gcc-runtime, libgcc: Symlink c++ header and startup files in target_triplet for SDK use

We build SDKs such that gcc-cross-candian is built for only one
target *-*-linux and then use -muclibc or -mmusl to let it compile
code for other libc variants. This works fine when libc = glibc
however it does not work for c++ programs when libc != glibc since
there are c++ headers installed under ${includedir}/c++/${BINV}/${TARGET_SYS}
which is fine when gcc-runtime and gcc-cross-candian uses same --target options
gxx includedir searches in right triplet, but it fails with musl/uclibc
since gcc will look for glibc based triplet but gcc-runtime will install
them under musl/uclibc triplet.

This patch symlinks the musl/uclibc triplet to glibc triplet when libc != glibc

This fixes SDKs for musl/uclibc

(From OE-Core rev: fcaaabb401fffcda4db9a7d1f927a2a404e4776d)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/cross-canadian.bbclass

@@ -68,6 +68,7 @@ python () {
     elif tarch == "mips64":
         d.appendVar("CANADIANEXTRAOS", " linux-gnun32 linux-uclibcn32 linux-musln32")
     if tarch == "arm" or tarch == "armeb":
+        d.appendVar("CANADIANEXTRAOS", " linux-musleabi linux-uclibceabi")
         d.setVar("TARGET_OS", "linux-gnueabi")
     else:
         d.setVar("TARGET_OS", "linux")

meta/recipes-devtools/gcc/gcc-runtime.inc

@@ -73,9 +73,21 @@ do_install () {
 	if [ "${TARGET_VENDOR_MULTILIB_ORIGINAL}" != "" -a "${TARGET_VENDOR}" != "${TARGET_VENDOR_MULTILIB_ORIGINAL}" ]; then
 		ln -s ${TARGET_SYS} ${D}${includedir}/c++/${BINV}/${TARGET_ARCH}${TARGET_VENDOR_MULTILIB_ORIGINAL}-${TARGET_OS}
 	fi
+
+}
+
+do_install_append_class-target () {
 	if [ "${TARGET_OS}" = "linux-gnuspe" ]; then
 		ln -s ${TARGET_SYS} ${D}${includedir}/c++/${BINV}/${TARGET_ARCH}${TARGET_VENDOR}-linux
 	fi
+	if [ "${TCLIBC}" != "glibc" ]; then
+		case "${TARGET_OS}" in
+			"linux-musl" | "linux-uclibc" | "linux-*spe") extra_target_os="linux";;
+			"linux-musleabi" | "linux-uclibceabi") extra_target_os="linux-gnueabi";;
+			*) extra_target_os="linux";;
+		esac
+		ln -s ${TARGET_SYS} ${D}${includedir}/c++/${BINV}/${TARGET_ARCH}${TARGET_VENDOR}-$extra_target_os
+	fi
 	chown -R root:root ${D}
 }
 

meta/recipes-devtools/gcc/libgcc.inc

@@ -2,6 +2,17 @@ require libgcc-common.inc
 
 DEPENDS = "virtual/${TARGET_PREFIX}gcc virtual/${TARGET_PREFIX}g++"
 
+do_install_append_class-target () {
+	if [ "${TCLIBC}" != "glibc" ]; then
+		case "${TARGET_OS}" in
+			"linux-musl" | "linux-uclibc" | "linux-*spe") extra_target_os="linux";;
+			"linux-musleabi" | "linux-uclibceabi") extra_target_os="linux-gnueabi";;
+			*) extra_target_os="linux";;
+		esac
+		ln -s ${TARGET_SYS} ${D}${libdir}/${TARGET_ARCH}${TARGET_VENDOR}-$extra_target_os
+	fi
+}
+
 PACKAGES = "\
     ${PN} \
     ${PN}-dev \
@@ -19,6 +30,7 @@ FILES_${PN}-dev = "\
     ${base_libdir}/libgcc*.so \
     ${@base_conditional('BASETARGET_SYS', '${TARGET_SYS}', '', '${libdir}/${BASETARGET_SYS}', d)} \
     ${libdir}/${TARGET_SYS}/${BINV}* \
+    ${libdir}/${TARGET_ARCH}${TARGET_VENDOR}* \
 "
 
 LIBGCCBUILDTREENAME = "gcc-build-internal-"