Made a script to build docker images easier to use.

Summary:
- Removed double indirection via command-line args (i.e. two `--`
  options of `build_docker_image.sh`).
- Added a comment on how to build 2-stage clang install into the
  `build_docker_image.sh`, it used to be only in the `docs/Docker.rst`.

Reviewers: klimek, mehdi_amini

Reviewed By: klimek

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35050

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307256 91177308-0d34-0410-b5e6-96231b3b80d8

docs/Docker.rst

@@ -88,15 +88,11 @@ compiled by the system compiler in the debian8 image:
     ./llvm/utils/docker/build_docker_image.sh \
 	--source debian8 \
 	--docker-repository clang-debian8 --docker-tag "staging" \
-	-- \
 	-p clang -i install-clang -i install-clang-headers \
 	-- \
 	-DCMAKE_BUILD_TYPE=Release
 
-Note there are two levels of ``--`` indirection. First one separates
-``build_docker_image.sh`` arguments from ``llvm/utils/build_install_llvm.sh``
-arguments. Second one separates CMake arguments from ``build_install_llvm.sh``
-arguments. Note that build like that doesn't use a 2-stage build process that
+Note that a build like that doesn't use a 2-stage build process that
 you probably want for clang. Running a 2-stage build is a little more intricate,
 this command will do that:
 
@@ -108,7 +104,6 @@ this command will do that:
     ./build_docker_image.sh \
 	--source debian8 \
 	--docker-repository clang-debian8 --docker-tag "staging" \
-	-- \
 	-p clang -i stage2-install-clang -i stage2-install-clang-headers \
 	-- \
 	-DLLVM_TARGETS_TO_BUILD=Native -DCMAKE_BUILD_TYPE=Release \
@@ -178,7 +173,6 @@ debian8-based image using the latest ``google/stable`` sources for you:
 
     ./llvm/utils/docker/build_docker_image.sh \
 	-s debian8 --d clang-debian8 -t "staging" \
-	-- \
 	--branch branches/google/stable \
 	-p clang -i install-clang -i install-clang-headers \
 	-- \

utils/docker/build_docker_image.sh

@@ -16,20 +16,37 @@ BUILDSCRIPT_ARGS=""
 
 function show_usage() {
   usage=$(cat << EOF
-Usage: build_docker_image.sh [options] [-- [buildscript_args]...]
+Usage: build_docker_image.sh [options] [-- [cmake_args]...]
 
 Available options:
+  General:
+    -h|--help               show this help message
+  Docker-specific:
     -s|--source             image source dir (i.e. debian8, nvidia-cuda, etc)
     -d|--docker-repository  docker repository for the image
     -t|--docker-tag         docker tag for the image
-Required options: --source and --docker-repository.
+  LLVM-specific:
+    -b|--branch         svn branch to checkout, i.e. 'trunk',
+                        'branches/release_40'
+                        (default: 'trunk')
+    -r|--revision       svn revision to checkout
+    -p|--llvm-project   name of an svn project to checkout. Will also add the
+                        project to a list LLVM_ENABLE_PROJECTS, passed to CMake.
+                        For clang, please use 'clang', not 'cfe'.
+                        Project 'llvm' is always included and ignored, if
+                        specified.
+                        Can be specified multiple times.
+    -i|--install-target name of a cmake install target to build and include in
+                        the resulting archive. Can be specified multiple times.
 
-All options after '--' are passed to buildscript (see
-scripts/build_install_llvm.sh).
+Required options: --source and --docker-repository, at least one
+  --install-target.
+
+All options after '--' are passed to CMake invocation.
 
 For example, running:
 $ build_docker_image.sh -s debian8 -d mydocker/debian8-clang -t latest \ 
-  -- -p clang -i install-clang -i install-clang-headers
+  -p clang -i install-clang -i install-clang-headers
 will produce two docker images:
     mydocker/debian8-clang-build:latest - an intermediate image used to compile
       clang.
@@ -38,13 +55,20 @@ Please note that this example produces a not very useful installation, since it
 doesn't override CMake defaults, which produces a Debug and non-boostrapped
 version of clang.
 
-For an example of a somewhat more useful build, search for 2-stage build
-instructions in llvm/docs/Docker.rst.
+To get a 2-stage clang build, you could use this command:
+$ ./build_docker_image.sh -s debian8 -d mydocker/clang-debian8 -t "latest" \ 
+    -p clang -i stage2-install-clang -i stage2-install-clang-headers \ 
+    -- \ 
+    -DLLVM_TARGETS_TO_BUILD=Native -DCMAKE_BUILD_TYPE=Release \ 
+    -DBOOTSTRAP_CMAKE_BUILD_TYPE=Release \ 
+    -DCLANG_ENABLE_BOOTSTRAP=ON \ 
+    -DCLANG_BOOTSTRAP_TARGETS="install-clang;install-clang-headers"
 EOF
 )
   echo "$usage"
 }
 
+SEEN_INSTALL_TARGET=0
 while [[ $# -gt 0 ]]; do
   case "$1" in
     -h|--help)
@@ -66,9 +90,16 @@ while [[ $# -gt 0 ]]; do
       DOCKER_TAG="$1"
       shift
       ;;
+    -i|--install-target|-r|--revision|-b|--branch|-p|--llvm-project)
+      if [ "$1" == "-i" ] || [ "$1" == "--install-target" ]; then
+        SEEN_INSTALL_TARGET=1
+      fi
+      BUILDSCRIPT_ARGS="$BUILDSCRIPT_ARGS $1 $2"
+      shift 2
+      ;;
     --)
       shift
-      BUILDSCRIPT_ARGS="$*"
+      BUILDSCRIPT_ARGS="$BUILDSCRIPT_ARGS -- $*"
       shift $#
       ;;
     *)
@@ -94,6 +125,11 @@ if [ "$DOCKER_REPOSITORY" == "" ]; then
   exit 1
 fi
 
+if [ $SEEN_INSTALL_TARGET -eq 0 ]; then
+  echo "Please provide at least one --install-target"
+  exit 1
+fi
+
 cd $(dirname $0)
 if [ ! -d $IMAGE_SOURCE ]; then
   echo "No sources for '$IMAGE_SOURCE' were found in $PWD"