Fix string/bug-strncat1.c build with GCC 8.

GCC 8 warns about strncat calls with truncated output.
string/bug-strncat1.c tests such a call; this patch disables the
warning for it.

Tested (compilation) with GCC 8 for x86_64-linux-gnu with
build-many-glibcs.py (in conjunction with Martin's patch to allow
glibc to build).

	* string/bug-strncat1.c: Include <libc-diag.h>.
	(main): Disable -Wstringop-truncation for strncat call for GCC 8.

(cherry picked from commit ec72135e5f1d061cb5cf7cd1b855fd6290be10d9)

diff --git a/ChangeLog b/ChangeLog
index 65633dbc7fb473e16d2f8ea7479b30738fea23fb..d4223dbb9e5e2c043e256a4d3f5e6fc6957cb6de 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-14  Joseph Myers  <joseph@codesourcery.com>
+
+       * string/bug-strncat1.c: Include <libc-diag.h>.
+       (main): Disable -Wstringop-truncation for strncat call for GCC 8.
+
 2018-06-14  Joseph Myers  <joseph@codesourcery.com>
 
        * string/tester.c (test_strncat) [__GNUC_PREREQ (7, 0)]: Also

diff --git a/string/bug-strncat1.c b/string/bug-strncat1.c
index f1b5c37c5cd14b96fbb9672486700de22e0a7720..b22beba4d3d672b88ae6ae8c84b96f8de86d5454 100644 (file)
--- a/string/bug-strncat1.c
+++ b/string/bug-strncat1.c
@@ -4,13 +4,21 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <libc-diag.h>
 
 char d[3] = "\0\1\2";
 
 int
 main (void)
 {
+  DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (8, 0)
+  /* GCC 8 warns about strncat truncating output; this is deliberately
+     tested here.  */
+  DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
+#endif
   strncat (d, "\5\6", 1);
+  DIAG_POP_NEEDS_COMMENT;
   if (d[0] != '\5')
     {
       puts ("d[0] != '\\5'");