gcc/libc: Change bootstrap to use an intermediate sysroot and hence no longer overwrite files

Based upon patches from Dexuan Cui <dexuan.cui@intel.com>

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/siteconfig.bbclass

@@ -10,13 +10,15 @@ python siteconfig_do_siteconfig () {
 	sstate_install(shared_state, d)
 }
 
+EXTRASITECONFIG ?= ""
+
 siteconfig_do_siteconfig_gencache () {
 	mkdir -p ${WORKDIR}/site_config
 	gen-site-config ${FILE_DIRNAME}/site_config \
 		>${WORKDIR}/site_config/configure.ac
 	cd ${WORKDIR}/site_config
 	autoconf
-        CONFIG_SITE="" ./configure ${CONFIGUREOPTS} --cache-file ${PN}_cache
+        CONFIG_SITE="" ${EXTRASITECONFIG} ./configure ${CONFIGUREOPTS} --cache-file ${PN}_cache
 	sed -n -e "/ac_cv_c_bigendian/p" -e "/ac_cv_sizeof_/p" \
 		-e "/ac_cv_type_/p" -e "/ac_cv_header_/p" -e "/ac_cv_func_/p" \
 		< ${PN}_cache > ${PN}_config

meta/conf/bitbake.conf

@@ -293,6 +293,7 @@ STAGING_PYDIR = "${STAGING_DIR}/lib/python2.4"
 # This should really be MULTIMACH_TARGET_SYS but that breaks "all" and machine 
 # specific packages - hack around it for now.
 STAGING_DIR_TARGET = "${STAGING_DIR}/${BASEPKG_TARGET_SYS}"
+STAGING_DIR_TCBOOTSTRAP = "${STAGING_DIR_TARGET}-tcbootstrap"
 
 # Setting DEPLOY_DIR outside of TMPDIR is helpful, when you are using
 # packaged staging and/or multimachine.

meta/recipes-core/eglibc/eglibc-initial.inc

@@ -45,8 +45,15 @@ do_install () {
        install -m 644 csu/crt[1in].o ${D}${libdir}
        ${CC} -nostdlib -nostartfiles -shared -x c /dev/null \
                -o ${D}${libdir}/libc.so
+
+	# add links to linux-libc-headers: gcc-{cross,crossdk}-intermediate need this.
+	for t in linux asm asm-generic; do
+		ln -s ${STAGING_DIR_TARGET}${includedir}/$t ${D}${includedir}/
+	done
 }
 
 do_siteconfig () {
 	:
 }
+
+do_populate_sysroot[sstate-outputdirs] = "${STAGING_DIR_TCBOOTSTRAP}"

meta/recipes-core/eglibc/eglibc.inc

@@ -4,6 +4,21 @@ STAGINGCC = "gcc-cross-intermediate"
 STAGINGCC_virtclass-nativesdk = "gcc-crosssdk-intermediate"
 PATH_prepend = "${STAGING_BINDIR_TOOLCHAIN}.${STAGINGCC}:"
 
+TOOLCHAIN_OPTIONS = " --sysroot=${STAGING_DIR_TCBOOTSTRAP}"
+
+# siteconfig.bbclass runs configure which needs a working compiler
+# For the compiler to work we need a working libc yet libc isn't 
+# in the sysroots directory at this point. This means the libc.so
+# linker script won't work as the --sysroot setting isn't correct.
+# Here we create a hacked up libc linker script and pass in the right
+# flags to let configure work. Ugly.
+EXTRASITECONFIG = "CFLAGS='${CFLAGS} -Wl,-L${WORKDIR}/site_config_libc -L${WORKDIR}/site_config_libc -L${SYSROOT_DESTDIR}${libdir} -L${SYSROOT_DESTDIR}${base_libdir} -Wl,-L${SYSROOT_DESTDIR}${libdir} -Wl,-L${SYSROOT_DESTDIR}${base_libdir}'"
+siteconfig_do_siteconfig_gencache_prepend = " \
+	mkdir -p ${WORKDIR}/site_config_libc; \
+	cp ${SYSROOT_DESTDIR}${libdir}/libc.so ${WORKDIR}/site_config_libc; \
+	sed -i -e 's# ${base_libdir}# ${SYSROOT_DESTDIR}${base_libdir}#g' -e 's# ${libdir}# ${SYSROOT_DESTDIR}${libdir}#g' ${WORKDIR}/site_config_libc/libc.so; \
+"
+
 # nptl needs unwind support in gcc, which can't be built without glibc.
 DEPENDS = "virtual/${TARGET_PREFIX}gcc-intermediate linux-libc-headers"
 #this leads to circular deps, so lets not add it yet

