Sam James <sam@xxxxxxxxxx> writes: > "Darrick J. Wong" <djwong@xxxxxxxxxx> writes: > >> From: Darrick J. Wong <djwong@xxxxxxxxxx> >> >> Apparently C++ compilers don't like the implicit void* casts that go on >> in the system headers. Compile a dummy program with the C++ compiler to >> make sure this works, so Darrick has /some/ chance of figuring these >> things out before the users do. > > Thanks, this is a good idea. Double thanks for the quick fix. > > 1) yes, it finds the breakage: > Tested-by: Sam James <sam@xxxxxxxxxx> > > 2) with the fix below (CC -> CXX): > Reviewed-by: Sam James <sam@xxxxxxxxxx> > > 3) another thing to think about is: > * -pedantic? > * maybe do one for a bunch of standards? (I think systemd does every > possible value [1]) > * doing the above for C as well > > I know that sounds a bit like overkill, but systemd > does it and it's cheap to do it versus the blowup if something goes > wrong. I don't have a strong opinion on this or how far you want to go > with it. ... thinking about this, it could've helped us with https://lore.kernel.org/linux-xfs/a216140e-1c8a-4d04-ba46-670646498622@xxxxxxxxxx/ > > [1] https://github.com/systemd/systemd/blob/3317aedff0901e08a8efc8346ad76b184d5d40ea/src/systemd/meson.build#L60 > >> >> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> >> --- >> configure.ac | 1 + >> include/builddefs.in | 7 +++++++ >> libxfs/Makefile | 8 +++++++- >> libxfs/dummy.cpp | 15 +++++++++++++++ >> 4 files changed, 30 insertions(+), 1 deletion(-) >> create mode 100644 libxfs/dummy.cpp >> >> diff --git a/configure.ac b/configure.ac >> index 0ffe2e5dfc53..04544f85395b 100644 >> --- a/configure.ac >> +++ b/configure.ac >> @@ -9,6 +9,7 @@ AC_PROG_INSTALL >> LT_INIT >> >> AC_PROG_CC >> +AC_PROG_CXX >> AC_ARG_VAR(BUILD_CC, [C compiler for build tools]) >> if test "${BUILD_CC+set}" != "set"; then >> if test $cross_compiling = no; then >> diff --git a/include/builddefs.in b/include/builddefs.in >> index 44f95234d21b..0f312b8b88fe 100644 >> --- a/include/builddefs.in >> +++ b/include/builddefs.in >> @@ -14,6 +14,7 @@ MALLOCLIB = @malloc_lib@ >> LOADERFLAGS = @LDFLAGS@ >> LTLDFLAGS = @LDFLAGS@ >> CFLAGS = @CFLAGS@ -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Wno-address-of-packed-member >> +CXXFLAGS = @CXXFLAGS@ -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Wno-address-of-packed-member >> BUILD_CFLAGS = @BUILD_CFLAGS@ -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 >> >> # make sure we don't pick up whacky LDFLAGS from the make environment and >> @@ -234,9 +235,15 @@ ifeq ($(ENABLE_GETTEXT),yes) >> GCFLAGS += -DENABLE_GETTEXT >> endif >> >> +# Override these if C++ needs other options >> +SANITIZER_CXXFLAGS = $(SANITIZER_CFLAGS) >> +GCXXFLAGS = $(GCFLAGS) >> +PCXXFLAGS = $(PCFLAGS) >> + >> BUILD_CFLAGS += $(GCFLAGS) $(PCFLAGS) >> # First, Sanitizer, Global, Platform, Local CFLAGS >> CFLAGS += $(FCFLAGS) $(SANITIZER_CFLAGS) $(OPTIMIZER) $(GCFLAGS) $(PCFLAGS) $(LCFLAGS) >> +CXXFLAGS += $(FCXXFLAGS) $(SANITIZER_CXXFLAGS) $(OPTIMIZER) $(GCXXFLAGS) $(PCXXFLAGS) $(LCXXFLAGS) >> >> include $(TOPDIR)/include/buildmacros >> >> diff --git a/libxfs/Makefile b/libxfs/Makefile >> index 1185a5e6cb26..bb851ab74204 100644 >> --- a/libxfs/Makefile >> +++ b/libxfs/Makefile >> @@ -125,6 +125,8 @@ CFILES = buf_mem.c \ >> xfs_trans_space.c \ >> xfs_types.c >> >> +LDIRT += dummy.o >> + >> # >> # Tracing flags: >> # -DMEM_DEBUG all zone memory use >> @@ -144,7 +146,11 @@ LTLIBS = $(LIBPTHREAD) $(LIBRT) >> # don't try linking xfs_repair with a debug libxfs. >> DEBUG = -DNDEBUG >> >> -default: ltdepend $(LTLIBRARY) >> +default: ltdepend $(LTLIBRARY) dummy.o >> + >> +dummy.o: dummy.cpp >> + @echo " [CXX] $@" >> + $(Q)$(CC) $(CXXFLAGS) -c $< > > $(CXX) ;) > >> >> # set up include/xfs header directory >> include $(BUILDRULES) >> diff --git a/libxfs/dummy.cpp b/libxfs/dummy.cpp >> new file mode 100644 >> index 000000000000..a872c00ad84b >> --- /dev/null >> +++ b/libxfs/dummy.cpp >> @@ -0,0 +1,15 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (c) 2024 Oracle. All Rights Reserved. >> + * Author: Darrick J. Wong <djwong@xxxxxxxxxx> >> + */ >> +#include "include/xfs.h" >> +#include "include/handle.h" >> +#include "include/jdm.h" >> + >> +/* Dummy program to test C++ compilation of user-exported xfs headers */ >> + >> +int main(int argc, char *argv[]) >> +{ >> + return 0; >> +} > > cheers, > sam
