[gcc r12-7059] rs6000: Fix up -D_FORTIFY_SOURCE* with -mabi=ieeelongdouble [PR104380]

[Jakub Jelinek <jakub@gcc.gnu.org>]

https://gcc.gnu.org/g:8d6fffc4bcd4afa0beb0efad4f3b95394aa15618

commit r12-7059-g8d6fffc4bcd4afa0beb0efad4f3b95394aa15618
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Feb 4 18:30:59 2022 +0100

    rs6000: Fix up -D_FORTIFY_SOURCE* with -mabi=ieeelongdouble [PR104380]
    
    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 __.
    
    2022-02-04  Jakub Jelinek  <jakub@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.

Diff:
---
 gcc/config/rs6000/rs6000.cc     |  5 +++++
 gcc/testsuite/gcc.dg/pr104380.c | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index b6f2309adfb..d9fc67d5d29 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -28069,6 +28069,7 @@ rs6000_mangle_decl_assembler_name (tree decl, tree id)
 	{
 	  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)
@@ -28078,6 +28079,10 @@ rs6000_mangle_decl_assembler_name (tree decl, tree id)
 		   && 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;
diff --git a/gcc/testsuite/gcc.dg/pr104380.c b/gcc/testsuite/gcc.dg/pr104380.c
new file mode 100644
index 00000000000..54b2a87cf44
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr104380.c
@@ -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;
+}