tree-vrp.c (check_array_ref): Bail out on zero-length arrays.

gcc/

2013-08-30  Meador Inge  <meadori@codesourcery.com>

	* tree-vrp.c (check_array_ref): Bail out on zero-length arrays.

gcc/testsuite/

2013-08-30  Meador Inge  <meadori@codesourcery.com>

	* gcc.dg/Warray-bounds-11.c: New testcase.

From-SVN: r202115
This commit is contained in:
Meador Inge 2013-08-30 16:36:46 +00:00 committed by Meador Inge
parent de5a5fa139
commit 0a6ea5c9c9
4 changed files with 23 additions and 2 deletions

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@ -1,3 +1,7 @@
2013-08-30 Meador Inge <meadori@codesourcery.com>
* tree-vrp.c (check_array_ref): Bail out on zero-length arrays.
2013-08-30 Marek Polacek <polacek@redhat.com>
* Makefile.in (ubsan.o): Add.

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@ -1,3 +1,7 @@
2013-08-30 Meador Inge <meadori@codesourcery.com>
* gcc.dg/Warray-bounds-11.c: New testcase.
2013-08-30 Marek Polacek <polacek@redhat.com>
* g++.dg/ubsan/div-by-zero-1.C: New test.

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@ -0,0 +1,12 @@
/* { dg-do compile } */
/* { dg-options "-O2 -Warray-bounds -std=gnu99" } */
/* Test zero-length arrays for GNU C. */
unsigned int a[] = { };
unsigned int size_a;
int test(void)
{
/* This should not warn. */
return size_a ? a[0] : 0;
}

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@ -6137,9 +6137,10 @@ check_array_ref (location_t location, tree ref, bool ignore_off_by_one)
low_sub = up_sub = TREE_OPERAND (ref, 1);
up_bound = array_ref_up_bound (ref);
/* Can not check flexible arrays. */
/* Can not check flexible arrays or zero-length arrays. */
if (!up_bound
|| TREE_CODE (up_bound) != INTEGER_CST)
|| TREE_CODE (up_bound) != INTEGER_CST
|| tree_int_cst_equal (up_bound, integer_minus_one_node))
return;
/* Accesses to trailing arrays via pointers may access storage