build script tweaks

factor out environment variable checks.
infer $GOROOT etc during build if not set.
it's still necessary to set them for yourself
to use the standard Makefiles.

when running all.bash, don't recompile all the
go packages in run.bash, since make.bash already did.

R=r
CC=golang-dev
http://codereview.appspot.com/609042

4 files changed, 84 insertions, 49 deletions

diff --git a/src/all.bash b/src/all.bash
index 67c19cd43..00c1ca74d 100755
--- a/src/all.bash
+++ b/src/all.bash
@@ -5,4 +5,4 @@
 
 set -e
 bash make.bash
-bash run.bash
+bash run.bash --no-rebuild
diff --git a/src/env.bash b/src/env.bash
new file mode 100644
index 000000000..6ab491ae4
--- /dev/null
+++ b/src/env.bash
@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+if test -z "$GOBIN"; then
+	if ! test -d "$HOME"/bin; then
+		echo '$GOBIN is not set and $HOME/bin is not a directory or does not exist.' 1>&2
+		echo 'mkdir $HOME/bin or set $GOBIN to a directory where binaries should' 1>&2
+		echo 'be installed.' 1>&2
+		exit 1
+	fi
+	GOBIN="$HOME/bin"
+elif ! test -d "$GOBIN"; then
+	echo '$GOBIN is not a directory or does not exist' 1>&2
+	echo 'create it or set $GOBIN differently' 1>&2
+	exit 1
+fi
+
+GOROOT=${GOROOT:-$(cd ..; pwd)}
+if ! test -f "$GOROOT"/include/u.h
+then
+	echo '$GOROOT is not set correctly or not exported' 1>&2
+	exit 1
+fi
+
+# Double-check that we're in $GOROOT, for people with multiple Go trees.
+# Various aspects of the build cd into $GOROOT-rooted paths,
+# making it easy to jump to a different tree and get confused.
+DIR1=$(cd ..; pwd)
+DIR2=$(cd $GOROOT; pwd)
+if [ "$DIR1" != "$DIR2" ]; then
+	echo 'Suspicious $GOROOT: does not match current directory.' 1>&2
+	exit 1
+fi
+
+GOARCH=${GOARCH:-$(uname -m | sed 's/^..86$/386/; s/^.86$/386/; s/x86_64/amd64/')}
+case "$GOARCH" in
+amd64 | 386 | arm)
+	;;
+*)
+	echo '$GOARCH is set to <'$GOARCH'>, must be amd64, 386, or arm' 1>&2
+	exit 1
+esac
+
+GOOS=${GOOS:-$(uname | tr A-Z a-z)}
+case "$GOOS" in
+darwin | freebsd | linux | mingw | nacl)
+	;;
+*)
+	echo '$GOOS is set to <'$GOOS'>, must be darwin, freebsd, linux, mingw, or nacl' 1>&2
+	exit 1
+esac
+
+export GOBIN GOROOT GOARCH GOOS
diff --git a/src/make.bash b/src/make.bash
index c2a350af7..d8638145e 100755
--- a/src/make.bash
+++ b/src/make.bash
@@ -4,48 +4,11 @@
 # license that can be found in the LICENSE file.
 
 set -e
+. ./env.bash
 
-if test -z "$GOBIN"; then
-	if ! test -d "$HOME"/bin; then
-		echo '$GOBIN is not set and $HOME/bin is not a directory or does not exist.' 1>&2
-		echo 'mkdir $HOME/bin or set $GOBIN to a directory where binaries should' 1>&2
-		echo 'be installed.' 1>&2
-		exit 1
-	fi
-	GOBIN="$HOME/bin"
-elif ! test -d "$GOBIN"; then
-	echo '$GOBIN is not a directory or does not exist' 1>&2
-	echo 'create it or set $GOBIN differently' 1>&2
-	exit 1
-fi
-
-GOBIN="${GOBIN:-$HOME/bin}"
 export MAKEFLAGS=-j4
-
 unset CDPATH	# in case user has it set
 
-if ! test -f "$GOROOT"/include/u.h
-then
-	echo '$GOROOT is not set correctly or not exported' 1>&2
-	exit 1
-fi
-
-case "$GOARCH" in
-amd64 | 386 | arm)
-	;;
-*)
-	echo '$GOARCH is set to <'$GOARCH'>, must be amd64, 386, or arm' 1>&2
-	exit 1
-esac
-
-case "$GOOS" in
-darwin | freebsd | linux | mingw | nacl)
-	;;
-*)
-	echo '$GOOS is set to <'$GOOS'>, must be darwin, freebsd, linux, mingw, or nacl' 1>&2
-	exit 1
-esac
-
 rm -f "$GOBIN"/quietgcc
 CC=${CC:-gcc}
 sed -e "s|@CC@|$CC|" < "$GOROOT"/src/quietgcc.bash > "$GOBIN"/quietgcc
diff --git a/src/run.bash b/src/run.bash
index 35d499f95..85dd59a55 100755
--- a/src/run.bash
+++ b/src/run.bash
@@ -4,12 +4,21 @@
 # license that can be found in the LICENSE file.
 
 set -e
+. ./env.bash
 
-GOBIN="${GOBIN:-$HOME/bin}"
+export MAKEFLAGS=-j4
+unset CDPATH	# in case user has it set
 
 # no core files, please
 ulimit -c 0
 
+# allow make.bash to avoid double-build of everything
+rebuild=true
+if [ "$1" = "--no-rebuild" ]; then
+	rebuild=false
+	shift
+fi
+		
 xcd() {
 	echo
 	echo --- cd $1
@@ -21,9 +30,11 @@ maketest() {
 	do
 		(
 			xcd $i
-			"$GOBIN"/gomake clean
-			time "$GOBIN"/gomake
-			"$GOBIN"/gomake install
+			if $rebuild; then
+				"$GOBIN"/gomake clean
+				time "$GOBIN"/gomake
+				"$GOBIN"/gomake install
+			fi
 			"$GOBIN"/gomake test
 		) || exit $?
 	done
@@ -36,20 +47,26 @@ maketest \
 # from what maketest does.
 
 (xcd pkg/sync;
-"$GOBIN"/gomake clean;
-time "$GOBIN"/gomake
+if $rebuild; then
+	"$GOBIN"/gomake clean;
+	time "$GOBIN"/gomake
+fi
 GOMAXPROCS=10 "$GOBIN"/gomake test
 ) || exit $?
 
 (xcd cmd/gofmt
-"$GOBIN"/gomake clean
-time "$GOBIN"/gomake
+if $rebuild; then
+	"$GOBIN"/gomake clean;
+	time "$GOBIN"/gomake
+fi
 time "$GOBIN"/gomake smoketest
 ) || exit $?
 
 (xcd cmd/ebnflint
-"$GOBIN"/gomake clean
-time "$GOBIN"/gomake
+if $rebuild; then
+	"$GOBIN"/gomake clean;
+	time "$GOBIN"/gomake
+fi
 time "$GOBIN"/gomake test
 ) || exit $?