[SPARK-8401] [BUILD] Scala version switching build enhancements

These commits address a few minor issues in the Scala cross-version support in the build:

  1. Correct two missing `${scala.binary.version}` pom file substitutions.
  2. Don't update `scala.binary.version` in parent POM. This property is set through profiles.
  3. Update the source of the generated scaladocs in `docs/_plugins/copy_api_dirs.rb`.
  4. Factor common code out of `dev/change-version-to-*.sh` and add some validation. We also test `sed` to see if it's GNU sed and try `gsed` as an alternative if not. This prevents the script from running with a non-GNU sed.

This is my original work and I license this work to the Spark project under the Apache License.

Author: Michael Allman <[email protected]>

Closes apache#6832 from mallman/scala-versions and squashes the following commits:

cde2f17 [Michael Allman] Delete dev/change-version-to-*.sh, replacing them with single dev/change-scala-version.sh script that takes a version as argument
02296f2 [Michael Allman] Make the scala version change scripts cross-platform by restricting ourselves to POSIX sed syntax instead of looking for GNU sed
ad9b40a [Michael Allman] Factor change-scala-version.sh out of change-version-to-*.sh, adding command line argument validation and testing for GNU sed
bdd20bf [Michael Allman] Update source of scaladocs when changing Scala version
475088e [Michael Allman] Replace jackson-module-scala_2.10 with jackson-module-scala_${scala.binary.version}

core/pom.xml

@@ -261,7 +261,7 @@
     </dependency>
     <dependency>
       <groupId>com.fasterxml.jackson.module</groupId>
-      <artifactId>jackson-module-scala_2.10</artifactId>
+      <artifactId>jackson-module-scala_${scala.binary.version}</artifactId>
     </dependency>
     <dependency>
       <groupId>org.apache.derby</groupId>

dev/change-scala-version.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+set -e
+
+usage() {
+  echo "Usage: $(basename $0) <version>" 1>&2
+  exit 1
+}
+
+if [ $# -ne 1 ]; then
+  usage
+fi
+
+TO_VERSION=$1
+
+VALID_VERSIONS=( 2.10 2.11 )
+
+check_scala_version() {
+  for i in ${VALID_VERSIONS[*]}; do [ $i = "$1" ] && return 0; done
+  echo "Invalid Scala version: $1. Valid versions: ${VALID_VERSIONS[*]}" 1>&2
+  exit 1
+}
+
+check_scala_version "$TO_VERSION"
+
+if [ $TO_VERSION = "2.11" ]; then
+  FROM_VERSION="2.10"
+else
+  FROM_VERSION="2.11"
+fi
+
+sed_i() {
+  sed -e "$1" "$2" > "$2.tmp" && mv "$2.tmp" "$2"
+}
+
+export -f sed_i
+
+BASEDIR=$(dirname $0)/..
+find "$BASEDIR" -name 'pom.xml' -not -path '*target*' -print \
+  -exec bash -c "sed_i 's/\(artifactId.*\)_'$FROM_VERSION'/\1_'$TO_VERSION'/g' {}" \;
+
+# Also update <scala.binary.version> in parent POM
+# Match any scala binary version to ensure idempotency
+sed_i '1,/<scala\.binary\.version>[0-9]*\.[0-9]*</s/<scala\.binary\.version>[0-9]*\.[0-9]*</<scala.binary.version>'$TO_VERSION'</' \
+  "$BASEDIR/pom.xml"
+
+# Update source of scaladocs
+echo "$BASEDIR/docs/_plugins/copy_api_dirs.rb"
+sed_i 's/scala\-'$FROM_VERSION'/scala\-'$TO_VERSION'/' "$BASEDIR/docs/_plugins/copy_api_dirs.rb"

dev/create-release/create-release.sh

@@ -122,13 +122,13 @@ if [[ ! "$@" =~ --skip-publish ]]; then
     -Phive-thriftserver -Phadoop-2.2 -Pspark-ganglia-lgpl -Pkinesis-asl \
     clean install
 
-  ./dev/change-version-to-2.11.sh
+  ./dev/change-scala-version.sh 2.11
 
   build/mvn -DskipTests -Pyarn -Phive -Prelease\
     -Dscala-2.11 -Phadoop-2.2 -Pspark-ganglia-lgpl -Pkinesis-asl \
     clean install
 
-  ./dev/change-version-to-2.10.sh
+  ./dev/change-scala-version.sh 2.10
 
   pushd $SPARK_REPO
 
@@ -205,7 +205,7 @@ if [[ ! "$@" =~ --skip-package ]]; then
 
     # TODO There should probably be a flag to make-distribution to allow 2.11 support
     if [[ $FLAGS == *scala-2.11* ]]; then
-      ./dev/change-version-to-2.11.sh
+      ./dev/change-scala-version.sh 2.11
     fi
 
     export ZINC_PORT=$ZINC_PORT

docs/building-spark.md

@@ -124,7 +124,7 @@ mvn -Pyarn -Phadoop-2.4 -Dhadoop.version=2.4.0 -Phive -Phive-thriftserver -Dskip
 # Building for Scala 2.11
 To produce a Spark package compiled with Scala 2.11, use the `-Dscala-2.11` property:
 
-    dev/change-version-to-2.11.sh
+    dev/change-scala-version.sh 2.11
     mvn -Pyarn -Phadoop-2.4 -Dscala-2.11 -DskipTests clean package
 
 Spark does not yet support its JDBC component for Scala 2.11.

pom.xml

@@ -614,7 +614,7 @@
            15.0, which causes runtime incompatibility issues. -->
       <dependency>
         <groupId>com.fasterxml.jackson.module</groupId>
-        <artifactId>jackson-module-scala_2.10</artifactId>
+        <artifactId>jackson-module-scala_${scala.binary.version}</artifactId>
         <version>${fasterxml.jackson.version}</version>
         <exclusions>
           <exclusion>