribute (id, string, min_len, max_len, decl_req)
     enum attrs id;
     const char *string;
     int min_len, max_len;
     int decl_req;
{
  char buf[100];

  attrtab[attrtab_idx].id = id;
  attrtab[attrtab_idx].name = get_identifier (string);
  attrtab[attrtab_idx].min = min_len;
  attrtab[attrtab_idx].max = max_len;
  attrtab[attrtab_idx++].decl_req = decl_req;

  sprintf (buf, "__%s__", string);

  attrtab[attrtab_idx].id = id;
  attrtab[attrtab_idx].name = get_identifier (buf);
  attrtab[attrtab_idx].min = min_len;
  attrtab[attrtab_idx].max = max_len;
  attrtab[attrtab_idx++].decl_req = decl_req;
}

/* Initialize attribute table.  */

static void
init_attributes ()
{
  add_attribute (A_PACKED, "packed", 0, 0, 0);
  add_attribute (A_NOCOMMON, "nocommon", 0, 0, 1);
  add_attribute (A_COMMON, "common", 0, 0, 1);
  add_attribute (A_NORETURN, "noreturn", 0, 0, 1);
  add_attribute (A_NORETURN, "volatile", 0, 0, 1);
  add_attribute (A_UNUSED, "unused", 0, 0, 0);
  add_attribute (A_CONST, "const", 0, 0, 1);
  add_attribute (A_T_UNION, "transparent_union", 0, 0, 0);
  add_attribute (A_CONSTRUCTOR, "constructor", 0, 0, 1);
  add_attribute (A_DESTRUCTOR, "destructor", 0, 0, 1);
  add_attribute (A_MODE, "mode", 1, 1, 1);
  add_attribute (A_SECTION, "section", 1, 1, 1);
  add_attribute (A_ALIGNED, "aligned", 0, 1, 0);
  add_attribute (A_FORMAT, "format", 3, 3, 1);
  add_attribute (A_FORMAT_ARG, "format_arg", 1, 1, 1);
  add_attribute (A_WEAK, "weak", 0, 0, 1);
  add_attribute (A_ALIAS, "alias", 1, 1, 1);
  add_attribute (A_NO_INSTRUMENT_FUNCTION, "no_instrument_function", 0, 0, 1);
  add_attribute (A_NO_CHECK_MEMORY_USAGE, "no_check_memory_usage", 0, 0, 1);
  add_attribute (A_MALLOC, "malloc", 0, 0, 1);
  add_attribute (A_NO_LIMIT_STACK, "no_stack_limit", 0, 0, 1);
  add_attribute (A_PURE, "pure", 0, 0, 1);
}
\f
/* Default implementation of valid_lang_attribute, below.  By default, there
   are no language-specific attributes.  */

static int
default_valid_lang_attribute (attr_name, attr_args, decl, type)
  tree attr_name ATTRIBUTE_UNUSED;
  tree attr_args ATTRIBUTE_UNUSED;
  tree decl ATTRIBUTE_UNUSED;
  tree type ATTRIBUTE_UNUSED;
{
  return 0;
}

/* Return a 1 if ATTR_NAME and ATTR_ARGS denote a valid language-specific
   attribute for either declaration DECL or type TYPE and 0 otherwise.  */

int (*valid_lang_attribute) PARAMS ((tree, tree, tree, tree))
     = default_valid_lang_attribute;

/* Process the attributes listed in ATTRIBUTES and PREFIX_ATTRIBUTES
   and install them in NODE, which is either a DECL (including a TYPE_DECL)
   or a TYPE.  PREFIX_ATTRIBUTES can appear after the declaration specifiers
   and declaration modifiers but before the declaration proper.  */

void
decl_attributes (node, attributes, prefix_attributes)
     tree node, attributes, prefix_attributes;
{
  tree decl = 0, type = 0;
  int is_type = 0;
  tree a;

  if (attrtab_idx == 0)
    init_attributes ();

  if (DECL_P (node))
    {
      decl = node;
      type = TREE_TYPE (decl);
      is_type = TREE_CODE (node) == TYPE_DECL;
    }
  else if (TYPE_P (node))
    type = node, is_type = 1;

#ifdef PRAGMA_INSERT_ATTRIBUTES
  /* If the code in c-pragma.c wants to insert some attributes then
     allow it to do so.  Do this before allowing machine back ends to
     insert attributes, so that they have the opportunity to override
     anything done here.  */
  PRAGMA_INSERT_ATTRIBUTES (node, & attributes, & prefix_attributes);
#endif

#ifdef INSERT_ATTRIBUTES
  INSERT_ATTRIBUTES (node, & attributes, & prefix_attributes);
#endif

  attributes = chainon (prefix_attributes, attributes);

  for (a = attributes; a; a = TREE_CHAIN (a))
    {
      tree name = TREE_PURPOSE (a);
      tree args = TREE_VALUE (a);
      int i;
      enum attrs id;

      for (i = 0; i < attrtab_idx; i++)
        if (attrtab[i].name == name)
          break;

      if (i == attrtab_idx)
        {
          if (! valid_machine_attribute (name, args, decl, type)
              && ! (* valid_lang_attribute) (name, args, decl, type))
            warning ("`%s' attribute directive ignored",
                     IDENTIFIER_POINTER (name));
          else if (decl != 0)
            type = TREE_TYPE (decl);
          continue;
        }
      else if (attrtab[i].decl_req && decl == 0)
        {
          warning ("`%s' attribute does not apply to types",
                   IDENTIFIER_POINTER (name));
          continue;
        }
      else if (list_length (args) < attrtab[i].min
               || list_length (args) > attrtab[i].max)
        {
          error ("wrong number of arguments specified for `%s' attribute",
                 IDENTIFIER_POINTER (name));
          continue;
        }

      id = attrtab[i].id;
      switch (id)
        {
        case A_PACKED:
          if (is_type)
            TYPE_PACKED (type) = 1;
          else if (TREE_CODE (decl) == FIELD_DECL)
            DECL_PACKED (decl) = 1;
          /* We can't set DECL_PACKED for a VAR_DECL, because the bit is
             used for DECL_REGISTER.  It wouldn't mean anything anyway.  */
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_NOCOMMON:
          if (TREE_CODE (decl) == VAR_DECL)
            DECL_COMMON (decl) = 0;
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_COMMON:
          if (TREE_CODE (decl) == VAR_DECL)
            DECL_COMMON (decl) = 1;
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_NORETURN:
          if (TREE_CODE (decl) == FUNCTION_DECL)
            TREE_THIS_VOLATILE (decl) = 1;
          else if (TREE_CODE (type) == POINTER_TYPE
                   && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
            TREE_TYPE (decl) = type
              = build_pointer_type
                (build_type_variant (TREE_TYPE (type),
                                     TREE_READONLY (TREE_TYPE (type)), 1));
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_MALLOC:
          if (TREE_CODE (decl) == FUNCTION_DECL)
            DECL_IS_MALLOC (decl) = 1;
          /* ??? TODO: Support types.  */
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_UNUSED:
          if (is_type)
            if (decl)
              TREE_USED (decl) = 1;
            else
              TREE_USED (type) = 1;
          else if (TREE_CODE (decl) == PARM_DECL
                   || TREE_CODE (decl) == VAR_DECL
                   || TREE_CODE (decl) == FUNCTION_DECL
                   || TREE_CODE (decl) == LABEL_DECL)
            TREE_USED (decl) = 1;
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_CONST:
          if (TREE_CODE (decl) == FUNCTION_DECL)
            TREE_READONLY (decl) = 1;
          else if (TREE_CODE (type) == POINTER_TYPE
                   && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
            TREE_TYPE (decl) = type
              = build_pointer_type
                (build_type_variant (TREE_TYPE (type), 1,
                                     TREE_THIS_VOLATILE (TREE_TYPE (type))));
          else
            warning ( "`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_PURE:
          if (TREE_CODE (decl) == FUNCTION_DECL)
            DECL_IS_PURE (decl) = 1;
          /* ??? TODO: Support types.  */
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;


        case A_T_UNION:
          if (is_type
              && TREE_CODE (type) == UNION_TYPE
              && (decl == 0
                  || (TYPE_FIELDS (type) != 0
                      && TYPE_MODE (type) == DECL_MODE (TYPE_FIELDS (type)))))
            TYPE_TRANSPARENT_UNION (type) = 1;
          else if (decl != 0 && TREE_CODE (decl) == PARM_DECL
                   && TREE_CODE (type) == UNION_TYPE
                   && TYPE_MODE (type) == DECL_MODE (TYPE_FIELDS (type)))
            DECL_TRANSPARENT_UNION (decl) = 1;
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_CONSTRUCTOR:
          if (TREE_CODE (decl) == FUNCTION_DECL
              && TREE_CODE (type) == FUNCTION_TYPE
              && decl_function_context (decl) == 0)
            {
              DECL_STATIC_CONSTRUCTOR (decl) = 1;
              TREE_USED (decl) = 1;
            }
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_DESTRUCTOR:
          if (TREE_CODE (decl) == FUNCTION_DECL
              && TREE_CODE (type) == FUNCTION_TYPE
              && decl_function_context (decl) == 0)
            {
              DECL_STATIC_DESTRUCTOR (decl) = 1;
              TREE_USED (decl) = 1;
            }
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_MODE:
          if (TREE_CODE (TREE_VALUE (args)) != IDENTIFIER_NODE)
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          else
            {
              int j;
              const char *p = IDENTIFIER_POINTER (TREE_VALUE (args));
              int len = strlen (p);
              enum machine_mode mode = VOIDmode;
              tree typefm;

              if (len > 4 && p[0] == '_' && p[1] == '_'
                  && p[len - 1] == '_' && p[len - 2] == '_')
                {
                  char *newp = (char *) alloca (len - 1);

                  strcpy (newp, &p[2]);
                  newp[len - 4] = '\0';
                  p = newp;
                }

              /* Give this decl a type with the specified mode.
                 First check for the special modes.  */
              if (! strcmp (p, "byte"))
                mode = byte_mode;
              else if (!strcmp (p, "word"))
                mode = word_mode;
              else if (! strcmp (p, "pointer"))
                mode = ptr_mode;
              else
                for (j = 0; j < NUM_MACHINE_MODES; j++)
                  if (!strcmp (p, GET_MODE_NAME (j)))
                    mode = (enum machine_mode) j;

              if (mode == VOIDmode)
                error ("unknown machine mode `%s'", p);
              else if (0 == (typefm = type_for_mode (mode,
                                                     TREE_UNSIGNED (type))))
                error ("no data type for mode `%s'", p);
              else
                {
                  TREE_TYPE (decl) = type = typefm;
                  DECL_SIZE (decl) = DECL_SIZE_UNIT (decl) = 0;
                  layout_decl (decl, 0);
                }
            }
          break;

        case A_SECTION:
#ifdef ASM_OUTPUT_SECTION_NAME
          if ((TREE_CODE (decl) == FUNCTION_DECL
               || TREE_CODE (decl) == VAR_DECL)
              && TREE_CODE (TREE_VALUE (args)) == STRING_CST)
            {
              if (TREE_CODE (decl) == VAR_DECL
                  && current_function_decl != NULL_TREE
                  && ! TREE_STATIC (decl))
                error_with_decl (decl,
                  "section attribute cannot be specified for local variables");
              /* The decl may have already been given a section attribute from
                 a previous declaration.  Ensure they match.  */
              else if (DECL_SECTION_NAME (decl) != NULL_TREE
                       && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
                                  TREE_STRING_POINTER (TREE_VALUE (args))) != 0)
                error_with_decl (node,
                                 "section of `%s' conflicts with previous declaration");
              else
                DECL_SECTION_NAME (decl) = TREE_VALUE (args);
            }
          else
            error_with_decl (node,
                           "section attribute not allowed for `%s'");
#else
          error_with_decl (node,
                  "section attributes are not supported for this target");
#endif
          break;

        case A_ALIGNED:
          {
            tree align_expr
              = (args ? TREE_VALUE (args)
                 : size_int (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
            int i;

            /* Strip any NOPs of any kind.  */
            while (TREE_CODE (align_expr) == NOP_EXPR
                   || TREE_CODE (align_expr) == CONVERT_EXPR
                   || TREE_CODE (align_expr) == NON_LVALUE_EXPR)
              align_expr = TREE_OPERAND (align_expr, 0);

            if (TREE_CODE (align_expr) != INTEGER_CST)
              {
                error ("requested alignment is not a constant");
                continue;
              }

            if ((i = tree_log2 (align_expr)) == -1)
              error ("requested alignment is not a power of 2");
            else if (i > HOST_BITS_PER_INT - 2)
              error ("requested alignment is too large");
            else if (is_type)
              {
                /* If we have a TYPE_DECL, then copy the type, so that we
                   don't accidentally modify a builtin type.  See pushdecl.  */
                if (decl && TREE_TYPE (decl) != error_mark_node
                    && DECL_ORIGINAL_TYPE (decl) == NULL_TREE)
                  {
                    tree tt = TREE_TYPE (decl);
                    DECL_ORIGINAL_TYPE (decl) = tt;
                    tt = build_type_copy (tt);
                    TYPE_NAME (tt) = decl;
                    TREE_USED (tt) = TREE_USED (decl);
                    TREE_TYPE (decl) = tt;
                    type = tt;
                  }

                TYPE_ALIGN (type) = (1 << i) * BITS_PER_UNIT;
                TYPE_USER_ALIGN (type) = 1;
              }
            else if (TREE_CODE (decl) != VAR_DECL
                     && TREE_CODE (decl) != FIELD_DECL)
              error_with_decl (decl,
                               "alignment may not be specified for `%s'");
            else
              {
                DECL_ALIGN (decl) = (1 << i) * BITS_PER_UNIT;
                DECL_USER_ALIGN (decl) = 1;
              }
          }
          break;

        case A_FORMAT:
          {
            tree format_type_id = TREE_VALUE (args);
            tree format_num_expr = TREE_VALUE (TREE_CHAIN (args));
            tree first_arg_num_expr
              = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
            unsigned HOST_WIDE_INT format_num, first_arg_num;
            enum format_type format_type;
            tree argument;
            unsigned int arg_num;

            if (TREE_CODE (decl) != FUNCTION_DECL)
              {
                error_with_decl (decl,
                         "argument format specified for non-function `%s'");
                continue;
              }

            if (TREE_CODE (format_type_id) != IDENTIFIER_NODE)
              {
                error ("unrecognized format specifier");
                continue;
              }
            else
              {
                const char *p = IDENTIFIER_POINTER (format_type_id);

                if (!strcmp (p, "printf") || !strcmp (p, "__printf__"))
                  format_type = printf_format_type;
                else if (!strcmp (p, "scanf") || !strcmp (p, "__scanf__"))
                  format_type = scanf_format_type;
                else if (!strcmp (p, "strftime")
                         || !strcmp (p, "__strftime__"))
                  format_type = strftime_format_type;
                else
                  {
                    warning ("`%s' is an unrecognized format function type", p);
                    continue;
                  }
              }

            /* Strip any conversions from the string index and first arg number
               and verify they are constants.  */
            while (TREE_CODE (format_num_expr) == NOP_EXPR
                   || TREE_CODE (format_num_expr) == CONVERT_EXPR
                   || TREE_CODE (format_num_expr) == NON_LVALUE_EXPR)
              format_num_expr = TREE_OPERAND (format_num_expr, 0);

            while (TREE_CODE (first_arg_num_expr) == NOP_EXPR
                   || TREE_CODE (first_arg_num_expr) == CONVERT_EXPR
                   || TREE_CODE (first_arg_num_expr) == NON_LVALUE_EXPR)
              first_arg_num_expr = TREE_OPERAND (first_arg_num_expr, 0);

            if (TREE_CODE (format_num_expr) != INTEGER_CST
                || TREE_INT_CST_HIGH (format_num_expr) != 0
                || TREE_CODE (first_arg_num_expr) != INTEGER_CST
                || TREE_INT_CST_HIGH (first_arg_num_expr) != 0)
              {
                error ("format string has invalid operand number");
                continue;
              }

            format_num = TREE_INT_CST_LOW (format_num_expr);
            first_arg_num = TREE_INT_CST_LOW (first_arg_num_expr);
            if (first_arg_num != 0 && first_arg_num <= format_num)
              {
                error ("format string arg follows the args to be formatted");
                continue;
              }

            /* If a parameter list is specified, verify that the format_num
               argument is actually a string, in case the format attribute
               is in error.  */
            argument = TYPE_ARG_TYPES (type);
            if (argument)
              {
                for (arg_num = 1; argument != 0 && arg_num != format_num;
                     ++arg_num, argument = TREE_CHAIN (argument))
                  ;

                if (! argument
                    || TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE
                  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (argument)))
                      != char_type_node))
                  {
                    error ("format string arg not a string type");
                    continue;
                  }

                else if (first_arg_num != 0)
                  {
                    /* Verify that first_arg_num points to the last arg,
                       the ...  */
                    while (argument)
                      arg_num++, argument = TREE_CHAIN (argument);

                    if (arg_num != first_arg_num)
                      {
                        error ("args to be formatted is not '...'");
                        continue;
                      }
                  }
              }

            record_function_format (DECL_NAME (decl),
                                    DECL_ASSEMBLER_NAME (decl),
                                    format_type, format_num, first_arg_num);
            break;
          }

        case A_FORMAT_ARG:
          {
            tree format_num_expr = TREE_VALUE (args);
            unsigned HOST_WIDE_INT format_num;
            unsigned int arg_num;
            tree argument;

            if (TREE_CODE (decl) != FUNCTION_DECL)
              {
                error_with_decl (decl,
                         "argument format specified for non-function `%s'");
                continue;
              }

            /* Strip any conversions from the first arg number and verify it
               is a constant.  */
            while (TREE_CODE (format_num_expr) == NOP_EXPR
                   || TREE_CODE (format_num_expr) == CONVERT_EXPR
                   || TREE_CODE (format_num_expr) == NON_LVALUE_EXPR)
              format_num_expr = TREE_OPERAND (format_num_expr, 0);

            if (TREE_CODE (format_num_expr) != INTEGER_CST
                || TREE_INT_CST_HIGH (format_num_expr) != 0)
              {
                error ("format string has invalid operand number");
                continue;
              }

            format_num = TREE_INT_CST_LOW (format_num_expr);

            /* If a parameter list is specified, verify that the format_num
               argument is actually a string, in case the format attribute
               is in error.  */
            argument = TYPE_ARG_TYPES (type);
            if (argument)
              {
                for (arg_num = 1; argument != 0 && arg_num != format_num;
                     ++arg_num, argument = TREE_CHAIN (argument))
                  ;

                if (! argument
                    || TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE
                  || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (argument)))
                      != char_type_node))
                  {
                    error ("format string arg not a string type");
                    continue;
                  }
              }

            if (TREE_CODE (TREE_TYPE (TREE_TYPE (decl))) != POINTER_TYPE
                || (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_TYPE (decl))))
                    != char_type_node))
              {
                error ("function does not return string type");
                continue;
              }

            record_international_format (DECL_NAME (decl),
                                         DECL_ASSEMBLER_NAME (decl),
                                         format_num);
            break;
          }

        case A_WEAK:
          declare_weak (decl);
          break;

        case A_ALIAS:
          if ((TREE_CODE (decl) == FUNCTION_DECL && DECL_INITIAL (decl))
              || (TREE_CODE (decl) != FUNCTION_DECL && ! DECL_EXTERNAL (decl)))
            error_with_decl (decl,
                             "`%s' defined both normally and as an alias");
          else if (decl_function_context (decl) == 0)
            {
              tree id;

              id = TREE_VALUE (args);
              if (TREE_CODE (id) != STRING_CST)
                {
                  error ("alias arg not a string");
                  break;
                }
              id = get_identifier (TREE_STRING_POINTER (id));
              /* This counts as a use of the object pointed to.  */
              TREE_USED (id) = 1;

              if (TREE_CODE (decl) == FUNCTION_DECL)
                DECL_INITIAL (decl) = error_mark_node;
              else
                DECL_EXTERNAL (decl) = 0;
              assemble_alias (decl, id);
            }
          else
            warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
          break;

        case A_NO_CHECK_MEMORY_USAGE:
          if (TREE_CODE (decl) != FUNCTION_DECL)
            {
              error_with_decl (decl,
                               "`%s' attribute applies only to functions",
                               IDENTIFIER_POINTER (name));
            }
          else if (DECL_INITIAL (decl))
            {
              error_with_decl (decl,
                               "can't set `%s' attribute after definition",
                               IDENTIFIER_POINTER (name));
            }
          else
            DECL_NO_CHECK_MEMORY_USAGE (decl) = 1;
          break;

        case A_NO_INSTRUMENT_FUNCTION:
          if (TREE_CODE (decl) != FUNCTION_DECL)
            {
              error_with_decl (decl,
                               "`%s' attribute applies only to functions",
                               IDENTIFIER_POINTER (name));
            }
          else if (DECL_INITIAL (decl))
            {
              error_with_decl (decl,
                               "can't set `%s' attribute after definition",
                               IDENTIFIER_POINTER (name));
            }
          else
            DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
          break;

        case A_NO_LIMIT_STACK:
          if (TREE_CODE (decl) != FUNCTION_DECL)
            {
              error_with_decl (decl,
                               "`%s' attribute applies only to functions",
                               IDENTIFIER_POINTER (name));
            }
          else if (DECL_INITIAL (decl))
            {
              error_with_decl (decl,
                               "can't set `%s' attribute after definition",
                               IDENTIFIER_POINTER (name));
            }
          else
            DECL_NO_LIMIT_STACK (decl) = 1;
          break;
        }
    }
}

/* Split SPECS_ATTRS, a list of declspecs and prefix attributes, into two
   lists.  SPECS_ATTRS may also be just a typespec (eg: RECORD_TYPE).

