Support javac as a compiler for Tycho

Currently Tycho is strictly using ecj as a compiler but in general it might be there are situations one wants to use javac for compilation even though it might not has full features supported (e.g. package restrictions). This is an attempt to make it possible to use javac at a very basic level.
eclipse-tycho · Jan 11, 2024 · 2725cbd · 2725cbd
1 parent dccc34e
commit 2725cbd
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diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
@@ -6,6 +6,7 @@ This page describes the noteworthy improvements provided by each release of Ecli
 
 ### backports:
 
+- using javac as the compiler for Tycho
 - new `mirror-target-platform` mojo
 - new director mojo
 - support for PDE Api Tools Annotations

diff --git a/tycho-compiler-plugin/pom.xml b/tycho-compiler-plugin/pom.xml
@@ -86,6 +86,11 @@
 			<artifactId>bcel</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+		    <groupId>org.codehaus.plexus</groupId>
+		    <artifactId>plexus-compiler-javac</artifactId>
+		    <version>2.14.2</version>
+		</dependency>
 	</dependencies>
 
 </project>
diff --git a/tycho-compiler-plugin/src/main/java/copied/org/apache/maven/plugin/AbstractCompilerMojo.java b/tycho-compiler-plugin/src/main/java/copied/org/apache/maven/plugin/AbstractCompilerMojo.java
@@ -57,6 +57,8 @@
  */
 public abstract class AbstractCompilerMojo extends AbstractMojo {
 
+    protected static final String JDT_COMPILER_ID = "jdt";
+
     public static final String DEFAULT_SOURCE_VERSION = "11";
 
     public static final String DEFAULT_TARGET_VERSION = "11";
@@ -144,8 +146,8 @@ public abstract class AbstractCompilerMojo extends AbstractMojo {
     /**
      * The compiler id of the compiler to use.
      */
-    @Parameter(property = "maven.compiler.compilerId", defaultValue = "jdt")
-    private String compilerId;
+    @Parameter(property = "maven.compiler.compilerId", defaultValue = JDT_COMPILER_ID)
+    protected String compilerId;
 
     /**
      * Version of the compiler to use, ex. "1.3", "1.5", if fork is set to true

diff --git a/tycho-compiler-plugin/src/main/java/org/eclipse/tycho/compiler/AbstractOsgiCompilerMojo.java b/tycho-compiler-plugin/src/main/java/org/eclipse/tycho/compiler/AbstractOsgiCompilerMojo.java
@@ -573,6 +573,7 @@ public List<String> getClasspathElements() throws MojoExecutionException {
         final List<String> classpath = new ArrayList<>();
         Set<String> seen = new HashSet<>();
         Set<String> includedPathes = new HashSet<>();
+        boolean useAccessRules = JDT_COMPILER_ID.equals(compilerId);
         for (ClasspathEntry cpe : getClasspath()) {
             Stream<File> classpathLocations = Stream
                     .concat(cpe.getLocations().stream(),
@@ -581,7 +582,7 @@ public List<String> getClasspathElements() throws MojoExecutionException {
                     .filter(AbstractOsgiCompilerMojo::isValidLocation).distinct();
             classpathLocations.forEach(location -> {
                 String path = location.getAbsolutePath();
-                String entry = path + toString(cpe.getAccessRules());
+                String entry = path + toString(cpe.getAccessRules(), useAccessRules);
                 if (seen.add(entry)) {
                     includedPathes.add(path);
                     classpath.add(entry);
@@ -646,19 +647,22 @@ protected BundleProject getBundleProject() throws MojoExecutionException {
         return (BundleProject) projectType;
     }
 
-    private String toString(Collection<AccessRule> rules) {
-        StringJoiner result = new StringJoiner(RULE_SEPARATOR, "[", "]"); // include all
-        if (rules != null) {
-            for (AccessRule rule : rules) {
-                result.add((rule.isDiscouraged() ? "~" : "+") + rule.getPattern());
+    private String toString(Collection<AccessRule> rules, boolean useAccessRules) {
+        if (useAccessRules) {
+            StringJoiner result = new StringJoiner(RULE_SEPARATOR, "[", "]"); // include all
+            if (rules != null) {
+                for (AccessRule rule : rules) {
+                    result.add((rule.isDiscouraged() ? "~" : "+") + rule.getPattern());
+                }
+                result.add(RULE_EXCLUDE_ALL);
+            } else {
+                // include everything, not strictly necessary, but lets make this obvious
+                //result.append("[+**/*]");
+                return "";
             }
-            result.add(RULE_EXCLUDE_ALL);
-        } else {
-            // include everything, not strictly necessary, but lets make this obvious
-            //result.append("[+**/*]");
-            return "";
+            return result.toString();
         }
-        return result.toString();
+        return "";
     }
 
