On December 7, 2017 5:55:47 PM GMT+01:00, Jakub Jelinek <ja...@redhat.com>
wrote:
>On Wed, Dec 06, 2017 at 05:30:53PM +0100, Jakub Jelinek wrote:
>> On Wed, Dec 06, 2017 at 09:20:15AM -0700, Martin Sebor wrote:
>> > Attached is a patch with the comment updated/simplified.
>> > The tests do the job they need to do today so I just removed
>> > the useless attribute but otherwise left them unchanged. If
>> > you would like to enhance them in some way please feel free.
>>
>> Ok for trunk, with a minor nit. I'll tweak the tests incrementally
>> when it is in.
>
>So here is the fix for those testcases.
>
>They didn't test what they meant to test, because they didn't FAIL
>without the patch. That is because the bug was that the -W* option
>affected code generation, so with -O2 -Wno-stringop-overflow it didn't
>trigger it.
>I've changed the tests to test both in a separate noipa function where
>it doesn't know about the aliasing and string lengths from the caller,
>in that case it does more verifications, including the content of the
>whole buffer, and the individual values of the lengths,
>and what you did before.
>
>Regtested on x86_64-linux and i686-linux, verified that with the
>r255446 tree-ssa-strlen.c change reverted it FAILs.
>
>Ok for trunk?
OK.
Richard.
>2017-12-07 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/83075
> * gcc.dg/tree-ssa/strncpy-2.c: Use size_t instead of unsigned, add
> separate function with noipa attribute to also verify behavior when
> optimizers don't know the sizes and aliasing, verify resulting sizes
> and array content. Add -Wstringop-overflow to dg-options.
> * gcc.dg/tree-ssa/strncat.c: Likewise.
>
>--- gcc/testsuite/gcc.dg/tree-ssa/strncpy-2.c.jj 2017-12-06
>20:11:54.000000000 +0100
>+++ gcc/testsuite/gcc.dg/tree-ssa/strncpy-2.c 2017-12-07
>13:31:32.719722416 +0100
>@@ -1,19 +1,35 @@
>-/* PR tree-optimization/83075 - Invalid strncpy optimization
>- { dg-do run }
>- { dg-options "-O2 -Wno-stringop-overflow" } */
>+/* PR tree-optimization/83075 - Invalid strncpy optimization */
>+/* { dg-do run } */
>+/* { dg-options "-O2 -Wstringop-overflow" } */
>
>-int main (void)
>+typedef __SIZE_TYPE__ size_t;
>+
>+__attribute__((noipa)) size_t
>+foo (char *p, char *q, size_t *r)
> {
>- char a[8] = "";
>+ size_t n0 = __builtin_strlen (p);
>+ __builtin_strncpy (q, p, n0); /* { dg-warning "specified bound
>depends on the length" } */
>+ size_t n1 = __builtin_strlen (p);
>+ *r = n0;
>+ return n1;
>+}
>
>+int
>+main ()
>+{
>+ char a[8] = "";
> __builtin_strcpy (a, "123");
>-
>- unsigned n0 = __builtin_strlen (a);
>-
>- __builtin_strncpy (a + 3, a, n0);
>-
>- unsigned n1 = __builtin_strlen (a);
>-
>+ size_t n0 = __builtin_strlen (a);
>+ __builtin_strncpy (a + 3, a, n0); /* { dg-warning "specified bound
>depends on the length" } */
>+ size_t n1 = __builtin_strlen (a);
> if (n1 == n0)
> __builtin_abort ();
>+ a[6] = '7';
>+ __builtin_strcpy (a, "456");
>+ size_t n2;
>+ if (foo (a, a + 3, &n2) != 7 || n2 != 3)
>+ __builtin_abort ();
>+ if (__builtin_memcmp (a, "4564567", sizeof "4564567"))
>+ __builtin_abort ();
>+ return 0;
> }
>--- gcc/testsuite/gcc.dg/tree-ssa/strncat.c.jj 2017-12-06
>20:11:54.000000000 +0100
>+++ gcc/testsuite/gcc.dg/tree-ssa/strncat.c 2017-12-07
>13:31:09.568008365 +0100
>@@ -1,19 +1,35 @@
>-/* PR tree-optimization/83075 - Invalid strncpy optimization
>- { dg-do run }
>- { dg-options "-O2 -Wno-stringop-overflow" } */
>+/* PR tree-optimization/83075 - Invalid strncpy optimization */
>+/* { dg-do run } */
>+/* { dg-options "-O2 -Wstringop-overflow" } */
>
>-int main (void)
>+typedef __SIZE_TYPE__ size_t;
>+
>+__attribute__((noipa)) size_t
>+foo (char *p, char *q, size_t *r)
> {
>- char a[8] = "";
>+ size_t n0 = __builtin_strlen (p);
>+ __builtin_strncat (q, p, n0); /* { dg-warning "specified bound
>depends on the length" } */
>+ size_t n1 = __builtin_strlen (p);
>+ *r = n0;
>+ return n1;
>+}
>
>+int
>+main ()
>+{
>+ char a[8] = "";
> __builtin_strcpy (a, "123");
>-
>- unsigned n0 = __builtin_strlen (a);
>-
>- __builtin_strncat (a + 3, a, n0);
>-
>- unsigned n1 = __builtin_strlen (a);
>-
>+ size_t n0 = __builtin_strlen (a);
>+ __builtin_strncat (a + 3, a, n0); /* { dg-warning "specified bound
>depends on the length" } */
>+ size_t n1 = __builtin_strlen (a);
> if (n1 == n0)
> __builtin_abort ();
>+ a[6] = '7';
>+ __builtin_strcpy (a, "456");
>+ size_t n2;
>+ if (foo (a, a + 3, &n2) != 6 || n2 != 3)
>+ __builtin_abort ();
>+ if (__builtin_memcmp (a, "456456\0", sizeof "456456\0"))
>+ __builtin_abort ();
>+ return 0;
> }
>
>
> Jakub
