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

From: Paul Cercueil
Date: Thu Apr 09 2015 - 11:10:10 EST

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.

Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Makefile | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 54430f9..5fff1b2 100644
--- a/Makefile
+++ b/Makefile
@@ -335,15 +335,6 @@ endif

-ifneq ($(CC),)
-ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)
-COMPILER := clang
-COMPILER := gcc
-export COMPILER
# Look for make include files relative to root of kernel src
MAKEFLAGS += --include-dir=$(srctree)

@@ -369,6 +360,13 @@ PERL = perl
PYTHON = python
CHECK = sparse

+ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)
+COMPILER := clang
+COMPILER := gcc
+export COMPILER
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void $(CF)

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