Merge pull request #268 from zhangkun83/protoc-artifact-maven

Build scripts to publish precompiled protoc binaries (Maven-based)

protoc-artifacts/README.md

+# Build scripts that publish pre-compiled protoc artifacts
+``protoc`` is the compiler for ``.proto`` files. It generates language bindings
+for the messages and/or RPC services from ``.proto`` files.
+
+Because ``protoc`` is a native executable, the scripts under this directory
+build and publish a ``protoc`` executable (a.k.a. artifact) to Maven
+repositories. The artifact can be used by build automation tools so that users
+would not need to compile and install ``protoc`` for their systems.
+
+## Versioning
+The version of the ``protoc`` artifact must be the same as the version of the
+Protobuf project.
+
+## Artifact name
+The name of a published ``protoc`` artifact is in the following format:
+``protoc-<version>-<os>-<arch>.exe``, e.g., ``protoc-3.0.0-alpha-3-windows-x86_64.exe``.
+
+## System requirement
+Install [Apache Maven](http://maven.apache.org/) if you don't have it.
+
+The scripts only work under Unix-like environments, e.g., Linux, MacOSX, and
+Cygwin or MinGW for Windows. Please see ``README.md`` of the Protobuf project
+for how to set up the build environment.
+
+## To install artifacts locally
+The following command will install the ``protoc`` artifact to your local Maven repository.
+```
+$ mvn install
+```
+
+## Cross-compilation
+The Maven script will try to detect the OS and the architecture from Java
+system properties. It's possible to build a protoc binary for an architecture
+that is different from what Java has detected, as long as you have the proper
+compilers installed. For example, MingGW32 only ships with 32-bit compilers,
+but you can still build 32-bit protoc under a 64-bit system, with the following
+command:
+```
+$ mvn install -Dos.detected.arch=x86_32
+```
+
+## To push artifacts to Maven Central
+Before you can upload artifacts to Maven Central repository, make sure you have
+read [this page](http://central.sonatype.org/pages/apache-maven.html) on how to
+configure GPG and Sonatype account.
+
+Use the following command to upload artifacts:
+```
+$ mvn clean deploy -P release
+```
+

protoc-artifacts/build-protoc.sh

+#!/bin/bash
+
+# Builds protoc executable into target/protoc.exe
+# To be run from Maven.
+# Usage: build-protoc.sh <OS> <ARCH>
+# <OS> and <ARCH> are ${os.detected.name} and ${os.detected.arch} from os-maven-plugin
+OS=$1
+ARCH=$2
+
+# Under Cygwin, bash doesn't have these in PATH when called from Maven which
+# runs in Windows version of Java.
+export PATH="/bin:/usr/bin:$PATH"
+
+############################################################################
+# Helper functions
+############################################################################
+E_PARAM_ERR=98
+E_ASSERT_FAILED=99
+
+fail()
+{
+  echo "Error: $1"
+  exit $E_ASSERT_FAILED
+}
+
+# Usage: assertEq VAL1 VAL2 $LINENO
+assertEq ()
+{
+  lineno=$3
+  if [ -z "$lineno" ]; then
+    echo "lineno not given"
+    exit $E_PARAM_ERR
+  fi
+
+  if [[ "$1" != "$2" ]]; then
+    echo "Assertion failed:  \"$1\" == \"$2\""
+    echo "File \"$0\", line $lineno"    # Give name of file and line number.
+    exit $E_ASSERT_FAILED
+  fi
+}
+############################################################################
+
+echo "Building protoc, OS=$OS ARCH=$ARCH"
+
+cd "$(dirname \"$0\")"
+WORKING_DIR=$(pwd)
+CONFIGURE_ARGS="--disable-shared"
+
+MAKE_TARGET="protoc"
+if [[ "$OS" == windows ]]; then
+  MAKE_TARGET="${MAKE_TARGET}.exe"
+fi
+
+if [[ "$(uname)" == CYGWIN* ]]; then
+  assertEq "$OS" windows $LINENO
+  # Use mingw32 compilers because executables produced by Cygwin compiler
+  # always have dependency on Cygwin DLL.
+  if [[ "$ARCH" == x86_64 ]]; then
+    CONFIGURE_ARGS="$CONFIGURE_ARGS --host=x86_64-w64-mingw32"
+  elif [[ "$ARCH" == x86_32 ]]; then
+    CONFIGURE_ARGS="$CONFIGURE_ARGS --host=i686-pc-mingw32"
+  else
+    fail "Unsupported arch by CYGWIN: $ARCH"
+  fi
+elif [[ "$(uname)" == MINGW32* ]]; then
+  assertEq "$OS" windows $LINENO
+  assertEq "$ARCH" x86_32 $LINENO
+elif [[ "$(uname)" == Linux* ]]; then
+  assertEq "$OS" linux $LINENO
+  if [[ "$ARCH" == x86_64 ]]; then
+    CONFIGURE_ARGS="$CONFIGURE_ARGS --host=x86_64-linux-gnu"
+  elif [[ "$ARCH" == x86_32 ]]; then
+    CONFIGURE_ARGS="$CONFIGURE_ARGS --host=i686-linux-gnu"
+  else
+    fail "Unsupported arch by CYGWIN: $ARCH"
+  fi
+elif [[ "$(uname)" == Darwin* ]]; then
+  assertEq "$OS" osx $LINENO
+else
+  fail "Unsupported system: $(uname)"
+fi
+
+# Override the default value set in configure.ac that has '-g' which produces
+# huge binary.
+export CXXFLAGS="-DNDEBUG"
+
+# Statically link libgcc and libstdc++.
+# -s to produce stripped binary.
+# And they don't work under Mac.
+if [[ "$OS" != osx ]]; then
+  export LDFLAGS="-static-libgcc -static-libstdc++ -s"
+fi
+
+cd "$WORKING_DIR"/.. && ./configure $CONFIGURE_ARGS &&
+  cd src && make clean && make $MAKE_TARGET &&
+  cd "$WORKING_DIR" && mkdir -p target &&
+  (cp ../src/protoc target/protoc.exe || cp ../src/protoc.exe target/protoc.exe)

