From a57d1aaafe47dadaa5fad8b73ec9e2e31bb5f123 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 8 Oct 2020 15:30:24 +0200 Subject: [PATCH] build: use PIE objects for static libraries if b_staticpic=false but b_pie=true If static_library is used as a convenience library (e.g. for link_whole) it should in principle not need position independent code. However, if the executables that the libraries is linked to are PIE, the non-PIC objects in the static library will cause linker errors. To avoid this, obey b_pie for static libraries if either b_staticpic=false or they use "pic: false". Without this patch, QEMU cannot use b_staticpic, which causes a slowdown on some QEMU benchmarks up to 20%. (cherry picked from commit 021d242f9ce8e6cd804af0c1eb4179b8c83fd470) Signed-off-by: Danilo C. L. de Paula --- mesonbuild/backend/backends.py | 2 +- mesonbuild/build.py | 18 +++++++++++------- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py index c84bb7534..f67efe370 100644 --- a/mesonbuild/backend/backends.py +++ b/mesonbuild/backend/backends.py @@ -694,7 +694,7 @@ class Backend: # Set -fPIC for static libraries by default unless explicitly disabled if isinstance(target, build.StaticLibrary) and target.pic: commands += compiler.get_pic_args() - if isinstance(target, build.Executable) and target.pie: + elif isinstance(target, (build.StaticLibrary, build.Executable)) and target.pie: commands += compiler.get_pie_args() # Add compile args needed to find external dependencies. Link args are # added while generating the link command. diff --git a/mesonbuild/build.py b/mesonbuild/build.py index a06979cea..90cbd1aa6 100644 --- a/mesonbuild/build.py +++ b/mesonbuild/build.py @@ -972,13 +972,13 @@ This will become a hard error in a future Meson release.''') if m.is_darwin() or m.is_windows(): self.pic = True else: - self.pic = self._extract_pic_pie(kwargs, 'pic') - if isinstance(self, Executable): + self.pic = self._extract_pic_pie(kwargs, 'pic', environment, 'b_staticpic') + if isinstance(self, Executable) or (isinstance(self, StaticLibrary) and not self.pic): # Executables must be PIE on Android if self.environment.machines[self.for_machine].is_android(): self.pie = True else: - self.pie = self._extract_pic_pie(kwargs, 'pie') + self.pie = self._extract_pic_pie(kwargs, 'pie', environment, 'b_pie') self.implicit_include_directories = kwargs.get('implicit_include_directories', True) if not isinstance(self.implicit_include_directories, bool): raise InvalidArguments('Implicit_include_directories must be a boolean.') @@ -990,14 +990,20 @@ This will become a hard error in a future Meson release.''') if self.gnu_symbol_visibility not in permitted: raise InvalidArguments('GNU symbol visibility arg {} not one of: {}'.format(self.symbol_visibility, ', '.join(permitted))) - def _extract_pic_pie(self, kwargs, arg): + def _extract_pic_pie(self, kwargs, arg, environment, option): # Check if we have -fPIC, -fpic, -fPIE, or -fpie in cflags all_flags = self.extra_args['c'] + self.extra_args['cpp'] if '-f' + arg.lower() in all_flags or '-f' + arg.upper() in all_flags: mlog.warning("Use the '{}' kwarg instead of passing '{}' manually to {!r}".format(arg, '-f' + arg, self.name)) return True - val = kwargs.get(arg, False) + if arg in kwargs: + val = kwargs[arg] + elif option in environment.coredata.base_options: + val = environment.coredata.base_options[option].value + else: + val = False + if not isinstance(val, bool): raise InvalidArguments('Argument {} to {!r} must be boolean'.format(arg, self.name)) return val @@ -1611,8 +1617,6 @@ class StaticLibrary(BuildTarget): def __init__(self, name, subdir, subproject, for_machine: MachineChoice, sources, objects, environment, kwargs): self.typename = 'static library' - if 'pic' not in kwargs and 'b_staticpic' in environment.coredata.base_options: - kwargs['pic'] = environment.coredata.base_options['b_staticpic'].value super().__init__(name, subdir, subproject, for_machine, sources, objects, environment, kwargs) if 'cs' in self.compilers: raise InvalidArguments('Static libraries not supported for C#.') -- 2.27.0