[gcc.git] / gcc / cp / expr.c

/* Convert language-specific tree expression to rtl instructions,
   for GNU compiler.
   Copyright (C) 1988, 92-97, 1998 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 "rtl.h"
#include "tree.h"
#include "flags.h"
#include "expr.h"
#include "cp-tree.h"
#include "toplev.h"

#if 0
static tree extract_aggr_init PROTO((tree, tree));
static tree extract_scalar_init PROTO((tree, tree));
#endif
static rtx cplus_expand_expr PROTO((tree, rtx, enum machine_mode,
				    enum expand_modifier));

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

static rtx
cplus_expand_expr (exp, target, tmode, modifier)
     tree exp;
     rtx target;
     enum machine_mode tmode;
     enum expand_modifier modifier;
{
  tree type = TREE_TYPE (exp);
  register enum machine_mode mode = TYPE_MODE (type);
  register enum tree_code code = TREE_CODE (exp);
  int ignore = target == const0_rtx;

  if (ignore)
    target = 0;

  /* No sense saving up arithmetic to be done
     if it's all in the wrong mode to form part of an address.
     And force_operand won't know whether to sign-extend or zero-extend.  */

  if (mode != Pmode && modifier == EXPAND_SUM)
    modifier = EXPAND_NORMAL;

  switch (code)
    {
    case AGGR_INIT_EXPR:
      {
	/* Something needs to be initialized, but we didn't know
	   where that thing was when building the tree.  For example,
	   it could be the return value of a function, or a parameter
	   to a function which lays down in the stack, or a temporary
	   variable which must be passed by reference.

	   Cleanups are handled in a language-specific way: they
	   might be run by the called function (true in GNU C++
	   for parameters with cleanups), or they might be
	   run by the caller, after the call (true in GNU C++
	   for other cleanup needs).  */

	tree func = TREE_OPERAND (exp, 0);
	tree args = TREE_OPERAND (exp, 1);
	tree type = TREE_TYPE (exp), slot;
	tree call_exp;
	rtx call_target, return_target;
	int pcc_struct_return = 0;

	/* The expression `init' wants to initialize what
	   `target' represents.  SLOT holds the slot for TARGET.  */
	slot = TREE_OPERAND (exp, 2);

	/* Should always be called with a target.  */
	my_friendly_assert (target != NULL_RTX, 205);

	/* The target the initializer will initialize (CALL_TARGET)
	   must now be directed to initialize the target we are
	   supposed to initialize (TARGET).  The semantics for
	   choosing what CALL_TARGET is is language-specific,
	   as is building the call which will perform the
	   initialization.  It is left here to show the choices that
	   exist for C++.  */
	   
	if (TREE_CODE (func) == ADDR_EXPR
	    && TREE_CODE (TREE_OPERAND (func, 0)) == FUNCTION_DECL
	    && DECL_CONSTRUCTOR_P (TREE_OPERAND (func, 0)))
	  {
	    type = build_pointer_type (type);
	    /* Don't clobber a value that might be part of a default
	       parameter value.  */
	    mark_addressable (slot);
	    if (TREE_PERMANENT (args))
	      args = expr_tree_cons (0, build1 (ADDR_EXPR, type, slot),
				TREE_CHAIN (args));
	    else
	      TREE_VALUE (args) = build1 (ADDR_EXPR, type, slot);
	    call_target = 0;
	  }
	else
	  {
	    call_target = target;
#ifdef PCC_STATIC_STRUCT_RETURN
	    if (aggregate_value_p (type))
	      {
		pcc_struct_return = 1;
		call_target = 0;
	      }
#endif
	  }

	call_exp = build (CALL_EXPR, type, func, args, NULL_TREE);
	TREE_SIDE_EFFECTS (call_exp) = 1;
	return_target = expand_call (call_exp, call_target, ignore);

	if (call_target)
	  /* Trust that the right thing has been done; it's too hard to
	     verify.  */
	  return return_target;