   The head of the declspec list is stored in DECLSPECS.
   The head of the attribute list is stored in PREFIX_ATTRIBUTES.

   Note that attributes in SPECS_ATTRS are stored in the TREE_PURPOSE of
   the list elements.  We drop the containing TREE_LIST nodes and link the
   resulting attributes together the way decl_attributes expects them.  */

void
split_specs_attrs (specs_attrs, declspecs, prefix_attributes)
     tree specs_attrs;
     tree *declspecs, *prefix_attributes;
{
  tree t, s, a, next, specs, attrs;

  /* This can happen after an __extension__ in pedantic mode.  */
  if (specs_attrs != NULL_TREE 
      && TREE_CODE (specs_attrs) == INTEGER_CST)
    {
      *declspecs = NULL_TREE;
      *prefix_attributes = NULL_TREE;
      return;
    }

  /* This can happen in c++ (eg: decl: typespec initdecls ';').  */
  if (specs_attrs != NULL_TREE
      && TREE_CODE (specs_attrs) != TREE_LIST)
    {
      *declspecs = specs_attrs;
      *prefix_attributes = NULL_TREE;
      return;
    }

  /* Remember to keep the lists in the same order, element-wise.  */

  specs = s = NULL_TREE;
  attrs = a = NULL_TREE;
  for (t = specs_attrs; t; t = next)
    {
      next = TREE_CHAIN (t);
      /* Declspecs have a non-NULL TREE_VALUE.  */
      if (TREE_VALUE (t) != NULL_TREE)
        {
          if (specs == NULL_TREE)
            specs = s = t;
          else
            {
              TREE_CHAIN (s) = t;
              s = t;
            }
        }
      else
        {
          if (attrs == NULL_TREE)
            attrs = a = TREE_PURPOSE (t);
          else
            {
              TREE_CHAIN (a) = TREE_PURPOSE (t);
              a = TREE_PURPOSE (t);
            }
          /* More attrs can be linked here, move A to the end.  */
          while (TREE_CHAIN (a) != NULL_TREE)
            a = TREE_CHAIN (a);
        }
    }

  /* Terminate the lists.  */
  if (s != NULL_TREE)
    TREE_CHAIN (s) = NULL_TREE;
  if (a != NULL_TREE)
    TREE_CHAIN (a) = NULL_TREE;

  /* All done.  */
  *declspecs = specs;
  *prefix_attributes = attrs;
}

/* Strip attributes from SPECS_ATTRS, a list of declspecs and attributes.
   This function is used by the parser when a rule will accept attributes
   in a particular position, but we don't want to support that just yet.

   A warning is issued for every ignored attribute.  */

tree
strip_attrs (specs_attrs)
     tree specs_attrs;
{
  tree specs, attrs;

  split_specs_attrs (specs_attrs, &specs, &attrs);

  while (attrs)
    {
      warning ("`%s' attribute ignored",
               IDENTIFIER_POINTER (TREE_PURPOSE (attrs)));
      attrs = TREE_CHAIN (attrs);
    }

  return specs;
}
\f
/* Check a printf/fprintf/sprintf/scanf/fscanf/sscanf format against
   a parameter list.  */

/* The meaningfully distinct length modifiers for format checking recognised
   by GCC.  */
enum format_lengths
{
  FMT_LEN_none,
  FMT_LEN_hh,
  FMT_LEN_h,
  FMT_LEN_l,
  FMT_LEN_ll,
  FMT_LEN_L,
  FMT_LEN_z,
  FMT_LEN_t,
  FMT_LEN_j,
  FMT_LEN_MAX
};


/* The standard versions in which various format features appeared.  */
enum format_std_version
{
  STD_C89,
  STD_C94,
  STD_C99,
  STD_EXT
};


/* Structure describing a length modifier supported in format checking, and
   possibly a doubled version such as "hh".  */
typedef struct
{
  /* Name of the single-character length modifier.  */
  const char *name;
  /* Index into a format_char_info.types array.  */
  enum format_lengths index;
  /* Standard version this length appears in.  */
  enum format_std_version std;
  /* Same, if the modifier can be repeated, or NULL if it can't.  */
  const char *double_name;
  enum format_lengths double_index;
  enum format_std_version double_std;
} format_length_info;


/* Structure desribing the combination of a conversion specifier
   (or a set of specifiers which act identically) and a length modifier.  */
typedef struct
{
  /* The standard version this combination of length and type appeared in.
     This is only relevant if greater than those for length and type
     individually; otherwise it is ignored.  */
  enum format_std_version std;
  /* The name to use for the type, if different from that generated internally
     (e.g., "signed size_t").  */
  const char *name;
  /* The type itself.  */
  tree *type;
} format_type_detail;


/* Macros to fill out tables of these.  */
#define BADLEN  { 0, NULL, NULL }
#define NOLENGTHS       { BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }


/* Structure desribing a format conversion specifier (or a set of specifiers
   which act identically), and the length modifiers used with it.  */
typedef struct
{
  const char *format_chars;
  int pointer_count;
  enum format_std_version std;
  /* Types accepted for each length modifier.  */
  format_type_detail types[FMT_LEN_MAX];
  /* List of other modifier characters allowed with these specifiers.
     This lists flags, and additionally "w" for width, "p" for precision,
     "a" for scanf "a" allocation extension (not applicable in C99 mode),
     "*" for scanf suppression, and "E" and "O" for those strftime
     modifiers.  */
  const char *flag_chars;
  /* List of additional flags describing these conversion specifiers.
     "c" for generic character pointers being allowed, "2" for strftime
     two digit year formats, "3" for strftime formats giving two digit
     years in some locales, "o" if use of strftime "O"
     is a GNU extension beyond C99, "W" if the argument is a pointer
     which is dereferenced and written into, "i" for printf integer
     formats where the '0' flag is ignored with precision, and "["
     for the starting character of a scanf scanset.  */
  const char *flags2;
} format_char_info;


/* Structure describing a particular kind of format processed by GCC.  */
typedef struct
{
  /* The name of this kind of format, for use in diagnostics.  */
  const char *name;
  /* Specifications of the length modifiers accepted; possibly NULL.  */
  const format_length_info *length_char_specs;
  /* Details of the conversion specification characters accepted.  */
  const format_char_info *conversion_specs;
} format_kind_info;


/* Structure describing details of a type expected in format checking,
   and the type to check against it.  */
typedef struct format_wanted_type
{
  /* The type wanted.  */
  tree wanted_type;
  /* The name of this type to use in diagnostics.  */
  const char *wanted_type_name;
  /* The level of indirection through pointers at which this type occurs.  */
  int pointer_count;
  /* Whether, when pointer_count is 1, to allow any character type when
     pedantic, rather than just the character or void type specified.  */
  int char_lenient_flag;
  /* Whether the argument, dereferenced once, is written into and so the
     argument must not be a pointer to a const-qualified type.  */
  int writing_in_flag;
  /* If warnings should be of the form "field precision is not type int",
     the name to use (in this case "field precision"), otherwise NULL,
     for "%s format, %s arg" type messages.  If (in an extension), this
     is a pointer type, wanted_type_name should be set to include the
     terminating '*' characters of the type name to give a correct
     message.  */
  const char *name;
  /* The actual parameter to check against the wanted type.  */
  tree param;
  /* The argument number of that parameter.  */
  int arg_num;
  /* The next type to check for this format conversion, or NULL if none.  */
  struct format_wanted_type *next;
} format_wanted_type;


static const format_length_info printf_length_specs[] =
{
  { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
  { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C99 },
  { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
  { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
  { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
  { "Z", FMT_LEN_z, STD_EXT, NULL, 0, 0 },
  { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
  { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
  { NULL, 0, 0, NULL, 0, 0 }
};


/* This differs from printf_length_specs only in that "Z" is not accepted.  */
static const format_length_info scanf_length_specs[] =
{
  { "h", FMT_LEN_h, STD_C89, "hh", FMT_LEN_hh, STD_C99 },
  { "l", FMT_LEN_l, STD_C89, "ll", FMT_LEN_ll, STD_C99 },
  { "q", FMT_LEN_ll, STD_EXT, NULL, 0, 0 },
  { "L", FMT_LEN_L, STD_C89, NULL, 0, 0 },
  { "z", FMT_LEN_z, STD_C99, NULL, 0, 0 },
  { "t", FMT_LEN_t, STD_C99, NULL, 0, 0 },
  { "j", FMT_LEN_j, STD_C99, NULL, 0, 0 },
  { NULL, 0, 0, NULL, 0, 0 }
};


#define T_I     &integer_type_node
#define T89_I   { STD_C89, NULL, T_I }
#define T99_I   { STD_C99, NULL, T_I }
#define T_L     &long_integer_type_node
#define T89_L   { STD_C89, NULL, T_L }
#define T_LL    &long_long_integer_type_node
#define T99_LL  { STD_C99, NULL, T_LL }
#define TEX_LL  { STD_EXT, NULL, T_LL }
#define T_S     &short_integer_type_node
#define T89_S   { STD_C89, NULL, T_S }
#define T_UI    &unsigned_type_node
#define T89_UI  { STD_C89, NULL, T_UI }
#define T99_UI  { STD_C99, NULL, T_UI }
#define T_UL    &long_unsigned_type_node
#define T89_UL  { STD_C89, NULL, T_UL }
#define T_ULL   &long_long_unsigned_type_node
#define T99_ULL { STD_C99, NULL, T_ULL }
#define TEX_ULL { STD_EXT, NULL, T_ULL }
#define T_US    &short_unsigned_type_node
#define T89_US  { STD_C89, NULL, T_US }
#define T_F     &float_type_node
#define T89_F   { STD_C89, NULL, T_F }
#define T99_F   { STD_C99, NULL, T_F }
#define T_D     &double_type_node
#define T89_D   { STD_C89, NULL, T_D }
#define T99_D   { STD_C99, NULL, T_D }
#define T_LD    &long_double_type_node
#define T89_LD  { STD_C89, NULL, T_LD }
#define T99_LD  { STD_C99, NULL, T_LD }
#define T_C     &char_type_node
#define T89_C   { STD_C89, NULL, T_C }
#define T_SC    &signed_char_type_node
#define T99_SC  { STD_C99, NULL, T_SC }
#define T_UC    &unsigned_char_type_node
#define T99_UC  { STD_C99, NULL, T_UC }
#define T_V     &void_type_node
#define T89_V   { STD_C89, NULL, T_V }
#define T_W     &wchar_type_node
#define T94_W   { STD_C94, "wchar_t", T_W }
#define TEX_W   { STD_EXT, "wchar_t", T_W }
#define T_WI    &wint_type_node
#define T94_WI  { STD_C94, "wint_t", T_WI }
#define TEX_WI  { STD_EXT, "wint_t", T_WI }
#define T_ST    &c_size_type_node
#define T99_ST  { STD_C99, "size_t", T_ST }
#define T_SST   &signed_size_type_node
#define T99_SST { STD_C99, "signed size_t", T_SST }
#define T_PD    &ptrdiff_type_node
#define T99_PD  { STD_C99, "ptrdiff_t", T_PD }
#define T_UPD   &unsigned_ptrdiff_type_node
#define T99_UPD { STD_C99, "unsigned ptrdiff_t", T_UPD }
#define T_IM    NULL /* intmax_t not yet implemented.  */
#define T99_IM  { STD_C99, "intmax_t", T_IM }
#define T_UIM   NULL /* uintmax_t not yet implemented.  */
#define T99_UIM { STD_C99, "uintmax_t", T_UIM }

static const format_char_info print_char_table[] =
{
  /* C89 conversion specifiers.  */
  { "di",  0, STD_C89, { T89_I,   T99_I,   T89_I,   T89_L,   T99_LL,  TEX_LL,  T99_SST, T99_PD,  T99_IM  }, "-wp0 +'I", "i" },
  { "oxX", 0, STD_C89, { T89_UI,  T99_UI,  T89_UI,  T89_UL,  T99_ULL, TEX_ULL, T99_ST,  T99_UPD, T99_UIM }, "-wp0#",    "i" },
  { "u",   0, STD_C89, { T89_UI,  T99_UI,  T89_UI,  T89_UL,  T99_ULL, TEX_ULL, T99_ST,  T99_UPD, T99_UIM }, "-wp0'I",   "i" },
  { "fgG", 0, STD_C89, { T89_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN  }, "-wp0 +#'", ""  },
  { "eE",  0, STD_C89, { T89_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN  }, "-wp0 +#",  ""  },
  { "c",   0, STD_C89, { T89_I,   BADLEN,  BADLEN,  T94_WI,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-w",       ""  },
  { "s",   1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-wp",      "c" },
  { "p",   1, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-w",       "c" },
  { "n",   1, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T99_LL,  BADLEN,  T99_SST, T99_PD,  T99_IM  }, "",         "W" },
  /* C99 conversion specifiers.  */
  { "F",   0, STD_C99, { T99_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN  }, "-wp0 +#'", ""  },
  { "aA",  0, STD_C99, { T99_D,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN  }, "-wp0 +#",  ""  },
  /* X/Open conversion specifiers.  */
  { "C",   0, STD_EXT, { TEX_WI,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-w",       ""  },
  { "S",   1, STD_EXT, { TEX_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-wp",      ""  },
  /* GNU conversion specifiers.  */
  { "m",   0, STD_EXT, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "-wp",      ""  },
  { NULL,  0, 0, NOLENGTHS, NULL, NULL }
};

static const format_char_info scan_char_table[] =
{
  /* C89 conversion specifiers.  */
  { "di",    1, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T99_LL,  TEX_LL,  T99_SST, T99_PD,  T99_IM  }, "*w",  "W"   },
  { "ouxX",  1, STD_C89, { T89_UI,  T99_UC,  T89_US,  T89_UL,  T99_ULL, TEX_ULL, T99_ST,  T99_UPD, T99_UIM }, "*w",  "W"   },
  { "efgEG", 1, STD_C89, { T89_F,   BADLEN,  BADLEN,  T89_D,   BADLEN,  T89_LD,  BADLEN,  BADLEN,  BADLEN  }, "*w",  "W"   },
  { "c",     1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "*w",  "cW"  },
  { "s",     1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "*aw", "cW"  },
  { "[",     1, STD_C89, { T89_C,   BADLEN,  BADLEN,  T94_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "*aw", "cW[" },
  { "p",     2, STD_C89, { T89_V,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "*w",  "W"   },
  { "n",     1, STD_C89, { T89_I,   T99_SC,  T89_S,   T89_L,   T99_LL,  BADLEN,  T99_SST, T99_PD,  T99_IM  }, "",    "W"   },
  /* C99 conversion specifiers.  */
  { "FaA",   1, STD_C99, { T99_F,   BADLEN,  BADLEN,  T99_D,   BADLEN,  T99_LD,  BADLEN,  BADLEN,  BADLEN  }, "*w",  "W"   },
  /* X/Open conversion specifiers.  */
  { "C",     1, STD_EXT, { TEX_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "*w",  "W"   },
  { "S",     1, STD_EXT, { TEX_W,   BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN,  BADLEN  }, "*aw", "W"   },
  { NULL, 0, 0, NOLENGTHS, NULL, NULL }
};

static format_char_info time_char_table[] =
{
  /* C89 conversion specifiers.  */
  { "ABZab",            0, STD_C89, NOLENGTHS, "^#",     ""   },
  { "cx",               0, STD_C89, NOLENGTHS, "E",      "3"  },
  { "HIMSUWdmw",        0, STD_C89, NOLENGTHS, "-_0Ow",  ""   },
  { "j",                0, STD_C89, NOLENGTHS, "-_0Ow",  "o"  },
  { "p",                0, STD_C89, NOLENGTHS, "#",      ""   },
  { "X",                0, STD_C89, NOLENGTHS, "E",      ""   },
  { "y",                0, STD_C89, NOLENGTHS, "EO-_0w", "2"  },
  { "Y",                0, STD_C89, NOLENGTHS, "-_0EOw", "o"  },
  { "%",                0, STD_C89, NOLENGTHS, "",       ""   },
  /* C99 conversion specifiers.  */
  { "C",                0, STD_C99, NOLENGTHS, "-_0EOw", "o"  },
  { "D",                0, STD_C99, NOLENGTHS, "",       "2"  },
  { "eVu",              0, STD_C99, NOLENGTHS, "-_0Ow",  ""   },
  { "FRTnrt",           0, STD_C99, NOLENGTHS, "",       ""   },
  { "g",                0, STD_C99, NOLENGTHS, "O-_0w",  "2o" },
  { "G",                0, STD_C99, NOLENGTHS, "-_0Ow",  "o"  },
  { "h",                0, STD_C99, NOLENGTHS, "^#",     ""   },
  { "z",                0, STD_C99, NOLENGTHS, "O",      "o"  },
  /* GNU conversion specifiers.  */
  { "kls",              0, STD_EXT, NOLENGTHS, "-_0Ow",  ""   },
  { "P",                0, STD_EXT, NOLENGTHS, "",       ""   },
  { NULL,               0, 0, NOLENGTHS, NULL, NULL }
};


/* This must be in the same order as enum format_type.  */
static const format_kind_info format_types[] =
{
  { "printf",   printf_length_specs, print_char_table },
  { "scanf",    scanf_length_specs,  scan_char_table  },
  { "strftime", NULL,                time_char_table  }
};


typedef struct function_format_info
{
  struct function_format_info *next;  /* next structure on the list */
  tree name;                    /* identifier such as "printf" */
  tree assembler_name;          /* optional mangled identifier (for C++) */
  enum format_type format_type; /* type of format (printf, scanf, etc.) */
  int format_num;               /* number of format argument */
  int first_arg_num;            /* number of first arg (zero for varargs) */
} function_format_info;

static function_format_info *function_format_list = NULL;

typedef struct international_format_info
{
  struct international_format_info *next;  /* next structure on the list */
  tree name;                    /* identifier such as "gettext" */
  tree assembler_name;          /* optional mangled identifier (for C++) */
  int format_num;               /* number of format argument */
} international_format_info;

static international_format_info *international_format_list = NULL;

static void check_format_info   PARAMS ((int *, function_format_info *, tree));
static void status_warning PARAMS ((int *, const char *, ...))
     ATTRIBUTE_PRINTF_2;

static void init_dollar_format_checking         PARAMS ((int, tree));
static int maybe_read_dollar_number             PARAMS ((int *, const char **, int,
                                                         tree, tree *));
static void finish_dollar_format_checking       PARAMS ((int *));

static void check_format_types  PARAMS ((int *, format_wanted_type *));

/* Initialize the table of functions to perform format checking on.
   The ISO C functions are always checked (whether <stdio.h> is
   included or not), since it is common to call printf without
   including <stdio.h>.  There shouldn't be a problem with this,
   since ISO C reserves these function names whether you include the
   header file or not.  In any case, the checking is harmless.  With
   -ffreestanding, these default attributes are disabled, and must be
   specified manually if desired.

