[Buildroot] [RFC] First hack for external toolchain support based on sysroot

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hi,

This evening, I had a quick look at implementing support for external
toolchain based on --sysroot. It seems to work, see the included patch.
It's very hacky at the moment, I'm waiting for your suggestions to
improve the patch.

Sincerly,

Thomas

---

Another external toolchain support solution

 * In toolchain/external-toolchain/ext-tool.mk, copy the contents of
   the sysroot directory to the staging dir.

 * In package/Makefile.in, add a --sysroot CFLAGS pointing to the
   staging dir

 * Remove the CFLAGS and LDFLAGS definition from
   TARGET_CONFIGURE_OPTS. I haven't investigated exactly why, but with
   these options, DirectFB fails to build because it cannot find
   PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, even if DirectFB's Makefile
   properly sets -D_GNU_SOURCE.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 package/Makefile.in                      |    4 +---
 toolchain/external-toolchain/ext-tool.mk |    6 ++++++
 2 files changed, 7 insertions(+), 3 deletions(-)

Index: buildroot2/package/Makefile.in
===================================================================
--- buildroot2.orig/package/Makefile.in
+++ buildroot2/package/Makefile.in
@@ -89,7 +89,7 @@
 # else it's an external toolchain
 #########################################################################
 else
-TARGET_CFLAGS=$(TARGET_OPTIMIZATION) $(TARGET_DEBUGGING) -I$(STAGING_DIR)/include -I$(STAGING_DIR)/usr/include -I$(TOOLCHAIN_EXTERNAL_PATH)/$(TOOLCHAIN_EXTERNAL_PREFIX)/include
+TARGET_CFLAGS=$(TARGET_OPTIMIZATION) $(TARGET_DEBUGGING) -I$(STAGING_DIR)/include -I$(STAGING_DIR)/usr/include -I$(TOOLCHAIN_EXTERNAL_PATH)/$(TOOLCHAIN_EXTERNAL_PREFIX)/include --sysroot $(STAGING_DIR)/
 TARGET_CXXFLAGS=$(TARGET_CFLAGS)
 TARGET_LDFLAGS=-L$(STAGING_DIR)/lib -L$(STAGING_DIR)/usr/lib
 endif
@@ -210,8 +210,6 @@
 		AR="$(TARGET_AR)" \
 		AS="$(TARGET_AS)" \
 		LD="$(TARGET_LD)" \
-		CFLAGS="$(TARGET_CFLAGS)" \
-		LDFLAGS="$(TARGET_LDFLAGS)" \
 		NM="$(TARGET_NM)" \
 		CC="$(TARGET_CC) $(TARGET_CFLAGS)" \
 		GCC="$(TARGET_CC) $(TARGET_CFLAGS)" \
Index: buildroot2/toolchain/external-toolchain/ext-tool.mk
===================================================================
--- buildroot2.orig/toolchain/external-toolchain/ext-tool.mk
+++ buildroot2/toolchain/external-toolchain/ext-tool.mk
@@ -44,6 +44,11 @@
  \
 	echo -n
 
+copy_toolchain_sysroot = \
+	SYSROOT_DIR=`$(TARGET_CC) -v 2>&1 | grep ^Configured | tr " " "\n" | grep -- "--with-sysroot" | cut -f2 -d=`; \
+	cp -a $${SYSROOT_DIR}/* $(STAGING_DIR)/ ; \
+	find $(STAGING_DIR) -type d | xargs chmod 755
+
 uclibc: dependencies $(TARGET_DIR)/lib/$(strip $(subst ",, $(BR2_TOOLCHAIN_EXTERNAL_LIB_C)))
 
 $(TARGET_DIR)/lib/$(strip $(subst ",, $(BR2_TOOLCHAIN_EXTERNAL_LIB_C))):
@@ -54,3 +59,4 @@
 	for libs in $(strip $(subst ",, $(BR2_TOOLCHAIN_EXTERNAL_LIBS))); do \
 		$(call copy_toolchain_lib_root, $$libs, /lib, $(BR2_TOOLCHAIN_EXTERNAL_STRIP)); \
 	done
+	$(call copy_toolchain_sysroot)
\ No newline at end of file


-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com