	/* If we're suffering under the ancient PCC_STATIC_STRUCT_RETURN
	   calling convention, we need to copy the return value out of
	   the static return buffer into slot.  */
	if (pcc_struct_return)
	  {
	    extern int flag_access_control;
	    int old_ac = flag_access_control;

	    tree init = build_decl (VAR_DECL, NULL_TREE,
				    build_reference_type (type));
	    DECL_RTL (init) = XEXP (return_target, 0);
	    init = convert_from_reference (init);

	    flag_access_control = 0;
	    expand_aggr_init (slot, init, LOOKUP_ONLYCONVERTING);
	    flag_access_control = old_ac;

	    if (TYPE_NEEDS_DESTRUCTOR (type))
	      {
		init = maybe_build_cleanup (init);
		if (init != NULL_TREE)
		  expand_expr (init, const0_rtx, VOIDmode, 0);
	      }
	  }

	return DECL_RTL (slot);
      }

    case PTRMEM_CST:
      {
	tree member;
	tree offset;
	
	/* Find the member.  */
	member = PTRMEM_CST_MEMBER (exp);

	if (TREE_CODE (member) == FIELD_DECL) 
	  {
	    /* Find the offset for the field.  */
	    offset = convert (sizetype,
			      size_binop (EASY_DIV_EXPR,
					  DECL_FIELD_BITPOS (member),
					  size_int (BITS_PER_UNIT)));

	    /* We offset all pointer to data members by 1 so that we
	       can distinguish between a null pointer to data member
	       and the first data member of a structure.  */
	    offset = size_binop (PLUS_EXPR, offset, size_int (1));
	
	    return expand_expr (cp_convert (type, offset), target, tmode,
				modifier);
	  }
	else
	  {
	    tree delta;
	    tree idx;
	    tree pfn;
	    tree delta2;

	    expand_ptrmemfunc_cst (exp, &delta, &idx, &pfn, &delta2);

	    return expand_expr (build_ptrmemfunc1 (type, delta, idx,
						   pfn, delta2),
				target, tmode, modifier);
	  }
      }

    case OFFSET_REF:
      {
	return expand_expr (default_conversion (resolve_offset_ref (exp)),
			    target, tmode, EXPAND_NORMAL);
      }

    case THUNK_DECL:
      return DECL_RTL (exp);

    case THROW_EXPR:
      expand_throw (TREE_OPERAND (exp, 0));
      return NULL;

    case VEC_INIT_EXPR:
      return expand_expr
	(expand_vec_init
	 (NULL_TREE, TREE_OPERAND (exp, 0),
	  build_binary_op (MINUS_EXPR, TREE_OPERAND (exp, 2),
			   integer_one_node),
	  TREE_OPERAND (exp, 1), 0), target, tmode, modifier);

    case NEW_EXPR:
      return expand_expr (build_new_1 (exp), target, tmode, modifier);

    default:
      break;
    }
  my_friendly_abort (40);
  /* NOTREACHED */
  return NULL;
}

void
init_cplus_expand ()
{
  lang_expand_expr = cplus_expand_expr;
}

/* If DECL had its rtl moved from where callers expect it
   to be, fix it up.  RESULT is the nominal rtl for the RESULT_DECL,
   which may be a pseudo instead of a hard register.  */

void
fixup_result_decl (decl, result)
     tree decl;
     rtx result;
{
  if (REG_P (result))
    {
      if (REGNO (result) >= FIRST_PSEUDO_REGISTER)
	{
	  rtx real_decl_result;

#ifdef FUNCTION_OUTGOING_VALUE
	  real_decl_result
	    = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl), current_function_decl);
#else
	  real_decl_result
	    = FUNCTION_VALUE (TREE_TYPE (decl), current_function_decl);
#endif
	  REG_FUNCTION_VALUE_P (real_decl_result) = 1;
	  result = real_decl_result;
	}
      store_expr (decl, result, 0);
      emit_insn (gen_rtx (USE, VOIDmode, result));
    }
}

