gcc/langhooks.h

   1 /* The lang_hooks data structure.
   2    Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef GCC_LANG_HOOKS_H
  22 #define GCC_LANG_HOOKS_H
  23
  24 /* This file should be #include-d after tree.h.  */
  25
  26 struct diagnostic_context;
  27
  28 /* A print hook for print_tree ().  */
  29 typedef void (*lang_print_tree_hook) (FILE *, tree, int indent);
  30
  31 /* The following hooks are documented in langhooks.c.  Must not be
  32    NULL.  */
  33
  34 struct lang_hooks_for_tree_inlining
  35 {
  36   tree (*walk_subtrees) (tree *, int *,
  37                          tree (*) (tree *, int *, void *),
  38                          void *, void *);
  39   int (*cannot_inline_tree_fn) (tree *);
  40   int (*disregard_inline_limits) (tree);
  41   tree (*add_pending_fn_decls) (void *, tree);
  42   int (*tree_chain_matters_p) (tree);
  43   int (*auto_var_in_fn_p) (tree, tree);
  44   tree (*copy_res_decl_for_inlining) (tree, tree, tree,
  45                                       void *, int *, tree);
  46   int (*anon_aggr_type_p) (tree);
  47   bool (*var_mod_type_p) (tree);
  48   int (*start_inlining) (tree);
  49   void (*end_inlining) (tree);
  50   tree (*convert_parm_for_inlining) (tree, tree, tree);
  51   int (*estimate_num_insns) (tree);
  52 };
  53
  54 struct lang_hooks_for_callgraph
  55 {
  56   /* Function passed as argument is needed and will be compiled.
  57      Lower the representation so the calls are explicit.  */
  58   void (*lower_function) (tree);
  59   /* Produce RTL for function passed as argument.  */
  60   void (*expand_function) (tree);
  61 };
  62
  63 /* Lang hooks for management of language-specific data or status
  64    when entering / leaving functions etc.  */
  65 struct lang_hooks_for_functions
  66 {
  67   /* Called when entering a function.  */
  68   void (*init) (struct function *);
  69
  70   /* Called when leaving a function.  */
  71   void (*final) (struct function *);
  72
  73   /* Called when entering a nested function.  */
  74   void (*enter_nested) (struct function *);
  75
  76   /* Called when leaving a nested function.  */
  77   void (*leave_nested) (struct function *);
  78 };
  79
  80 /* The following hooks are used by tree-dump.c.  */
  81
  82 struct lang_hooks_for_tree_dump
  83 {
  84   /* Dump language-specific parts of tree nodes.  Returns nonzero if it
  85      does not want the usual dumping of the second argument.  */
  86   bool (*dump_tree) (void *, tree);
  87
  88   /* Determine type qualifiers in a language-specific way.  */
  89   int (*type_quals) (tree);
  90 };
  91
  92 /* Hooks related to types.  */
  93
  94 struct lang_hooks_for_types
  95 {
  96   /* Return a new type (with the indicated CODE), doing whatever
  97      language-specific processing is required.  */
  98   tree (*make_type) (enum tree_code);
  99
 100   /* Given MODE and UNSIGNEDP, return a suitable type-tree with that
 101      mode.  */
 102   tree (*type_for_mode) (enum machine_mode, int);
 103
 104   /* Given PRECISION and UNSIGNEDP, return a suitable type-tree for an
 105      integer type with at least that precision.  */
 106   tree (*type_for_size) (unsigned, int);
 107
 108   /* Given an integer type T, return a type like T but unsigned.
 109      If T is unsigned, the value is T.  */
 110   tree (*unsigned_type) (tree);
 111
 112   /* Given an integer type T, return a type like T but signed.
