Currently we set _FORTIFY_SOURCE=2 as a compiler argument when the
meson 'optimization' setting is non-zero, the compiler is GCC and
the target is Linux.
While the default QEMU optimization level is 2, user could override
this by setting CFLAGS="-O0" or --extra-cflags="-O0" when running
configure and this won't be reflected in the meson 'optimization'
setting. As a result we try to enable _FORTIFY_SOURCE=2 and then the
user gets compile errors as it only works with optimization.
Rather than trying to improve detection in meson, it is simpler to
just check the __OPTIMIZE__ define from osdep.h.
The comment about being incompatible with clang appears to be
outdated, as compilation works fine without excluding clang.
In the coroutine code we must set _FORTIFY_SOURCE=0 to stop the
logic in osdep.h then enabling it.
Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
---
Re-sent due to previous bad patch submission
include/qemu/osdep.h | 4 ++++
meson.build | 10 ----------
util/coroutine-sigaltstack.c | 4 ++--
util/coroutine-ucontext.c | 4 ++--
4 files changed, 8 insertions(+), 14 deletions(-)
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 18b940db75..475a1c62ff 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -27,6 +27,10 @@
#ifndef QEMU_OSDEP_H
#define QEMU_OSDEP_H
+#if !defined _FORTIFY_SOURCE && defined __OPTIMIZE__ && __OPTIMIZE__ &&
defined __linux__
+# define _FORTIFY_SOURCE 2
+#endif
+
#include "config-host.h"
#ifdef NEED_CPU_H
#include CONFIG_TARGET
diff --git a/meson.build b/meson.build
index 5139db2ff7..b12ead85f6 100644
--- a/meson.build
+++ b/meson.build
@@ -479,16 +479,6 @@ if 'cpp' in all_languages
qemu_cxxflags = ['-D__STDC_LIMIT_MACROS', '-D__STDC_CONSTANT_MACROS',
'-D__STDC_FORMAT_MACROS'] + qemu_cflags
endif
-# clang does not support glibc + FORTIFY_SOURCE (is it still true?)
-if get_option('optimization') != '0' and targetos == 'linux'
- if cc.get_id() == 'gcc'
- qemu_cflags += ['-U_FORTIFY_SOURCE', '-D_FORTIFY_SOURCE=2']
- endif
- if 'cpp' in all_languages and cxx.get_id() == 'gcc'
- qemu_cxxflags += ['-U_FORTIFY_SOURCE', '-D_FORTIFY_SOURCE=2']
- endif
-endif
-
add_project_arguments(qemu_cflags, native: false, language: 'c')
add_project_arguments(cc.get_supported_arguments(warn_flags), native: false,
language: 'c')
if 'cpp' in all_languages
diff --git a/util/coroutine-sigaltstack.c b/util/coroutine-sigaltstack.c
index e2690c5f41..037d6416c4 100644
--- a/util/coroutine-sigaltstack.c
+++ b/util/coroutine-sigaltstack.c
@@ -22,9 +22,9 @@
*/
/* XXX Is there a nicer way to disable glibc's stack check for longjmp? */
-#ifdef _FORTIFY_SOURCE
#undef _FORTIFY_SOURCE
-#endif
+#define _FORTIFY_SOURCE 0
+
#include "qemu/osdep.h"
#include <pthread.h>
#include "qemu/coroutine_int.h"
diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c
index ddc98fb4f8..7b304c79d9 100644
--- a/util/coroutine-ucontext.c
+++ b/util/coroutine-ucontext.c
@@ -19,9 +19,9 @@
*/
/* XXX Is there a nicer way to disable glibc's stack check for longjmp? */
-#ifdef _FORTIFY_SOURCE
#undef _FORTIFY_SOURCE
-#endif
+#define _FORTIFY_SOURCE 0
+
#include "qemu/osdep.h"
#include <ucontext.h>
#include "qemu/coroutine_int.h"
--
2.41.0
