rust: cleanup for things patched in, make local-rust more reliable

classes/rust.bbclass

@@ -6,7 +6,6 @@ RUSTC_ARCHFLAGS += "--target=${TARGET_SYS} -C rpath"
 def rust_base_dep(d):
     # Taken from meta/classes/base.bbclass `base_dep_prepend` and modified to
     # use rust instead of gcc
-    
     deps = ""
     if not d.getVar('INHIBIT_DEFAULT_DEPS'):
         if (d.getVar('HOST_SYS', True) != d.getVar('BUILD_SYS', True)):
@@ -57,17 +56,17 @@ RUST_TARGET_SYS = "${@rust_base_triple(d, 'TARGET')}"
 #	-L${STAGING_BASE_LIBDIR_NATIVE}	\
 #"
 
+RUST_PATH_NATIVE = "${STAGING_LIBDIR_NATIVE}:${STAGING_BASE_LIBDIR_NATIVE}"
 
-# FIXME: the 'rustlib' element of this is to workaround rustc forgetting the libdir it was built with.
-RUST_PATH_NATIVE="${STAGING_LIBDIR_NATIVE}:${STAGING_BASE_LIBDIR_NATIVE}:${STAGING_LIBDIR_NATIVE}/${TARGET_SYS}/rustlib/${TARGET_SYS}/lib"
+## Note: the 'rustlib' element of this was a workaround rustc forgetting the
+## libdir it was built with. It now remembers so this should be unneeded
+#RUST_PATH_NATIVE .= ":${STAGING_LIBDIR_NATIVE}/${TARGET_SYS}/rustlib/${TARGET_SYS}/lib"
 
 # FIXME: set based on whether we are native vs cross vs buildsdk, etc
 export RUST_PATH ??= "${RUST_PATH_NATIVE}"
 
-# FIXME: set this to something (sysroot?) for each of target,native,cross
-# For now, tuned so target builds are correct. -native happens to work because
-# the target specs happen to match.
-export RUST_TARGET_PATH = "${STAGING_LIBDIR_NATIVE}/${TARGET_SYS}/rust/targets:${STAGING_LIBDIR_NATIVE}/rust/targets"
+## This is builtin to rustc with the value "$libdir/rust/targets"
+# RUST_TARGET_PATH = "foo:bar"
 
 CARGO = "cargo"
 

recipes/rust/rust.inc

@@ -15,6 +15,7 @@ LIC_FILES_CHKSUM ="\
 # For -native, we set this to "0" by default.
 USE_LOCAL_RUST = "1"
 
+# We generate local targets, and need to be able to locate them
 export RUST_TARGET_PATH="${WORKDIR}/targets/"
 
 ## arm-unknown-linux-gnueabihf
@@ -226,10 +227,17 @@ do_configure () {
 	unset CXXFLAGS
 	unset CPPFLAGS
 
-	# rpath is required otherwise rustc fails to resolve symbols
+        if [ "${USE_LOCAL_RUST}" -eq 1 ]; then
+            # FIXME: this path to rustc may not be quite right in the case
+            # where we're reinstalling the compiler. May want to try for a real
+            # path based on bitbake vars
+            my_conf="--enable-local-rust --local-rust-root=$(dirname $(which rustc))"
+        else
+            my_conf=""
+        fi
 
-	# TODO: consider setting --local-rust-root for -cross and -target
-	# builds.
+	# - rpath is required otherwise rustc fails to resolve symbols
+        # - submodule management is done by bitbake's fetching
 	${S}/configure					\
 		"--enable-rpath"			\
 		"--disable-verify-install"		\
@@ -245,7 +253,7 @@ do_configure () {
 		"--libdir=${libdir}"			\
 		"--bindir=${bindir}"			\
 		"--disable-manage-submodules"           \
-		${@base_conditional('USE_LOCAL_RUST', '1', '--enable-local-rust', '', d)} \
+                ${my_conf}                              \
 		${EXTRA_OECONF}
 }
 
@@ -289,7 +297,7 @@ do_install () {
 
 ## We abuse the BBCLASSEXTEND system to avoid creating multiple .bb for every
 ## rust version (which is what gcc does).
-## 
+##
 ## Right now 'target' doesn't need any special settings, but at some point we may need to:
 ##  - add an internal-rust-target
 ##  - set the PN of this package to something like "rust-internal" or otherwise