Rework support for downloading the stage0 rustc

Rust does something fairly different than in 1.7.  Instead of just
expecting the tarball to exist, it either expects an already extracted
and ready toolchain, or else it does everything itself.

To work with that, we'll always pass --use-local-rust to ./configure so
that bootstrap.py doesn't try to download anything.  We'll either
download and setup a snapshot ourselves, or use the system rust, based
on PACKAGECONFIG[local-rust] as before

recipes-devtools/rust/rust-snapshot-2015-12-18.inc

@@ -1,14 +0,0 @@
-## snapshot info taken from rust/src/snapshots.txt
-## TODO: find a way to add additional SRC_URIs based on the contents of an
-##       earlier SRC_URI.
-RS_DATE = "2015-12-18"
-RS_SRCHASH = "3391630"
-# linux-x86_64
-RS_ARCH = "linux-x86_64"
-RS_HASH = "97e2a5eb8904962df8596e95d6e5d9b574d73bf4"
-
-RUST_SNAPSHOT = "rust-stage0-${RS_DATE}-${RS_SRCHASH}-${RS_ARCH}-${RS_HASH}.tar.bz2"
-
-SRC_URI[rust-snapshot.md5sum] = "5c29eb06c8b6ce6ff52f544f31efabe1"
-SRC_URI[rust-snapshot.sha256sum] = "a8dc5203673ce43f47316beb02ee0c427edb7bbde2ab5fc662a06b52db2950e7"
-

recipes-devtools/rust/rust-snapshot-2016-05-24.inc

@@ -0,0 +1,13 @@
+## snapshot info taken from rust/src/stage0.txt
+## TODO: find a way to add additional SRC_URIs based on the contents of an
+##       earlier SRC_URI.
+RS_DATE = "2016-05-24"
+RS_VERSION = "1.9.0"
+RS_ARCH = "x86_64-unknown-linux-gnu"
+
+RUST_SNAPSHOT = "rustc-${RS_VERSION}-${RS_ARCH}.tar.gz"
+RUST_SNAPSHOT_URI = "https://static.rust-lang.org/dist/${RS_DATE}/${RUST_SNAPSHOT}"
+
+SRC_URI[rust-snapshot.md5sum] = "f1cf6d2fe15e4be18a08259f1540a4ae"
+SRC_URI[rust-snapshot.sha256sum] = "d0704d10237c66c3efafa6f7e5570c59a1d3fe5c6d99487540f90ebb37cd84c4"
+

recipes-devtools/rust/rust.inc

@@ -2,7 +2,7 @@
 inherit rust
 inherit rust-installer
 require rust-shared-source.inc
-require rust-snapshot-2015-12-18.inc
+require rust-snapshot-2016-05-24.inc
 
 LIC_FILES_CHKSUM ="file://COPYRIGHT;md5=43e1f1fb9c0ee3af66693d8c4fecafa8"
 
@@ -25,7 +25,9 @@ PACKAGECONFIG ??= ""
 # to have rust-cross built using rust-native.
 PACKAGECONFIG[local-rust] = ""
 
-SRC_URI += "${@bb.utils.contains('PACKAGECONFIG', 'local-rust', '', 'https://static.rust-lang.org/stage0-snapshots/${RUST_SNAPSHOT};unpack=0;name=rust-snapshot', d)}"
+FETCH_STAGE0 = "${@bb.utils.contains('PACKAGECONFIG', 'local-rust', 'false', 'true', d)}"
+
+SRC_URI += "${@bb.utils.contains('PACKAGECONFIG', 'local-rust', '', '${RUST_SNAPSHOT_URI};unpack=0;name=rust-snapshot', d)}"
 
 # We generate local targets, and need to be able to locate them
 export RUST_TARGET_PATH="${WORKDIR}/targets/"
@@ -389,15 +391,16 @@ do_configure () {
     # where we're reinstalling the compiler. May want to try for a real
     # path based on bitbake vars
     # Also will be wrong when relative libdir and/or bindir aren't 'bin' and 'lib'.
-    local_maybe_enable=disable
     local_rust_root=/not/set/do/not/use
-    if which rustc >/dev/null 2>&1; then
+    if ${FETCH_STAGE0}; then
+        mkdir -p dl
+        tar -xf ${WORKDIR}/${RUST_SNAPSHOT} -C dl
+        ./dl/rustc-${RS_VERSION}-${RS_ARCH}/install.sh --prefix=$PWD/dl
+        local_rust_root="$PWD/dl"
+    elif which rustc >/dev/null 2>&1; then
         local_rustc=$(which rustc)
         if [ -n "$local_rustc" ]; then
             local_rust_root=$(dirname $(dirname $local_rustc))
-            if [ -e "$local_rust_root/bin/rustc" ]; then
-                local_maybe_enable=enable
-            fi
         fi
     fi
 
@@ -426,7 +429,7 @@ do_configure () {
         "--libdir=${libdir}"                \
         "--bindir=${bindir}"                \
         "--platform-cfg=${WORKDIR}/mk-cfg/" \
-        ${@bb.utils.contains('PACKAGECONFIG', 'local-rust', '--$local_maybe_enable-local-rust --local-rust-root=$local_rust_root', '--local-rust-root=/not/a/dir', d)} \
+        "--enable-local-rust --local-rust-root=$local_rust_root" \
         ${EXTRA_OECONF}
 }
 
@@ -446,10 +449,6 @@ rust_runmake () {
 }
 
 do_compile () {
-    if ${@bb.utils.contains('PACKAGECONFIG', 'local-rust', 'false', 'true', d)}; then
-        mkdir -p dl
-        cp -f ${WORKDIR}/${RUST_SNAPSHOT} dl
-    fi
     rust_runmake
 }