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?
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