 113      If T is signed, the value is T.  */
 114   tree (*signed_type) (tree);
 115
 116   /* Return a type the same as TYPE except unsigned or signed
 117      according to UNSIGNEDP.  */
 118   tree (*signed_or_unsigned_type) (int, tree);
 119
 120   /* Given a type, apply default promotions to unnamed function
 121      arguments and return the new type.  Return the same type if no
 122      change.  Required by any language that supports variadic
 123      arguments.  The default hook aborts.  */
 124   tree (*type_promotes_to) (tree);
 125
 126   /* This routine is called in tree.c to print an error message for
 127      invalid use of an incomplete type.  VALUE is the expression that
 128      was used (or 0 if that isn't known) and TYPE is the type that was
 129      invalid.  */
 130   void (*incomplete_type_error) (tree value, tree type);
 131 };
 132
 133 /* Language hooks related to decls and the symbol table.  */
 134
 135 struct lang_hooks_for_decls
 136 {
 137   /* Enter a new lexical scope.  Argument is always zero when called
 138      from outside the front end.  */
 139   void (*pushlevel) (int);
 140
 141   /* Exit a lexical scope and return a BINDING for that scope.
 142      Takes three arguments:
 143      KEEP -- nonzero if there were declarations in this scope.
 144      REVERSE -- reverse the order of decls before returning them.
 145      FUNCTIONBODY -- nonzero if this level is the body of a function.  */
 146   tree (*poplevel) (int, int, int);
 147
 148   /* Returns nonzero if we are in the global binding level.  Ada
 149      returns -1 for an undocumented reason used in stor-layout.c.  */
 150   int (*global_bindings_p) (void);
 151
 152   /* Insert BLOCK at the end of the list of subblocks of the
 153      current binding level.  This is used when a BIND_EXPR is expanded,
 154      to handle the BLOCK node inside the BIND_EXPR.  */
 155   void (*insert_block) (tree);
 156
 157   /* Set the BLOCK node for the current scope level.  */
 158   void (*set_block) (tree);
 159
 160   /* Function to add a decl to the current scope level.  Takes one
 161      argument, a decl to add.  Returns that decl, or, if the same
 162      symbol is already declared, may return a different decl for that
 163      name.  */
 164   tree (*pushdecl) (tree);
 165
 166   /* Returns the chain of decls so far in the current scope level.  */
 167   tree (*getdecls) (void);
 168
 169   /* Returns true when we should warn for an unused global DECL.
 170      We will already have checked that it has static binding.  */
 171   bool (*warn_unused_global) (tree);
 172
 173   /* Obtain a list of globals and do final output on them at end
 174      of compilation */
 175   void (*final_write_globals) (void);
 176
 177   /* Do necessary preparations before assemble_variable can proceed.  */
 178   void (*prepare_assemble_variable) (tree);
 179
 180   /* True if this decl may be called via a sibcall.  */
 181   bool (*ok_for_sibcall) (tree);
 182 };
 183
 184 /* Language-specific hooks.  See langhooks-def.h for defaults.  */
 185
 186 struct lang_hooks
 187 {
 188   /* String identifying the front end.  e.g. "GNU C++".  */
 189   const char *name;
 190
 191   /* sizeof (struct lang_identifier), so make_node () creates
 192      identifier nodes long enough for the language-specific slots.  */
 193   size_t identifier_size;
 194
 195   /* Determines the size of any language-specific 'x' or 'c' nodes.
 196      Since it is called from make_node, the only information available
 197      is the tree code.  Expected to abort on unrecognized codes.  */
 198   size_t (*tree_size) (enum tree_code);
 199
 200   /* The first callback made to the front end, for simple
 201      initialization needed before any calls to handle_option.  Return
 202      the language mask to filter the switch array with.  */
 203   unsigned int (*init_options) (unsigned int argc, const char **argv);
 204
 205   /* Callback used to perform language-specific initialization for the
 206      global diagnostic context structure.  */
 207   void (*initialize_diagnostics) (struct diagnostic_context *);
 208
 209   /* Handle the switch CODE, which has real type enum opt_code from
 210      options.h.  If the switch takes an argument, it is passed in ARG
 211      which points to permanent storage.  The handler is responsible for
 212      checking whether ARG is NULL, which indicates that no argument
 213      was in fact supplied.  For -f and -W switches, VALUE is 1 or 0
 214      for the positive and negative forms respectively.
