gistfile1.txt

#!/bin/bash
#
# Script which finds an appropriate rustc to execute based on the current
# directory.  We begin by walking up the set of directories until we find
# one that contains "src/comp/rustc.rc".  

# Walk up directories looking for the main rust directory.  Don't walk
# past the home directory of the current user, just seems unsanitary.

if [ -z "$1" ]; then
    STAGES="stage2 stage1"
else
    STAGES="$1"
fi

DIR="$PWD"
while [[ "$DIR" != "/" && "$DIR" != "$HOME" ]]; do
    if [[ -r "$DIR/src/rustc/rustc.rc" ]]; then
        for stage in ${STAGES}; do
            # Use glob to search through all architectures. 
            # But if some stage doesn't exist, then
            # the glob will keep the "*" rather than return the
            # empty set, so we have to check within the for loop
            # too.
            for rustc in "$DIR"/build/*/$stage/bin/rustc; do
                if [[ -x "$rustc" ]]; then
                    echo "$rustc"
                    exit 0
                fi
            done
        done
        break
    fi
    DIR=$(dirname "$DIR")
done

# Fallback to /usr/local/bin/rustc, if any:
echo /usr/local/bin/rustc
exit 0