On Fri, Feb 4, 2022 at 11:58 AM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> The following testcase FAILs when configured with
> --with-long-double-format=ieee . Only happens in the -std=c* modes, not the
> GNU modes; while the glibc headers have __asm redirects of
> vsnprintf and __vsnprinf_chk to __vsnprintfieee128 and
> __vsnprintf_chkieee128, the vsnprintf fortification extern inline gnu_inline
> always_inline wrapper calls __builtin_vsnprintf_chk and we actually emit
> a call to __vsnprinf_chk (i.e. with IBM extended long double) instead of
> __vsnprintf_chkieee128.
>
> rs6000_mangle_decl_assembler_name already had cases for *printf and *scanf,
> so this just adds another case for *printf_chk. *scanf_chk doesn't exist.
> __ prefixing isn't done because *printf_chk already starts with __.
>
> Bootstrapped/regtested on powerpc64le-linux, ok for trunk?
Okay.
Thanks, David
>
> 2022-02-04 Jakub Jelinek <ja...@redhat.com>
>
> PR target/104380
> * config/rs6000/rs6000.cc (rs6000_mangle_decl_assembler_name): Also
> adjust mangling of __builtin*printf_chk.
>
> * gcc.dg/pr104380.c: New test.
>
> --- gcc/config/rs6000/rs6000.cc.jj 2022-01-28 10:01:41.224837656 +0100
> +++ gcc/config/rs6000/rs6000.cc 2022-02-04 12:31:27.651715472 +0100
> @@ -28228,6 +28228,7 @@ rs6000_mangle_decl_assembler_name (tree
> {
> size_t printf_len = strlen ("printf");
> size_t scanf_len = strlen ("scanf");
> + size_t printf_chk_len = strlen ("printf_chk");
>
> if (len >= printf_len
> && strcmp (name + len - printf_len, "printf") == 0)
> @@ -28237,6 +28238,10 @@ rs6000_mangle_decl_assembler_name (tree
> && strcmp (name + len - scanf_len, "scanf") == 0)
> newname = xasprintf ("__isoc99_%sieee128", name);
>
> + else if (len >= printf_chk_len
> + && strcmp (name + len - printf_chk_len, "printf_chk") == 0)
> + newname = xasprintf ("%sieee128", name);
> +
> else if (name[len - 1] == 'l')
> {
> bool uses_ieee128_p = false;
> --- gcc/testsuite/gcc.dg/pr104380.c.jj 2022-02-04 12:51:50.152643364 +0100
> +++ gcc/testsuite/gcc.dg/pr104380.c 2022-02-04 12:53:25.092317741 +0100
> @@ -0,0 +1,32 @@
> +/* PR target/104380 */
> +/* This test needs runtime that provides __*_chk functions. */
> +/* { dg-do run { target *-*-linux* *-*-gnu* *-*-uclinux* } } */
> +/* { dg-options "-O2 -std=c99" } */
> +
> +#define FORTIFY_SOURCE 2
> +#include <stdio.h>
> +#include <stdarg.h>
> +
> +static char buf[4096];
> +static char gfmt[] = "%Lg";
> +
> +static int __attribute__ ((noipa))
> +foo (char *str, const char *fmt, ...)
> +{
> + int ret;
> + va_list ap;
> + va_start (ap, fmt);
> + ret = vsnprintf (str, 4096, fmt, ap);
> + va_end (ap);
> + return ret;
> +}
> +
> +int
> +main ()
> +{
> + long double dval = 128.0L;
> + int ret = foo (buf, gfmt, dval);
> + if (ret != 3 || __builtin_strcmp (buf, "128") != 0)
> + __builtin_abort ();
> + return 0;
> +}
>
> Jakub
>