   Also initialize the name of function that modify the format string for
   internationalization purposes.  */

void
init_function_format_info ()
{
  if (flag_hosted)
    {
      /* Functions from ISO/IEC 9899:1990.  */
      record_function_format (get_identifier ("printf"), NULL_TREE,
                              printf_format_type, 1, 2);
      record_function_format (get_identifier ("__builtin_printf"), NULL_TREE,
                              printf_format_type, 1, 2);
      record_function_format (get_identifier ("fprintf"), NULL_TREE,
                              printf_format_type, 2, 3);
      record_function_format (get_identifier ("sprintf"), NULL_TREE,
                              printf_format_type, 2, 3);
      record_function_format (get_identifier ("scanf"), NULL_TREE,
                              scanf_format_type, 1, 2);
      record_function_format (get_identifier ("fscanf"), NULL_TREE,
                              scanf_format_type, 2, 3);
      record_function_format (get_identifier ("sscanf"), NULL_TREE,
                              scanf_format_type, 2, 3);
      record_function_format (get_identifier ("vprintf"), NULL_TREE,
                              printf_format_type, 1, 0);
      record_function_format (get_identifier ("vfprintf"), NULL_TREE,
                              printf_format_type, 2, 0);
      record_function_format (get_identifier ("vsprintf"), NULL_TREE,
                              printf_format_type, 2, 0);
      record_function_format (get_identifier ("strftime"), NULL_TREE,
                              strftime_format_type, 3, 0);
    }

  if (flag_hosted && flag_isoc99)
    {
      /* ISO C99 adds the snprintf and vscanf family functions.  */
      record_function_format (get_identifier ("snprintf"), NULL_TREE,
                              printf_format_type, 3, 4);
      record_function_format (get_identifier ("vsnprintf"), NULL_TREE,
                              printf_format_type, 3, 0);
      record_function_format (get_identifier ("vscanf"), NULL_TREE,
                              scanf_format_type, 1, 0);
      record_function_format (get_identifier ("vfscanf"), NULL_TREE,
                              scanf_format_type, 2, 0);
      record_function_format (get_identifier ("vsscanf"), NULL_TREE,
                              scanf_format_type, 2, 0);
    }

  if (flag_hosted && flag_noniso_default_format_attributes)
    {
      /* Uniforum/GNU gettext functions, not in ISO C.  */
      record_international_format (get_identifier ("gettext"), NULL_TREE, 1);
      record_international_format (get_identifier ("dgettext"), NULL_TREE, 2);
      record_international_format (get_identifier ("dcgettext"), NULL_TREE, 2);
    }

  check_function_format_ptr = check_function_format;
}

/* Record information for argument format checking.  FUNCTION_IDENT is
   the identifier node for the name of the function to check (its decl
   need not exist yet).
   FORMAT_TYPE specifies the type of format checking.  FORMAT_NUM is the number
   of the argument which is the format control string (starting from 1).
   FIRST_ARG_NUM is the number of the first actual argument to check
   against the format string, or zero if no checking is not be done
   (e.g. for varargs such as vfprintf).  */

static void
record_function_format (name, assembler_name, format_type,
                        format_num, first_arg_num)
      tree name;
      tree assembler_name;
      enum format_type format_type;
      int format_num;
      int first_arg_num;
{
  function_format_info *info;

  /* Re-use existing structure if it's there.  */

  for (info = function_format_list; info; info = info->next)
    {
      if (info->name == name && info->assembler_name == assembler_name)
        break;
    }
  if (! info)
    {
      info = (function_format_info *) xmalloc (sizeof (function_format_info));
      info->next = function_format_list;
      function_format_list = info;

      info->name = name;
      info->assembler_name = assembler_name;
    }

  info->format_type = format_type;
  info->format_num = format_num;
  info->first_arg_num = first_arg_num;
}

/* Record information for the names of function that modify the format
   argument to format functions.  FUNCTION_IDENT is the identifier node for
   the name of the function (its decl need not exist yet) and FORMAT_NUM is
   the number of the argument which is the format control string (starting
   from 1).  */

static void
record_international_format (name, assembler_name, format_num)
      tree name;
      tree assembler_name;
      int format_num;
{
  international_format_info *info;

  /* Re-use existing structure if it's there.  */

  for (info = international_format_list; info; info = info->next)
    {
      if (info->name == name && info->assembler_name == assembler_name)
        break;
    }

  if (! info)
    {
      info
        = (international_format_info *)
          xmalloc (sizeof (international_format_info));
      info->next = international_format_list;
      international_format_list = info;

      info->name = name;
      info->assembler_name = assembler_name;
    }

  info->format_num = format_num;
}
\f
/* Check the argument list of a call to printf, scanf, etc.
   NAME is the function identifier.
   ASSEMBLER_NAME is the function's assembler identifier.
   (Either NAME or ASSEMBLER_NAME, but not both, may be NULL_TREE.)
   PARAMS is the list of argument values.  */

void
check_function_format (status, name, assembler_name, params)
     int *status;
     tree name;
     tree assembler_name;
     tree params;
{
  function_format_info *info;

  /* See if this function is a format function.  */
  for (info = function_format_list; info; info = info->next)
    {
      if (info->assembler_name
          ? (info->assembler_name == assembler_name)
          : (info->name == name))
        {
          /* Yup; check it.  */
          check_format_info (status, info, params);
          break;
        }
    }
}

/* This function replaces `warning' inside the printf format checking
   functions.  If the `status' parameter is non-NULL, then it is
   dereferenced and set to 1 whenever a warning is caught.  Otherwise
   it warns as usual by replicating the innards of the warning
   function from diagnostic.c.  */
static void
status_warning VPARAMS ((int *status, const char *msgid, ...))
{
#ifndef ANSI_PROTOTYPES
  int *status;
  const char *msgid;
#endif
  va_list ap;
  diagnostic_context dc;

  if (status)
    *status = 1;
  else
    {
      VA_START (ap, msgid);

#ifndef ANSI_PROTOTYPES
      status = va_arg (ap, int *);
      msgid = va_arg (ap, const char *);
#endif

      /* This duplicates the warning function behavior.  */
      set_diagnostic_context
        (&dc, msgid, &ap, input_filename, lineno, /* warn = */ 1);
      report_diagnostic (&dc);

      va_end (ap);
    }
}

/* Variables used by the checking of $ operand number formats.  */
static char *dollar_arguments_used = NULL;
static int dollar_arguments_alloc = 0;
static int dollar_arguments_count;
static int dollar_first_arg_num;
static int dollar_max_arg_used;
static int dollar_format_warned;

/* Initialize the checking for a format string that may contain $
   parameter number specifications; we will need to keep track of whether
   each parameter has been used.  FIRST_ARG_NUM is the number of the first
   argument that is a parameter to the format, or 0 for a vprintf-style
   function; PARAMS is the list of arguments starting at this argument.  */

static void
init_dollar_format_checking (first_arg_num, params)
     int first_arg_num;
     tree params;
{
  dollar_first_arg_num = first_arg_num;
  dollar_arguments_count = 0;
  dollar_max_arg_used = 0;
  dollar_format_warned = 0;
  if (first_arg_num > 0)
    {
      while (params)
        {
          dollar_arguments_count++;
          params = TREE_CHAIN (params);
        }
    }
  if (dollar_arguments_alloc < dollar_arguments_count)
    {
      if (dollar_arguments_used)
        free (dollar_arguments_used);
      dollar_arguments_alloc = dollar_arguments_count;
      dollar_arguments_used = xmalloc (dollar_arguments_alloc);
    }
  if (dollar_arguments_alloc)
    memset (dollar_arguments_used, 0, dollar_arguments_alloc);
}


/* Look for a decimal number followed by a $ in *FORMAT.  If DOLLAR_NEEDED
   is set, it is an error if one is not found; otherwise, it is OK.  If
   such a number is found, check whether it is within range and mark that
   numbered operand as being used for later checking.  Returns the operand
   number if found and within range, zero if no such number was found and
   this is OK, or -1 on error.  PARAMS points to the first operand of the
   format; PARAM_PTR is made to point to the parameter referred to.  If
   a $ format is found, *FORMAT is updated to point just after it.  */

static int
maybe_read_dollar_number (status, format, dollar_needed, params, param_ptr)
     int *status;
     const char **format;
     int dollar_needed;
     tree params;
     tree *param_ptr;
{
  int argnum;
  int overflow_flag;
  const char *fcp = *format;
  if (*fcp < '0' || *fcp > '9')
    {
      if (dollar_needed)
        {
          status_warning (status, "missing $ operand number in format");
          return -1;
        }
      else
        return 0;
    }
  argnum = 0;
  overflow_flag = 0;
  while (*fcp >= '0' && *fcp <= '9')
    {
      int nargnum;
      nargnum = 10 * argnum + (*fcp - '0');
      if (nargnum < 0 || nargnum / 10 != argnum)
        overflow_flag = 1;
      argnum = nargnum;
      fcp++;
    }
  if (*fcp != '$')
    {
      if (dollar_needed)
        {
          status_warning (status, "missing $ operand number in format");
          return -1;
        }
      else
        return 0;
    }
  *format = fcp + 1;
  if (pedantic && !dollar_format_warned)
    {
      status_warning (status, "ISO C does not support %%n$ operand number formats");
      dollar_format_warned = 1;
    }
  if (overflow_flag || argnum == 0
      || (dollar_first_arg_num && argnum > dollar_arguments_count))
    {
      status_warning (status, "operand number out of range in format");
      return -1;
    }
  if (argnum > dollar_max_arg_used)
    dollar_max_arg_used = argnum;
  /* For vprintf-style functions we may need to allocate more memory to
     track which arguments are used.  */
  while (dollar_arguments_alloc < dollar_max_arg_used)
    {
      int nalloc;
      nalloc = 2 * dollar_arguments_alloc + 16;
      dollar_arguments_used = xrealloc (dollar_arguments_used, nalloc);
      memset (dollar_arguments_used + dollar_arguments_alloc, 0,
              nalloc - dollar_arguments_alloc);
      dollar_arguments_alloc = nalloc;
    }
  dollar_arguments_used[argnum - 1] = 1;
  if (dollar_first_arg_num)
    {
      int i;
      *param_ptr = params;
      for (i = 1; i < argnum && *param_ptr != 0; i++)
        *param_ptr = TREE_CHAIN (*param_ptr);

      if (*param_ptr == 0)
        {
          /* This case shouldn't be caught here.  */
          abort ();
        }
    }
  else
    *param_ptr = 0;
  return argnum;
}


/* Finish the checking for a format string that used $ operand number formats
   instead of non-$ formats.  We check for unused operands before used ones
   (a serious error, since the implementation of the format function
   can't know what types to pass to va_arg to find the later arguments).
   and for unused operands at the end of the format (if we know how many
   arguments the format had, so not for vprintf).  If there were operand
   numbers out of range on a non-vprintf-style format, we won't have reached
   here.  */

static void
finish_dollar_format_checking (status)
     int *status;
{
  int i;
  for (i = 0; i < dollar_max_arg_used; i++)
    {
      if (!dollar_arguments_used[i])
        status_warning (status, "format argument %d unused before used argument %d in $-style format",
                 i + 1, dollar_max_arg_used);
    }
  if (dollar_first_arg_num && dollar_max_arg_used < dollar_arguments_count)
    status_warning (status, "unused arguments in $-style format");
}


/* Check the argument list of a call to printf, scanf, etc.
   INFO points to the function_format_info structure.
   PARAMS is the list of argument values.  */

static void
check_format_info (status, info, params)
     int *status;
     function_format_info *info;
     tree params;
{
  int i;
  int arg_num;
  int suppressed, wide, precise;
  const char *length_chars = NULL;
  enum format_lengths length_chars_val = FMT_LEN_none;
  enum format_std_version length_chars_std = STD_C89;
  int format_char;
  int format_length;
  tree format_tree;
  tree cur_param;
  tree wanted_type;
  int main_arg_num;
  tree main_arg_params;
  enum format_std_version wanted_type_std;
  const char *wanted_type_name;
  format_wanted_type width_wanted_type;
  format_wanted_type precision_wanted_type;
  format_wanted_type main_wanted_type;
  format_wanted_type *first_wanted_type;
  format_wanted_type *last_wanted_type;
  tree first_fillin_param;
  const char *format_chars;
  const format_kind_info *fki = NULL;
  const format_length_info *fli = NULL;
  const format_char_info *fci = NULL;
  char flag_chars[8];
  /* -1 if no conversions taking an operand have been found; 0 if one has
     and it didn't use $; 1 if $ formats are in use.  */
  int has_operand_number = -1;

  /* Skip to format argument.  If the argument isn't available, there's
     no work for us to do; prototype checking will catch the problem.  */
  for (arg_num = 1; ; ++arg_num)
    {
      if (params == 0)
        return;
      if (arg_num == info->format_num)
        break;
      params = TREE_CHAIN (params);
    }
  format_tree = TREE_VALUE (params);
  params = TREE_CHAIN (params);
  if (format_tree == 0)
    return;

  /* We can only check the format if it's a string constant.  */
  while (TREE_CODE (format_tree) == NOP_EXPR)
    format_tree = TREE_OPERAND (format_tree, 0); /* strip coercion */

  if (TREE_CODE (format_tree) == CALL_EXPR
      && TREE_CODE (TREE_OPERAND (format_tree, 0)) == ADDR_EXPR
      && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (format_tree, 0), 0))
          == FUNCTION_DECL))
    {
      tree function = TREE_OPERAND (TREE_OPERAND (format_tree, 0), 0);

      /* See if this is a call to a known internationalization function
         that modifies the format arg.  */
      international_format_info *info;

      for (info = international_format_list; info; info = info->next)
        if (info->assembler_name
            ? (info->assembler_name == DECL_ASSEMBLER_NAME (function))
            : (info->name == DECL_NAME (function)))
          {
            tree inner_args;
            int i;

            for (inner_args = TREE_OPERAND (format_tree, 1), i = 1;
                 inner_args != 0;
                 inner_args = TREE_CHAIN (inner_args), i++)
              if (i == info->format_num)
                {
                  format_tree = TREE_VALUE (inner_args);

                  while (TREE_CODE (format_tree) == NOP_EXPR)
                    format_tree = TREE_OPERAND (format_tree, 0);
                }
          }
    }

  if (integer_zerop (format_tree))
    {
      status_warning (status, "null format string");
      return;
    }
  if (TREE_CODE (format_tree) != ADDR_EXPR)
    {
      /* The user may get multiple warnings if the supplied argument
         isn't even a string pointer.  */
      /* Functions taking a va_list normally pass a non-literal format
         string.  These functions typically are declared with
         first_arg_num == 0, so avoid warning in those cases.  */
      if (info->first_arg_num != 0 && warn_format > 1)
        status_warning (status, "format not a string literal, argument types not checked");
      return;
    }
  format_tree = TREE_OPERAND (format_tree, 0);
  if (TREE_CODE (format_tree) != STRING_CST)
    {
      /* The user may get multiple warnings if the supplied argument
         isn't even a string pointer.  */
      /* Functions taking a va_list normally pass a non-literal format
         string.  These functions typically are declared with
         first_arg_num == 0, so avoid warning in those cases.  */
      if (info->first_arg_num != 0 && warn_format > 1)
        status_warning (status, "format not a string literal, argument types not checked");
      return;
    }
  if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (format_tree))) != char_type_node)
    {
      status_warning (status, "format is a wide character string");
      return;
    }
  format_chars = TREE_STRING_POINTER (format_tree);
  format_length = TREE_STRING_LENGTH (format_tree);
  if (format_length <= 1)
    status_warning (status, "zero-length format string");
  if (format_chars[--format_length] != 0)
    {
      status_warning (status, "unterminated format string");
      return;
    }
  /* Skip to first argument to check.  */
  while (arg_num + 1 < info->first_arg_num)
    {
      if (params == 0)
        return;
      params = TREE_CHAIN (params);
      ++arg_num;
    }

  first_fillin_param = params;
  init_dollar_format_checking (info->first_arg_num, first_fillin_param);
  fki = &format_types[info->format_type];
  while (1)
    {
      int aflag;
      first_wanted_type = NULL;
      last_wanted_type = NULL;
      if (*format_chars == 0)
        {
          if (format_chars - TREE_STRING_POINTER (format_tree) != format_length)
            status_warning (status, "embedded `\\0' in format");
          if (info->first_arg_num != 0 && params != 0
              && has_operand_number <= 0)
            status_warning (status, "too many arguments for format");
          if (has_operand_number > 0)
            finish_dollar_format_checking (status);
          return;
        }
      if (*format_chars++ != '%')
        continue;
      if (*format_chars == 0)
        {
          status_warning (status, "spurious trailing `%%' in format");
          continue;
        }
      if (*format_chars == '%')
        {
          ++format_chars;
          continue;
        }
      flag_chars[0] = 0;
      suppressed = wide = precise = FALSE;
      main_arg_num = 0;
      main_arg_params = 0;
      if (info->format_type == scanf_format_type)
        {
          int non_zero_width_char = FALSE;
          suppressed = *format_chars == '*';
          if (suppressed)
            ++format_chars;
          else if (has_operand_number != 0)
            {
              int opnum;
              opnum = maybe_read_dollar_number (status, &format_chars,
                                                has_operand_number == 1,
                                                first_fillin_param,
                                                &main_arg_params);
              if (opnum == -1)
                return;
              else if (opnum > 0)
                {
                  has_operand_number = 1;
                  main_arg_num = opnum + info->first_arg_num - 1;
                }
              else
                has_operand_number = 0;
            }
          while (ISDIGIT (*format_chars))
            {
              wide = TRUE;
              if (*format_chars != '0')
                non_zero_width_char = TRUE;
              ++format_chars;
            }
          if (wide && !non_zero_width_char)
            status_warning (status, "zero width in scanf format");
        }
      else if (info->format_type == strftime_format_type)
        {
          while (*format_chars != 0 && index ("_-0^#", *format_chars) != 0)
            {
              if (pedantic)
                status_warning (status, "ISO C does not support the strftime `%c' flag",
                         *format_chars);
              if (index (flag_chars, *format_chars) != 0)
                {
                  status_warning (status, "repeated `%c' flag in format",
                           *format_chars);
                  ++format_chars;
                }
              else
                {
                  i = strlen (flag_chars);
                  flag_chars[i++] = *format_chars++;
                  flag_chars[i] = 0;
                }
            }
          while (ISDIGIT ((unsigned char) *format_chars))
            {
              wide = TRUE;
              ++format_chars;
            }
          if (wide && pedantic)
            status_warning (status, "ISO C does not support strftime format width");
          if (*format_chars == 'E' || *format_chars == 'O')
            {
              i = strlen (flag_chars);
              flag_chars[i++] = *format_chars++;
              flag_chars[i] = 0;
              if (*format_chars == 'E' || *format_chars == 'O')
                {
                  status_warning (status, "multiple E/O modifiers in format");
                  while (*format_chars == 'E' || *format_chars == 'O')
                    ++format_chars;
                }
            }
        }
      else if (info->format_type == printf_format_type)
        {
          if (has_operand_number != 0)
            {
              int opnum;
              opnum = maybe_read_dollar_number (status, &format_chars,
                                                0, first_fillin_param,
                                                &main_arg_params);
              if (opnum == -1)
                return;
              else if (opnum > 0)
                {
                  has_operand_number = 1;
                  main_arg_num = opnum + info->first_arg_num - 1;
                }
            }

