Re: [PATCH v2] Makefile: Fix detection of clang when cross-compiling

[Behan Webster]

Resent since gmail HTML-ified my previous email...

On Wed, Apr 22, 2015 at 7:33 AM, Michal Marek <mmarek@xxxxxxx 
<mailto:mmarek@xxxxxxx>> wrote:

   On Fri, Apr 17, 2015 at 11:35:04PM +0200, Paul Cercueil wrote:
    > When the host's C compiler is clang, and when attempting to
    > cross-compile Linux e.g. to MIPS with mipsel-linux-gcc, the Makefile
    > would incorrectly detect the use of clang, which resulted in
    > clang-specific flags being passed to mipsel-linux-gcc.
    >
    > This can be verified under Debian by installing the "clang" package,
    > and then using it as the default compiler with:
    > sudo update-alternatives --config cc
    >
    > This patch moves the detection of clang after the $(CC) variable is
    > initialized to the name of the cross-compiler, so that the check
   applies
    > to the cross-compiler and not the host's C compiler.
    >
    > v2: Move the detection of clang after the inclusion of the
    > arch/*/Makefile (as they might set $(CROSS_COMPILE))
    >
    > Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx
   <mailto:paul@xxxxxxxxxxxxxxx>>

   Applied to kbuild.git#kbuild. I will push it after v4.1-rc1 becomes
   available, though.


Drat. I wish I saw this earlier.

This breaks patches which check for the value of COMPILER in 
arch/*/Makefile. This detection must be performed before the inclusion 
of the arch Makefile.

Can I move this to after the initialization of CC but before the include?

I'm not sure that being able to define the default compiler per arch is 
necessary. But I know I need to be able to add arch specific flags for 
clang.

Behan

--
Behan Webster
behanw@xxxxxxxxxxxxxxxxxx <mailto:behanw@xxxxxxxxxxxxxxxxxx>
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