#if 0
/* Expand this initialization inline and see if it's simple enough that
   it can be done at compile-time.  */

static tree
extract_aggr_init (decl, init)
     tree decl, init;
{
  return 0;
}

static tree
extract_scalar_init (decl, init)
     tree decl, init;
{
  rtx value, insns, insn;
  extern struct obstack temporary_obstack;
  tree t = NULL_TREE;

  push_obstacks (&temporary_obstack, &temporary_obstack);
  start_sequence ();
  value = expand_expr (init, NULL_RTX, VOIDmode, 0);
  insns = get_insns ();
  end_sequence ();
  reg_scan (insns, max_reg_num (), 0);
  jump_optimize (insns, 0, 0, 1);
  pop_obstacks ();

  for (insn = insns; insn; insn = NEXT_INSN (insn))
    {
      rtx r, to;

      if (GET_CODE (insn) == NOTE)
	continue;
      else if (GET_CODE (insn) != INSN)
	return 0;

      r = PATTERN (insn);
      if (GET_CODE (r) != SET)
	return 0;

      to = XEXP (r, 0);

      if (! (to == value
	     || (GET_CODE (to) == SUBREG && XEXP (to, 0) == value)))
	return 0;

      r = XEXP (r, 1);

      switch (GET_CODE (r))
	{
	case CONST_INT:
	  t = build_int_2 (XEXP (r, 0), 0);
	  break;
	default:
	  return 0;
	}
    }

  return t; 
}
#endif

int
extract_init (decl, init)
     tree decl ATTRIBUTE_UNUSED, init ATTRIBUTE_UNUSED;
{
  return 0;

#if 0
  if (IS_AGGR_TYPE (TREE_TYPE (decl))
      || TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
    init = extract_aggr_init (decl, init);
  else
    init = extract_scalar_init (decl, init);

  if (init == NULL_TREE)
    return 0;

  DECL_INITIAL (decl) = init;
  return 1;
#endif
}

void
do_case (start, end)
     tree start, end;
{
  tree value1 = NULL_TREE, value2 = NULL_TREE, label;

  if (start != NULL_TREE && TREE_TYPE (start) != NULL_TREE 
      && POINTER_TYPE_P (TREE_TYPE (start)))
    error ("pointers are not permitted as case values");

  if (end && pedantic)
    pedwarn ("ANSI C++ forbids range expressions in switch statement");

  if (processing_template_decl)
    {
      add_tree (build_min_nt (CASE_LABEL, start, end));
      return;
    }

  if (start)
    value1 = check_cp_case_value (start);
  if (end)
    value2 = check_cp_case_value (end);
  
  label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);

  if (value1 != error_mark_node
      && value2 != error_mark_node)
    {
      tree duplicate;
      int success;

      if (end)
	success = pushcase_range (value1, value2, convert_and_check,
				  label, &duplicate);
      else if (start)
	success = pushcase (value1, convert_and_check, label, &duplicate);
      else
	success = pushcase (NULL_TREE, 0, label, &duplicate);