          while (*format_chars != 0 && index (" +#0-'I", *format_chars) != 0)
            {
              if (index (flag_chars, *format_chars) != 0)
                status_warning (status, "repeated `%c' flag in format", *format_chars++);
              else
                {
                  i = strlen (flag_chars);
                  flag_chars[i++] = *format_chars++;
                  flag_chars[i] = 0;
                }
            }
          /* "If the space and + flags both appear,
             the space flag will be ignored."  */
          if (index (flag_chars, ' ') != 0
              && index (flag_chars, '+') != 0)
            status_warning (status, "use of both ` ' and `+' flags in format");
          /* "If the 0 and - flags both appear,
             the 0 flag will be ignored."  */
          if (index (flag_chars, '0') != 0
              && index (flag_chars, '-') != 0)
            status_warning (status, "use of both `0' and `-' flags in format");
          if (index (flag_chars, '\'') && pedantic)
            status_warning (status, "ISO C does not support the `'' format flag");
          if (index (flag_chars, 'I') && pedantic)
            status_warning (status, "ISO C does not support the `I' format flag");
          if (*format_chars == '*')
            {
              wide = TRUE;
              /* "...a field width...may be indicated by an asterisk.
                 In this case, an int argument supplies the field width..."  */
              ++format_chars;
              if (params == 0)
                {
                  status_warning (status, "too few arguments for format");
                  return;
                }
              if (has_operand_number != 0)
                {
                  int opnum;
                  opnum = maybe_read_dollar_number (status, &format_chars,
                                                    has_operand_number == 1,
                                                    first_fillin_param,
                                                    &params);
                  if (opnum == -1)
                    return;
                  else if (opnum > 0)
                    {
                      has_operand_number = 1;
                      arg_num = opnum + info->first_arg_num - 1;
                    }
                  else
                    has_operand_number = 0;
                }
              if (info->first_arg_num != 0)
                {
                  cur_param = TREE_VALUE (params);
                  if (has_operand_number <= 0)
                    {
                      params = TREE_CHAIN (params);
                      ++arg_num;
                    }
                  width_wanted_type.wanted_type = integer_type_node;
                  width_wanted_type.wanted_type_name = NULL;
                  width_wanted_type.pointer_count = 0;
                  width_wanted_type.char_lenient_flag = 0;
                  width_wanted_type.writing_in_flag = 0;
                  width_wanted_type.name = _("field width");
                  width_wanted_type.param = cur_param;
                  width_wanted_type.arg_num = arg_num;
                  width_wanted_type.next = NULL;
                  if (last_wanted_type != 0)
                    last_wanted_type->next = &width_wanted_type;
                  if (first_wanted_type == 0)
                    first_wanted_type = &width_wanted_type;
                  last_wanted_type = &width_wanted_type;
                }
            }
          else
            {
              while (ISDIGIT (*format_chars))
                {
                  wide = TRUE;
                  ++format_chars;
                }
            }
          if (*format_chars == '.')
            {
              precise = TRUE;
              ++format_chars;
              /* "...a...precision...may be indicated by an asterisk.
                 In this case, an int argument supplies the...precision."  */
              if (*format_chars == '*')
                {
                  ++format_chars;
                  if (has_operand_number != 0)
                    {
                      int opnum;
                      opnum = maybe_read_dollar_number (status, &format_chars,
                                                        has_operand_number == 1,
                                                        first_fillin_param,
                                                        &params);
                      if (opnum == -1)
                        return;
                      else if (opnum > 0)
                        {
                          has_operand_number = 1;
                          arg_num = opnum + info->first_arg_num - 1;
                        }
                      else
                        has_operand_number = 0;
                    }
                  if (info->first_arg_num != 0)
                    {
                      if (params == 0)
                        {
                          status_warning (status, "too few arguments for format");
                          return;
                        }
                      cur_param = TREE_VALUE (params);
                      if (has_operand_number <= 0)
                        {
                          params = TREE_CHAIN (params);
                          ++arg_num;
                        }
                      precision_wanted_type.wanted_type = integer_type_node;
                      precision_wanted_type.wanted_type_name = NULL;
                      precision_wanted_type.pointer_count = 0;
                      precision_wanted_type.char_lenient_flag = 0;
                      precision_wanted_type.writing_in_flag = 0;
                      precision_wanted_type.name = _("field precision");
                      precision_wanted_type.param = cur_param;
                      precision_wanted_type.arg_num = arg_num;
                      precision_wanted_type.next = NULL;
                      if (last_wanted_type != 0)
                        last_wanted_type->next = &precision_wanted_type;
                      if (first_wanted_type == 0)
                        first_wanted_type = &precision_wanted_type;
                      last_wanted_type = &precision_wanted_type;
                    }
                }
              else
                {
                  while (ISDIGIT (*format_chars))
                    ++format_chars;
                }
            }
        }

      aflag = 0;

      fli = fki->length_char_specs;
      if (fli)
        {
          while (fli->name != 0 && fli->name[0] != *format_chars)
            fli++;
          if (fli->name != 0)
            {
              format_chars++;
              if (fli->double_name != 0 && fli->name[0] == *format_chars)
                {
                  format_chars++;
                  length_chars = fli->double_name;
                  length_chars_val = fli->double_index;
                  length_chars_std = fli->double_std;
                }
              else
                {
                  length_chars = fli->name;
                  length_chars_val = fli->index;
                  length_chars_std = fli->std;
                }
            }
          else
            {
              length_chars = NULL;
              length_chars_val = FMT_LEN_none;
              length_chars_std = STD_C89;
            }
          if (pedantic)
            {
              /* Warn if the length modifier is non-standard.  */
              if (length_chars_std == STD_EXT)
                status_warning (status, "ISO C does not support the `%s' %s length modifier",
                         length_chars, fki->name);
              else if ((length_chars_std == STD_C99 && !flag_isoc99)
                       || (length_chars_std == STD_C94 && !flag_isoc94))
                status_warning (status, "ISO C89 does not support the `%s' %s length modifier",
                         length_chars, fki->name);
            }
          if (*format_chars == 'a' && info->format_type == scanf_format_type
              && !flag_isoc99)
            {
              if (format_chars[1] == 's' || format_chars[1] == 'S'
                  || format_chars[1] == '[')
                {
                  /* `a' is used as a flag.  */
                  aflag = 1;
                  format_chars++;
                }
            }
          if (suppressed && length_chars_val != FMT_LEN_none)
            status_warning (status, "use of `*' and `%s' together in format", length_chars);
        }
      format_char = *format_chars;
      if (format_char == 0
          || (info->format_type != strftime_format_type && format_char == '%'))
        {
          status_warning (status, "conversion lacks type at end of format");
          continue;
        }
      format_chars++;
      fci = fki->conversion_specs;
      while (fci->format_chars != 0
             && index (fci->format_chars, format_char) == 0)
          ++fci;
      if (fci->format_chars == 0)
        {
          if (ISGRAPH(format_char))
            status_warning (status, "unknown conversion type character `%c' in format",
                     format_char);
          else
            status_warning (status, "unknown conversion type character 0x%x in format",
                     format_char);
          continue;
        }
      if (pedantic)
        {
          if (fci->std == STD_EXT)
            status_warning (status, "ISO C does not support the `%%%c' %s format",
                     format_char, fki->name);
          else if ((fci->std == STD_C99 && !flag_isoc99)
                   || (fci->std == STD_C94 && !flag_isoc94))
            status_warning (status, "ISO C89 does not support the `%%%c' %s format",
                     format_char, fki->name);
          if (index (flag_chars, 'O') != 0)
            {
              if (index (fci->flags2, 'o') != 0)
                status_warning (status, "ISO C does not support `%%O%c'", format_char);
              else if (!flag_isoc99 && index (fci->flag_chars, 'O') != 0)
                status_warning (status, "ISO C89 does not support `%%O%c'", format_char);
            }
          if (!flag_isoc99 && index (flag_chars, 'E'))
            status_warning (status, "ISO C89 does not support `%%E%c'", format_char);
        }
      if (wide && index (fci->flag_chars, 'w') == 0)
        status_warning (status, "width used with `%c' format", format_char);
      if (index (fci->flags2, '3') != 0
          || (format_char == 'y' && index (flag_chars, 'E')))
        status_warning (status, "`%%%c' yields only last 2 digits of year in some locales",
                 format_char);
      else if (index (fci->flags2, '2') != 0)
        status_warning (status, "`%%%c' yields only last 2 digits of year", format_char);
      if (precise && index (fci->flag_chars, 'p') == 0)
        status_warning (status, "precision used with `%c' format", format_char);
      if (aflag && index (fci->flag_chars, 'a') == 0)
        {
          status_warning (status, "`a' flag used with `%c' format", format_char);
          /* To simplify the following code.  */
          aflag = 0;
        }
      /* The a flag is a GNU extension.  */
      else if (pedantic && aflag)
        status_warning (status, "ISO C does not support the `a' flag");
      if (index (fci->flags2, '[') != 0)
        {
          /* Skip over scan set, in case it happens to have '%' in it.  */
          if (*format_chars == '^')
            ++format_chars;
          /* Find closing bracket; if one is hit immediately, then
             it's part of the scan set rather than a terminator.  */
          if (*format_chars == ']')
            ++format_chars;
          while (*format_chars && *format_chars != ']')
            ++format_chars;
          if (*format_chars != ']')
            /* The end of the format string was reached.  */
            status_warning (status, "no closing `]' for `%%[' format");
        }
      if (suppressed)
        {
          if (index (fci->flag_chars, '*') == 0)
            status_warning (status, "suppression of `%c' conversion in format", format_char);
          continue;
        }
      for (i = 0; flag_chars[i] != 0; ++i)
        {
          if (index (fci->flag_chars, flag_chars[i]) == 0)
            status_warning (status, "flag `%c' used with type `%c'",
                     flag_chars[i], format_char);
        }
      if (info->format_type == strftime_format_type)
        continue;
      if (precise && index (flag_chars, '0') != 0
          && (index (fci->flags2, 'i') != 0))
        status_warning (status, "`0' flag ignored with precision specifier and `%c' format",
                 format_char);
      wanted_type = (fci->types[length_chars_val].type
                     ? *fci->types[length_chars_val].type : 0);
      wanted_type_name = fci->types[length_chars_val].name;
      wanted_type_std = fci->types[length_chars_val].std;
      if (wanted_type == 0)
        {
          status_warning (status, "use of `%s' length modifier with `%c' type character",
                   length_chars, format_char);
          /* Heuristic: skip one argument when an invalid length/type
             combination is encountered.  */
          arg_num++;
          if (params == 0)
            {
              status_warning (status, "too few arguments for format");
              return;
            }
          params = TREE_CHAIN (params);
          continue;
        }
      else if (pedantic
               /* Warn if non-standard, provided it is more non-standard
                  than the length and type characters that may already
                  have been warned for.  */
               && wanted_type_std > length_chars_std
               && wanted_type_std > fci->std)
        {
          if (wanted_type_std == STD_EXT)
            status_warning (status, "ISO C does not support the `%%%s%c' %s format",
                     length_chars, format_char, fki->name);
          else if ((wanted_type_std == STD_C99 && !flag_isoc99)
                   || (wanted_type_std == STD_C94 && !flag_isoc94))
            status_warning (status, "ISO C89 does not support the `%%%s%c' %s format",
                     length_chars, format_char, fki->name);
        }

      /* Finally. . .check type of argument against desired type!  */
      if (info->first_arg_num == 0)
        continue;
      if (fci->pointer_count == 0 && wanted_type == void_type_node)
        {
          if (main_arg_num != 0)
            status_warning (status, "operand number specified for format taking no argument");
        }
      else
        {
          if (main_arg_num != 0)
            {
              arg_num = main_arg_num;
              params = main_arg_params;
            }
          else
            {
              ++arg_num;
              if (has_operand_number > 0)
                {
                  status_warning (status, "missing $ operand number in format");
                  return;
                }
              else
                has_operand_number = 0;
              if (params == 0)
                {
                  status_warning (status, "too few arguments for format");
                  return;
                }
            }
          cur_param = TREE_VALUE (params);
          params = TREE_CHAIN (params);
          main_wanted_type.wanted_type = wanted_type;
          main_wanted_type.wanted_type_name = wanted_type_name;
          main_wanted_type.pointer_count = fci->pointer_count + aflag;
          main_wanted_type.char_lenient_flag = 0;
          if (index (fci->flags2, 'c') != 0)
            main_wanted_type.char_lenient_flag = 1;
          main_wanted_type.writing_in_flag = 0;
          if (index (fci->flags2, 'W') != 0)
            main_wanted_type.writing_in_flag = 1;
          main_wanted_type.name = NULL;
          main_wanted_type.param = cur_param;
          main_wanted_type.arg_num = arg_num;
          main_wanted_type.next = NULL;
          if (last_wanted_type != 0)
            last_wanted_type->next = &main_wanted_type;
          if (first_wanted_type == 0)
            first_wanted_type = &main_wanted_type;
          last_wanted_type = &main_wanted_type;
        }

      if (first_wanted_type != 0)
        check_format_types (status, first_wanted_type);

    }
}


/* Check the argument types from a single format conversion (possibly
   including width and precision arguments).  */
static void
check_format_types (status, types)
     int *status;
     format_wanted_type *types;
{
  for (; types != 0; types = types->next)
    {
      tree cur_param;
      tree cur_type;
      tree orig_cur_type;
      tree wanted_type;
      int arg_num;
      int i;
      int char_type_flag;
      cur_param = types->param;
      cur_type = TREE_TYPE (cur_param);
      if (TREE_CODE (cur_type) == ERROR_MARK)
        continue;
      char_type_flag = 0;
      wanted_type = types->wanted_type;
      arg_num = types->arg_num;

      /* The following should not occur here.  */
      if (wanted_type == 0)
        abort ();
      if (wanted_type == void_type_node && types->pointer_count == 0)
        abort ();

      STRIP_NOPS (cur_param);

      /* Check the types of any additional pointer arguments
         that precede the "real" argument.  */
      for (i = 0; i < types->pointer_count; ++i)
        {
          if (TREE_CODE (cur_type) == POINTER_TYPE)
            {
              cur_type = TREE_TYPE (cur_type);
              if (TREE_CODE (cur_type) == ERROR_MARK)
                break;

              if (cur_param != 0 && TREE_CODE (cur_param) == ADDR_EXPR)
                cur_param = TREE_OPERAND (cur_param, 0);
              else
                cur_param = 0;

              /* See if this is an attempt to write into a const type with
                 scanf or with printf "%n".  Note: the writing in happens
                 at the first indirection only, if for example
                 void * const * is passed to scanf %p; passing
                 const void ** is simply passing an incompatible type.  */
              if (types->writing_in_flag
                  && i == 0
                  && (TYPE_READONLY (cur_type)
                      || (cur_param != 0
                          && (TREE_CODE_CLASS (TREE_CODE (cur_param)) == 'c'
                              || (DECL_P (cur_param)
                                  && TREE_READONLY (cur_param))))))
                status_warning (status, "writing into constant object (arg %d)", arg_num);

              /* If there are extra type qualifiers beyond the first
                 indirection, then this makes the types technically
                 incompatible.  */
              if (i > 0
                  && pedantic
                  && (TYPE_READONLY (cur_type)
                      || TYPE_VOLATILE (cur_type)
                      || TYPE_RESTRICT (cur_type)))
                status_warning (status, "extra type qualifiers in format argument (arg %d)",
                         arg_num);

            }
          else
            {
              if (types->pointer_count == 1)
                status_warning (status, "format argument is not a pointer (arg %d)", arg_num);
              else
                status_warning (status, "format argument is not a pointer to a pointer (arg %d)", arg_num);
              break;
            }
        }

      if (i < types->pointer_count)
        continue;

      orig_cur_type = cur_type;
      cur_type = TYPE_MAIN_VARIANT (cur_type);

      /* Check whether the argument type is a character type.  This leniency
         only applies to certain formats, flagged with 'c'.
      */
      if (types->char_lenient_flag)
        char_type_flag = (cur_type == char_type_node
                          || cur_type == signed_char_type_node
                          || cur_type == unsigned_char_type_node);

      /* Check the type of the "real" argument, if there's a type we want.  */
      if (wanted_type == cur_type)
        continue;
      /* If we want `void *', allow any pointer type.
         (Anything else would already have got a warning.)
         With -pedantic, only allow pointers to void and to character
         types.  */
      if (wanted_type == void_type_node
          && (!pedantic || (i == 1 && char_type_flag)))
        continue;
      /* Don't warn about differences merely in signedness, unless
         -pedantic.  With -pedantic, warn if the type is a pointer
         target and not a character type, and for character types at
         a second level of indirection.  */
      if (TREE_CODE (wanted_type) == INTEGER_TYPE
          && TREE_CODE (cur_type) == INTEGER_TYPE
          && (! pedantic || i == 0 || (i == 1 && char_type_flag))
          && (TREE_UNSIGNED (wanted_type)
              ? wanted_type == unsigned_type (cur_type)
              : wanted_type == signed_type (cur_type)))
        continue;
      /* Likewise, "signed char", "unsigned char" and "char" are
         equivalent but the above test won't consider them equivalent.  */
      if (wanted_type == char_type_node
          && (! pedantic || i < 2)
          && char_type_flag)
        continue;
      /* Now we have a type mismatch.  */
      {
        register const char *this;
        register const char *that;

        this = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (wanted_type)));
        that = 0;
        if (TYPE_NAME (orig_cur_type) != 0
            && TREE_CODE (orig_cur_type) != INTEGER_TYPE
            && !(TREE_CODE (orig_cur_type) == POINTER_TYPE
                 && TREE_CODE (TREE_TYPE (orig_cur_type)) == INTEGER_TYPE))
          {
            if (TREE_CODE (TYPE_NAME (orig_cur_type)) == TYPE_DECL
                && DECL_NAME (TYPE_NAME (orig_cur_type)) != 0)
              that = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (orig_cur_type)));
            else
              that = IDENTIFIER_POINTER (TYPE_NAME (orig_cur_type));
          }

        /* A nameless type can't possibly match what the format wants.
           So there will be a warning for it.
           Make up a string to describe vaguely what it is.  */
        if (that == 0)
          {
            if (TREE_CODE (orig_cur_type) == POINTER_TYPE)
              that = "pointer";
            else
              that = "different type";
          }

        /* Make the warning better in case of mismatch of int vs long.  */
        if (TREE_CODE (orig_cur_type) == INTEGER_TYPE
            && TREE_CODE (wanted_type) == INTEGER_TYPE
            && TYPE_PRECISION (orig_cur_type) == TYPE_PRECISION (wanted_type)
            && TYPE_NAME (orig_cur_type) != 0
            && TREE_CODE (TYPE_NAME (orig_cur_type)) == TYPE_DECL)
          that = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (orig_cur_type)));

        if (strcmp (this, that) != 0)
          {
            /* There may be a better name for the format, e.g. size_t,
               but we should allow for programs with a perverse typedef
               making size_t something other than what the compiler
               thinks.  */
            if (types->wanted_type_name != 0
                && strcmp (types->wanted_type_name, that) != 0)
              this = types->wanted_type_name;
            if (types->name != 0)
              status_warning (status, "%s is not type %s (arg %d)", types->name, this,
                       arg_num);
            else
              status_warning (status, "%s format, %s arg (arg %d)", this, that, arg_num);
          }
      }
    }
}
\f
/* Print a warning if a constant expression had overflow in folding.
   Invoke this function on every expression that the language
   requires to be a constant expression.
   Note the ANSI C standard says it is erroneous for a
   constant expression to overflow.  */

void
constant_expression_warning (value)
     tree value;
{
  if ((TREE_CODE (value) == INTEGER_CST || TREE_CODE (value) == REAL_CST
       || TREE_CODE (value) == COMPLEX_CST)
      && TREE_CONSTANT_OVERFLOW (value) && pedantic)
    pedwarn ("overflow in constant expression");
}

