Add maven build for gcc-bridge maven-plugin

tools/gcc-bridge/maven-plugin/README.md

@@ -7,3 +7,15 @@ project targeting the JVM.
 See the [gcc-bridge-example](https://github.com/bedatadriven/gcc-bridge-example) project on GitHub for an example
 of how to use the plugin to incorporate C sources in a Maven Project.
 
+## Development builds
+
+At this stage, the maven plugin cannot be built using gradle, and so must be built separatetly.  You can do so with the following steps
+
+1. Export the renjin toolchain to your local maven repository by invoking `./gradlew publishToMavenLocal` in the root folder of the Renjin project
+2. Ensure the `<version>` in the `pom.xml` in this directory matches the version generated by `allprojects.project.version` in the `build.gradle` of the root folder
+3. Invoke `mvn package` in this directory
+4. Manually install the jar into your local maven repository:  
+   ```mvn install:install-file -Dfile=<path to maven plugn>/target/gcc-bridge-maven-plugin-3.5-betadev.jar -DgroupId=org.renjin -DartifactId=gcc-bridge-maven-plugin -Dversion=<version> -Dpackaging=jar -DpomFile=pom.xml```  
+   _(adapt the `<path>` and `<version>` to suit)_
+
+The `gcc-bridge-example` should now use your local toolchain to build.

tools/gcc-bridge/maven-plugin/pom.xml

@@ -0,0 +1,111 @@
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.renjin</groupId>
+  <artifactId>gcc-bridge-maven-plugin</artifactId>
+  <version>3.5-betadev</version>
+  <name>Renjin GCC Bridge Maven Plugin</name>
+
+  <packaging>maven-plugin</packaging>
+
+  <properties>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <maven.compiler.target>1.8</maven.compiler.target>
+  </properties>
+
+  <repositories>
+    <repository>
+      <id>bedatadriven-public</id>
+      <url>https://nexus.bedatadriven.com/content/groups/public/</url>
+    </repository>
+  </repositories>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-plugin-api</artifactId>
+      <version>2.0</version>
+    </dependency>
+
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-project</artifactId>
+      <type>jar</type>
+      <version>2.2.1</version>
+    </dependency>
+
+    <!-- dependencies to annotations -->
+    <dependency>
+      <groupId>org.apache.maven.plugin-tools</groupId>
+      <artifactId>maven-plugin-annotations</artifactId>
+      <version>3.4</version>
+      <scope>provided</scope>
+    </dependency>
+
+    <dependency>
+      <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-compiler-api</artifactId>
+      <version>2.7</version>
+      <exclusions>
+        <exclusion>
+          <groupId>org.codehaus.plexus</groupId>
+          <artifactId>plexus-component-api</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+    <dependency>
+      <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-utils</artifactId>
+      <type>jar</type>
+      <version>1.0.4</version>
+    </dependency>
+    <dependency>
+      <groupId>org.renjin</groupId>
+      <artifactId>gcc-bridge-compiler</artifactId>
+      <version>3.5-betadev</version>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.11</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.renjin</groupId>
+      <artifactId>renjin-soot</artifactId>
+      <version>2.9.198</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-plugin-plugin</artifactId>
+        <version>3.5</version>
+<!--
+        <configuration>
+          <goalPrefix>gcc-bridge</goalPrefix>
+        </configuration>
+        <executions>
+          <execution>
+            <id>default-descriptor</id>
+            <goals>
+              <goal>descriptor</goal>
+            </goals>
+            <phase>process-classes</phase>
+          </execution>
+          <execution>
+            <id>help-descriptor</id>
+            <goals>
+              <goal>helpmojo</goal>
+            </goals>
+            <phase>process-classes</phase>
+          </execution>
+        </executions>
+-->
+      </plugin>
+    </plugins>
+  </build>
+
+</project>