Re: [PATCH] btrfs-progs: Fix cross-compile error for mktables

On 2017年08月15日 15:14, Goffredo Baroncelli wrote:

Hi Qu,

On 08/15/2017 04:19 AM, Qu Wenruo wrote:

quoted

When cross compiling btrfs-progs, following error will prevent
btrfs-progs to be compiled:

     [CC]     mktables
     [TABLE]  kernel-lib/tables.c
/bin/sh: ./mktables: cannot execute binary file: Exec format error
make: *** No rule to make target 'kernel-lib/tables.c', needed by 'kernel-lib/tables.o'.  Stop.

"mktables" should only be executed in host environment, while @CC
set by autoconf will follow host/build/target setting, causing mktables
to be cross-compiled.

The fix is to introduce a new @HOSTCC for mktables, which will not be
affected by host/build/target settings.

Reported-by: Hallo32 <redacted>
Suggested-by: David Sterba <redacted>

this idea was a my suggestion.... :(

Sorry, I though all that 2 mails are from David.
And David still likes the idea to let git manage that file...

So correct tag should be:

Suggested-by: Goffredo Baroncelli <redacted>

Thanks for pointing this out.
Qu

quoted

Signed-off-by: Qu Wenruo <redacted>
---
Tested with AArch64 cross-toolchain created by buildroot.
---
  Makefile        | 2 +-
  Makefile.inc.in | 1 +
  configure.ac    | 1 +
  3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index b3e2b636..0395e37f 100644
--- a/Makefile
+++ b/Makefile

@@ -323,7 +323,7 @@ version.h: version.sh version.h.in configure.ac
  
  mktables: kernel-lib/mktables.c
  	@echo "    [CC]     $@"
-	$(Q)$(CC) $(CFLAGS) $< -o $@
+	$(Q)$(HOSTCC) $(CFLAGS) $< -o $@
  
  kernel-lib/tables.c: mktables
  	@echo "    [TABLE]  $@"

diff --git a/Makefile.inc.in b/Makefile.inc.in
index 4e1b68cb..308acca3 100644
--- a/Makefile.inc.in
+++ b/Makefile.inc.in

@@ -4,6 +4,7 @@
  export
  
  CC = @CC@
+HOSTCC = @HOSTCC@
  LN_S = @LN_S@
  AR = @AR@
  RM = @RM@

diff --git a/configure.ac b/configure.ac
index 30055f85..f6051ebd 100644
--- a/configure.ac
+++ b/configure.ac

@@ -26,6 +26,7 @@ AC_CONFIG_SRCDIR([btrfs.c])
  AC_PREFIX_DEFAULT([/usr/local])
  
  AC_PROG_CC
+AC_PATH_PROGS([HOSTCC], [gcc clang])
  AC_CANONICAL_HOST
  AC_C_CONST
  AC_C_VOLATILE