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re PR c/36970 (GCC should display a warning when trying to free a static array)

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PR c/36970
	* builtins.c (maybe_emit_free_warning): New function.
	(expand_builtin): Process BUILT_IN_FREE even at -O0.  Call
	maybe_emit_free_warning for BUILT_IN_FREE.

	* gcc.dg/free-1.c: New test.
	* gcc.dg/free-2.c: New test.

From-SVN: r138362
This commit is contained in:
Jakub Jelinek 2008-07-31 10:02:49 +02:00 committed by Jakub Jelinek
parent 1e1d38871b
commit f9555f402c
5 changed files with 89 additions and 1 deletions
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5
gcc/ChangeLog
View File

@ -1,5 +1,10 @@
2008-07-31 Jakub Jelinek <jakub@redhat.com>
PR c/36970
* builtins.c (maybe_emit_free_warning): New function.
(expand_builtin): Process BUILT_IN_FREE even at -O0. Call
maybe_emit_free_warning for BUILT_IN_FREE.
PR debug/36278
* dwarf2out.c (get_context_die): New function.
(force_decl_die, force_type_die): Use it.

29
gcc/builtins.c
View File

@ -207,6 +207,7 @@ static rtx expand_builtin_memory_chk (tree, rtx, enum machine_mode,
enum built_in_function);
static void maybe_emit_chk_warning (tree, enum built_in_function);
static void maybe_emit_sprintf_chk_warning (tree, enum built_in_function);
static void maybe_emit_free_warning (tree);
static tree fold_builtin_object_size (tree, tree);
static tree fold_builtin_strcat_chk (tree, tree, tree, tree);
static tree fold_builtin_strncat_chk (tree, tree, tree, tree, tree);
@ -6130,7 +6131,8 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode,
if (!optimize
&& !called_as_built_in (fndecl)
&& DECL_ASSEMBLER_NAME_SET_P (fndecl)
&& fcode != BUILT_IN_ALLOCA)
&& fcode != BUILT_IN_ALLOCA
&& fcode != BUILT_IN_FREE)
return expand_call (exp, target, ignore);
/* The built-in function expanders test for target == const0_rtx
@ -7007,6 +7009,10 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode,
maybe_emit_sprintf_chk_warning (exp, fcode);
break;
case BUILT_IN_FREE:
maybe_emit_free_warning (exp);
break;
default: /* just do library call, if unknown builtin */
break;
}
@ -11981,6 +11987,27 @@ maybe_emit_sprintf_chk_warning (tree exp, enum built_in_function fcode)
}
}
/* Emit warning if a free is called with address of a variable. */
static void
maybe_emit_free_warning (tree exp)
{
tree arg = CALL_EXPR_ARG (exp, 0);
STRIP_NOPS (arg);
if (TREE_CODE (arg) != ADDR_EXPR)
return;
arg = get_base_address (TREE_OPERAND (arg, 0));
if (arg == NULL || INDIRECT_REF_P (arg))
return;
if (SSA_VAR_P (arg))
warning (0, "%Kattempt to free a non-heap object %qD", exp, arg);
else
warning (0, "%Kattempt to free a non-heap object", exp);
}
/* Fold a call to __builtin_object_size with arguments PTR and OST,
if possible. */

4
gcc/testsuite/ChangeLog
View File

@ -1,5 +1,9 @@
2008-07-31 Jakub Jelinek <jakub@redhat.com>
PR c/36970
* gcc.dg/free-1.c: New test.
* gcc.dg/free-2.c: New test.
PR debug/36278
* g++.dg/debug/namespace2.C: New test.

26
gcc/testsuite/gcc.dg/free-1.c Normal file
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@ -0,0 +1,26 @@
/* PR c/36970 */
/* { dg-do compile } */
/* { dg-options "-O2" } */
extern void free (void *);
char *p, buf3[10], d;
struct S { char a; int b; } *r;
void foo (void)
{
char buf[10], buf2[10], c;
static char buf4[10], e;
char *q = buf;
free (p);
free (q); /* { dg-warning "attempt to free a non-heap object" } */
free (buf2); /* { dg-warning "attempt to free a non-heap object" } */
free (&c); /* { dg-warning "attempt to free a non-heap object" } */
free (buf3); /* { dg-warning "attempt to free a non-heap object" } */
free (&d); /* { dg-warning "attempt to free a non-heap object" } */
free (buf4); /* { dg-warning "attempt to free a non-heap object" } */
free (&e); /* { dg-warning "attempt to free a non-heap object" } */
free (&r->a);
free ("abcd"); /* { dg-warning "attempt to free a non-heap object" } */
free (L"abcd"); /* { dg-warning "attempt to free a non-heap object" } */
}

26
gcc/testsuite/gcc.dg/free-2.c Normal file
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@ -0,0 +1,26 @@
/* PR c/36970 */
/* { dg-do compile } */
/* { dg-options "-O0" } */
extern void free (void *);
char *p, buf3[10], d;
struct S { char a; int b; } *r;
void foo (void)
{
char buf[10], buf2[10], c;
static char buf4[10], e;
char *q = buf;
free (p);
free (q); /* At -O0 no warning is reported here. */
free (buf2); /* { dg-warning "attempt to free a non-heap object" } */
free (&c); /* { dg-warning "attempt to free a non-heap object" } */
free (buf3); /* { dg-warning "attempt to free a non-heap object" } */
free (&d); /* { dg-warning "attempt to free a non-heap object" } */
free (buf4); /* { dg-warning "attempt to free a non-heap object" } */
free (&e); /* { dg-warning "attempt to free a non-heap object" } */
free (&r->a);
free ("abcd"); /* { dg-warning "attempt to free a non-heap object" } */
free (L"abcd"); /* { dg-warning "attempt to free a non-heap object" } */
}