meta/recipes-core/glibc/glibc-initial.inc

@@ -53,8 +53,15 @@ do_install () {
 	install -m 644 csu/crt[1in].o ${D}${libdir}
 	${CC} -nostdlib -nostartfiles -shared -x c /dev/null \
 		-o ${D}${libdir}/libc.so
+
+	# add links to linux-libc-headers: gcc-{cross,crossdk}-intermediate need this.
+	for t in linux asm asm-generic; do
+		ln -s ${STAGING_DIR_TARGET}${includedir}/$t ${D}${includedir}/
+	done
 }
 
 do_siteconfig () {
 	:
 }
+
+do_populate_sysroot[sstate-outputdirs] = "${STAGING_DIR_TCBOOTSTRAP}"

meta/recipes-core/glibc/glibc.inc

@@ -21,6 +21,21 @@ STAGINGCC = "gcc-cross-intermediate"
 STAGINGCC_virtclass-nativesdk = "gcc-crosssdk-intermediate"
 PATH_prepend = "${STAGING_BINDIR_TOOLCHAIN}.${STAGINGCC}:"
 
+TOOLCHAIN_OPTIONS = " --sysroot=${STAGING_DIR_TCBOOTSTRAP}"
+
+# siteconfig.bbclass runs configure which needs a working compiler
+# For the compiler to work we need a working libc yet libc isn't
+# in the sysroots directory at this point. This means the libc.so
+# linker script won't work as the --sysroot setting isn't correct.
+# Here we create a hacked up libc linker script and pass in the right
+# flags to let configure work. Ugly.
+EXTRASITECONFIG = "CFLAGS='${CFLAGS} -Wl,-L${WORKDIR}/site_config_libc -L${WORKDIR}/site_config_libc -L${SYSROOT_DESTDIR}${libdir} -L${SYSROOT_DESTDIR}${base_libdir} -Wl,-L${SYSROOT_DESTDIR}${libdir} -Wl,-L${SYSROOT_DESTDIR}${base_libdir}'"
+siteconfig_do_siteconfig_gencache_prepend = " \
+	mkdir -p ${WORKDIR}/site_config_libc; \
+	cp ${SYSROOT_DESTDIR}${libdir}/libc.so ${WORKDIR}/site_config_libc; \
+	sed -i -e 's# ${base_libdir}# ${SYSROOT_DESTDIR}${base_libdir}#g' -e 's# ${libdir}# ${SYSROOT_DESTDIR}${libdir}#g' ${WORKDIR}/site_config_libc/libc.so; \
+"
+
 inherit autotools
 
 GLIBC_EXTRA_OECONF ?= ""

meta/recipes-devtools/gcc/gcc-cross-intermediate.inc

@@ -14,13 +14,13 @@ EXTRA_OECONF = "--with-local-prefix=${STAGING_DIR_TARGET}${target_prefix} \
 		--enable-languages=c \
                 ${OPTSPACE} \
 		--program-prefix=${TARGET_PREFIX} \
-		--with-sysroot=${STAGING_DIR_TARGET} \
-		--with-build-sysroot=${STAGING_DIR_TARGET} \
+		--with-sysroot=${STAGING_DIR_TCBOOTSTRAP} \
+		--with-build-sysroot=${STAGING_DIR_TCBOOTSTRAP} \
 		${EXTRA_OECONF_INTERMEDIATE} \
 		${@get_gcc_fpu_setting(bb, d)}"
 
 do_populate_sysroot[sstate-inputdirs] = "${SYSROOT_DESTDIR}/${STAGING_DIR_HOST} ${SYSROOT_DESTDIR}/${STAGING_DIR_TARGET}/${target_base_libdir}"
-do_populate_sysroot[sstate-outputdirs] = "${STAGING_DIR_HOST} ${STAGING_DIR_TARGET}/${target_base_libdir}"
+do_populate_sysroot[sstate-outputdirs] = "${STAGING_DIR_HOST} ${STAGING_DIR_TCBOOTSTRAP}/${target_base_libdir}"
 
 do_compile () {
     oe_runmake