meson.build | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)
The large comment in the patch says it all; the -no-pie flag is broken and
this is why it was not included in QEMU_LDFLAGS before commit a988b4c5614
("build: move remaining compiler flag tests to meson", 2023-05-18). And
some distros made things even worse, so we have to add it to the compiler
command line.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1664
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
meson.build | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/meson.build b/meson.build
index 0a5cdefd4d3d..20accae99281 100644
--- a/meson.build
+++ b/meson.build
@@ -265,12 +265,21 @@ endif
# Meson currently only handles pie as a boolean for now, so if the user
# has explicitly disabled PIE we need to extend our cflags.
+#
+# -no-pie is supposedly a linker flag that has no effect on the compiler
+# command line, but some distros, that didn't quite know what they were
+# doing, made local changes to gcc's specs file that turned it into
+# a compiler command-line flag.
+#
+# What about linker flags? For a static build, no PIE is implied by -static
+# which we added above (and if it's not because of the same specs patching,
+# there's nothing we can do: compilation will fail, report a bug to your
+# distro and do not use --disable-pie in the meanwhile). For dynamic linking,
+# instead, we can't add -no-pie because it overrides -shared: the linker then
+# tries to build an executable instead of a shared library and fails. So
+# don't add -no-pie anywhere and cross fingers. :(
if not get_option('b_pie')
- qemu_common_flags += cc.get_supported_arguments('-fno-pie')
- if not get_option('prefer_static')
- # No PIE is implied by -static which we added above.
- qemu_ldflags += cc.get_supported_link_arguments('-no-pie')
- endif
+ qemu_common_flags += cc.get_supported_arguments('-fno-pie', '-no-pie')
endif
if not get_option('stack_protector').disabled()
--
2.40.1
Am 23.05.23 um 09:30 schrieb Paolo Bonzini: > The large comment in the patch says it all; the -no-pie flag is broken and > this is why it was not included in QEMU_LDFLAGS before commit a988b4c5614 > ("build: move remaining compiler flag tests to meson", 2023-05-18). And > some distros made things even worse, so we have to add it to the compiler > command line. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1664 > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > meson.build | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > > diff --git a/meson.build b/meson.build > index 0a5cdefd4d3d..20accae99281 100644 > --- a/meson.build > +++ b/meson.build > @@ -265,12 +265,21 @@ endif > > # Meson currently only handles pie as a boolean for now, so if the user > # has explicitly disabled PIE we need to extend our cflags. > +# > +# -no-pie is supposedly a linker flag that has no effect on the compiler > +# command line, but some distros, that didn't quite know what they were > +# doing, made local changes to gcc's specs file that turned it into > +# a compiler command-line flag. > +# > +# What about linker flags? For a static build, no PIE is implied by -static > +# which we added above (and if it's not because of the same specs patching, > +# there's nothing we can do: compilation will fail, report a bug to your > +# distro and do not use --disable-pie in the meanwhile). For dynamic linking, > +# instead, we can't add -no-pie because it overrides -shared: the linker then > +# tries to build an executable instead of a shared library and fails. So > +# don't add -no-pie anywhere and cross fingers. :( > if not get_option('b_pie') > - qemu_common_flags += cc.get_supported_arguments('-fno-pie') > - if not get_option('prefer_static') > - # No PIE is implied by -static which we added above. > - qemu_ldflags += cc.get_supported_link_arguments('-no-pie') > - endif > + qemu_common_flags += cc.get_supported_arguments('-fno-pie', '-no-pie') > endif > > if not get_option('stack_protector').disabled() I tested that QEMU builds on Windows with MSYS2 mingw64. One unrelated note: The DLL loader doesn't find the libslirp-0.dll when QEMU was built with libslirp from the subprojects folder and started from the build folder. It's necessary to copy this library to a folder in the DLL search path. Tested-by: Volker Rümelin <vr_qemu@t-online.de>
On 5/23/23 00:30, Paolo Bonzini wrote: > The large comment in the patch says it all; the -no-pie flag is broken and > this is why it was not included in QEMU_LDFLAGS before commit a988b4c5614 > ("build: move remaining compiler flag tests to meson", 2023-05-18). And > some distros made things even worse, so we have to add it to the compiler > command line. > > Resolves:https://gitlab.com/qemu-project/qemu/-/issues/1664 > Signed-off-by: Paolo Bonzini<pbonzini@redhat.com> > --- > meson.build | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Richard Henderson <richard.henderson@linaro.org> r~
On 23/5/23 09:30, Paolo Bonzini wrote: > The large comment in the patch says it all; the -no-pie flag is broken and > this is why it was not included in QEMU_LDFLAGS before commit a988b4c5614 > ("build: move remaining compiler flag tests to meson", 2023-05-18). And > some distros made things even worse, so we have to add it to the compiler > command line. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1664 > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > meson.build | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > > diff --git a/meson.build b/meson.build > index 0a5cdefd4d3d..20accae99281 100644 > --- a/meson.build > +++ b/meson.build > @@ -265,12 +265,21 @@ endif > > # Meson currently only handles pie as a boolean for now, so if the user > # has explicitly disabled PIE we need to extend our cflags. > +# > +# -no-pie is supposedly a linker flag that has no effect on the compiler > +# command line, but some distros, that didn't quite know what they were > +# doing, made local changes to gcc's specs file that turned it into > +# a compiler command-line flag. > +# > +# What about linker flags? For a static build, no PIE is implied by -static > +# which we added above (and if it's not because of the same specs patching, > +# there's nothing we can do: compilation will fail, report a bug to your > +# distro and do not use --disable-pie in the meanwhile). For dynamic linking, > +# instead, we can't add -no-pie because it overrides -shared: the linker then > +# tries to build an executable instead of a shared library and fails. So > +# don't add -no-pie anywhere and cross fingers. :( > if not get_option('b_pie') > - qemu_common_flags += cc.get_supported_arguments('-fno-pie') > - if not get_option('prefer_static') > - # No PIE is implied by -static which we added above. > - qemu_ldflags += cc.get_supported_link_arguments('-no-pie') > - endif > + qemu_common_flags += cc.get_supported_arguments('-fno-pie', '-no-pie') > endif This removes this annoying warning with Clang on Darwin/Aarch64: clang: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument] Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
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