Message ID | 1342193500-5708-1-git-send-email-kwolf@redhat.com |
---|---|
State | New |
Headers | show |
On 13 July 2012 16:31, Kevin Wolf <kwolf@redhat.com> wrote: > +#ifdef CONFIG_VALGRIND_H > +/* Work around an unused variable in the valgrind.h macro... */ > +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" > +static inline void valgrind_stack_deregister(CoroutineUContext *co) > +{ > + VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id); > +} > +#pragma GCC diagnostic error "-Wunused-but-set-variable" > +#endif '#pragma .. error' will defeat the configure code which makes warnings not fatal in release builds. -- PMM
Am 13.07.2012 17:37, schrieb Peter Maydell: > On 13 July 2012 16:31, Kevin Wolf <kwolf@redhat.com> wrote: >> +#ifdef CONFIG_VALGRIND_H >> +/* Work around an unused variable in the valgrind.h macro... */ >> +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" >> +static inline void valgrind_stack_deregister(CoroutineUContext *co) >> +{ >> + VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id); >> +} >> +#pragma GCC diagnostic error "-Wunused-but-set-variable" >> +#endif > > '#pragma .. error' will defeat the configure code which makes warnings > not fatal in release builds. I know. What's your suggestion? Switch only to warning? Then it would be easy to miss warnings. Disabling the valgrind code for gcc < 4.6 is better, but still not really nice. I thought having part of one file always use -Werror for this one warning is the best compromise, but I won't insist on it. Kevin
On 07/13/2012 10:06 AM, Kevin Wolf wrote: > Am 13.07.2012 17:37, schrieb Peter Maydell: >> On 13 July 2012 16:31, Kevin Wolf <kwolf@redhat.com> wrote: >>> +#ifdef CONFIG_VALGRIND_H >>> +/* Work around an unused variable in the valgrind.h macro... */ >>> +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" >>> +static inline void valgrind_stack_deregister(CoroutineUContext *co) >>> +{ >>> + VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id); >>> +} >>> +#pragma GCC diagnostic error "-Wunused-but-set-variable" >>> +#endif >> >> '#pragma .. error' will defeat the configure code which makes warnings >> not fatal in release builds. > > I know. What's your suggestion? Switch only to warning? Then it would be > easy to miss warnings. Disabling the valgrind code for gcc < 4.6 is > better, but still not really nice. But you're already disabling the valgrind code for gcc too old to honor #pragma GCC diagnostic ignored "-Wunused-but-set-variable" so what's the difference in making your configure check for CONFIG_VALGRIND_H _also_ check that gcc is new enough to honor push/pop of diagnostic?
Am 13.07.2012 18:13, schrieb Eric Blake: > On 07/13/2012 10:06 AM, Kevin Wolf wrote: >> Am 13.07.2012 17:37, schrieb Peter Maydell: >>> On 13 July 2012 16:31, Kevin Wolf <kwolf@redhat.com> wrote: >>>> +#ifdef CONFIG_VALGRIND_H >>>> +/* Work around an unused variable in the valgrind.h macro... */ >>>> +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" >>>> +static inline void valgrind_stack_deregister(CoroutineUContext *co) >>>> +{ >>>> + VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id); >>>> +} >>>> +#pragma GCC diagnostic error "-Wunused-but-set-variable" >>>> +#endif >>> >>> '#pragma .. error' will defeat the configure code which makes warnings >>> not fatal in release builds. >> >> I know. What's your suggestion? Switch only to warning? Then it would be >> easy to miss warnings. Disabling the valgrind code for gcc < 4.6 is >> better, but still not really nice. > > But you're already disabling the valgrind code for gcc too old to honor > > #pragma GCC diagnostic ignored "-Wunused-but-set-variable" > > so what's the difference in making your configure check for > CONFIG_VALGRIND_H _also_ check that gcc is new enough to honor push/pop > of diagnostic? The practical difference for me is that the RHEL 6 gcc knows ignored/warning/error (since gcc 4.2), but not push/pop (since gcc 4.6), so my test machine still wouldn't have valgrind support and I could drop the patch wholesale. Kevin
diff --git a/configure b/configure index 500fe24..aae73f4 100755 --- a/configure +++ b/configure @@ -2855,6 +2855,22 @@ if compile_prog "" "" ; then fi ######################################## +# check if we have valgrind/valgrind.h + +valgrind_h=no +cat > $TMPC << EOF +#include <valgrind/valgrind.h> +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" +int main(void) { + VALGRIND_STACK_DEREGISTER(0); + return 0; +} +EOF +if compile_prog "" "" ; then + valgrind_h=yes +fi + +######################################## # check if environ is declared has_environ=no @@ -3380,6 +3396,10 @@ if test "$linux_magic_h" = "yes" ; then echo "CONFIG_LINUX_MAGIC_H=y" >> $config_host_mak fi +if test "$valgrind_h" = "yes" ; then + echo "CONFIG_VALGRIND_H=y" >> $config_host_mak +fi + if test "$has_environ" = "yes" ; then echo "CONFIG_HAS_ENVIRON=y" >> $config_host_mak fi diff --git a/coroutine-ucontext.c b/coroutine-ucontext.c index 5f43083..e3c450b 100644 --- a/coroutine-ucontext.c +++ b/coroutine-ucontext.c @@ -30,6 +30,10 @@ #include "qemu-common.h" #include "qemu-coroutine-int.h" +#ifdef CONFIG_VALGRIND_H +#include <valgrind/valgrind.h> +#endif + enum { /* Maximum free pool size prevents holding too many freed coroutines */ POOL_MAX_SIZE = 64, @@ -43,6 +47,11 @@ typedef struct { Coroutine base; void *stack; jmp_buf env; + +#ifdef CONFIG_VALGRIND_H + unsigned int valgrind_stack_id; +#endif + } CoroutineUContext; /** @@ -159,6 +168,11 @@ static Coroutine *coroutine_new(void) uc.uc_stack.ss_size = stack_size; uc.uc_stack.ss_flags = 0; +#ifdef CONFIG_VALGRIND_H + co->valgrind_stack_id = + VALGRIND_STACK_REGISTER(co->stack, co->stack + stack_size); +#endif + arg.p = co; makecontext(&uc, (void (*)(void))coroutine_trampoline, @@ -185,6 +199,16 @@ Coroutine *qemu_coroutine_new(void) return co; } +#ifdef CONFIG_VALGRIND_H +/* Work around an unused variable in the valgrind.h macro... */ +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" +static inline void valgrind_stack_deregister(CoroutineUContext *co) +{ + VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id); +} +#pragma GCC diagnostic error "-Wunused-but-set-variable" +#endif + void qemu_coroutine_delete(Coroutine *co_) { CoroutineUContext *co = DO_UPCAST(CoroutineUContext, base, co_); @@ -196,6 +220,10 @@ void qemu_coroutine_delete(Coroutine *co_) return; } +#ifdef CONFIG_VALGRIND_H + valgrind_stack_deregister(co); +#endif + g_free(co->stack); g_free(co); }