[Qemu-devel] [PATCH] Fix warnings suppressors to honor --disable-werror

[Qemu-devel] [PATCH] Fix warnings suppressors to honor --disable-werror

[Markus Armbruster]

Replace

    #pragma GCC diagnostic ignored FOO
    [Troublesome code...]
    #pragma GCC diagnostic error FOO

by

    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored FOO
    [Troublesome code...]
    #pragma GCC diagnostic pop

Broken in commit 3f4349d, commit 092bb30, and commit c95e308.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
 configure                | 2 ++
 coroutine-ucontext.c     | 3 ++-
 include/ui/qemu-pixman.h | 3 ++-
 ui/gtk.c                 | 3 ++-
 4 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/configure b/configure
index 0788e27..41097a2 100755
--- a/configure
+++ b/configure
@@ -3244,8 +3244,10 @@ fi
 
 pragma_disable_unused_but_set=no
 cat > $TMPC << EOF
+#pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-but-set-variable"
 #pragma GCC diagnostic ignored "-Wstrict-prototypes"
+#pragma GCC diagnostic pop
 
 int main(void) {
     return 0;
diff --git a/coroutine-ucontext.c b/coroutine-ucontext.c
index 867a662..4bf2cde 100644
--- a/coroutine-ucontext.c
+++ b/coroutine-ucontext.c
@@ -169,6 +169,7 @@ Coroutine *qemu_coroutine_new(void)
 #ifdef CONFIG_VALGRIND_H
 #ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
 /* Work around an unused variable in the valgrind.h macro... */
+#pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-but-set-variable"
 #endif
 static inline void valgrind_stack_deregister(CoroutineUContext *co)
@@ -176,7 +177,7 @@ static inline void valgrind_stack_deregister(CoroutineUContext *co)
     VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id);
 }
 #ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
-#pragma GCC diagnostic error "-Wunused-but-set-variable"
+#pragma GCC diagnostic pop
 #endif
 #endif
 
diff --git a/include/ui/qemu-pixman.h b/include/ui/qemu-pixman.h
index b032f52..882e2a3 100644
--- a/include/ui/qemu-pixman.h
+++ b/include/ui/qemu-pixman.h
@@ -8,11 +8,12 @@
 
 /* pixman-0.16.0 headers have a redundant declaration */
 #ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
+#pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wredundant-decls"
 #endif
 #include <pixman.h>
 #ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
-#pragma GCC diagnostic error "-Wredundant-decls"
+#pragma GCC diagnostic pop
 #endif
 
 #include "qemu/typedefs.h"
diff --git a/ui/gtk.c b/ui/gtk.c
index 1e105e2..c2c6e38 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -38,11 +38,12 @@
 
 #ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
 /* Work around an -Wstrict-prototypes warning in GTK headers */
+#pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wstrict-prototypes"
 #endif
 #include <gtk/gtk.h>
 #ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
-#pragma GCC diagnostic error "-Wstrict-prototypes"
+#pragma GCC diagnostic pop
 #endif
 
 
-- 
1.7.11.7

Re: [Qemu-devel] [PATCH] Fix warnings suppressors to honor --disable-werror

[Eric Blake]

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On 04/16/2013 05:51 AM, Markus Armbruster wrote:
> Replace
> 
>     #pragma GCC diagnostic ignored FOO
>     [Troublesome code...]
>     #pragma GCC diagnostic error FOO
> 
> by
> 
>     #pragma GCC diagnostic push
>     #pragma GCC diagnostic ignored FOO
>     [Troublesome code...]
>     #pragma GCC diagnostic pop

Older gcc does not understand #pragma GCC diagnostic push.  Are you sure
this solution works with all versions of gcc in common use for compiling
qemu?

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH] Fix warnings suppressors to honor --disable-werror

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> On 04/16/2013 05:51 AM, Markus Armbruster wrote:
>> Replace
>> 
>>     #pragma GCC diagnostic ignored FOO
>>     [Troublesome code...]
>>     #pragma GCC diagnostic error FOO
>> 
>> by
>> 
>>     #pragma GCC diagnostic push
>>     #pragma GCC diagnostic ignored FOO
>>     [Troublesome code...]
>>     #pragma GCC diagnostic pop
>
> Older gcc does not understand #pragma GCC diagnostic push.  Are you sure
> this solution works with all versions of gcc in common use for compiling
> qemu?

The first patch hunk should take care of the problem:

diff --git a/configure b/configure
index 0788e27..41097a2 100755
--- a/configure
+++ b/configure
@@ -3244,8 +3244,10 @@ fi
 
 pragma_disable_unused_but_set=no
 cat > $TMPC << EOF
+#pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-but-set-variable"
 #pragma GCC diagnostic ignored "-Wstrict-prototypes"
+#pragma GCC diagnostic pop
 
 int main(void) {
     return 0;

If gcc chokes on push/pop, we simply refrain from suppressing warnings.
You may have to --disable-werror then.  I prefer that over breaking
--disable-werror for everyone.

Testing with a suitably antique gcc appreciated!

Re: [Qemu-devel] [PATCH] Fix warnings suppressors to honor --disable-werror

[Anthony Liguori]

Applied.  Thanks.

Regards,

Anthony Liguori