| Message ID | 1343661187-6312-1-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | New |
| Headers | show |
Thanks, applied. On Mon, Jul 30, 2012 at 3:13 PM, Peter Maydell <peter.maydell@linaro.org> wrote: > Split the configure test that checks for valgrind into two, one > part checking whether we have the gcc pragma to disable unused-but-set > variables, and the other part checking for the existence of valgrind.h. > The first of these has to be compiled with -Werror and the second > does not and shouldn't generate any warnings. > > This (a) allows us to enable "make errors in configure tests be > build failures" and (b) enables use of valgrind on systems with > a gcc which doesn't know about -Wunused-but-set-varibale, like > Debian squeeze. > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > This can be applied now and I think it ought to be sufficient > that we could then apply the 11-patch configure series I sent > earlier. If patch 1 in that series still causes trouble after > this, then I'd suggest committing patches 2-10, to save yet > more people sending patches to the list for those. > > configure | 23 +++++++++++++++++++++-- > coroutine-ucontext.c | 4 ++++ > 2 files changed, 25 insertions(+), 2 deletions(-) > > diff --git a/configure b/configure > index c65b5f6..1d713de 100755 > --- a/configure > +++ b/configure > @@ -2873,14 +2873,29 @@ if compile_prog "" "" ; then > fi > > ######################################## > +# check whether we can disable the -Wunused-but-set-variable > +# option with a pragma (this is needed to silence a warning in > +# some versions of the valgrind VALGRIND_STACK_DEREGISTER macro.) > +# This test has to be compiled with -Werror as otherwise an > +# unknown pragma is only a warning. > +pragma_disable_unused_but_set=no > +cat > $TMPC << EOF > +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" > +int main(void) { > + return 0; > +} > +EOF > +if compile_prog "-Werror" "" ; then > + pragma_disable_unused_but_set=yes > +fi > + > +######################################## > # check if we have valgrind/valgrind.h > > valgrind_h=no > cat > $TMPC << EOF > #include <valgrind/valgrind.h> > -#pragma GCC diagnostic ignored "-Wunused-but-set-variable" > int main(void) { > - VALGRIND_STACK_DEREGISTER(0); > return 0; > } > EOF > @@ -3397,6 +3412,10 @@ if test "$linux_magic_h" = "yes" ; then > echo "CONFIG_LINUX_MAGIC_H=y" >> $config_host_mak > fi > > +if test "$pragma_disable_unused_but_set" = "yes" ; then > + echo "CONFIG_PRAGMA_DISABLE_UNUSED_BUT_SET=y" >> $config_host_mak > +fi > + > if test "$valgrind_h" = "yes" ; then > echo "CONFIG_VALGRIND_H=y" >> $config_host_mak > fi > diff --git a/coroutine-ucontext.c b/coroutine-ucontext.c > index e3c450b..784081a 100644 > --- a/coroutine-ucontext.c > +++ b/coroutine-ucontext.c > @@ -200,14 +200,18 @@ Coroutine *qemu_coroutine_new(void) > } > > #ifdef CONFIG_VALGRIND_H > +#ifdef CONFIG_PRAGMA_DISABLE_UNUSED_BUT_SET > /* Work around an unused variable in the valgrind.h macro... */ > #pragma GCC diagnostic ignored "-Wunused-but-set-variable" > +#endif > static inline void valgrind_stack_deregister(CoroutineUContext *co) > { > VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id); > } > +#ifdef CONFIG_PRAGMA_DISABLE_UNUSED_BUT_SET > #pragma GCC diagnostic error "-Wunused-but-set-variable" > #endif > +#endif > > void qemu_coroutine_delete(Coroutine *co_) > { > -- > 1.7.9.5 >
diff --git a/configure b/configure index c65b5f6..1d713de 100755 --- a/configure +++ b/configure @@ -2873,14 +2873,29 @@ if compile_prog "" "" ; then fi ######################################## +# check whether we can disable the -Wunused-but-set-variable +# option with a pragma (this is needed to silence a warning in +# some versions of the valgrind VALGRIND_STACK_DEREGISTER macro.) +# This test has to be compiled with -Werror as otherwise an +# unknown pragma is only a warning. +pragma_disable_unused_but_set=no +cat > $TMPC << EOF +#pragma GCC diagnostic ignored "-Wunused-but-set-variable" +int main(void) { + return 0; +} +EOF +if compile_prog "-Werror" "" ; then + pragma_disable_unused_but_set=yes +fi + +######################################## # check if we have valgrind/valgrind.h valgrind_h=no cat > $TMPC << EOF #include <valgrind/valgrind.h> -#pragma GCC diagnostic ignored "-Wunused-but-set-variable" int main(void) { - VALGRIND_STACK_DEREGISTER(0); return 0; } EOF @@ -3397,6 +3412,10 @@ if test "$linux_magic_h" = "yes" ; then echo "CONFIG_LINUX_MAGIC_H=y" >> $config_host_mak fi +if test "$pragma_disable_unused_but_set" = "yes" ; then + echo "CONFIG_PRAGMA_DISABLE_UNUSED_BUT_SET=y" >> $config_host_mak +fi + if test "$valgrind_h" = "yes" ; then echo "CONFIG_VALGRIND_H=y" >> $config_host_mak fi diff --git a/coroutine-ucontext.c b/coroutine-ucontext.c index e3c450b..784081a 100644 --- a/coroutine-ucontext.c +++ b/coroutine-ucontext.c @@ -200,14 +200,18 @@ Coroutine *qemu_coroutine_new(void) } #ifdef CONFIG_VALGRIND_H +#ifdef CONFIG_PRAGMA_DISABLE_UNUSED_BUT_SET /* Work around an unused variable in the valgrind.h macro... */ #pragma GCC diagnostic ignored "-Wunused-but-set-variable" +#endif static inline void valgrind_stack_deregister(CoroutineUContext *co) { VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id); } +#ifdef CONFIG_PRAGMA_DISABLE_UNUSED_BUT_SET #pragma GCC diagnostic error "-Wunused-but-set-variable" #endif +#endif void qemu_coroutine_delete(Coroutine *co_) {
Split the configure test that checks for valgrind into two, one part checking whether we have the gcc pragma to disable unused-but-set variables, and the other part checking for the existence of valgrind.h. The first of these has to be compiled with -Werror and the second does not and shouldn't generate any warnings. This (a) allows us to enable "make errors in configure tests be build failures" and (b) enables use of valgrind on systems with a gcc which doesn't know about -Wunused-but-set-varibale, like Debian squeeze. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- This can be applied now and I think it ought to be sufficient that we could then apply the 11-patch configure series I sent earlier. If patch 1 in that series still causes trouble after this, then I'd suggest committing patches 2-10, to save yet more people sending patches to the list for those. configure | 23 +++++++++++++++++++++-- coroutine-ucontext.c | 4 ++++ 2 files changed, 25 insertions(+), 2 deletions(-)