      if (success == 1)
	{
	  if (end)
	    error ("case label not within a switch statement");
	  else if (start)
	    cp_error ("case label `%E' not within a switch statement", start);
	  else
	    error ("default label not within a switch statement");
	}
      else if (success == 2)
	{
	  if (end)
	    {
	      error ("duplicate (or overlapping) case value");
	      cp_error_at ("this is the first entry overlapping that value",
			   duplicate);
	    }
	  else if (start)
	    {
	      cp_error ("duplicate case value `%E'", start);
	      cp_error_at ("previously used here", duplicate);
	    }
	  else
	    {
	      error ("multiple default labels in one switch");
	      cp_error_at ("this is the first default label", duplicate);
	    }
	}
      else if (success == 3)
	warning ("case value out of range");
      else if (success == 4)
	warning ("empty range specified");
      else if (success == 5)
	{
	  if (end)
	    error ("case label within scope of cleanup or variable array");
	  else if (! start)
	    error ("`default' label within scope of cleanup or variable array");
	  else
	    cp_error ("case label `%E' within scope of cleanup or variable array", start);
	}
    }
  define_case_label ();
}
Commit	Line	Data
8d08fdba MS	1	/* Convert language-specific tree expression to rtl instructions,
8d08fdba MS	2	for GNU compiler.
0b5be897	3	Copyright (C) 1988, 92-97, 1998 Free Software Foundation, Inc.
8d08fdba MS	4
	5	This file is part of GNU CC.
	6
	7	GNU CC is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2, or (at your option)
	10	any later version.
	11
	12	GNU CC is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with GNU CC; see the file COPYING. If not, write to
e9fa0c7c RK	19	the Free Software Foundation, 59 Temple Place - Suite 330,
e9fa0c7c RK	20	Boston, MA 02111-1307, USA. */
8d08fdba MS	21
	22
	23	#include "config.h"
8d052bc7	24	#include "system.h"
8d08fdba MS	25	#include "rtl.h"
	26	#include "tree.h"
	27	#include "flags.h"
	28	#include "expr.h"
	29	#include "cp-tree.h"
54f92bfb	30	#include "toplev.h"
8d08fdba	31
1bbe34be	32	#if 0
994ac65b	33	static tree extract_aggr_init PROTO((tree, tree));
49c249e1	34	static tree extract_scalar_init PROTO((tree, tree));
1bbe34be	35	#endif
9f617717 L	36	static rtx cplus_expand_expr PROTO((tree, rtx, enum machine_mode,
9f617717 L	37	enum expand_modifier));
49c249e1	38
8d08fdba MS	39	/* Hook used by expand_expr to expand language-specific tree codes. */
8d08fdba MS	40
9f617717	41	static rtx
8d08fdba MS	42	cplus_expand_expr (exp, target, tmode, modifier)
	43	tree exp;
	44	rtx target;
	45	enum machine_mode tmode;
	46	enum expand_modifier modifier;
	47	{
	48	tree type = TREE_TYPE (exp);
	49	register enum machine_mode mode = TYPE_MODE (type);
	50	register enum tree_code code = TREE_CODE (exp);
8d08fdba MS	51	int ignore = target == const0_rtx;
	52
	53	if (ignore)
de22184b	54	target = 0;
8d08fdba MS	55
	56	/* No sense saving up arithmetic to be done
	57	if it's all in the wrong mode to form part of an address.
	58	And force_operand won't know whether to sign-extend or zero-extend. */
	59
	60	if (mode != Pmode && modifier == EXPAND_SUM)
	61	modifier = EXPAND_NORMAL;
	62
	63	switch (code)
	64	{
02531345	65	case AGGR_INIT_EXPR:
8d08fdba MS	66	{
	67	/* Something needs to be initialized, but we didn't know
	68	where that thing was when building the tree. For example,
	69	it could be the return value of a function, or a parameter
	70	to a function which lays down in the stack, or a temporary
	71	variable which must be passed by reference.
	72
	73	Cleanups are handled in a language-specific way: they
