| Message ID | 20190907094027.9537-6-romain.naour@smile.fr |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Add the support for Clang cross-compiler | expand |
On 07/09/2019 11:40, Romain Naour wrote: > Until now we provided only CROSS_COMPILE to the kernel > buildsystem to use our GCC cross-compiler. Internally, > the buildsystem defined CC=$(CROSS_COMPILE)gcc. I don't like that we have to patch every package that happens to refer to gcc... Note that we have roughly 70 packages that use CROSS_COMPILE, so unless you checked all of them, it is likely that some of them are still referring to gcc as well (most of them probably not because we set CC=... in TARGET_CONFIGURE_OPTS, which gets used by most packages (but not by linux.mk)). Therefore, maybe a better alternative is to lie to the packages :-) We can symlink gcc etc. to clang instead of the toolchain wrapper. Then we just have to find a way to convert g++ to clang++ etc, but note that clang behaves correctly when called as aarch64-none-linux-gnu-g++ (i.e. it acts as if it was called through clang-c++), so we can probably work with that. Regards, Arnout > Since Clang can now be used as cross-compiler, Buildroot > may define in the future TARGET_CC to use clang instead > of GCC. > > In order to build the kernel with the selected compiler, > make sure to define CC=$(TARGET_CC) in LINUX_MAKE_FLAGS. > > Signed-off-by: Romain Naour <romain.naour@smile.fr> > Cc: Matt Weber <matthew.weber@rockwellcollins.com> > Cc: Valentin Korenblit <valentinkorenblit@gmail.com> > --- > linux/linux.mk | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/linux/linux.mk b/linux/linux.mk > index 29d2f0ee69..d381c96d85 100644 > --- a/linux/linux.mk > +++ b/linux/linux.mk > @@ -128,6 +128,7 @@ LINUX_MAKE_FLAGS = \ > ARCH=$(KERNEL_ARCH) \ > INSTALL_MOD_PATH=$(TARGET_DIR) \ > CROSS_COMPILE="$(TARGET_CROSS)" \ > + CC="$(TARGET_CC)" \ > DEPMOD=$(HOST_DIR)/sbin/depmod > > ifeq ($(BR2_REPRODUCIBLE),y) >
diff --git a/linux/linux.mk b/linux/linux.mk index 29d2f0ee69..d381c96d85 100644 --- a/linux/linux.mk +++ b/linux/linux.mk @@ -128,6 +128,7 @@ LINUX_MAKE_FLAGS = \ ARCH=$(KERNEL_ARCH) \ INSTALL_MOD_PATH=$(TARGET_DIR) \ CROSS_COMPILE="$(TARGET_CROSS)" \ + CC="$(TARGET_CC)" \ DEPMOD=$(HOST_DIR)/sbin/depmod ifeq ($(BR2_REPRODUCIBLE),y)
Until now we provided only CROSS_COMPILE to the kernel buildsystem to use our GCC cross-compiler. Internally, the buildsystem defined CC=$(CROSS_COMPILE)gcc. Since Clang can now be used as cross-compiler, Buildroot may define in the future TARGET_CC to use clang instead of GCC. In order to build the kernel with the selected compiler, make sure to define CC=$(TARGET_CC) in LINUX_MAKE_FLAGS. Signed-off-by: Romain Naour <romain.naour@smile.fr> Cc: Matt Weber <matthew.weber@rockwellcollins.com> Cc: Valentin Korenblit <valentinkorenblit@gmail.com> --- linux/linux.mk | 1 + 1 file changed, 1 insertion(+)