/* Print a warning if an expression had overflow in folding.
   Invoke this function on every expression that
   (1) appears in the source code, and
   (2) might be a constant expression that overflowed, and
   (3) is not already checked by convert_and_check;
   however, do not invoke this function on operands of explicit casts.  */

void
overflow_warning (value)
     tree value;
{
  if ((TREE_CODE (value) == INTEGER_CST
       || (TREE_CODE (value) == COMPLEX_CST
           && TREE_CODE (TREE_REALPART (value)) == INTEGER_CST))
      && TREE_OVERFLOW (value))
    {
      TREE_OVERFLOW (value) = 0;
      if (skip_evaluation == 0)
        warning ("integer overflow in expression");
    }
  else if ((TREE_CODE (value) == REAL_CST
            || (TREE_CODE (value) == COMPLEX_CST
                && TREE_CODE (TREE_REALPART (value)) == REAL_CST))
           && TREE_OVERFLOW (value))
    {
      TREE_OVERFLOW (value) = 0;
      if (skip_evaluation == 0)
        warning ("floating point overflow in expression");
    }
}

/* Print a warning if a large constant is truncated to unsigned,
   or if -Wconversion is used and a constant < 0 is converted to unsigned.
   Invoke this function on every expression that might be implicitly
   converted to an unsigned type.  */

void
unsigned_conversion_warning (result, operand)
     tree result, operand;
{
  if (TREE_CODE (operand) == INTEGER_CST
      && TREE_CODE (TREE_TYPE (result)) == INTEGER_TYPE
      && TREE_UNSIGNED (TREE_TYPE (result))
      && skip_evaluation == 0
      && !int_fits_type_p (operand, TREE_TYPE (result)))
    {
      if (!int_fits_type_p (operand, signed_type (TREE_TYPE (result))))
        /* This detects cases like converting -129 or 256 to unsigned char.  */
        warning ("large integer implicitly truncated to unsigned type");
      else if (warn_conversion)
        warning ("negative integer implicitly converted to unsigned type");
    }
}

/* Convert EXPR to TYPE, warning about conversion problems with constants.
   Invoke this function on every expression that is converted implicitly,
   i.e. because of language rules and not because of an explicit cast.  */

tree
convert_and_check (type, expr)
     tree type, expr;
{
  tree t = convert (type, expr);
  if (TREE_CODE (t) == INTEGER_CST)
    {
      if (TREE_OVERFLOW (t))
        {
          TREE_OVERFLOW (t) = 0;

          /* Do not diagnose overflow in a constant expression merely
             because a conversion overflowed.  */
          TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (expr);

          /* No warning for converting 0x80000000 to int.  */
          if (!(TREE_UNSIGNED (type) < TREE_UNSIGNED (TREE_TYPE (expr))
                && TREE_CODE (TREE_TYPE (expr)) == INTEGER_TYPE
                && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (expr))))
            /* If EXPR fits in the unsigned version of TYPE,
               don't warn unless pedantic.  */
            if ((pedantic
                 || TREE_UNSIGNED (type)
                 || ! int_fits_type_p (expr, unsigned_type (type)))
                && skip_evaluation == 0)
              warning ("overflow in implicit constant conversion");
        }
      else
        unsigned_conversion_warning (t, expr);
    }
  return t;
}
\f
void
c_expand_expr_stmt (expr)
     tree expr;
{
  /* Do default conversion if safe and possibly important,
     in case within ({...}).  */
  if ((TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE && lvalue_p (expr))
      || TREE_CODE (TREE_TYPE (expr)) == FUNCTION_TYPE)
    expr = default_conversion (expr);

  if (TREE_TYPE (expr) != error_mark_node
      && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
      && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
    error ("expression statement has incomplete type");

  last_expr_type = TREE_TYPE (expr); 
  add_stmt (build_stmt (EXPR_STMT, expr));
}
\f
/* Validate the expression after `case' and apply default promotions.  */

tree
check_case_value (value)
     tree value;
{
  if (value == NULL_TREE)
    return value;

  /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue.  */
  STRIP_TYPE_NOPS (value);
  /* In C++, the following is allowed:

       const int i = 3;
       switch (...) { case i: ... }

     So, we try to reduce the VALUE to a constant that way.  */
  if (c_language == clk_cplusplus)
    {
      value = decl_constant_value (value);
      STRIP_TYPE_NOPS (value);
      value = fold (value);
    }

  if (TREE_CODE (value) != INTEGER_CST
      && value != error_mark_node)
    {
      error ("case label does not reduce to an integer constant");
      value = error_mark_node;
    }
  else
    /* Promote char or short to int.  */
    value = default_conversion (value);

  constant_expression_warning (value);

  return value;
}
\f
/* Return an integer type with BITS bits of precision,
   that is unsigned if UNSIGNEDP is nonzero, otherwise signed.  */

tree
type_for_size (bits, unsignedp)
     unsigned bits;
     int unsignedp;
{
  if (bits == TYPE_PRECISION (integer_type_node))
    return unsignedp ? unsigned_type_node : integer_type_node;

  if (bits == TYPE_PRECISION (signed_char_type_node))
    return unsignedp ? unsigned_char_type_node : signed_char_type_node;

  if (bits == TYPE_PRECISION (short_integer_type_node))
    return unsignedp ? short_unsigned_type_node : short_integer_type_node;

  if (bits == TYPE_PRECISION (long_integer_type_node))
    return unsignedp ? long_unsigned_type_node : long_integer_type_node;

  if (bits == TYPE_PRECISION (long_long_integer_type_node))
    return (unsignedp ? long_long_unsigned_type_node
            : long_long_integer_type_node);

  if (bits == TYPE_PRECISION (widest_integer_literal_type_node))
    return (unsignedp ? widest_unsigned_literal_type_node
            : widest_integer_literal_type_node);

  if (bits <= TYPE_PRECISION (intQI_type_node))
    return unsignedp ? unsigned_intQI_type_node : intQI_type_node;

  if (bits <= TYPE_PRECISION (intHI_type_node))
    return unsignedp ? unsigned_intHI_type_node : intHI_type_node;

  if (bits <= TYPE_PRECISION (intSI_type_node))
    return unsignedp ? unsigned_intSI_type_node : intSI_type_node;

  if (bits <= TYPE_PRECISION (intDI_type_node))
    return unsignedp ? unsigned_intDI_type_node : intDI_type_node;

  return 0;
}

/* Return a data type that has machine mode MODE.
   If the mode is an integer,
   then UNSIGNEDP selects between signed and unsigned types.  */

tree
type_for_mode (mode, unsignedp)
     enum machine_mode mode;
     int unsignedp;
{
  if (mode == TYPE_MODE (integer_type_node))
    return unsignedp ? unsigned_type_node : integer_type_node;

  if (mode == TYPE_MODE (signed_char_type_node))
    return unsignedp ? unsigned_char_type_node : signed_char_type_node;

  if (mode == TYPE_MODE (short_integer_type_node))
    return unsignedp ? short_unsigned_type_node : short_integer_type_node;

  if (mode == TYPE_MODE (long_integer_type_node))
    return unsignedp ? long_unsigned_type_node : long_integer_type_node;

  if (mode == TYPE_MODE (long_long_integer_type_node))
    return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;

  if (mode == TYPE_MODE (widest_integer_literal_type_node))
    return unsignedp ? widest_unsigned_literal_type_node
                     : widest_integer_literal_type_node;

  if (mode == TYPE_MODE (intQI_type_node))
    return unsignedp ? unsigned_intQI_type_node : intQI_type_node;

  if (mode == TYPE_MODE (intHI_type_node))
    return unsignedp ? unsigned_intHI_type_node : intHI_type_node;

  if (mode == TYPE_MODE (intSI_type_node))
    return unsignedp ? unsigned_intSI_type_node : intSI_type_node;

  if (mode == TYPE_MODE (intDI_type_node))
    return unsignedp ? unsigned_intDI_type_node : intDI_type_node;

#if HOST_BITS_PER_WIDE_INT >= 64
  if (mode == TYPE_MODE (intTI_type_node))
    return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
#endif

  if (mode == TYPE_MODE (float_type_node))
    return float_type_node;

  if (mode == TYPE_MODE (double_type_node))
    return double_type_node;

  if (mode == TYPE_MODE (long_double_type_node))
    return long_double_type_node;

  if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
    return build_pointer_type (char_type_node);

  if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
    return build_pointer_type (integer_type_node);

#ifdef VECTOR_MODE_SUPPORTED_P
  if (mode == TYPE_MODE (V4SF_type_node) && VECTOR_MODE_SUPPORTED_P (mode))
    return V4SF_type_node;
  if (mode == TYPE_MODE (V4SI_type_node) && VECTOR_MODE_SUPPORTED_P (mode))
    return V4SI_type_node;
  if (mode == TYPE_MODE (V2SI_type_node) && VECTOR_MODE_SUPPORTED_P (mode))
    return V2SI_type_node;
  if (mode == TYPE_MODE (V4HI_type_node) && VECTOR_MODE_SUPPORTED_P (mode))
    return V4HI_type_node;
  if (mode == TYPE_MODE (V8QI_type_node) && VECTOR_MODE_SUPPORTED_P (mode))
    return V8QI_type_node;
#endif

  return 0;
}

/* Return an unsigned type the same as TYPE in other respects. */
tree
unsigned_type (type)
     tree type;
{
  tree type1 = TYPE_MAIN_VARIANT (type);
  if (type1 == signed_char_type_node || type1 == char_type_node)
    return unsigned_char_type_node;
  if (type1 == integer_type_node)
    return unsigned_type_node;
  if (type1 == short_integer_type_node)
    return short_unsigned_type_node;
  if (type1 == long_integer_type_node)
    return long_unsigned_type_node;
  if (type1 == long_long_integer_type_node)
    return long_long_unsigned_type_node;
  if (type1 == widest_integer_literal_type_node)
    return widest_unsigned_literal_type_node;
#if HOST_BITS_PER_WIDE_INT >= 64
  if (type1 == intTI_type_node)
    return unsigned_intTI_type_node;
#endif
  if (type1 == intDI_type_node)
    return unsigned_intDI_type_node;
  if (type1 == intSI_type_node)
    return unsigned_intSI_type_node;
  if (type1 == intHI_type_node)
    return unsigned_intHI_type_node;
  if (type1 == intQI_type_node)
    return unsigned_intQI_type_node;

  return signed_or_unsigned_type (1, type);
}

/* Return a signed type the same as TYPE in other respects.  */

tree
signed_type (type)
     tree type;
{
  tree type1 = TYPE_MAIN_VARIANT (type);
  if (type1 == unsigned_char_type_node || type1 == char_type_node)
    return signed_char_type_node;
  if (type1 == unsigned_type_node)
    return integer_type_node;
  if (type1 == short_unsigned_type_node)
    return short_integer_type_node;
  if (type1 == long_unsigned_type_node)
    return long_integer_type_node;
  if (type1 == long_long_unsigned_type_node)
    return long_long_integer_type_node;
  if (type1 == widest_unsigned_literal_type_node)
    return widest_integer_literal_type_node;
#if HOST_BITS_PER_WIDE_INT >= 64
  if (type1 == unsigned_intTI_type_node)
    return intTI_type_node;
#endif
  if (type1 == unsigned_intDI_type_node)
    return intDI_type_node;
  if (type1 == unsigned_intSI_type_node)
    return intSI_type_node;
  if (type1 == unsigned_intHI_type_node)
    return intHI_type_node;
  if (type1 == unsigned_intQI_type_node)
    return intQI_type_node;

  return signed_or_unsigned_type (0, type);
}

/* Return a type the same as TYPE except unsigned or
   signed according to UNSIGNEDP.  */

tree
signed_or_unsigned_type (unsignedp, type)
     int unsignedp;
     tree type;
{
  if (! INTEGRAL_TYPE_P (type)
      || TREE_UNSIGNED (type) == unsignedp)
    return type;

  if (TYPE_PRECISION (type) == TYPE_PRECISION (signed_char_type_node))
    return unsignedp ? unsigned_char_type_node : signed_char_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
    return unsignedp ? unsigned_type_node : integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (short_integer_type_node))
    return unsignedp ? short_unsigned_type_node : short_integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (long_integer_type_node))
    return unsignedp ? long_unsigned_type_node : long_integer_type_node;
  if (TYPE_PRECISION (type) == TYPE_PRECISION (long_long_integer_type_node))
    return (unsignedp ? long_long_unsigned_type_node
            : long_long_integer_type_node);
  if (TYPE_PRECISION (type) == TYPE_PRECISION (widest_integer_literal_type_node))
    return (unsignedp ? widest_unsigned_literal_type_node
            : widest_integer_literal_type_node);
  return type;
}
\f
/* Return the minimum number of bits needed to represent VALUE in a
   signed or unsigned type, UNSIGNEDP says which.  */

unsigned int
min_precision (value, unsignedp)
     tree value;
     int unsignedp;
{
  int log;

  /* If the value is negative, compute its negative minus 1.  The latter
     adjustment is because the absolute value of the largest negative value
     is one larger than the largest positive value.  This is equivalent to
     a bit-wise negation, so use that operation instead.  */

  if (tree_int_cst_sgn (value) < 0)
    value = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (value), value));

  /* Return the number of bits needed, taking into account the fact
     that we need one more bit for a signed than unsigned type.  */

  if (integer_zerop (value))
    log = 0;
  else
    log = tree_floor_log2 (value);

  return log + 1 + ! unsignedp;
}
\f
/* Print an error message for invalid operands to arith operation CODE.
   NOP_EXPR is used as a special case (see truthvalue_conversion).  */

void
binary_op_error (code)
     enum tree_code code;
{
  register const char *opname;

  switch (code)
    {
    case NOP_EXPR:
      error ("invalid truth-value expression");
      return;

    case PLUS_EXPR:
      opname = "+"; break;
    case MINUS_EXPR:
      opname = "-"; break;
    case MULT_EXPR:
      opname = "*"; break;
    case MAX_EXPR:
      opname = "max"; break;
    case MIN_EXPR:
      opname = "min"; break;
    case EQ_EXPR:
      opname = "=="; break;
    case NE_EXPR:
      opname = "!="; break;
    case LE_EXPR:
      opname = "<="; break;
    case GE_EXPR:
      opname = ">="; break;
    case LT_EXPR:
      opname = "<"; break;
    case GT_EXPR:
      opname = ">"; break;
    case LSHIFT_EXPR:
      opname = "<<"; break;
    case RSHIFT_EXPR:
      opname = ">>"; break;
    case TRUNC_MOD_EXPR:
    case FLOOR_MOD_EXPR:
      opname = "%"; break;
    case TRUNC_DIV_EXPR:
    case FLOOR_DIV_EXPR:
      opname = "/"; break;
    case BIT_AND_EXPR:
      opname = "&"; break;
    case BIT_IOR_EXPR:
      opname = "|"; break;
    case TRUTH_ANDIF_EXPR:
      opname = "&&"; break;
    case TRUTH_ORIF_EXPR:
      opname = "||"; break;
    case BIT_XOR_EXPR:
      opname = "^"; break;
    case LROTATE_EXPR:
    case RROTATE_EXPR:
      opname = "rotate"; break;
    default:
      opname = "unknown"; break;
    }
  error ("invalid operands to binary %s", opname);
}
\f
/* Subroutine of build_binary_op, used for comparison operations.
   See if the operands have both been converted from subword integer types
   and, if so, perhaps change them both back to their original type.
   This function is also responsible for converting the two operands
   to the proper common type for comparison.

   The arguments of this function are all pointers to local variables
   of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
   RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.

   If this function returns nonzero, it means that the comparison has
   a constant value.  What this function returns is an expression for
   that value.  */

tree
shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr)
     tree *op0_ptr, *op1_ptr;
     tree *restype_ptr;
     enum tree_code *rescode_ptr;
{
  register tree type;
  tree op0 = *op0_ptr;
  tree op1 = *op1_ptr;
  int unsignedp0, unsignedp1;
  int real1, real2;
  tree primop0, primop1;
  enum tree_code code = *rescode_ptr;

  /* Throw away any conversions to wider types
     already present in the operands.  */

  primop0 = get_narrower (op0, &unsignedp0);
  primop1 = get_narrower (op1, &unsignedp1);

  /* Handle the case that OP0 does not *contain* a conversion
     but it *requires* conversion to FINAL_TYPE.  */

  if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
    unsignedp0 = TREE_UNSIGNED (TREE_TYPE (op0));
  if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
    unsignedp1 = TREE_UNSIGNED (TREE_TYPE (op1));

  /* If one of the operands must be floated, we cannot optimize.  */
  real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
  real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;

  /* If first arg is constant, swap the args (changing operation
     so value is preserved), for canonicalization.  Don't do this if
     the second arg is 0.  */

  if (TREE_CONSTANT (primop0)
      && ! integer_zerop (primop1) && ! real_zerop (primop1))
    {
      register tree tem = primop0;
      register int temi = unsignedp0;
      primop0 = primop1;
      primop1 = tem;
      tem = op0;
      op0 = op1;
      op1 = tem;
      *op0_ptr = op0;
      *op1_ptr = op1;
      unsignedp0 = unsignedp1;
      unsignedp1 = temi;
      temi = real1;
      real1 = real2;
      real2 = temi;

      switch (code)
        {
        case LT_EXPR:
          code = GT_EXPR;
          break;
        case GT_EXPR:
          code = LT_EXPR;
          break;
        case LE_EXPR:
          code = GE_EXPR;
          break;
        case GE_EXPR:
          code = LE_EXPR;
          break;
        default:
          break;
        }
      *rescode_ptr = code;
    }

  /* If comparing an integer against a constant more bits wide,
     maybe we can deduce a value of 1 or 0 independent of the data.
     Or else truncate the constant now
     rather than extend the variable at run time.

     This is only interesting if the constant is the wider arg.
     Also, it is not safe if the constant is unsigned and the
     variable arg is signed, since in this case the variable
     would be sign-extended and then regarded as unsigned.
     Our technique fails in this case because the lowest/highest
     possible unsigned results don't follow naturally from the
     lowest/highest possible values of the variable operand.
     For just EQ_EXPR and NE_EXPR there is another technique that
     could be used: see if the constant can be faithfully represented
     in the other operand's type, by truncating it and reextending it
     and see if that preserves the constant's value.  */

  if (!real1 && !real2
      && TREE_CODE (primop1) == INTEGER_CST
      && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
    {
      int min_gt, max_gt, min_lt, max_lt;
      tree maxval, minval;
      /* 1 if comparison is nominally unsigned.  */
      int unsignedp = TREE_UNSIGNED (*restype_ptr);
      tree val;

      type = signed_or_unsigned_type (unsignedp0, TREE_TYPE (primop0));

      /* If TYPE is an enumeration, then we need to get its min/max
         values from it's underlying integral type, not the enumerated
         type itself.  */
      if (TREE_CODE (type) == ENUMERAL_TYPE)
        type = type_for_size (TYPE_PRECISION (type), unsignedp0);

      maxval = TYPE_MAX_VALUE (type);
      minval = TYPE_MIN_VALUE (type);

      if (unsignedp && !unsignedp0)
        *restype_ptr = signed_type (*restype_ptr);

      if (TREE_TYPE (primop1) != *restype_ptr)
        primop1 = convert (*restype_ptr, primop1);
      if (type != *restype_ptr)
        {
          minval = convert (*restype_ptr, minval);
          maxval = convert (*restype_ptr, maxval);
        }

      if (unsignedp && unsignedp0)
        {
          min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
          max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
          min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
          max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
        }
      else
        {
          min_gt = INT_CST_LT (primop1, minval);
          max_gt = INT_CST_LT (primop1, maxval);
          min_lt = INT_CST_LT (minval, primop1);
          max_lt = INT_CST_LT (maxval, primop1);
        }

      val = 0;
      /* This used to be a switch, but Genix compiler can't handle that.  */
      if (code == NE_EXPR)
        {
          if (max_lt || min_gt)
            val = boolean_true_node;
        }
      else if (code == EQ_EXPR)
        {
          if (max_lt || min_gt)
            val = boolean_false_node;
        }
      else if (code == LT_EXPR)
        {
          if (max_lt)
            val = boolean_true_node;
          if (!min_lt)
            val = boolean_false_node;
        }
      else if (code == GT_EXPR)
        {
          if (min_gt)
            val = boolean_true_node;
          if (!max_gt)
            val = boolean_false_node;
        }
      else if (code == LE_EXPR)
        {
          if (!max_gt)
            val = boolean_true_node;
          if (min_gt)
            val = boolean_false_node;
        }
      else if (code == GE_EXPR)
        {
          if (!min_lt)
            val = boolean_true_node;
          if (max_lt)
            val = boolean_false_node;
        }

      /* If primop0 was sign-extended and unsigned comparison specd,
         we did a signed comparison above using the signed type bounds.
         But the comparison we output must be unsigned.