	74	might be run by the called function (true in GNU C++
	75	for parameters with cleanups), or they might be
	76	run by the caller, after the call (true in GNU C++
	77	for other cleanup needs). */
	78
	79	tree func = TREE_OPERAND (exp, 0);
	80	tree args = TREE_OPERAND (exp, 1);
	81	tree type = TREE_TYPE (exp), slot;
8d08fdba MS	82	tree call_exp;
	83	rtx call_target, return_target;
	84	int pcc_struct_return = 0;
	85
	86	/* The expression `init' wants to initialize what
	87	`target' represents. SLOT holds the slot for TARGET. */
	88	slot = TREE_OPERAND (exp, 2);
	89
02531345 JM	90	/* Should always be called with a target. */
02531345 JM	91	my_friendly_assert (target != NULL_RTX, 205);
8d08fdba MS	92
	93	/* The target the initializer will initialize (CALL_TARGET)
	94	must now be directed to initialize the target we are
	95	supposed to initialize (TARGET). The semantics for
	96	choosing what CALL_TARGET is is language-specific,
	97	as is building the call which will perform the
	98	initialization. It is left here to show the choices that
	99	exist for C++. */
	100
	101	if (TREE_CODE (func) == ADDR_EXPR
	102	&& TREE_CODE (TREE_OPERAND (func, 0)) == FUNCTION_DECL
	103	&& DECL_CONSTRUCTOR_P (TREE_OPERAND (func, 0)))
	104	{
f30432d7	105	type = build_pointer_type (type);
8d08fdba MS	106	/* Don't clobber a value that might be part of a default
8d08fdba MS	107	parameter value. */
c19a8067	108	mark_addressable (slot);
8d08fdba	109	if (TREE_PERMANENT (args))
e66d884e	110	args = expr_tree_cons (0, build1 (ADDR_EXPR, type, slot),
8d08fdba MS	111	TREE_CHAIN (args));
	112	else
	113	TREE_VALUE (args) = build1 (ADDR_EXPR, type, slot);
	114	call_target = 0;
	115	}
8d08fdba MS	116	else
8d08fdba MS	117	{
8d08fdba	118	call_target = target;
6b4e8391 JM	119	#ifdef PCC_STATIC_STRUCT_RETURN
	120	if (aggregate_value_p (type))
	121	{
	122	pcc_struct_return = 1;
	123	call_target = 0;
	124	}
8d08fdba MS	125	#endif
8d08fdba MS	126	}
8d08fdba	127
4dabb379	128	call_exp = build (CALL_EXPR, type, func, args, NULL_TREE);
8d08fdba	129	TREE_SIDE_EFFECTS (call_exp) = 1;
e8abc66f	130	return_target = expand_call (call_exp, call_target, ignore);
8d08fdba	131
02531345	132	if (call_target)
56841f01 JM	133	/* Trust that the right thing has been done; it's too hard to
	134	verify. */
	135	return return_target;
8d08fdba	136
02531345 JM	137	/* If we're suffering under the ancient PCC_STATIC_STRUCT_RETURN
	138	calling convention, we need to copy the return value out of
	139	the static return buffer into slot. */
	140	if (pcc_struct_return)
8d08fdba	141	{
02531345 JM	142	extern int flag_access_control;
02531345 JM	143	int old_ac = flag_access_control;
8d08fdba	144
02531345 JM	145	tree init = build_decl (VAR_DECL, NULL_TREE,
	146	build_reference_type (type));
	147	DECL_RTL (init) = XEXP (return_target, 0);
2a66ec2b	148	init = convert_from_reference (init);
8d08fdba	149
02531345	150	flag_access_control = 0;
b370501f	151	expand_aggr_init (slot, init, LOOKUP_ONLYCONVERTING);
02531345 JM	152	flag_access_control = old_ac;
	153
	154	if (TYPE_NEEDS_DESTRUCTOR (type))
	155	{
2a66ec2b	156	init = maybe_build_cleanup (init);
02531345 JM	157	if (init != NULL_TREE)
	158	expand_expr (init, const0_rtx, VOIDmode, 0);
	159	}
8d08fdba MS	160	}
8d08fdba MS	161
8d08fdba MS	162	return DECL_RTL (slot);
	163	}
	164
61a127b3 MM	165	case PTRMEM_CST:
	166	{
	167	tree member;
	168	tree offset;
	169
	170	/* Find the member. */
	171	member = PTRMEM_CST_MEMBER (exp);
	172
	173	if (TREE_CODE (member) == FIELD_DECL)
	174	{
	175	/* Find the offset for the field. */
	176	offset = convert (sizetype,
	177	size_binop (EASY_DIV_EXPR,
