autotools-package: also handle pre-installed external toolchain in .la fixup

The .la fixup handling looks for paths starting with /usr and assumes
that they are missing the installation prefix (i.e. $(STAGING_DIR)). It
already handles the cases that $(STAGING_DIR) itself and $(BASE_DIR)
are under /usr, but it does not yet handle the case that a
pre-installed external toolchain is under /usr (and tracks that fact
in some .la file). For instance, if you use buildroot to generate a
toolchain with HOST_DIR=/usr/local/some_path, this problem will occur.

Fix this in the same way as $(STAGING_DIR) and $(BASE_DIR), but in
addition check that TOOLCHAIN_EXTERNAL_INSTALL_DIR is non-empty. For
internal toolchains, it is empty and the sed expression would fail.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reported-by: Carlos Soto <csotoalonso@gmail.com>
Cc: Carlos Soto <csotoalonso@gmail.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/pkg-autotools.mk

@@ -304,10 +304,13 @@ endif
 # needs to be applied to any path that starts with /usr.
 #
 # To protect against the case that the output or staging directories
-# themselves are under /usr, we first substitute away any occurrences
-# of these directories as @BASE_DIR@ and @STAGING_DIR@. Note that
-# STAGING_DIR can be outside BASE_DIR when the user sets BR2_HOST_DIR
-# to a custom value.
+# or the pre-installed external toolchain themselves are under /usr,
+# we first substitute away any occurrences of these directories as
+# @BASE_DIR@, @STAGING_DIR@ and @TOOLCHAIN_EXTERNAL_INSTALL_DIR@ respectively.
+# Note that STAGING_DIR can be outside BASE_DIR when the user sets
+# BR2_HOST_DIR to a custom value. Note that TOOLCHAIN_EXTERNAL_INSTALL_DIR
+# can be under @BASE_DIR@ when it's a downloaded toolchain, and can be empty
+# when we use an internal toolchain.
 #
 ifndef $(2)_INSTALL_STAGING_CMDS
 define $(2)_INSTALL_STAGING_CMDS
@@ -315,7 +318,11 @@ define $(2)_INSTALL_STAGING_CMDS
 	find $$(STAGING_DIR)/usr/lib* -name "*.la" | xargs --no-run-if-empty \
 		$$(SED) "s:$$(BASE_DIR):@BASE_DIR@:g" \
 			-e "s:$$(STAGING_DIR):@STAGING_DIR@:g" \
+			$$(if $$(TOOLCHAIN_EXTERNAL_INSTALL_DIR),\
+				-e "s:$$(TOOLCHAIN_EXTERNAL_INSTALL_DIR):@TOOLCHAIN_EXTERNAL_INSTALL_DIR@:g") \
 			-e "s:\(['= ]\)/usr:\\1@STAGING_DIR@/usr:g" \
+			$$(if $$(TOOLCHAIN_EXTERNAL_INSTALL_DIR),\
+				-e "s:@TOOLCHAIN_EXTERNAL_INSTALL_DIR@:$$(TOOLCHAIN_EXTERNAL_INSTALL_DIR):g") \
 			-e "s:@STAGING_DIR@:$$(STAGING_DIR):g" \
 			-e "s:@BASE_DIR@:$$(BASE_DIR):g"
 endef