         Also, for inequalities, VAL is no good; but if the signed
         comparison had *any* fixed result, it follows that the
         unsigned comparison just tests the sign in reverse
         (positive values are LE, negative ones GE).
         So we can generate an unsigned comparison
         against an extreme value of the signed type.  */

      if (unsignedp && !unsignedp0)
        {
          if (val != 0)
            switch (code)
              {
              case LT_EXPR:
              case GE_EXPR:
                primop1 = TYPE_MIN_VALUE (type);
                val = 0;
                break;

              case LE_EXPR:
              case GT_EXPR:
                primop1 = TYPE_MAX_VALUE (type);
                val = 0;
                break;

              default:
                break;
              }
          type = unsigned_type (type);
        }

      if (!max_gt && !unsignedp0 && TREE_CODE (primop0) != INTEGER_CST)
        {
          /* This is the case of (char)x >?< 0x80, which people used to use
             expecting old C compilers to change the 0x80 into -0x80.  */
          if (val == boolean_false_node)
            warning ("comparison is always false due to limited range of data type");
          if (val == boolean_true_node)
            warning ("comparison is always true due to limited range of data type");
        }

      if (!min_lt && unsignedp0 && TREE_CODE (primop0) != INTEGER_CST)
        {
          /* This is the case of (unsigned char)x >?< -1 or < 0.  */
          if (val == boolean_false_node)
            warning ("comparison is always false due to limited range of data type");
          if (val == boolean_true_node)
            warning ("comparison is always true due to limited range of data type");
        }

      if (val != 0)
        {
          /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
          if (TREE_SIDE_EFFECTS (primop0))
            return build (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
          return val;
        }

      /* Value is not predetermined, but do the comparison
         in the type of the operand that is not constant.
         TYPE is already properly set.  */
    }
  else if (real1 && real2
           && (TYPE_PRECISION (TREE_TYPE (primop0))
               == TYPE_PRECISION (TREE_TYPE (primop1))))
    type = TREE_TYPE (primop0);

  /* If args' natural types are both narrower than nominal type
     and both extend in the same manner, compare them
     in the type of the wider arg.
     Otherwise must actually extend both to the nominal
     common type lest different ways of extending
     alter the result.
     (eg, (short)-1 == (unsigned short)-1  should be 0.)  */

  else if (unsignedp0 == unsignedp1 && real1 == real2
           && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
           && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
    {
      type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
      type = signed_or_unsigned_type (unsignedp0
                                      || TREE_UNSIGNED (*restype_ptr),
                                      type);
      /* Make sure shorter operand is extended the right way
         to match the longer operand.  */
      primop0 = convert (signed_or_unsigned_type (unsignedp0, TREE_TYPE (primop0)),
                         primop0);
      primop1 = convert (signed_or_unsigned_type (unsignedp1, TREE_TYPE (primop1)),
                         primop1);
    }
  else
    {
      /* Here we must do the comparison on the nominal type
         using the args exactly as we received them.  */
      type = *restype_ptr;
      primop0 = op0;
      primop1 = op1;

      if (!real1 && !real2 && integer_zerop (primop1)
          && TREE_UNSIGNED (*restype_ptr))
        {
          tree value = 0;
          switch (code)
            {
            case GE_EXPR:
              /* All unsigned values are >= 0, so we warn if extra warnings
                 are requested.  However, if OP0 is a constant that is
                 >= 0, the signedness of the comparison isn't an issue,
                 so suppress the warning.  */
              if (extra_warnings && !in_system_header
                  && ! (TREE_CODE (primop0) == INTEGER_CST
                        && ! TREE_OVERFLOW (convert (signed_type (type),
                                                     primop0))))
                warning ("comparison of unsigned expression >= 0 is always true");
              value = boolean_true_node;
              break;

            case LT_EXPR:
              if (extra_warnings && !in_system_header
                  && ! (TREE_CODE (primop0) == INTEGER_CST
                        && ! TREE_OVERFLOW (convert (signed_type (type),
                                                     primop0))))
                warning ("comparison of unsigned expression < 0 is always false");
              value = boolean_false_node;
              break;

            default:
              break;
            }

          if (value != 0)
            {
              /* Don't forget to evaluate PRIMOP0 if it has side effects.  */
              if (TREE_SIDE_EFFECTS (primop0))
                return build (COMPOUND_EXPR, TREE_TYPE (value),
                              primop0, value);
              return value;
            }
        }
    }

  *op0_ptr = convert (type, primop0);
  *op1_ptr = convert (type, primop1);

  *restype_ptr = boolean_type_node;

  return 0;
}
\f
/* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
   or validate its data type for an `if' or `while' statement or ?..: exp.

   This preparation consists of taking the ordinary
   representation of an expression expr and producing a valid tree
   boolean expression describing whether expr is nonzero.  We could
   simply always do build_binary_op (NE_EXPR, expr, boolean_false_node, 1),
   but we optimize comparisons, &&, ||, and !.

   The resulting type should always be `boolean_type_node'.  */

tree
truthvalue_conversion (expr)
     tree expr;
{
  if (TREE_CODE (expr) == ERROR_MARK)
    return expr;

#if 0 /* This appears to be wrong for C++.  */
  /* These really should return error_mark_node after 2.4 is stable.
     But not all callers handle ERROR_MARK properly.  */
  switch (TREE_CODE (TREE_TYPE (expr)))
    {
    case RECORD_TYPE:
      error ("struct type value used where scalar is required");
      return boolean_false_node;

    case UNION_TYPE:
      error ("union type value used where scalar is required");
      return boolean_false_node;

    case ARRAY_TYPE:
      error ("array type value used where scalar is required");
      return boolean_false_node;

    default:
      break;
    }
#endif /* 0 */

  switch (TREE_CODE (expr))
    {
    case EQ_EXPR:
    case NE_EXPR: case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
    case TRUTH_ANDIF_EXPR:
    case TRUTH_ORIF_EXPR:
    case TRUTH_AND_EXPR:
    case TRUTH_OR_EXPR:
    case TRUTH_XOR_EXPR:
    case TRUTH_NOT_EXPR:
      TREE_TYPE (expr) = boolean_type_node;
      return expr;

    case ERROR_MARK:
      return expr;

    case INTEGER_CST:
      return integer_zerop (expr) ? boolean_false_node : boolean_true_node;

    case REAL_CST:
      return real_zerop (expr) ? boolean_false_node : boolean_true_node;

    case ADDR_EXPR:
      /* If we are taking the address of a external decl, it might be zero
         if it is weak, so we cannot optimize.  */
      if (DECL_P (TREE_OPERAND (expr, 0))
          && DECL_EXTERNAL (TREE_OPERAND (expr, 0)))
        break;

      if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
        return build (COMPOUND_EXPR, boolean_type_node,
                      TREE_OPERAND (expr, 0), boolean_true_node);
      else
        return boolean_true_node;

    case COMPLEX_EXPR:
      return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
                               ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
                              truthvalue_conversion (TREE_OPERAND (expr, 0)),
                              truthvalue_conversion (TREE_OPERAND (expr, 1)),
                              0);

    case NEGATE_EXPR:
    case ABS_EXPR:
    case FLOAT_EXPR:
    case FFS_EXPR:
      /* These don't change whether an object is non-zero or zero.  */
      return truthvalue_conversion (TREE_OPERAND (expr, 0));

    case LROTATE_EXPR:
    case RROTATE_EXPR:
      /* These don't change whether an object is zero or non-zero, but
         we can't ignore them if their second arg has side-effects.  */
      if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
        return build (COMPOUND_EXPR, boolean_type_node, TREE_OPERAND (expr, 1),
                      truthvalue_conversion (TREE_OPERAND (expr, 0)));
      else
        return truthvalue_conversion (TREE_OPERAND (expr, 0));

    case COND_EXPR:
      /* Distribute the conversion into the arms of a COND_EXPR.  */
      return fold (build (COND_EXPR, boolean_type_node, TREE_OPERAND (expr, 0),
                          truthvalue_conversion (TREE_OPERAND (expr, 1)),
                          truthvalue_conversion (TREE_OPERAND (expr, 2))));

    case CONVERT_EXPR:
      /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
         since that affects how `default_conversion' will behave.  */
      if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
          || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
        break;
      /* fall through...  */
    case NOP_EXPR:
      /* If this is widening the argument, we can ignore it.  */
      if (TYPE_PRECISION (TREE_TYPE (expr))
          >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
        return truthvalue_conversion (TREE_OPERAND (expr, 0));
      break;

    case MINUS_EXPR:
      /* With IEEE arithmetic, x - x may not equal 0, so we can't optimize
         this case.  */
      if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
          && TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE)
        break;
      /* fall through...  */
    case BIT_XOR_EXPR:
      /* This and MINUS_EXPR can be changed into a comparison of the
         two objects.  */
      if (TREE_TYPE (TREE_OPERAND (expr, 0))
          == TREE_TYPE (TREE_OPERAND (expr, 1)))
        return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
                                TREE_OPERAND (expr, 1), 1);
      return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
                              fold (build1 (NOP_EXPR,
                                            TREE_TYPE (TREE_OPERAND (expr, 0)),
                                            TREE_OPERAND (expr, 1))), 1);

    case BIT_AND_EXPR:
      if (integer_onep (TREE_OPERAND (expr, 1))
          && TREE_TYPE (expr) != boolean_type_node)
        /* Using convert here would cause infinite recursion.  */
        return build1 (NOP_EXPR, boolean_type_node, expr);
      break;

    case MODIFY_EXPR:
      if (warn_parentheses && C_EXP_ORIGINAL_CODE (expr) == MODIFY_EXPR)
        warning ("suggest parentheses around assignment used as truth value");
      break;

    default:
      break;
    }

  if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
    {
      tree tem = save_expr (expr);
      return (build_binary_op
              ((TREE_SIDE_EFFECTS (expr)
                ? TRUTH_OR_EXPR : TRUTH_ORIF_EXPR),
               truthvalue_conversion (build_unary_op (REALPART_EXPR, tem, 0)),
               truthvalue_conversion (build_unary_op (IMAGPART_EXPR, tem, 0)),
               0));
    }

  return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
}
\f
#if !USE_CPPLIB
/* Read the rest of a #-directive from input stream FINPUT.
   In normal use, the directive name and the white space after it
   have already been read, so they won't be included in the result.
   We allow for the fact that the directive line may contain
   a newline embedded within a character or string literal which forms
   a part of the directive.

   The value is a string in a reusable buffer.  It remains valid
   only until the next time this function is called.

   The terminating character ('\n' or EOF) is left in FINPUT for the
   caller to re-read.  */

char *
get_directive_line (finput)
     register FILE *finput;
{
  static char *directive_buffer = NULL;
  static unsigned buffer_length = 0;
  register char *p;
  register char *buffer_limit;
  register int looking_for = 0;
  register int char_escaped = 0;

  if (buffer_length == 0)
    {
      directive_buffer = (char *)xmalloc (128);
      buffer_length = 128;
    }

  buffer_limit = &directive_buffer[buffer_length];

  for (p = directive_buffer; ; )
    {
      int c;

      /* Make buffer bigger if it is full.  */
      if (p >= buffer_limit)
        {
          register unsigned bytes_used = (p - directive_buffer);

          buffer_length *= 2;
          directive_buffer
            = (char *)xrealloc (directive_buffer, buffer_length);
          p = &directive_buffer[bytes_used];
          buffer_limit = &directive_buffer[buffer_length];
        }

      c = getc (finput);

      /* Discard initial whitespace.  */
      if ((c == ' ' || c == '\t') && p == directive_buffer)
        continue;

      /* Detect the end of the directive.  */
      if (looking_for == 0
          && (c == '\n' || c == EOF))
        {
          ungetc (c, finput);
          c = '\0';
        }

      *p++ = c;

      if (c == 0)
        return directive_buffer;

      /* Handle string and character constant syntax.  */
      if (looking_for)
        {
          if (looking_for == c && !char_escaped)
            looking_for = 0;    /* Found terminator... stop looking.  */
        }
      else
        if (c == '\'' || c == '"')
          looking_for = c;      /* Don't stop buffering until we see another
                                   one of these (or an EOF).  */

      /* Handle backslash.  */
      char_escaped = (c == '\\' && ! char_escaped);
    }
}
#endif /* USE_CPPLIB */
\f
/* Make a variant type in the proper way for C/C++, propagating qualifiers
   down to the element type of an array.  */

tree
c_build_qualified_type (type, type_quals)
     tree type;
     int type_quals;
{
  /* A restrict-qualified pointer type must be a pointer to object or
     incomplete type.  Note that the use of POINTER_TYPE_P also allows
     REFERENCE_TYPEs, which is appropriate for C++.  Unfortunately,
     the C++ front-end also use POINTER_TYPE for pointer-to-member
     values, so even though it should be illegal to use `restrict'
     with such an entity we don't flag that here.  Thus, special case
     code for that case is required in the C++ front-end.  */
  if ((type_quals & TYPE_QUAL_RESTRICT)
      && (!POINTER_TYPE_P (type)
          || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
    {
      error ("invalid use of `restrict'");
      type_quals &= ~TYPE_QUAL_RESTRICT;
    }

  if (TREE_CODE (type) == ARRAY_TYPE)
    return build_array_type (c_build_qualified_type (TREE_TYPE (type),
                                                     type_quals),
                             TYPE_DOMAIN (type));
  return build_qualified_type (type, type_quals);
}

/* Apply the TYPE_QUALS to the new DECL.  */

void
c_apply_type_quals_to_decl (type_quals, decl)
     int type_quals;
     tree decl;
{
  if ((type_quals & TYPE_QUAL_CONST)
      || (TREE_TYPE (decl) 
          && TREE_CODE (TREE_TYPE (decl)) == REFERENCE_TYPE))
    TREE_READONLY (decl) = 1;
  if (type_quals & TYPE_QUAL_VOLATILE)
    {
      TREE_SIDE_EFFECTS (decl) = 1;
      TREE_THIS_VOLATILE (decl) = 1;
    }
  if (type_quals & TYPE_QUAL_RESTRICT)
    {
      if (!TREE_TYPE (decl)
          || !POINTER_TYPE_P (TREE_TYPE (decl))
          || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (TREE_TYPE (decl))))
        error ("invalid use of `restrict'");
      else if (flag_strict_aliasing)
        {
          /* No two restricted pointers can point at the same thing.
             However, a restricted pointer can point at the same thing
             as an unrestricted pointer, if that unrestricted pointer
             is based on the restricted pointer.  So, we make the
             alias set for the restricted pointer a subset of the
             alias set for the type pointed to by the type of the
             decl.  */

          HOST_WIDE_INT pointed_to_alias_set
            = get_alias_set (TREE_TYPE (TREE_TYPE (decl)));

          if (pointed_to_alias_set == 0)
            /* It's not legal to make a subset of alias set zero.  */
            ;
          else
            {
              DECL_POINTER_ALIAS_SET (decl) = new_alias_set ();
              record_alias_subset  (pointed_to_alias_set,
                                    DECL_POINTER_ALIAS_SET (decl));
            }
        }
    }
}


/* Return the typed-based alias set for T, which may be an expression
   or a type.  Return -1 if we don't do anything special.  */

HOST_WIDE_INT
lang_get_alias_set (t)
     tree t;
{
  tree u;

  /* Permit type-punning when accessing a union, provided the access
     is directly through the union.  For example, this code does not
     permit taking the address of a union member and then storing
     through it.  Even the type-punning allowed here is a GCC
     extension, albeit a common and useful one; the C standard says
     that such accesses have implementation-defined behavior.  */
  for (u = t;
       TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF;
       u = TREE_OPERAND (u, 0))
    if (TREE_CODE (u) == COMPONENT_REF
        && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE)
      return 0;

  /* If this is a char *, the ANSI C standard says it can alias
     anything.  Note that all references need do this.  */
  if (TREE_CODE_CLASS (TREE_CODE (t)) == 'r'
      && TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
      && TYPE_PRECISION (TREE_TYPE (t)) == TYPE_PRECISION (char_type_node))
    return 0;

  /* That's all the expressions we handle specially.  */
  if (! TYPE_P (t))
    return -1;

  /* The C standard specifically allows aliasing between signed and
     unsigned variants of the same type.  We treat the signed
     variant as canonical.  */
  if (TREE_CODE (t) == INTEGER_TYPE && TREE_UNSIGNED (t))
    {
      tree t1 = signed_type (t);

      /* t1 == t can happen for boolean nodes which are always unsigned.  */
      if (t1 != t)
        return get_alias_set (t1);
    }
  else if (POINTER_TYPE_P (t))
    {
      tree t1;

      /* Unfortunately, there is no canonical form of a pointer type.
         In particular, if we have `typedef int I', then `int *', and
         `I *' are different types.  So, we have to pick a canonical
         representative.  We do this below.

         Technically, this approach is actually more conservative that
         it needs to be.  In particular, `const int *' and `int *'
         chould be in different alias sets, according to the C and C++
         standard, since their types are not the same, and so,
         technically, an `int **' and `const int **' cannot point at
         the same thing.