 215
 216      Return 1 if the switch is valid, 0 if invalid, and -1 if it's
 217      valid and should not be treated as language-independent too.  */
 218   int (*handle_option) (size_t code, const char *arg, int value);
 219
 220   /* Return false to use the default complaint about a missing
 221      argument, otherwise output a complaint and return true.  */
 222   bool (*missing_argument) (const char *opt, size_t code);
 223
 224   /* Called when all command line options have been parsed to allow
 225      further processing and initialization
 226
 227      Should return true to indicate that a compiler back-end is
 228      not required, such as with the -E option.
 229
 230      If errorcount is nonzero after this call the compiler exits
 231      immediately and the finish hook is not called.  */
 232   bool (*post_options) (const char **);
 233
 234   /* Called after post_options to initialize the front end.  Return
 235      false to indicate that no further compilation be performed, in
 236      which case the finish hook is called immediately.  */
 237   bool (*init) (void);
 238
 239   /* Called at the end of compilation, as a finalizer.  */
 240   void (*finish) (void);
 241
 242   /* Parses the entire file.  The argument is nonzero to cause bison
 243      parsers to dump debugging information during parsing.  */
 244   void (*parse_file) (int);
 245
 246   /* Called immediately after parsing to clear the binding stack.  */
 247   void (*clear_binding_stack) (void);
 248
 249   /* Called to obtain the alias set to be used for an expression or type.
 250      Returns -1 if the language does nothing special for it.  */
 251   HOST_WIDE_INT (*get_alias_set) (tree);
 252
 253   /* Called with an expression that is to be processed as a constant.
 254      Returns either the same expression or a language-independent
 255      constant equivalent to its input.  */
 256   tree (*expand_constant) (tree);
 257
 258   /* Called by expand_expr for language-specific tree codes.
 259      Fourth argument is actually an enum expand_modifier.  */
 260   rtx (*expand_expr) (tree, rtx, enum machine_mode, int);
 261
 262   /* Prepare expr to be an argument of a TRUTH_NOT_EXPR or other logical
 263      operation.
 264
 265      This preparation consists of taking the ordinary representation
 266      of an expression expr and producing a valid tree boolean
 267      expression describing whether expr is nonzero.  We could simply
 268      always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
 269      but we optimize comparisons, &&, ||, and !.
 270
 271      The result should be an expression of boolean type (if not an
 272      error_mark_node).  */
 273   tree (*truthvalue_conversion) (tree);
 274
 275   /* Hook called by safe_from_p for language-specific tree codes.  It is
 276      up to the language front-end to install a hook if it has any such
 277      codes that safe_from_p needs to know about.  Since same_from_p will
 278      recursively explore the TREE_OPERANDs of an expression, this hook
 279      should not reexamine those pieces.  This routine may recursively
 280      call safe_from_p; it should always pass `0' as the TOP_P
 281      parameter.  */
 282   int (*safe_from_p) (rtx, tree);
 283
 284   /* Function to finish handling an incomplete decl at the end of
 285      compilation.  Default hook is does nothing.  */
 286   void (*finish_incomplete_decl) (tree);
 287
 288   /* Function used by unsafe_for_reeval.  A non-negative number is
 289      returned directly from unsafe_for_reeval, a negative number falls
 290      through.  The default hook returns a negative number.  */
 291   int (*unsafe_for_reeval) (tree);
 292
 293   /* Mark EXP saying that we need to be able to take the address of
 294      it; it should not be allocated in a register.  Return true if
 295      successful.  */
 296   bool (*mark_addressable) (tree);
 297
 298   /* Hook called by staticp for language-specific tree codes.  */
 299   int (*staticp) (tree);
 300
 301   /* Replace the DECL_LANG_SPECIFIC data, which may be NULL, of the
 302      DECL_NODE with a newly GC-allocated copy.  */
 303   void (*dup_lang_specific_decl) (tree);
 304
 305   /* Called before its argument, an UNSAVE_EXPR, is to be
 306      unsaved.  Modify it in-place so that all the evaluate only once
 307      things are cleared out.  */
 308   tree (*unsave_expr_now) (tree);
 309
 310   /* Called by expand_expr to build and return the cleanup-expression
 311      for the passed TARGET_EXPR.  Return NULL if there is none.  */
 312   tree (*maybe_build_cleanup) (tree);
