From 7c2acc7062fe863cb71ff5849bb121deafe8df4b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 8 Apr 2013 12:11:27 +0100 Subject: [PATCH] configure: Don't fall back to gthread coroutine backend The gthread coroutine backend is broken and does not produce a working QEMU; it is only useful for some very limited debugging situations. Clean up the backend selection logic in configure so that it now runs "if on windows use windows; else prefer ucontext; else sigaltstack". To do this we refactor the configure code to separate out "test whether we have a working ucontext", "pick a default if user didn't specify" and "validate that user didn't specify something invalid", rather than having all three of these run together. We also simplify the Makefile logic so it just links in the backend the configure script selects. Signed-off-by: Peter Maydell Message-id: 1365419487-19867-3-git-send-email-peter.maydell@linaro.org Signed-off-by: Anthony Liguori --- Makefile.objs | 11 +------- configure | 69 +++++++++++++++++++++++++++++++++----------------- tests/Makefile | 14 +--------- 3 files changed, 48 insertions(+), 46 deletions(-) diff --git a/Makefile.objs b/Makefile.objs index f99841ce54..e568c018b3 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -16,16 +16,7 @@ block-obj-y += qapi-types.o qapi-visit.o block-obj-y += qemu-coroutine.o qemu-coroutine-lock.o qemu-coroutine-io.o block-obj-y += qemu-coroutine-sleep.o -ifeq ($(CONFIG_UCONTEXT_COROUTINE),y) -block-obj-$(CONFIG_POSIX) += coroutine-ucontext.o -else -ifeq ($(CONFIG_SIGALTSTACK_COROUTINE),y) -block-obj-$(CONFIG_POSIX) += coroutine-sigaltstack.o -else -block-obj-$(CONFIG_POSIX) += coroutine-gthread.o -endif -endif -block-obj-$(CONFIG_WIN32) += coroutine-win32.o +block-obj-y += coroutine-$(CONFIG_COROUTINE_BACKEND).o ifeq ($(CONFIG_VIRTIO)$(CONFIG_VIRTFS)$(CONFIG_PCI),yyy) # Lots of the fsdev/9pcode is pulled in by vl.c via qemu_fsdev_add. diff --git a/configure b/configure index a097fde479..3738de4bd6 100755 --- a/configure +++ b/configure @@ -3071,31 +3071,58 @@ fi ########################################## # check and set a backend for coroutine -# default is ucontext, but always fallback to gthread -# windows autodetected by make -if test "$coroutine" = "" -o "$coroutine" = "ucontext"; then - if test "$darwin" != "yes"; then - cat > $TMPC << EOF +# We prefer ucontext, but it's not always possible. The fallback +# is sigcontext. gthread is not selectable except explicitly, because +# it is not functional enough to run QEMU proper. (It is occasionally +# useful for debugging purposes.) On Windows the only valid backend +# is the Windows-specific one. + +ucontext_works=no +if test "$darwin" != "yes"; then + cat > $TMPC << EOF #include #ifdef __stub_makecontext #error Ignoring glibc stub makecontext which will always fail #endif int main(void) { makecontext(0, 0, 0); return 0; } EOF - if compile_prog "" "" ; then - coroutine_backend=ucontext - else - coroutine_backend=gthread - fi + if compile_prog "" "" ; then + ucontext_works=yes + fi +fi + +if test "$coroutine" = ""; then + if test "$mingw32" = "yes"; then + coroutine=win32 + elif test "$ucontext_works" = "yes"; then + coroutine=ucontext + else + coroutine=sigaltstack fi -elif test "$coroutine" = "gthread" ; then - coroutine_backend=gthread -elif test "$coroutine" = "windows" ; then - coroutine_backend=windows -elif test "$coroutine" = "sigaltstack" ; then - coroutine_backend=sigaltstack else - error_exit "unknown coroutine backend $coroutine" + case $coroutine in + windows) + if test "$mingw32" != "yes"; then + error_exit "'windows' coroutine backend only valid for Windows" + fi + # Unfortunately the user visible backend name doesn't match the + # coroutine-*.c filename for this case, so we have to adjust it here. + coroutine=win32 + ;; + ucontext) + if test "$ucontext_works" != "yes"; then + feature_not_found "ucontext" + fi + ;; + gthread|sigaltstack) + if test "$mingw32" = "yes"; then + error_exit "only the 'windows' coroutine backend is valid for Windows" + fi + ;; + *) + error_exit "unknown coroutine backend $coroutine" + ;; + esac fi ########################################## @@ -3402,7 +3429,7 @@ echo "GLX support $glx" echo "libiscsi support $libiscsi" echo "build guest agent $guest_agent" echo "seccomp support $seccomp" -echo "coroutine backend $coroutine_backend" +echo "coroutine backend $coroutine" echo "GlusterFS support $glusterfs" echo "virtio-blk-data-plane $virtio_blk_data_plane" echo "gcov $gcov_tool" @@ -3735,11 +3762,7 @@ if test "$rbd" = "yes" ; then echo "CONFIG_RBD=y" >> $config_host_mak fi -if test "$coroutine_backend" = "ucontext" ; then - echo "CONFIG_UCONTEXT_COROUTINE=y" >> $config_host_mak -elif test "$coroutine_backend" = "sigaltstack" ; then - echo "CONFIG_SIGALTSTACK_COROUTINE=y" >> $config_host_mak -fi +echo "CONFIG_COROUTINE_BACKEND=$coroutine" >> $config_host_mak if test "$open_by_handle_at" = "yes" ; then echo "CONFIG_OPEN_BY_HANDLE=y" >> $config_host_mak diff --git a/tests/Makefile b/tests/Makefile index 567e36e777..7fa15c6c08 100644 --- a/tests/Makefile +++ b/tests/Makefile @@ -24,19 +24,7 @@ gcov-files-test-string-input-visitor-y = qapi/string-input-visitor.c check-unit-y += tests/test-string-output-visitor$(EXESUF) gcov-files-test-string-output-visitor-y = qapi/string-output-visitor.c check-unit-y += tests/test-coroutine$(EXESUF) -ifeq ($(CONFIG_WIN32),y) -gcov-files-test-coroutine-y = coroutine-win32.c -else -ifeq ($(CONFIG_UCONTEXT_COROUTINE),y) -gcov-files-test-coroutine-y = coroutine-ucontext.c -else -ifeq ($(CONFIG_SIGALTSTACK_COROUTINE),y) -gcov-files-test-coroutine-y = coroutine-sigaltstack.c -else -gcov-files-test-coroutine-y = coroutine-gthread.c -endif -endif -endif +gcov-files-test-coroutine-y = coroutine-$(CONFIG_COROUTINE_BACKEND).c check-unit-y += tests/test-visitor-serialization$(EXESUF) check-unit-y += tests/test-iov$(EXESUF) gcov-files-test-iov-y = util/iov.c