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re PR tree-optimization/68680 (On-stack VLA does not cause instrumentation with -fstack-protector)

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PR tree-optimization/68680
	* calls.c (special_function_p): Return ECF_MAY_BE_ALLOCA for
	BUILT_IN_ALLOCA{,_WITH_ALIGN}.  Don't check for __builtin_alloca
	by name.

	* gcc.target/i386/pr68680.c: New test.

From-SVN: r231279
This commit is contained in:
Jakub Jelinek 2015-12-04 17:32:22 +01:00 • committed by Jakub Jelinek
parent 83b58b6b0e
commit 4e722cf1dc
4 changed files with 37 additions and 6 deletions
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5
gcc/ChangeLog
View file

@ -1,5 +1,10 @@
2015-12-04 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/68680
* calls.c (special_function_p): Return ECF_MAY_BE_ALLOCA for
BUILT_IN_ALLOCA{,_WITH_ALIGN}. Don't check for __builtin_alloca
by name.
PR tree-optimization/68671
* tree-ssa-reassoc.c (maybe_optimize_range_tests): For basic
blocks starting with the successor of first bb we've modified

20
gcc/calls.c
View file

@ -502,12 +502,9 @@ special_function_p (const_tree fndecl, int flags)
/* We assume that alloca will always be called by name. It
makes no sense to pass it as a pointer-to-function to
anything that does not understand its behavior. */
if (((IDENTIFIER_LENGTH (name_decl) == 6
&& name[0] == 'a'
&& ! strcmp (name, "alloca"))
|| (IDENTIFIER_LENGTH (name_decl) == 16
&& name[0] == '_'
&& ! strcmp (name, "__builtin_alloca"))))
if (IDENTIFIER_LENGTH (name_decl) == 6
&& name[0] == 'a'
&& ! strcmp (name, "alloca"))
flags |= ECF_MAY_BE_ALLOCA;
/* Disregard prefix _, __, __x or __builtin_. */
@ -553,6 +550,17 @@ special_function_p (const_tree fndecl, int flags)
flags |= ECF_NORETURN;
}
if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
switch (DECL_FUNCTION_CODE (fndecl))
{
case BUILT_IN_ALLOCA:
case BUILT_IN_ALLOCA_WITH_ALIGN:
flags |= ECF_MAY_BE_ALLOCA;
break;
default:
break;
}
return flags;
}

3
gcc/testsuite/ChangeLog
View file

@ -1,5 +1,8 @@
2015-12-04 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/68680
* gcc.target/i386/pr68680.c: New test.
PR tree-optimization/68671
* gcc.dg/pr68671.c: New test.

15
gcc/testsuite/gcc.target/i386/pr68680.c Normal file
View file

@ -0,0 +1,15 @@
/* PR tree-optimization/68680 */
/* { dg-do compile } */
/* { dg-options "-O2 -fstack-protector-strong" } */
int foo (char *);
int
bar (unsigned long x)
{
char a[x];
return foo (a);
}
/* Verify that this function is stack protected. */
/* { dg-final { scan-assembler "stack_chk_fail" } } */