[Buildroot] [RFC v3 2/4] meson: change from global to per package cross-compilation.conf

[Yann E. MORIN <yann.morin.1998@free.fr>]

Peter, All,

On 2018-08-19 01:15 +0200, Peter Seiderer spake thusly:
> On Thu, 16 Aug 2018 13:57:45 +0200, Thomas Petazzoni <thomas.petazzoni@bootlin.com> wrote:
> > On Thu, 19 Jul 2018 22:43:53 +0200, Peter Seiderer wrote:
> > > -define HOST_MESON_INSTALL_CROSS_CONF
> > > +define HOST_MESON_INSTALL_CROSS_CONF_IN
> > >  	mkdir -p $(HOST_DIR)/etc/meson
> > >  	sed -e "s%@TARGET_CROSS@%$(TARGET_CROSS)%g" \
> > >  	    -e "s%@TARGET_ARCH@%$(ARCH)%g" \
> > > @@ -31,9 +31,9 @@ define HOST_MESON_INSTALL_CROSS_CONF
> > >  	    -e "s%@TARGET_CXXFLAGS@%$(HOST_MESON_SED_CXXFLAGS)%g" \
> > >  	    -e "s%@HOST_DIR@%$(HOST_DIR)%g" \
> > >  	    $(HOST_MESON_PKGDIR)/cross-compilation.conf.in \  
> > > -	    > $(HOST_DIR)/etc/meson/cross-compilation.conf    
> > > +	    > $(HOST_DIR)/etc/meson/cross-compilation.conf.in  
> > 
> > I am not super happy with this approach, because this file is not meant
> > to be used just during the build of Buildroot packages, but potentially
> > after the Buildroot build is finished, for people to easily
> > cross-compile Meson-based software manually. To me, this file is
> > similar to toolchainfile.cmake that pkg-cmake.mk is installing, and
> > which allows to easily cross-compile stuff with CMake outside of
> > Buildroot, using the Buildroot generated toolchain.
> > 
> > So I would prefer to:
> > 
> >  - Move this file to
> >    $(HOST_DIR)/usr/share/buildroot/meson-cross-compilation.conf or
> >    something like that, so that we are a bit consistent with what we do
> >    for CMake.
> > 
> >  - Keep it directly usable.
> > 
> >  - Pass the additional CFLAGS/LDFLAGS to packages on the command line
> >    rather than through this file.
> >    https://mesonbuild.com/howtox.html#set-extra-compiler-and-linker-flags-from-the-outside-when-eg-building-distro-packages
> >    seems to say this is possible, no ? Or does it override the ones
> >    from the cross-compilation.conf ?
> 
> The CFLAGS are ignored, e.g. with 'LIBDRM_CONF_ENV += CFLAGS=-DAO_NO_SPARC_V9' in package/libdrm/libdrm.mk:

What if you _also_ pass them in LIBDRM_NINJA_ENV ?

Regards,
Yann E. MORIN.

> 	$ make libdrm V=1
> [...]
> 
> ... CFLAGS=-DAO_NO_SPARC_V9 host/bin/meson --prefix=/usr --libdir=lib --default-library=shared --buildtype=debug --cross-file=.../host/etc/meson/cross-compilation.conf -Dcairo-tests=false -Dmanpages=false -Dintel=false -Dradeon=true -Damdgpu=true -Dnouveau=true -Dvmwgfx=false -Domap=false -Detnaviv=true -Dexynos=false -Dfreedreno=false -Dtegra=false -Dvc4=false -Dudev=true -Dvalgrind=false -Dinstall-test-programs=true .../build/libdrm-2.4.93/ .../build/libdrm-2.4.93//build
> The Meson build system
> Version: 0.47.1
> Source dir: .../build/libdrm-2.4.93
> Build dir: .../build/libdrm-2.4.93/build
> Build type: cross build
> WARNING: Unknown options: "manpages"
> Project name: libdrm
> Project version: 2.4.93
> Appending CFLAGS from environment: '-DAO_NO_SPARC_V9'
> Appending CFLAGS from environment: '-DAO_NO_SPARC_V9'
> Native C compiler: cc (gcc 8.1.1 "cc (SUSE Linux) 8.1.1 20180719 [gcc-8-branch revision 262874]")
> Cross C compiler: /home/seiderer/Work/Buildroot/build_libdrm_c99/host/bin/sparc-linux-gcc (gcc 6.4.0)
> 
> [...]
> 
> [1/104] .../host/bin/sparc-linux-gcc -Ilibkms/libkms@@kms at sha -Ilibkms -I../libkms -I. -I../ -I../include/drm -fdiagnostics-color=always -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -std=gnu99 -O0 -g -include config.h -fPIC -Wall -Wextra -Wsign-compare -Werror=undef -Werror-implicit-function-declaration -Wpointer-arith -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations -Wnested-externs -Wpacked -Wswitch-enum -Wmissing-format-attribute -Wstrict-aliasing=2 -Winit-self -Winline -Wshadow -Wdeclaration-after-statement -Wold-style-definition -Wno-unused-parameter -Wno-attributes -Wno-long-long -Wno-missing-field-initializers -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g2 -MD -MQ 'libkms/libkms@@kms at sha/api.c.o' -MF 'libkms/libkms@@kms at sha/api.c.o.d' -o 'libkms/libkms@@kms at sha/api.c.o' -c ../libkms/api.c
> 
> Only the c_args from cross-compilation.conf ('-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -g2')
> are used (in contrast to the 'Appending CFLAGS from environment' message)...
> 
> Regards,
> Peter
> 
> > 
> > Thanks!
> > 
> > Thomas
> 

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