protoc-artifacts/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.google</groupId>
+    <artifactId>google</artifactId>
+    <version>1</version>
+  </parent>
+  <groupId>com.google.protobuf</groupId>
+  <artifactId>protoc</artifactId>
+  <version>3.0.0-alpha-3-pre</version>
+  <packaging>pom</packaging>
+  <name>Protobuf Compiler</name>
+  <description>
+    Protobuf Compiler (protoc) is a compiler for .proto files. It generates
+    language-specific code for Protobuf messages and RPC interfaces.
+  </description>
+  <inceptionYear>2008</inceptionYear>
+  <url>https://developers.google.com/protocol-buffers/</url>
+  <licenses>
+    <license>
+      <name>New BSD license</name>
+      <url>http://www.opensource.org/licenses/bsd-license.php</url>
+      <distribution>repo</distribution>
+    </license>
+  </licenses>
+  <scm>
+    <url>https://github.com/google/protobuf</url>
+    <connection>
+      scm:git:https://github.com/google/protobuf.git
+    </connection>
+  </scm>
+  <build>
+    <extensions>
+      <extension>
+        <groupId>kr.motd.maven</groupId>
+        <artifactId>os-maven-plugin</artifactId>
+        <version>1.2.3.Final</version>
+      </extension>
+    </extensions>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>exec-maven-plugin</artifactId>
+        <version>1.1.1</version>
+        <executions>
+          <execution>
+            <phase>compile</phase>
+            <goals>
+              <goal>exec</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <executable>bash</executable>
+          <arguments>
+            <argument>build-protoc.sh</argument>
+            <argument>${os.detected.name}</argument>
+            <argument>${os.detected.arch}</argument>
+          </arguments>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>build-helper-maven-plugin</artifactId>
+        <version>1.8</version>
+        <executions>
+          <execution>
+            <id>attach-artifacts</id>
+            <phase>package</phase>
+            <goals>
+              <goal>attach-artifact</goal>
+            </goals>
+            <configuration>
+              <artifacts>
+                <artifact>
+                  <file>${basedir}/target/protoc.exe</file>
+                  <classifier>${os.detected.name}-${os.detected.arch}</classifier>
+                  <type>exe</type>
+                </artifact>
+              </artifacts>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+  <profiles>
+    <profile>
+      <id>release</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-gpg-plugin</artifactId>
+            <version>1.5</version>
+            <executions>
+              <execution>
+                <id>sign-artifacts</id>
+                <phase>verify</phase>
+                <goals>
+                  <goal>sign</goal>
+                </goals>
+              </execution>
+            </executions>
+          </plugin>
+          <plugin>
+            <groupId>org.sonatype.plugins</groupId>
+            <artifactId>nexus-staging-maven-plugin</artifactId>
+            <version>1.6.3</version>
+            <extensions>true</extensions>
+            <configuration>
+               <serverId>sonatype-nexus-staging</serverId>
+               <nexusUrl>https://oss.sonatype.org/</nexusUrl>
+               <autoReleaseAfterClose>false</autoReleaseAfterClose>
+            </configuration>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
+</project>