	178	DECL_FIELD_BITPOS (member),
	179	size_int (BITS_PER_UNIT)));
	180
	181	/* We offset all pointer to data members by 1 so that we
	182	can distinguish between a null pointer to data member
	183	and the first data member of a structure. */
	184	offset = size_binop (PLUS_EXPR, offset, size_int (1));
	185
	186	return expand_expr (cp_convert (type, offset), target, tmode,
	187	modifier);
	188	}
	189	else
	190	{
e08a8f45 MM	191	tree delta;
	192	tree idx;
	193	tree pfn;
	194	tree delta2;
	195
	196	expand_ptrmemfunc_cst (exp, &delta, &idx, &pfn, &delta2);
	197
	198	return expand_expr (build_ptrmemfunc1 (type, delta, idx,
	199	pfn, delta2),
	200	target, tmode, modifier);
61a127b3 MM	201	}
	202	}
	203
8d08fdba MS	204	case OFFSET_REF:
8d08fdba MS	205	{
8d08fdba MS	206	return expand_expr (default_conversion (resolve_offset_ref (exp)),
8d08fdba MS	207	target, tmode, EXPAND_NORMAL);
8d08fdba MS	208	}
8d08fdba MS	209
8926095f MS	210	case THUNK_DECL:
	211	return DECL_RTL (exp);
	212
8d2733ca MS	213	case THROW_EXPR:
	214	expand_throw (TREE_OPERAND (exp, 0));
	215	return NULL;
	216
a80e4195 MS	217	case VEC_INIT_EXPR:
	218	return expand_expr
	219	(expand_vec_init
	220	(NULL_TREE, TREE_OPERAND (exp, 0),
	221	build_binary_op (MINUS_EXPR, TREE_OPERAND (exp, 2),
337c90cc	222	integer_one_node),
a80e4195 MS	223	TREE_OPERAND (exp, 1), 0), target, tmode, modifier);
a80e4195 MS	224
a0d5fba7 JM	225	case NEW_EXPR:
	226	return expand_expr (build_new_1 (exp), target, tmode, modifier);
	227
8d08fdba MS	228	default:
	229	break;
	230	}
	231	my_friendly_abort (40);
	232	/* NOTREACHED */
	233	return NULL;
	234	}
	235
	236	void
	237	init_cplus_expand ()
	238	{
	239	lang_expand_expr = cplus_expand_expr;
	240	}
	241
	242	/* If DECL had its rtl moved from where callers expect it
	243	to be, fix it up. RESULT is the nominal rtl for the RESULT_DECL,
	244	which may be a pseudo instead of a hard register. */
	245
	246	void
	247	fixup_result_decl (decl, result)
	248	tree decl;
	249	rtx result;
	250	{
	251	if (REG_P (result))
	252	{
	253	if (REGNO (result) >= FIRST_PSEUDO_REGISTER)
	254	{
	255	rtx real_decl_result;
	256
	257	#ifdef FUNCTION_OUTGOING_VALUE
	258	real_decl_result
	259	= FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl), current_function_decl);
	260	#else
	261	real_decl_result
	262	= FUNCTION_VALUE (TREE_TYPE (decl), current_function_decl);
	263	#endif
	264	REG_FUNCTION_VALUE_P (real_decl_result) = 1;
	265	result = real_decl_result;
	266	}
28cbf42c	267	store_expr (decl, result, 0);
8d08fdba MS	268	emit_insn (gen_rtx (USE, VOIDmode, result));
	269	}
	270	}
	271
994ac65b	272	#if 0
28cbf42c MS	273	/* Expand this initialization inline and see if it's simple enough that
	274	it can be done at compile-time. */
	275
	276	static tree
	277	extract_aggr_init (decl, init)
	278	tree decl, init;
	279	{
	280	return 0;
	281	}
	282
	283	static tree
	284	extract_scalar_init (decl, init)
	285	tree decl, init;
	286	{
	287	rtx value, insns, insn;
	288	extern struct obstack temporary_obstack;
	289	tree t = NULL_TREE;
	290
	291	push_obstacks (&temporary_obstack, &temporary_obstack);
	292	start_sequence ();
	293	value = expand_expr (init, NULL_RTX, VOIDmode, 0);
	294	insns = get_insns ();
	295	end_sequence ();
	296	reg_scan (insns, max_reg_num (), 0);
	297	jump_optimize (insns, 0, 0, 1);
	298	pop_obstacks ();
	299
	300	for (insn = insns; insn; insn = NEXT_INSN (insn))
	301	{
	302	rtx r, to;
	303
	304	if (GET_CODE (insn) == NOTE)
	305	continue;
	306	else if (GET_CODE (insn) != INSN)
	307	return 0;
	308
	309	r = PATTERN (insn);
	310	if (GET_CODE (r) != SET)
	311	return 0;
	312
	313	to = XEXP (r, 0);
	314