         But, the standard is wrong.  In particular, this code is
         legal C++:

            int *ip;
            int **ipp = &ip;
            const int* const* cipp = &ip;

         And, it doesn't make sense for that to be legal unless you
         can dereference IPP and CIPP.  So, we ignore cv-qualifiers on
         the pointed-to types.  This issue has been reported to the
         C++ committee.  */
      t1 = TYPE_MAIN_VARIANT (TREE_TYPE (t));
      t1 = ((TREE_CODE (t) == POINTER_TYPE)
           ? build_pointer_type (t1) : build_reference_type (t1));
      if (t1 != t)
        return get_alias_set (t1);
    }
  /* It's not yet safe to use alias sets for classes in C++ because
     the TYPE_FIELDs list for a class doesn't mention base classes.  */
  else if (c_language == clk_cplusplus && AGGREGATE_TYPE_P (t))
    return 0;

  return -1;
}

/* Build tree nodes and builtin functions common to both C and C++ language
   frontends.
   CPLUS_MODE is nonzero if we are called from the C++ frontend, we generate
   some stricter prototypes in that case.
   NO_BUILTINS and NO_NONANSI_BUILTINS contain the respective values of
   the language frontend flags flag_no_builtin and
   flag_no_nonansi_builtin.  */

void
c_common_nodes_and_builtins (cplus_mode, no_builtins, no_nonansi_builtins)
    int cplus_mode, no_builtins, no_nonansi_builtins;
{
  tree temp;
  tree memcpy_ftype, memset_ftype, strlen_ftype;
  tree bzero_ftype, bcmp_ftype, puts_ftype, printf_ftype;
  tree endlink, int_endlink, double_endlink, unsigned_endlink;
  tree sizetype_endlink;
  tree ptr_ftype, ptr_ftype_unsigned;
  tree void_ftype_any, void_ftype_int, int_ftype_any, sizet_ftype_any;
  tree double_ftype_double, double_ftype_double_double;
  tree float_ftype_float, ldouble_ftype_ldouble;
  tree int_ftype_cptr_cptr_sizet;
  tree int_ftype_string_string, string_ftype_ptr_ptr;
  tree long_ftype_long;
  tree longlong_ftype_longlong;
  /* Either char* or void*.  */
  tree traditional_ptr_type_node;
  /* Either const char* or const void*.  */
  tree traditional_cptr_type_node;
  tree traditional_len_type_node;
  tree traditional_len_endlink;
  tree va_list_ref_type_node;
  tree va_list_arg_type_node;

  pushdecl (build_decl (TYPE_DECL, get_identifier ("__builtin_va_list"),
                        va_list_type_node));

  pushdecl (build_decl (TYPE_DECL, get_identifier ("__builtin_ptrdiff_t"),
                        ptrdiff_type_node));

  pushdecl (build_decl (TYPE_DECL, get_identifier ("__builtin_size_t"),
                        sizetype));

  if (TREE_CODE (va_list_type_node) == ARRAY_TYPE)
    {
      va_list_arg_type_node = va_list_ref_type_node =
        build_pointer_type (TREE_TYPE (va_list_type_node));
    }
  else
    {
      va_list_arg_type_node = va_list_type_node;
      va_list_ref_type_node = build_reference_type (va_list_type_node);
    }
 
  endlink = void_list_node;
  int_endlink = tree_cons (NULL_TREE, integer_type_node, endlink);
  double_endlink = tree_cons (NULL_TREE, double_type_node, endlink);
  unsigned_endlink = tree_cons (NULL_TREE, unsigned_type_node, endlink);

  ptr_ftype = build_function_type (ptr_type_node, NULL_TREE);
  ptr_ftype_unsigned = build_function_type (ptr_type_node, unsigned_endlink);
  sizetype_endlink = tree_cons (NULL_TREE, TYPE_DOMAIN (sizetype), endlink);
  /* We realloc here because sizetype could be int or unsigned.  S'ok.  */
  ptr_ftype_sizetype = build_function_type (ptr_type_node, sizetype_endlink);

  sizet_ftype_any = build_function_type (sizetype, NULL_TREE);
  int_ftype_any = build_function_type (integer_type_node, NULL_TREE);
  void_ftype_any = build_function_type (void_type_node, NULL_TREE);
  void_ftype = build_function_type (void_type_node, endlink);
  void_ftype_int = build_function_type (void_type_node, int_endlink);
  void_ftype_ptr
    = build_function_type (void_type_node,
                           tree_cons (NULL_TREE, ptr_type_node, endlink));

  float_ftype_float
    = build_function_type (float_type_node,
                           tree_cons (NULL_TREE, float_type_node, endlink));

  double_ftype_double
    = build_function_type (double_type_node, double_endlink);

  ldouble_ftype_ldouble
    = build_function_type (long_double_type_node,
                           tree_cons (NULL_TREE, long_double_type_node,
                                      endlink));

  double_ftype_double_double
    = build_function_type (double_type_node,
                           tree_cons (NULL_TREE, double_type_node,
                                      double_endlink));

  int_ftype_int
    = build_function_type (integer_type_node, int_endlink);

  long_ftype_long
    = build_function_type (long_integer_type_node,
                           tree_cons (NULL_TREE, long_integer_type_node,
                                      endlink));

  longlong_ftype_longlong
    = build_function_type (long_long_integer_type_node,
                           tree_cons (NULL_TREE, long_long_integer_type_node,
                                      endlink));

  int_ftype_cptr_cptr_sizet
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, const_ptr_type_node,
                                      tree_cons (NULL_TREE, const_ptr_type_node,
                                                 tree_cons (NULL_TREE,
                                                            sizetype,
                                                            endlink))));

  void_zero_node = build_int_2 (0, 0);
  TREE_TYPE (void_zero_node) = void_type_node;

  /* Prototype for strcpy.  */
  string_ftype_ptr_ptr
    = build_function_type (string_type_node,
                           tree_cons (NULL_TREE, string_type_node,
                                      tree_cons (NULL_TREE,
                                                 const_string_type_node,
                                                 endlink)));

  traditional_len_type_node = (flag_traditional && ! cplus_mode
                               ? integer_type_node : sizetype);
  traditional_len_endlink = tree_cons (NULL_TREE, traditional_len_type_node,
                                       endlink);

  /* Prototype for strcmp.  */
  int_ftype_string_string
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, const_string_type_node,
                                      tree_cons (NULL_TREE,
                                                 const_string_type_node,
                                                 endlink)));

  /* Prototype for strlen.  */
  strlen_ftype
    = build_function_type (traditional_len_type_node,
                           tree_cons (NULL_TREE, const_string_type_node,
                                      endlink));

  traditional_ptr_type_node = (flag_traditional && ! cplus_mode
                               ? string_type_node : ptr_type_node);
  traditional_cptr_type_node = (flag_traditional && ! cplus_mode
                               ? const_string_type_node : const_ptr_type_node);

  /* Prototype for memcpy.  */
  memcpy_ftype
    = build_function_type (traditional_ptr_type_node,
                           tree_cons (NULL_TREE, ptr_type_node,
                                      tree_cons (NULL_TREE, const_ptr_type_node,
                                                 sizetype_endlink)));

  /* Prototype for memset.  */
  memset_ftype
    = build_function_type (traditional_ptr_type_node,
                           tree_cons (NULL_TREE, ptr_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 tree_cons (NULL_TREE,
                                                            sizetype,
                                                            endlink))));

  /* Prototype for bzero.  */
  bzero_ftype
    = build_function_type (void_type_node,
                           tree_cons (NULL_TREE, traditional_ptr_type_node,
                                      traditional_len_endlink));

  /* Prototype for bcmp.  */
  bcmp_ftype
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, traditional_cptr_type_node,
                                      tree_cons (NULL_TREE,
                                                 traditional_cptr_type_node,
                                                 traditional_len_endlink)));

  /* Prototype for puts.  */
  puts_ftype
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, const_string_type_node,
                                      endlink));

  /* Prototype for printf.  */
  printf_ftype
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, const_string_type_node,
                                      NULL_TREE));

  builtin_function ("__builtin_constant_p", default_function_type,
                    BUILT_IN_CONSTANT_P, BUILT_IN_NORMAL, NULL_PTR);

  builtin_function ("__builtin_return_address", ptr_ftype_unsigned,
                    BUILT_IN_RETURN_ADDRESS, BUILT_IN_NORMAL, NULL_PTR);

  builtin_function ("__builtin_frame_address", ptr_ftype_unsigned,
                    BUILT_IN_FRAME_ADDRESS, BUILT_IN_NORMAL, NULL_PTR);

  builtin_function ("__builtin_alloca", ptr_ftype_sizetype,
                    BUILT_IN_ALLOCA, BUILT_IN_NORMAL, "alloca");
  builtin_function ("__builtin_ffs", int_ftype_int, BUILT_IN_FFS,
                    BUILT_IN_NORMAL, NULL_PTR);
  /* Define alloca, ffs as builtins.
     Declare _exit just to mark it as volatile.  */
  if (! no_builtins && ! no_nonansi_builtins)
    {
#ifndef SMALL_STACK
      temp = builtin_function ("alloca", ptr_ftype_sizetype,
                               BUILT_IN_ALLOCA, BUILT_IN_NORMAL, NULL_PTR);
      /* Suppress error if redefined as a non-function.  */
      DECL_BUILT_IN_NONANSI (temp) = 1;
#endif
      temp = builtin_function ("ffs", int_ftype_int, BUILT_IN_FFS,
                               BUILT_IN_NORMAL, NULL_PTR);
      /* Suppress error if redefined as a non-function.  */
      DECL_BUILT_IN_NONANSI (temp) = 1;
      temp = builtin_function ("_exit", void_ftype_int,
                               0, NOT_BUILT_IN, NULL_PTR);
      TREE_THIS_VOLATILE (temp) = 1;
      TREE_SIDE_EFFECTS (temp) = 1;
      /* Suppress error if redefined as a non-function.  */
      DECL_BUILT_IN_NONANSI (temp) = 1;

      /* The system prototypes for these functions have many
         variations, so don't specify parameters to avoid conflicts.
         The expand_* functions check the argument types anyway.  */
      temp = builtin_function ("bzero", void_ftype_any,
                               BUILT_IN_BZERO, BUILT_IN_NORMAL, NULL_PTR);
      DECL_BUILT_IN_NONANSI (temp) = 1;
      temp = builtin_function ("bcmp", int_ftype_any,
                               BUILT_IN_BCMP, BUILT_IN_NORMAL, NULL_PTR);
      DECL_BUILT_IN_NONANSI (temp) = 1;
    }

  builtin_function ("__builtin_abs", int_ftype_int, BUILT_IN_ABS,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_fabsf", float_ftype_float, BUILT_IN_FABS,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_fabs", double_ftype_double, BUILT_IN_FABS,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_fabsl", ldouble_ftype_ldouble, BUILT_IN_FABS,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_labs", long_ftype_long, BUILT_IN_LABS,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_llabs", longlong_ftype_longlong, BUILT_IN_LLABS,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_saveregs", ptr_ftype, BUILT_IN_SAVEREGS,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_classify_type", default_function_type,
                    BUILT_IN_CLASSIFY_TYPE, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_next_arg", ptr_ftype, BUILT_IN_NEXT_ARG,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_args_info", int_ftype_int, BUILT_IN_ARGS_INFO,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_setjmp",
                    build_function_type (integer_type_node,
                                         tree_cons (NULL_TREE, ptr_type_node,
                                                    endlink)),
                    BUILT_IN_SETJMP, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_longjmp",
                    build_function_type (void_type_node,
                                         tree_cons (NULL_TREE, ptr_type_node,
                                                    tree_cons (NULL_TREE,
                                                               integer_type_node,
                                                               endlink))),
                    BUILT_IN_LONGJMP, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_trap", void_ftype, BUILT_IN_TRAP,
                    BUILT_IN_NORMAL, NULL_PTR);

  /* ISO C99 IEEE Unordered compares.  */
  builtin_function ("__builtin_isgreater", default_function_type,
                    BUILT_IN_ISGREATER, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_isgreaterequal", default_function_type,
                    BUILT_IN_ISGREATEREQUAL, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_isless", default_function_type,
                    BUILT_IN_ISLESS, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_islessequal", default_function_type,
                    BUILT_IN_ISLESSEQUAL, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_islessgreater", default_function_type,
                    BUILT_IN_ISLESSGREATER, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_isunordered", default_function_type,
                    BUILT_IN_ISUNORDERED, BUILT_IN_NORMAL, NULL_PTR);

  /* Untyped call and return.  */
  builtin_function ("__builtin_apply_args", ptr_ftype,
                    BUILT_IN_APPLY_ARGS, BUILT_IN_NORMAL, NULL_PTR);

  temp = tree_cons (NULL_TREE,
                    build_pointer_type (build_function_type (void_type_node,
                                                             NULL_TREE)),
                    tree_cons (NULL_TREE,
                               ptr_type_node,
                               tree_cons (NULL_TREE,
                                          sizetype,
                                          endlink)));
  builtin_function ("__builtin_apply",
                    build_function_type (ptr_type_node, temp),
                    BUILT_IN_APPLY, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_return", void_ftype_ptr,
                    BUILT_IN_RETURN, BUILT_IN_NORMAL, NULL_PTR);

  /* Support for varargs.h and stdarg.h.  */
  builtin_function ("__builtin_varargs_start",
                    build_function_type (void_type_node,
                                         tree_cons (NULL_TREE,
                                                    va_list_ref_type_node,
                                                    endlink)),
                    BUILT_IN_VARARGS_START, BUILT_IN_NORMAL, NULL_PTR);

  builtin_function ("__builtin_stdarg_start",
                    build_function_type (void_type_node,
                                         tree_cons (NULL_TREE,
                                                    va_list_ref_type_node,
                                                    NULL_TREE)),
                    BUILT_IN_STDARG_START, BUILT_IN_NORMAL, NULL_PTR);

  builtin_function ("__builtin_va_end",
                    build_function_type (void_type_node,
                                         tree_cons (NULL_TREE,
                                                    va_list_ref_type_node,
                                                    endlink)),
                    BUILT_IN_VA_END, BUILT_IN_NORMAL, NULL_PTR);

  builtin_function ("__builtin_va_copy",
                    build_function_type (void_type_node,
                                         tree_cons (NULL_TREE,
                                                    va_list_ref_type_node,
                                                    tree_cons (NULL_TREE,
                                                      va_list_arg_type_node,
                                                      endlink))),
                    BUILT_IN_VA_COPY, BUILT_IN_NORMAL, NULL_PTR);

  /* ??? Ought to be `T __builtin_expect(T, T)' for any type T.  */
  builtin_function ("__builtin_expect",
                    build_function_type (long_integer_type_node,
                                         tree_cons (NULL_TREE,
                                                    long_integer_type_node,
                                                    tree_cons (NULL_TREE,
                                                        long_integer_type_node,
                                                        endlink))),
                    BUILT_IN_EXPECT, BUILT_IN_NORMAL, NULL_PTR);

  /* Currently under experimentation.  */
  builtin_function ("__builtin_memcpy", memcpy_ftype, BUILT_IN_MEMCPY,
                    BUILT_IN_NORMAL, "memcpy");
  builtin_function ("__builtin_memcmp", int_ftype_cptr_cptr_sizet,
                    BUILT_IN_MEMCMP, BUILT_IN_NORMAL, "memcmp");
  builtin_function ("__builtin_memset", memset_ftype,
                    BUILT_IN_MEMSET, BUILT_IN_NORMAL, "memset");
  builtin_function ("__builtin_bzero", bzero_ftype,
                    BUILT_IN_BZERO, BUILT_IN_NORMAL, "bzero");
  builtin_function ("__builtin_bcmp", bcmp_ftype,
                    BUILT_IN_BCMP, BUILT_IN_NORMAL, "bcmp");
  builtin_function ("__builtin_strcmp", int_ftype_string_string,
                    BUILT_IN_STRCMP, BUILT_IN_NORMAL, "strcmp");
  builtin_function ("__builtin_strcpy", string_ftype_ptr_ptr,
                    BUILT_IN_STRCPY, BUILT_IN_NORMAL, "strcpy");
  builtin_function ("__builtin_strlen", strlen_ftype,
                    BUILT_IN_STRLEN, BUILT_IN_NORMAL, "strlen");
  builtin_function ("__builtin_sqrtf", float_ftype_float,
                    BUILT_IN_FSQRT, BUILT_IN_NORMAL, "sqrtf");
  builtin_function ("__builtin_fsqrt", double_ftype_double,
                    BUILT_IN_FSQRT, BUILT_IN_NORMAL, "sqrt");
  builtin_function ("__builtin_sqrtl", ldouble_ftype_ldouble,
                    BUILT_IN_FSQRT, BUILT_IN_NORMAL, "sqrtl");
  builtin_function ("__builtin_sinf", float_ftype_float,
                    BUILT_IN_SIN, BUILT_IN_NORMAL, "sinf");
  builtin_function ("__builtin_sin", double_ftype_double,
                    BUILT_IN_SIN, BUILT_IN_NORMAL, "sin");
  builtin_function ("__builtin_sinl", ldouble_ftype_ldouble,
                    BUILT_IN_SIN, BUILT_IN_NORMAL, "sinl");
  builtin_function ("__builtin_cosf", float_ftype_float,
                    BUILT_IN_COS, BUILT_IN_NORMAL, "cosf");
  builtin_function ("__builtin_cos", double_ftype_double,
                    BUILT_IN_COS, BUILT_IN_NORMAL, "cos");
  builtin_function ("__builtin_cosl", ldouble_ftype_ldouble,
                    BUILT_IN_COS, BUILT_IN_NORMAL, "cosl");
  built_in_decls[BUILT_IN_PUTCHAR] =
    builtin_function ("__builtin_putchar", int_ftype_int,
                      BUILT_IN_PUTCHAR, BUILT_IN_NORMAL, "putchar");
  built_in_decls[BUILT_IN_PUTS] =
    builtin_function ("__builtin_puts", puts_ftype,
                      BUILT_IN_PUTS, BUILT_IN_NORMAL, "puts");
  builtin_function ("__builtin_printf", printf_ftype,
                    BUILT_IN_PRINTF, BUILT_IN_NORMAL, "printf");
  /* We declare these without argument so that the initial declaration
     for these identifiers is a builtin.  That allows us to redeclare
     them later with argument without worrying about the explicit
     declarations in stdio.h being taken as the initial declaration.
     Also, save the _DECL for these so we can use them later.  */
  built_in_decls[BUILT_IN_FWRITE] =
    builtin_function ("__builtin_fwrite", sizet_ftype_any,
                      BUILT_IN_FWRITE, BUILT_IN_NORMAL, "fwrite");
  built_in_decls[BUILT_IN_FPUTC] =
    builtin_function ("__builtin_fputc", int_ftype_any,
                      BUILT_IN_FPUTC, BUILT_IN_NORMAL, "fputc");
  built_in_decls[BUILT_IN_FPUTS] =
    builtin_function ("__builtin_fputs", int_ftype_any,
                      BUILT_IN_FPUTS, BUILT_IN_NORMAL, "fputs");

  if (! no_builtins)
    {
      builtin_function ("abs", int_ftype_int, BUILT_IN_ABS,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("fabsf", float_ftype_float, BUILT_IN_FABS,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("fabs", double_ftype_double, BUILT_IN_FABS,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("fabsl", ldouble_ftype_ldouble, BUILT_IN_FABS,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("labs", long_ftype_long, BUILT_IN_LABS,
                        BUILT_IN_NORMAL, NULL_PTR);
      if (flag_isoc99 || ! no_nonansi_builtins)
        builtin_function ("llabs", longlong_ftype_longlong, BUILT_IN_LLABS,
                          BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("memcpy", memcpy_ftype, BUILT_IN_MEMCPY,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("memcmp", int_ftype_cptr_cptr_sizet, BUILT_IN_MEMCMP,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("memset", memset_ftype, BUILT_IN_MEMSET,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("strcmp", int_ftype_string_string, BUILT_IN_STRCMP,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("strcpy", string_ftype_ptr_ptr, BUILT_IN_STRCPY,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("strlen", strlen_ftype, BUILT_IN_STRLEN,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("sqrtf", float_ftype_float, BUILT_IN_FSQRT,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("sqrt", double_ftype_double, BUILT_IN_FSQRT,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("sqrtl", ldouble_ftype_ldouble, BUILT_IN_FSQRT,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("sinf", float_ftype_float, BUILT_IN_SIN,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("sin", double_ftype_double, BUILT_IN_SIN,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("sinl", ldouble_ftype_ldouble, BUILT_IN_SIN,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("cosf", float_ftype_float, BUILT_IN_COS,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("cos", double_ftype_double, BUILT_IN_COS,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("cosl", ldouble_ftype_ldouble, BUILT_IN_COS,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("printf", printf_ftype, BUILT_IN_PRINTF,
                        BUILT_IN_NORMAL, NULL_PTR);
      /* We declare these without argument so that the initial
         declaration for these identifiers is a builtin.  That allows
         us to redeclare them later with argument without worrying
         about the explicit declarations in stdio.h being taken as the
         initial declaration.  */
      builtin_function ("fputc", int_ftype_any, BUILT_IN_FPUTC,
                        BUILT_IN_NORMAL, NULL_PTR);
      builtin_function ("fputs", int_ftype_any, BUILT_IN_FPUTS,
                        BUILT_IN_NORMAL, NULL_PTR);

