dashboard: add linux-amd64-clang builder.

Fixes golang/go#8805.

LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/152790043

dashboard/coordinator/main.go

@@ -52,6 +52,7 @@ type imageInfo struct {
 
 var images = map[string]*imageInfo{
 	"gobuilders/linux-x86-base":  {url: "https://storage.googleapis.com/go-builder-data/docker-linux.base.tar.gz"},
+	"gobuilders/linux-x86-clang": {url: "http://storage.googleapis.com/go-builder-data/docker-linux.clang.tar.gz"},
 	"gobuilders/linux-x86-gccgo": {url: "https://storage.googleapis.com/go-builder-data/docker-linux.gccgo.tar.gz"},
 	"gobuilders/linux-x86-nacl":  {url: "https://storage.googleapis.com/go-builder-data/docker-linux.nacl.tar.gz"},
 	"gobuilders/linux-x86-sid":   {url: "https://storage.googleapis.com/go-builder-data/docker-linux.sid.tar.gz"},
@@ -87,6 +88,8 @@ func main() {
 	})
 	addBuilder(buildConfig{name: "linux-386-sid", image: "gobuilders/linux-x86-sid"})
 	addBuilder(buildConfig{name: "linux-amd64-sid", image: "gobuilders/linux-x86-sid"})
+	addBuilder(buildConfig{name: "linux-386-clang", image: "gobuilders/linux-x86-clang"})
+	addBuilder(buildConfig{name: "linux-amd64-clang", image: "gobuilders/linux-x86-clang"})
 
 	if (*just != "") != (*rev != "") {
 		log.Fatalf("--just and --rev must be used together")

dashboard/env/linux-x86-clang/Dockerfile

@@ -0,0 +1,20 @@
+# Copyright 2014 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.
+
+# gobuilders/linux-x86-clang for building with clang instead of gcc.
+
+FROM debian:wheezy
+MAINTAINER golang-dev <golang-dev@googlegroups.com>
+
+ENV DEBIAN_FRONTEND noninteractive
+
+ADD /sources/clang-deps.list /etc/apt/sources.list.d/
+
+ADD /scripts/install-apt-deps.sh /scripts/
+RUN /scripts/install-apt-deps.sh
+
+ADD /scripts/build-go-builder.sh /scripts/
+RUN GO_REV=073fc578434b BUILDER_REV=8845ca94a310 /scripts/build-go-builder.sh && test -f /usr/local/bin/builder
+
+ENV CC /usr/bin/clang

dashboard/env/linux-x86-clang/Makefile

@@ -0,0 +1,15 @@
+# Copyright 2014 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.
+
+docker: Dockerfile
+	docker build -t gobuilders/linux-x86-clang .
+
+docker-linux.clang.tar.gz: docker
+	docker save gobuilders/linux-x86-clang | gzip | (cd ../../coordinator/buildongce && go run create.go --write_object=go-builder-data/docker-linux.clang.tar.gz)
+
+check: docker
+	docker run gobuilders/linux-x86-clang /usr/local/bin/builder -rev=fa76e8393654 -buildroot=/ -v -report=false linux-amd64-temp
+
+check32: docker
+	docker run gobuilders/linux-x86-clang /usr/local/bin/builder -rev=fa76e8393654 -buildroot=/ -v -report=false linux-386-temp

dashboard/env/linux-x86-clang/scripts/build-go-builder.sh

@@ -0,0 +1,20 @@
+set -ex
+
+export GOPATH=/gopath
+export GOROOT=/goroot
+PREFIX=/usr/local
+: ${GO_REV:?"need to be set to the golang repo revision used to build the builder."}
+: ${BUILDER_REV:?"need to be set to the go.tools repo revision for the builder."}
+
+mkdir -p $GOROOT
+curl -s https://storage.googleapis.com/gobuilder/go-snap.tar.gz | tar x --no-same-owner -zv -C $GOROOT
+(cd $GOROOT/src && hg pull -r $GO_REV -u && find && ./make.bash)
+
+GO_TOOLS=$GOPATH/src/code.google.com/p/go.tools
+mkdir -p $GO_TOOLS
+curl -s https://storage.googleapis.com/gobuilder/go.tools-snap.tar.gz | tar x --no-same-owner -zv -C $GO_TOOLS
+
+mkdir -p $PREFIX/bin
+(cd $GO_TOOLS && hg pull -r $BUILDER_REV -u && GOBIN=$PREFIX/bin /goroot/bin/go install code.google.com/p/go.tools/dashboard/builder)
+
+rm -fR $GOROOT/bin $GOROOT/pkg $GOPATH

dashboard/env/linux-x86-clang/scripts/install-apt-deps.sh

@@ -0,0 +1,19 @@
+set -ex
+
+apt-get update
+# For running curl to get the hg starter tarballs (faster than hg clone).
+apt-get install -y --no-install-recommends curl ca-certificates
+# Optionally used by some net/http tests:
+apt-get install -y --no-install-recommends strace 
+# For building Go's bootstrap 'dist' prog
+apt-get install -y --no-install-recommends wget
+wget -O - http://llvm.org/apt/llvm-snapshot.gpg.key | apt-key add -
+apt-get update
+apt-get install -y --no-install-recommends clang-3.5
+# TODO(cmang): move these into a 386 image that derives from this one.
+apt-get install -y --no-install-recommends libc6-dev-i386
+# For interacting with the Go source & subrepos:
+apt-get install -y --no-install-recommends mercurial git-core
+
+apt-get clean
+rm -fr /var/lib/apt/lists

dashboard/env/linux-x86-clang/sources/clang-deps.list

@@ -0,0 +1,3 @@
+# The debian sources for stable clang builds, taken from http://llvm.org/apt/
+deb http://llvm.org/apt/wheezy/ llvm-toolchain-wheezy main
+deb-src http://llvm.org/apt/wheezy/ llvm-toolchain-wheezy main