beb53fb8 JM	315	if (! (to == value
beb53fb8 JM	316	\|\| (GET_CODE (to) == SUBREG && XEXP (to, 0) == value)))
28cbf42c MS	317	return 0;
	318
	319	r = XEXP (r, 1);
	320
	321	switch (GET_CODE (r))
	322	{
	323	case CONST_INT:
	324	t = build_int_2 (XEXP (r, 0), 0);
	325	break;
	326	default:
	327	return 0;
	328	}
	329	}
	330
	331	return t;
	332	}
1bbe34be	333	#endif
28cbf42c MS	334
	335	int
	336	extract_init (decl, init)
b370501f	337	tree decl ATTRIBUTE_UNUSED, init ATTRIBUTE_UNUSED;
28cbf42c MS	338	{
	339	return 0;
	340
9e9ff709	341	#if 0
28cbf42c MS	342	if (IS_AGGR_TYPE (TREE_TYPE (decl))
	343	\|\| TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
	344	init = extract_aggr_init (decl, init);
	345	else
	346	init = extract_scalar_init (decl, init);
	347
	348	if (init == NULL_TREE)
	349	return 0;
	350
	351	DECL_INITIAL (decl) = init;
	352	return 1;
9e9ff709	353	#endif
28cbf42c	354	}
5566b478 MS	355
	356	void
	357	do_case (start, end)
	358	tree start, end;
	359	{
	360	tree value1 = NULL_TREE, value2 = NULL_TREE, label;
	361
ce122a86 MS	362	if (start != NULL_TREE && TREE_TYPE (start) != NULL_TREE
ce122a86 MS	363	&& POINTER_TYPE_P (TREE_TYPE (start)))
8251199e	364	error ("pointers are not permitted as case values");
fc378698	365
5566b478	366	if (end && pedantic)
8251199e	367	pedwarn ("ANSI C++ forbids range expressions in switch statement");
5566b478	368
5156628f	369	if (processing_template_decl)
5566b478 MS	370	{
	371	add_tree (build_min_nt (CASE_LABEL, start, end));
	372	return;
	373	}
	374
	375	if (start)
	376	value1 = check_cp_case_value (start);
	377	if (end)
	378	value2 = check_cp_case_value (end);
	379
	380	label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
	381
	382	if (value1 != error_mark_node
	383	&& value2 != error_mark_node)
	384	{
	385	tree duplicate;
	386	int success;
	387
	388	if (end)
	389	success = pushcase_range (value1, value2, convert_and_check,
	390	label, &duplicate);
	391	else if (start)
	392	success = pushcase (value1, convert_and_check, label, &duplicate);
	393	else
	394	success = pushcase (NULL_TREE, 0, label, &duplicate);
	395
	396	if (success == 1)
	397	{
	398	if (end)
8251199e	399	error ("case label not within a switch statement");
5566b478	400	else if (start)
8251199e	401	cp_error ("case label `%E' not within a switch statement", start);
5566b478	402	else
8251199e	403	error ("default label not within a switch statement");
5566b478 MS	404	}
	405	else if (success == 2)
	406	{
	407	if (end)
	408	{
8251199e JM	409	error ("duplicate (or overlapping) case value");
8251199e JM	410	cp_error_at ("this is the first entry overlapping that value",
5566b478 MS	411	duplicate);
	412	}
	413	else if (start)
	414	{
8251199e JM	415	cp_error ("duplicate case value `%E'", start);
8251199e JM	416	cp_error_at ("previously used here", duplicate);
5566b478 MS	417	}
	418	else
	419	{
8251199e JM	420	error ("multiple default labels in one switch");
8251199e JM	421	cp_error_at ("this is the first default label", duplicate);
5566b478 MS	422	}
	423	}
	424	else if (success == 3)
8251199e	425	warning ("case value out of range");
5566b478	426	else if (success == 4)
8251199e	427	warning ("empty range specified");
5566b478 MS	428	else if (success == 5)
	429	{
	430	if (end)
8251199e	431	error ("case label within scope of cleanup or variable array");
eb448459	432	else if (! start)
8251199e	433	error ("`default' label within scope of cleanup or variable array");
5566b478	434	else
8251199e	435	cp_error ("case label `%E' within scope of cleanup or variable array", start);
5566b478 MS	436	}
5566b478 MS	437	}
b370501f	438	define_case_label ();
5566b478	439	}