[glibc/siddhesh/fortify3] DONTUPSTREAM: Enable _FORTIFY_SOURCE=3 for gcc

[glibc/siddhesh/fortify3] DONTUPSTREAM: Enable _FORTIFY_SOURCE=3 for gcc

[Siddhesh Poyarekar]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=3f976e67965fd6c570d63bd53b894fe2651946cc

commit 3f976e67965fd6c570d63bd53b894fe2651946cc
Author: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date:   Fri Oct 8 10:24:31 2021 +0530

    DONTUPSTREAM: Enable _FORTIFY_SOURCE=3 for gcc
    
    Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

Diff:
---
 include/features.h | 3 ++-
 misc/sys/cdefs.h   | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/features.h b/include/features.h
index d974eabfaf..8bae2c7dcb 100644
--- a/include/features.h
+++ b/include/features.h
@@ -412,7 +412,8 @@
 #  warning _FORTIFY_SOURCE requires compiling with optimization (-O)
 # elif !__GNUC_PREREQ (4, 1)
 #  warning _FORTIFY_SOURCE requires GCC 4.1 or later
-# elif _FORTIFY_SOURCE > 2 && __glibc_clang_prereq (9, 0)
+# elif _FORTIFY_SOURCE > 2 && (__glibc_clang_prereq (9, 0) \
+			       || __GNUC_PREREQ (12,0))
 #  if _FORTIFY_SOURCE > 3
 #   warning _FORTIFY_SOURCE > 3 is treated like 3 on this platform
 #  endif
diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index 4dac9d264d..c8e10aae17 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -142,7 +142,8 @@
 #define __bos0(ptr) __builtin_object_size (ptr, 0)
 
 /* Use __builtin_dynamic_object_size at _FORTIFY_SOURCE=3 when available.  */
-#if __USE_FORTIFY_LEVEL == 3 && __glibc_clang_prereq (9, 0)
+#if __USE_FORTIFY_LEVEL == 3 && (__glibc_clang_prereq (9, 0) \
+				 || __GNUC_PREREQ (12,0))
 # define __glibc_objsize0(__o) __builtin_dynamic_object_size (__o, 0)
 # define __glibc_objsize(__o) __builtin_dynamic_object_size (__o, 1)
 #else