[glibc] Fix malloc tests build with GCC 10.

[Joseph Myers <jsm28 at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=e6e24243905957c36596f50a22af0acfd83793e2

commit e6e24243905957c36596f50a22af0acfd83793e2
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Mon Jun 10 22:12:08 2019 +0000

    Fix malloc tests build with GCC 10.
    
    GCC mainline has recently added warn_unused_result attributes to some
    malloc-like built-in functions, where glibc previously had them in its
    headers only for __USE_FORTIFY_LEVEL > 0.  This results in those
    attributes being newly in effect for building the glibc testsuite, so
    resulting in new warnings that break the build where tests
    deliberately call such functions and ignore the result.  Thus patch
    duly adds calls to DIAG_* macros around those calls to disable the
    warning.
    
    Tested with build-many-glibcs.py for aarch64-linux-gnu.
    
    	* malloc/tst-calloc.c: Include <libc-diag.h>.
    	(null_test): Ignore -Wunused-result around calls to calloc.
    	* malloc/tst-mallocfork.c: Include <libc-diag.h>.
    	(do_test): Ignore -Wunused-result around call to malloc.

Diff:
---
 ChangeLog               | 7 +++++++
 malloc/tst-calloc.c     | 7 ++++++-
 malloc/tst-mallocfork.c | 6 ++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 55afdcb..e3f6070 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2019-06-10  Joseph Myers  <joseph@codesourcery.com>
+
+	* malloc/tst-calloc.c: Include <libc-diag.h>.
+	(null_test): Ignore -Wunused-result around calls to calloc.
+	* malloc/tst-mallocfork.c: Include <libc-diag.h>.
+	(do_test): Ignore -Wunused-result around call to malloc.
+
 2019-06-07  Florian Weimer  <fweimer@redhat.com>
 
 	Linux: Add getdents64 system call.
diff --git a/malloc/tst-calloc.c b/malloc/tst-calloc.c
index 1eac6ae..aa3f26d 100644
--- a/malloc/tst-calloc.c
+++ b/malloc/tst-calloc.c
@@ -22,6 +22,7 @@
 #include <malloc.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <libc-diag.h>
 
 
 /* Number of samples per size.  */
@@ -95,12 +96,16 @@ static void
 null_test (void)
 {
   /* If the size is 0 the result is implementation defined.  Just make
-     sure the program doesn't crash.  */
+     sure the program doesn't crash.  The result of calloc is
+     deliberately ignored, so do not warn about that.  */
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (10, "-Wunused-result");
   calloc (0, 0);
   calloc (0, UINT_MAX);
   calloc (UINT_MAX, 0);
   calloc (0, ~((size_t) 0));
   calloc (~((size_t) 0), 0);
+  DIAG_POP_NEEDS_COMMENT;
 }
 
 
diff --git a/malloc/tst-mallocfork.c b/malloc/tst-mallocfork.c
index 4ff6ec0..00851a1 100644
--- a/malloc/tst-mallocfork.c
+++ b/malloc/tst-mallocfork.c
@@ -7,6 +7,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <libc-diag.h>
 
 static void
 sig_handler (int signum)
@@ -25,7 +26,12 @@ do_test (void)
   struct sigaction action = { .sa_handler = sig_handler };
   sigemptyset (&action.sa_mask);
 
+  DIAG_PUSH_NEEDS_COMMENT;
+  DIAG_IGNORE_NEEDS_COMMENT (10, "-Wunused-result");
+  /* The result of malloc is deliberately ignored, so do not warn
+     about that.  */
   malloc (sizeof (int));
+  DIAG_POP_NEEDS_COMMENT;
 
   if (sigaction (SIGALRM, &action, NULL) != 0)
     {