      /* Declare these functions volatile
         to avoid spurious "control drops through" warnings.  */
      temp = builtin_function ("abort", cplus_mode ? void_ftype : void_ftype_any,
                               0, NOT_BUILT_IN, NULL_PTR);
      TREE_THIS_VOLATILE (temp) = 1;
      TREE_SIDE_EFFECTS (temp) = 1;

#if 0 /* ??? The C++ frontend used to do this.  */
      /* Well, these are actually ANSI, but we can't set DECL_BUILT_IN on
         them...  */
      DECL_BUILT_IN_NONANSI (temp) = 1;
#endif
      temp = builtin_function ("exit",
                               cplus_mode ? void_ftype_int : void_ftype_any,
                               0, NOT_BUILT_IN, NULL_PTR);
      TREE_THIS_VOLATILE (temp) = 1;
      TREE_SIDE_EFFECTS (temp) = 1;

#if 0 /* ??? The C++ frontend used to do this.  */
      /* Well, these are actually ANSI, but we can't set DECL_BUILT_IN on
         them...  */
      DECL_BUILT_IN_NONANSI (temp) = 1;
#endif
    }

#if 0
  /* Support for these has not been written in either expand_builtin
     or build_function_call.  */
  builtin_function ("__builtin_div", default_ftype, BUILT_IN_DIV,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_ldiv", default_ftype, BUILT_IN_LDIV,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_ffloor", double_ftype_double, BUILT_IN_FFLOOR,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_fceil", double_ftype_double, BUILT_IN_FCEIL,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_fmod", double_ftype_double_double,
                    BUILT_IN_FMOD, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_frem", double_ftype_double_double,
                    BUILT_IN_FREM, BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_getexp", double_ftype_double, BUILT_IN_GETEXP,
                    BUILT_IN_NORMAL, NULL_PTR);
  builtin_function ("__builtin_getman", double_ftype_double, BUILT_IN_GETMAN,
                    BUILT_IN_NORMAL, NULL_PTR);
#endif

  main_identifier_node = get_identifier ("main");

  /* ??? Perhaps there's a better place to do this.  But it is related
     to __builtin_va_arg, so it isn't that off-the-wall.  */
  lang_type_promotes_to = simple_type_promotes_to;
}

tree
build_va_arg (expr, type)
     tree expr, type;
{
  return build1 (VA_ARG_EXPR, type, expr);
}
\f
/* Given a type, apply default promotions wrt unnamed function arguments
   and return the new type.  Return NULL_TREE if no change.  */
/* ??? There is a function of the same name in the C++ front end that
   does something similar, but is more thorough and does not return NULL
   if no change.  We could perhaps share code, but it would make the
   self_promoting_type property harder to identify.  */

tree
simple_type_promotes_to (type)
     tree type;
{
  if (TYPE_MAIN_VARIANT (type) == float_type_node)
    return double_type_node;

  if (C_PROMOTING_INTEGER_TYPE_P (type))
    {
      /* Traditionally, unsignedness is preserved in default promotions.
         Also preserve unsignedness if not really getting any wider.  */
      if (TREE_UNSIGNED (type)
          && (flag_traditional
              || TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
        return unsigned_type_node;
      return integer_type_node;
    }

  return NULL_TREE;
}

/* Return 1 if PARMS specifies a fixed number of parameters
   and none of their types is affected by default promotions.  */

int
self_promoting_args_p (parms)
     tree parms;
{
  register tree t;
  for (t = parms; t; t = TREE_CHAIN (t))
    {
      register tree type = TREE_VALUE (t);

      if (TREE_CHAIN (t) == 0 && type != void_type_node)
        return 0;

      if (type == 0)
        return 0;

      if (TYPE_MAIN_VARIANT (type) == float_type_node)
        return 0;

      if (C_PROMOTING_INTEGER_TYPE_P (type))
        return 0;
    }
  return 1;
}

/* Recognize certain built-in functions so we can make tree-codes
   other than CALL_EXPR.  We do this when it enables fold-const.c
   to do something useful.  */
/* ??? By rights this should go in builtins.c, but only C and C++
   implement build_{binary,unary}_op.  Not exactly sure what bits
   of functionality are actually needed from those functions, or
   where the similar functionality exists in the other front ends.  */

tree
expand_tree_builtin (function, params, coerced_params)
     tree function, params, coerced_params;
{
  enum tree_code code;

  if (DECL_BUILT_IN_CLASS (function) != BUILT_IN_NORMAL)
    return NULL_TREE;

  switch (DECL_FUNCTION_CODE (function))
    {
    case BUILT_IN_ABS:
    case BUILT_IN_LABS:
    case BUILT_IN_LLABS:
    case BUILT_IN_FABS:
      if (coerced_params == 0)
        return integer_zero_node;
      return build_unary_op (ABS_EXPR, TREE_VALUE (coerced_params), 0);

    case BUILT_IN_ISGREATER:
      if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT)
        code = UNLE_EXPR;
      else
        code = LE_EXPR;
      goto unordered_cmp;

    case BUILT_IN_ISGREATEREQUAL:
      if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT)
        code = UNLT_EXPR;
      else
        code = LT_EXPR;
      goto unordered_cmp;

    case BUILT_IN_ISLESS:
      if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT)
        code = UNGE_EXPR;
      else
        code = GE_EXPR;
      goto unordered_cmp;

    case BUILT_IN_ISLESSEQUAL:
      if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT)
        code = UNGT_EXPR;
      else
        code = GT_EXPR;
      goto unordered_cmp;

    case BUILT_IN_ISLESSGREATER:
      if (TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT)
        code = UNEQ_EXPR;
      else
        code = EQ_EXPR;
      goto unordered_cmp;

    case BUILT_IN_ISUNORDERED:
      if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT)
        return integer_zero_node;
      code = UNORDERED_EXPR;
      goto unordered_cmp;

    unordered_cmp:
      {
        tree arg0, arg1;

        if (params == 0
            || TREE_CHAIN (params) == 0)
          {
            error ("too few arguments to function `%s'",
                   IDENTIFIER_POINTER (DECL_NAME (function)));
            return error_mark_node;
          }
        else if (TREE_CHAIN (TREE_CHAIN (params)) != 0)
          {
            error ("too many arguments to function `%s'",
                   IDENTIFIER_POINTER (DECL_NAME (function)));
            return error_mark_node;
          }

        arg0 = TREE_VALUE (params);
        arg1 = TREE_VALUE (TREE_CHAIN (params));
        arg0 = build_binary_op (code, arg0, arg1, 0);
        if (code != UNORDERED_EXPR)
          arg0 = build_unary_op (TRUTH_NOT_EXPR, arg0, 0);
        return arg0;
      }
      break;

    default:
      break;
    }

  return NULL_TREE;
}

/* Returns non-zero if CODE is the code for a statement.  */

int
statement_code_p (code)
     enum tree_code code;
{
  switch (code)
    {
    case EXPR_STMT:
    case COMPOUND_STMT:
    case DECL_STMT:
    case IF_STMT:
    case FOR_STMT:
    case WHILE_STMT:
    case DO_STMT:
    case RETURN_STMT:
    case BREAK_STMT:
    case CONTINUE_STMT:
    case SCOPE_STMT:
    case SWITCH_STMT:
    case GOTO_STMT:
    case LABEL_STMT:
    case ASM_STMT:
    case CASE_LABEL:
      return 1;

    default:
      if (lang_statement_code_p)
        return (*lang_statement_code_p) (code);
      return 0;
    }
}

/* Walk the statemen tree, rooted at *tp.  Apply FUNC to all the
   sub-trees of *TP in a pre-order traversal.  FUNC is called with the
   DATA and the address of each sub-tree.  If FUNC returns a non-NULL
   value, the traversal is aborted, and the value returned by FUNC is
   returned.  If FUNC sets WALK_SUBTREES to zero, then the subtrees of
   the node being visited are not walked.

   We don't need a without_duplicates variant of this one because the
   statement tree is a tree, not a graph.  */

tree 
walk_stmt_tree (tp, func, data)
     tree *tp;
     walk_tree_fn func;
     void *data;
{
  enum tree_code code;
  int walk_subtrees;
  tree result;
  int i, len;

#define WALK_SUBTREE(NODE)                              \
  do                                                    \
    {                                                   \
      result = walk_stmt_tree (&(NODE), func, data);    \
      if (result)                                       \
        return result;                                  \
    }                                                   \
  while (0)

  /* Skip empty subtrees.  */
  if (!*tp)
    return NULL_TREE;

  /* Skip subtrees below non-statement nodes.  */
  if (!statement_code_p (TREE_CODE (*tp)))
    return NULL_TREE;

  /* Call the function.  */
  walk_subtrees = 1;
  result = (*func) (tp, &walk_subtrees, data);

  /* If we found something, return it.  */
  if (result)
    return result;

  /* Even if we didn't, FUNC may have decided that there was nothing
     interesting below this point in the tree.  */
  if (!walk_subtrees)
    return NULL_TREE;

  /* FUNC may have modified the tree, recheck that we're looking at a
     statement node.  */
  code = TREE_CODE (*tp);
  if (!statement_code_p (code))
    return NULL_TREE;

  /* Walk over all the sub-trees of this operand.  Statement nodes never
     contain RTL, and we needn't worry about TARGET_EXPRs.  */
  len = TREE_CODE_LENGTH (code);

  /* Go through the subtrees.  We need to do this in forward order so
     that the scope of a FOR_EXPR is handled properly.  */
  for (i = 0; i < len; ++i)
    WALK_SUBTREE (TREE_OPERAND (*tp, i));

  /* Finally visit the chain.  This can be tail-recursion optimized if
     we write it this way.  */
  return walk_stmt_tree (&TREE_CHAIN (*tp), func, data);

#undef WALK_SUBTREE
}

/* Used to compare case labels.  K1 and K2 are actually tree nodes
   representing case labels, or NULL_TREE for a `default' label.
   Returns -1 if K1 is ordered before K2, -1 if K1 is ordered after
   K2, and 0 if K1 and K2 are equal.  */

int
case_compare (k1, k2)
     splay_tree_key k1;
     splay_tree_key k2;
{
  /* Consider a NULL key (such as arises with a `default' label) to be
     smaller than anything else.  */
  if (!k1)
    return k2 ? -1 : 0;
  else if (!k2)
    return k1 ? 1 : 0;

  return tree_int_cst_compare ((tree) k1, (tree) k2);
}

/* Process a case label for the range LOW_VALUE ... HIGH_VALUE.  If
   LOW_VALUE and HIGH_VALUE are both NULL_TREE then this case label is
   actually a `default' label.  If only HIGH_VALUE is NULL_TREE, then
   case label was declared using the usual C/C++ syntax, rather than
   the GNU case range extension.  CASES is a tree containing all the
   case ranges processed so far; COND is the condition for the
   switch-statement itself.  Returns the CASE_LABEL created, or
   ERROR_MARK_NODE if no CASE_LABEL is created.  */

tree
c_add_case_label (cases, cond, low_value, high_value)
     splay_tree cases;
     tree cond;
     tree low_value;
     tree high_value;
{
  tree type;
  tree label;
  tree case_label;
  splay_tree_node node;

  /* Create the LABEL_DECL itself.  */
  label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
  DECL_CONTEXT (label) = current_function_decl;

  /* If there was an error processing the switch condition, bail now
     before we get more confused.  */
  if (!cond || cond == error_mark_node)
    {
      /* Add a label anyhow so that the back-end doesn't think that
         the beginning of the switch is unreachable.  */
      if (!cases->root)
        add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
      return error_mark_node;
    }

  if ((low_value && TREE_TYPE (low_value) 
       && POINTER_TYPE_P (TREE_TYPE (low_value))) 
      || (high_value && TREE_TYPE (high_value)
          && POINTER_TYPE_P (TREE_TYPE (high_value))))
    error ("pointers are not permitted as case values");

  /* Case ranges are a GNU extension.  */
  if (high_value && pedantic)
    {
      if (c_language == clk_cplusplus)
        pedwarn ("ISO C++ forbids range expressions in switch statements");
      else
        pedwarn ("ISO C forbids range expressions in switch statements");
    }

  type = TREE_TYPE (cond);
  if (low_value)
    {
      low_value = check_case_value (low_value);
      low_value = convert_and_check (type, low_value);
    }
  if (high_value)
    {
      high_value = check_case_value (high_value);
      high_value = convert_and_check (type, high_value);
    }

  /* If an error has occurred, bail out now.  */
  if (low_value == error_mark_node || high_value == error_mark_node)
    {
      if (!cases->root)
        add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
      return error_mark_node;
    }

  /* If the LOW_VALUE and HIGH_VALUE are the same, then this isn't
     really a case range, even though it was written that way.  Remove
     the HIGH_VALUE to simplify later processing.  */
  if (tree_int_cst_equal (low_value, high_value))
    high_value = NULL_TREE;
  if (low_value && high_value 
      && !tree_int_cst_lt (low_value, high_value)) 
    warning ("empty range specified");

  /* Look up the LOW_VALUE in the table of case labels we already
     have.  */
  node = splay_tree_lookup (cases, (splay_tree_key) low_value);
  /* If there was not an exact match, check for overlapping ranges.
     There's no need to do this if there's no LOW_VALUE or HIGH_VALUE;
     that's a `default' label and the only overlap is an exact match.  */
  if (!node && (low_value || high_value))
    {
      splay_tree_node low_bound;
      splay_tree_node high_bound;

      /* Even though there wasn't an exact match, there might be an
         overlap between this case range and another case range.
         Since we've (inductively) not allowed any overlapping case
         ranges, we simply need to find the greatest low case label
         that is smaller that LOW_VALUE, and the smallest low case
         label that is greater than LOW_VALUE.  If there is an overlap
         it will occur in one of these two ranges.  */
      low_bound = splay_tree_predecessor (cases,
                                          (splay_tree_key) low_value);
      high_bound = splay_tree_successor (cases,
                                         (splay_tree_key) low_value);

      /* Check to see if the LOW_BOUND overlaps.  It is smaller than
         the LOW_VALUE, so there is no need to check unless the
         LOW_BOUND is in fact itself a case range.  */
      if (low_bound
          && CASE_HIGH ((tree) low_bound->value)
          && tree_int_cst_compare (CASE_HIGH ((tree) low_bound->value),
                                    low_value) >= 0)
        node = low_bound;
      /* Check to see if the HIGH_BOUND overlaps.  The low end of that
         range is bigger than the low end of the current range, so we
         are only interested if the current range is a real range, and
         not an ordinary case label.  */
      else if (high_bound 
               && high_value
               && (tree_int_cst_compare ((tree) high_bound->key,
                                         high_value)
                   <= 0))
        node = high_bound;
    }
  /* If there was an overlap, issue an error.  */
  if (node)
    {
      tree duplicate = CASE_LABEL_DECL ((tree) node->value);

      if (high_value)
        {
          error ("duplicate (or overlapping) case value");
          error_with_decl (duplicate, 
                           "this is the first entry overlapping that value");
        }
      else if (low_value)
        {
          error ("duplicate case value") ;
          error_with_decl (duplicate, "previously used here");
        }
      else
        {
          error ("multiple default labels in one switch");
          error_with_decl (duplicate, "this is the first default label");
        }
      if (!cases->root)
        add_stmt (build_case_label (NULL_TREE, NULL_TREE, label));
    }

  /* Add a CASE_LABEL to the statement-tree.  */
  case_label = add_stmt (build_case_label (low_value, high_value, label));
  /* Register this case label in the splay tree.  */
  splay_tree_insert (cases, 
                     (splay_tree_key) low_value,
                     (splay_tree_value) case_label);

  return case_label;
}

/* Mark P (a stmt_tree) for GC.  The use of a `void *' for the
   parameter allows this function to be used as a GC-marking
   function.  */

void
mark_stmt_tree (p)
     void *p;
{
  stmt_tree st = (stmt_tree) p;

  ggc_mark_tree (st->x_last_stmt);
  ggc_mark_tree (st->x_last_expr_type);
}

/* Mark LD for GC.  */

void
c_mark_lang_decl (c)
     struct c_lang_decl *c;
{
  ggc_mark_tree (c->saved_tree);
}

/* Mark F for GC.  */

void
mark_c_language_function (f)
     struct language_function *f;
{
  if (!f)
    return;

  mark_stmt_tree (&f->x_stmt_tree);
  ggc_mark_tree (f->x_scope_stmt_stack);
}

/* Hook used by expand_expr to expand language-specific tree codes.  */

rtx
c_expand_expr (exp, target, tmode, modifier)
     tree exp;
     rtx target;
     enum machine_mode tmode;
     enum expand_modifier modifier;
{
  switch (TREE_CODE (exp))
    {
    case STMT_EXPR:
      {
        tree rtl_expr;
        rtx result;

        /* Since expand_expr_stmt calls free_temp_slots after every
           expression statement, we must call push_temp_slots here.
           Otherwise, any temporaries in use now would be considered
           out-of-scope after the first EXPR_STMT from within the
           STMT_EXPR.  */
        push_temp_slots ();
        rtl_expr = expand_start_stmt_expr ();
        expand_stmt (STMT_EXPR_STMT (exp));
        expand_end_stmt_expr (rtl_expr);
        result = expand_expr (rtl_expr, target, tmode, modifier);
        pop_temp_slots ();
        return result;
      }
      break;
      
    default:
      abort ();
    }

  abort ();
  return NULL;
}

/* Hook used by safe_from_p to handle language-specific tree codes.  */

int
c_safe_from_p (target, exp)
     rtx target;
     tree exp;
{
  /* We can see statements here when processing the body of a
     statement-expression.  For a declaration statement declaring a
     variable, look at the variable's initializer.  */
  if (TREE_CODE (exp) == DECL_STMT) 
    {
      tree decl = DECL_STMT_DECL (exp);

      if (TREE_CODE (decl) == VAR_DECL
          && DECL_INITIAL (decl)
          && !safe_from_p (target, DECL_INITIAL (decl), /*top_p=*/0))
        return 0;
    }

  /* For any statement, we must follow the statement-chain.  */
  if (statement_code_p (TREE_CODE (exp)) && TREE_CHAIN (exp))
    return safe_from_p (target, TREE_CHAIN (exp), /*top_p=*/0);

  /* Assume everything else is safe.  */
  return 1;
}

/* Tree code classes. */

#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,

static char c_tree_code_type[] = {
  'x',
#include "c-common.def"
};
#undef DEFTREECODE

/* Table indexed by tree code giving number of expression
   operands beyond the fixed part of the node structure.
   Not used for types or decls.  */

#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,

static int c_tree_code_length[] = {
  0,
#include "c-common.def"
};
#undef DEFTREECODE

/* Names of tree components.
   Used for printing out the tree and error messages.  */
#define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,

static const char *c_tree_code_name[] = {
  "@@dummy",
#include "c-common.def"
};
#undef DEFTREECODE

/* Adds the tree codes specific to the C front end to the list of all
   tree codes. */

void
add_c_tree_codes ()
{
  memcpy (tree_code_type + (int) LAST_AND_UNUSED_TREE_CODE,
          c_tree_code_type,
          (int)LAST_C_TREE_CODE - (int)LAST_AND_UNUSED_TREE_CODE);
  memcpy (tree_code_length + (int) LAST_AND_UNUSED_TREE_CODE,
          c_tree_code_length,
          (LAST_C_TREE_CODE - (int)LAST_AND_UNUSED_TREE_CODE) * sizeof (int));
  memcpy (tree_code_name + (int) LAST_AND_UNUSED_TREE_CODE,
          c_tree_code_name,
          (LAST_C_TREE_CODE - (int)LAST_AND_UNUSED_TREE_CODE) * sizeof (char *));
}