Script to build librustc only

librustc_build

#!/bin/bash
# Just rebuild librustc and friends from the rust source.
# This probably works as long as you use the same source tree your binaries
# were built from and you don't modify anything outside of src/librustc*

echo If rustc fails with '"multiple dylib candidates for `rustc_...` found"' you
echo should move away '"librustc_llvm-*.so"' from the '"candidate #1"' directory.
echo

# Grab these from `make -pn`
export CFG_FILENAME_EXTRA=4e7c5e5c
export CFG_BOOTSTRAP_KEY=242588639
export CFG_COMPILER_HOST_TRIPLE=x86_64-unknown-linux-gnu
export CFG_LIBDIR_RELATIVE=lib
export CFG_PREFIX=/usr/local
export CFG_RELEASE=1.0.0-dev
export CFG_RELEASE_CHANNEL=dev
export CFG_RELEASE_NUM=1.0.0
export CFG_VERSION=1.0.0-dev

ln -sf /usr/lib/rust/rust-nightly/lib/librustc_back-$CFG_FILENAME_EXTRA.so
ln -sf /usr/lib/rust/rust-nightly/lib/librustc_llvm-$CFG_FILENAME_EXTRA.so

rustclib()
{
	echo rustc -L. -O -A unstable ${CFG_FILENAME_EXTRA:+-C extra-filename=-$CFG_FILENAME_EXTRA} $1/lib.rs
	rustc -L. -O -A unstable ${CFG_FILENAME_EXTRA:+-C extra-filename=-$CFG_FILENAME_EXTRA} $1/lib.rs
	echo done $1
}

rustclib librustc
rustclib librustc_borrowck &
rustclib librustc_trans &
rustclib librustc_resolve &
rustclib librustc_typeck &
wait
rustclib librustc_driver

echo rustc -L. -O -A unstable --cfg rustc -o rustc driver/driver.rs
rustc -L. -O -A unstable --cfg rustc -o rustc driver/driver.rs
echo done rustc

echo
echo Run with:
echo LD_LIBRARY_PATH=$(pwd) $(pwd)/rustc -L$(rustc --print sysroot)/lib/rustlib/$CFG_COMPILER_HOST_TRIPLE/lib/

This would probably work better with rust-lang/rust#16402 fixed.