package/gcc-bare-metal: add multiple tuple support

Add support to gcc-bare-metal to support multiple architecture tuples
with the BR2_TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH string.

To do this, custom configure, build and install commands are needed, so that
each step goes through a loop of the architecture tuples in the list.

To keep consistency with autotools, all the relevant host configurations have
been copied into the HOST_GCC_BARE_METAL_CONF_OPTS while removing any
configurations that do not apply to gcc and removing redundant configs.

autotools redundant configs covered by $(HOST_CONFIGURE_OPTS):
	CFLAGS="$$(HOST_CFLAGS)"
	LDFLAGS="$$(HOST_LDFLAGS)"

autotools configs not applicable to gcc:
	--disable-gtk-doc
	--disable-gtk-doc-html
	--disable-doc
	--disable-docs
	--disable-documentation
	--disable-debug
	--with-xmlto=no
	--with-fop=no
	--disable-nls

While we're at it: the following configuration option was incorrect:
--disable-initfini_array -> --disable-initfini-array
configure converts - to _ anyway so it makes no difference, but it's
better to be consistent.

Signed-off-by: Neal Frager <neal.frager@amd.com>
[Arnout: keep --disable-libstdcxx-pch and better explanation for
--disable-initfini-array]
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

package/gcc-bare-metal/gcc-bare-metal.mk

@@ -20,15 +20,9 @@ HOST_GCC_BARE_METAL_DEPENDENCIES = \
 	host-mpfr \
 	host-isl
 
-# gcc doesn't support in-tree build, so we create a 'build'
-# subdirectory in the gcc sources, and build from there.
-define HOST_GCC_BARE_METAL_CONFIGURE_SYMLINK
-	mkdir -p $(@D)/build
-	ln -sf ../configure $(@D)/build/configure
-endef
-
-HOST_GCC_BARE_METAL_PRE_CONFIGURE_HOOKS += HOST_GCC_BARE_METAL_CONFIGURE_SYMLINK
-HOST_GCC_BARE_METAL_SUBDIR = build
+# Don't build documentation. It takes up extra space / build time,
+# and sometimes needs specific makeinfo versions to work
+HOST_GCC_BARE_METAL_CONF_ENV = MAKEINFO=missing
 
 HOST_GCC_BARE_METAL_MAKE_OPTS = \
 	$(HOST_GCC_COMMON_MAKE_OPTS) \
@@ -38,8 +32,13 @@ HOST_GCC_BARE_METAL_MAKE_OPTS = \
 HOST_GCC_BARE_METAL_INSTALL_OPTS = install-gcc install-target-libgcc
 
 HOST_GCC_BARE_METAL_CONF_OPTS = \
-	--target=$(TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH_TUPLE) \
-	--disable-initfini_array \
+	--prefix=$(HOST_DIR) \
+	--sysconfdir=$(HOST_DIR)/etc \
+	--localstatedir=$(HOST_DIR)/var \
+	$(if $$($$(PKG)_OVERRIDE_SRCDIR),,--disable-dependency-tracking) \
+	$(QUIET) \
+	--disable-shared \
+	--disable-initfini-array \
 	--disable-__cxa_atexit \
 	--disable-libstdcxx-pch \
 	--with-newlib \
@@ -54,9 +53,38 @@ HOST_GCC_BARE_METAL_CONF_OPTS = \
 	--with-gmp=$(HOST_DIR) \
 	--with-mpc=$(HOST_DIR) \
 	--with-mpfr=$(HOST_DIR) \
-	--with-isl=$(HOST_DIR) \
-	--with-sysroot=$(TOOLCHAIN_BARE_METAL_BUILDROOT_SYSROOT) \
-	AR_FOR_TARGET=$(HOST_DIR)/bin/$(TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH_TUPLE)-ar \
-	RANLIB_FOR_TARGET=$(HOST_DIR)/bin/$(TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH_TUPLE)-ranlib
+	--with-isl=$(HOST_DIR)
+
+define HOST_GCC_BARE_METAL_CONFIGURE_CMDS
+	$(foreach arch_tuple, $(TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH_TUPLE), \
+		mkdir -p $(@D)/build-$(arch_tuple) && \
+		cd $(@D)/build-$(arch_tuple) && \
+		$(HOST_CONFIGURE_OPTS) \
+		$(HOST_GCC_BARE_METAL_CONF_ENV) \
+		CONFIG_SITE=/dev/null \
+		$(@D)/configure \
+			$(HOST_GCC_BARE_METAL_CONF_OPTS) \
+			--target=$(arch_tuple) \
+			--with-sysroot=$(HOST_DIR)/$(arch_tuple)/sysroot \
+			AR_FOR_TARGET=$(HOST_DIR)/bin/$(arch_tuple)-ar \
+			RANLIB_FOR_TARGET=$(HOST_DIR)/bin/$(arch_tuple)-ranlib
+	)
+endef
+
+define HOST_GCC_BARE_METAL_BUILD_CMDS
+	$(foreach arch_tuple, $(TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH_TUPLE), \
+		$(HOST_MAKE_ENV) $(MAKE) \
+			$(HOST_GCC_BARE_METAL_MAKE_OPTS) \
+			-C $(@D)/build-$(arch_tuple)
+	)
+endef
+
+define HOST_GCC_BARE_METAL_INSTALL_CMDS
+	$(foreach arch_tuple, $(TOOLCHAIN_BARE_METAL_BUILDROOT_ARCH_TUPLE), \
+		$(HOST_MAKE_ENV) $(MAKE) \
+			$(HOST_GCC_BARE_METAL_INSTALL_OPTS) \
+			-C $(@D)/build-$(arch_tuple)
+	)
+endef
 
 $(eval $(host-autotools-package))