 313
 314   /* Set the DECL_ASSEMBLER_NAME for a node.  If it is the sort of
 315      thing that the assembler should talk about, set
 316      DECL_ASSEMBLER_NAME to an appropriate IDENTIFIER_NODE.
 317      Otherwise, set it to the ERROR_MARK_NODE to ensure that the
 318      assembler does not talk about it.  */
 319   void (*set_decl_assembler_name) (tree);
 320
 321   /* Return nonzero if fold-const is free to use bit-field
 322      optimizations, for instance in fold_truthop().  */
 323   bool (*can_use_bit_fields_p) (void);
 324
 325   /* Nonzero if TYPE_READONLY and TREE_READONLY should always be honored.  */
 326   bool honor_readonly;
 327
 328   /* Nonzero if this front end does not generate a dummy BLOCK between
 329      the outermost scope of the function and the FUNCTION_DECL.  See
 330      is_body_block in stmt.c, and its callers.  */
 331   bool no_body_blocks;
 332
 333   /* The front end can add its own statistics to -fmem-report with
 334      this hook.  It should output to stderr.  */
 335   void (*print_statistics) (void);
 336
 337   /* Called by print_tree when there is a tree of class 'x' that it
 338      doesn't know how to display.  */
 339   lang_print_tree_hook print_xnode;
 340
 341   /* Called to print language-dependent parts of a class 'd', class
 342      't', and IDENTIFIER_NODE nodes.  */
 343   lang_print_tree_hook print_decl;
 344   lang_print_tree_hook print_type;
 345   lang_print_tree_hook print_identifier;
 346
 347   /* Computes the name to use to print a declaration.  DECL is the
 348      non-NULL declaration in question.  VERBOSITY determines what
 349      information will be printed: 0: DECL_NAME, demangled as
 350      necessary.  1: and scope information.  2: and any other
 351      information that might be interesting, such as function parameter
 352      types in C++.  */
 353   const char *(*decl_printable_name) (tree decl, int verbosity);
 354
 355   /* Called by report_error_function to print out function name.  */
 356   void (*print_error_function) (struct diagnostic_context *, const char *);
 357
 358   /* Called from expr_size to calculate the size of the value of an
 359      expression in a language-dependent way.  Returns a tree for the size
 360      in bytes.  A frontend can call lhd_expr_size to get the default
 361      semantics in cases that it doesn't want to handle specially.  */
 362   tree (*expr_size) (tree);
 363
 364   /* Called from uninitialized_vars_warning to find out if a variable is
 365      uninitialized based on DECL_INITIAL. */
 366   bool (*decl_uninit) (tree);
 367
 368   /* Pointers to machine-independent attribute tables, for front ends
 369      using attribs.c.  If one is NULL, it is ignored.  Respectively, a
 370      table of attributes specific to the language, a table of
 371      attributes common to two or more languages (to allow easy
 372      sharing), and a table of attributes for checking formats.  */
 373   const struct attribute_spec *attribute_table;
 374   const struct attribute_spec *common_attribute_table;
 375   const struct attribute_spec *format_attribute_table;
 376
 377   /* Function-related language hooks.  */
 378   struct lang_hooks_for_functions function;
 379
 380   struct lang_hooks_for_tree_inlining tree_inlining;
 381
 382   struct lang_hooks_for_callgraph callgraph;
 383
 384   struct lang_hooks_for_tree_dump tree_dump;
 385
 386   struct lang_hooks_for_decls decls;
 387
 388   struct lang_hooks_for_types types;
 389
 390   /* Whenever you add entries here, make sure you adjust langhooks-def.h
 391      and langhooks.c accordingly.  */
 392 };
 393
 394 /* Each front end provides its own.  */
 395 extern const struct lang_hooks lang_hooks;
 396
 397 #endif /* GCC_LANG_HOOKS_H */