     @Override
@@ -719,7 +723,7 @@ protected CompilerConfiguration getCompilerConfiguration(List<String> compileSou
                 List<Entry<String, String>> copy = new ArrayList<>(
                         compilerConfiguration.getCustomCompilerArgumentsEntries());
                 compilerConfiguration.getCustomCompilerArgumentsEntries().clear();
-                compilerConfiguration.addCompilerCustomArgument("-properties", prefsFilePath);
+                addCompilerCustomArgument(compilerConfiguration, "-properties", prefsFilePath);
                 compilerConfiguration.getCustomCompilerArgumentsEntries().addAll(copy);
             }
         }
@@ -738,7 +742,7 @@ protected CompilerConfiguration getCompilerConfiguration(List<String> compileSou
                 if (jreClasspathEntry.isModule()) {
                     Collection<String> modules = jreClasspathEntry.getLimitModules();
                     if (!modules.isEmpty()) {
-                        compilerConfiguration.addCompilerCustomArgument("--limit-modules", String.join(",", modules));
+                        addCompilerCustomArgument(compilerConfiguration, "--limit-modules", String.join(",", modules));
                     }
                 }
             }
@@ -782,7 +786,7 @@ private void configureCompilerLog(CompilerConfiguration compilerConfiguration) t
             fileExtension = "log";
         }
         logPath = logPath + logFileName + "." + fileExtension;
-        compilerConfiguration.addCompilerCustomArgument("-log", logPath);
+        addCompilerCustomArgument(compilerConfiguration, "-log", logPath);
     }
 
     private void configureBootclasspathAccessRules(CompilerConfiguration compilerConfiguration)
@@ -811,8 +815,8 @@ private void configureBootclasspathAccessRules(CompilerConfiguration compilerCon
                     .addAll(getBundleProject().getBootClasspathExtraAccessRules(DefaultReactorProject.adapt(project)));
         }
         if (!accessRules.isEmpty()) {
-            compilerConfiguration.addCompilerCustomArgument("org.osgi.framework.system.packages",
-                    toString(accessRules));
+            addCompilerCustomArgument(compilerConfiguration, "org.osgi.framework.system.packages",
+                    toString(accessRules, true));
         }
     }
 
@@ -837,7 +841,7 @@ private void configureJavaHome(CompilerConfiguration compilerConfiguration) thro
                     .orElseThrow(() -> new MojoExecutionException(
                             "useJDK = BREE configured, but no toolchain of type 'jdk' with id '" + toolchainId
                                     + "' found. See https://maven.apache.org/guides/mini/guide-using-toolchains.html"));
-            compilerConfiguration.addCompilerCustomArgument("use.java.home", osgiToolchain.getJavaHome());
+            addCompilerCustomArgument(compilerConfiguration, "use.java.home", osgiToolchain.getJavaHome());
             configureBootClassPath(compilerConfiguration, osgiToolchain);
         }
     }
@@ -851,14 +855,22 @@ private void configureBootClassPath(CompilerConfiguration compilerConfiguration,
                 if (includeParent != null) {
                     Xpp3Dom[] includes = includeParent.getChildren("include");
                     if (includes.length > 0) {
-                        compilerConfiguration.addCompilerCustomArgument("-bootclasspath", scanBootclasspath(
+                        addCompilerCustomArgument(compilerConfiguration, "-bootclasspath", scanBootclasspath(
                                 osgiToolchain.getJavaHome(), includes, bootClassPath.getChild("excludes")));
                     }
                 }
             }
         }
     }
 
+    protected boolean addCompilerCustomArgument(CompilerConfiguration compilerConfiguration, String key, String value) {
+        if (JDT_COMPILER_ID.equals(compilerId)) {
+            compilerConfiguration.addCompilerCustomArgument(key, value);
+            return true;
+        }
+        return false;
+    }
+
     private String scanBootclasspath(String javaHome, Xpp3Dom[] includes, Xpp3Dom excludeParent) {
         DirectoryScanner scanner = new DirectoryScanner();
         scanner.setBasedir(javaHome);

diff --git a/tycho-its/projects/tycho-compiler-plugin/javac/pom.xml b/tycho-its/projects/tycho-compiler-plugin/javac/pom.xml
@@ -0,0 +1,36 @@
+<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/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<groupId>org.eclipse.tycho.it</groupId>
+	<artifactId>javac.parent</artifactId>
+	<version>1.0.0-SNAPSHOT</version>
+	<packaging>pom</packaging>
+	<properties>
+		<tycho-version>5.0.0-SNAPSHOT</tycho-version>
+	</properties>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.eclipse.tycho</groupId>
+				<artifactId>tycho-maven-plugin</artifactId>
+				<version>${tycho-version}</version>
+				<extensions>true</extensions>
+			</plugin>
+			<plugin>
+				<groupId>org.eclipse.tycho</groupId>
+				<artifactId>tycho-compiler-plugin</artifactId>
+				<version>${tycho-version}</version>
+				<configuration>
+					<compilerId>javac</compilerId>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+	<modules>
+		<module>simple</module>
+	</modules>
+</project>
diff --git a/tycho-its/projects/tycho-compiler-plugin/javac/simple/META-INF/MANIFEST.MF b/tycho-its/projects/tycho-compiler-plugin/javac/simple/META-INF/MANIFEST.MF
@@ -0,0 +1,4 @@
+Manifest-Version: 1.0
+Bundle-ManifestVersion: 2
+Bundle-SymbolicName: simple
+Bundle-Version: 1.0.0.qualifier
diff --git a/tycho-its/projects/tycho-compiler-plugin/javac/simple/build.properties b/tycho-its/projects/tycho-compiler-plugin/javac/simple/build.properties
@@ -0,0 +1,4 @@
+source.. = src/
+output.. = bin/
+bin.includes = META-INF/,\
+               .
diff --git a/tycho-its/projects/tycho-compiler-plugin/javac/simple/pom.xml b/tycho-its/projects/tycho-compiler-plugin/javac/simple/pom.xml
@@ -0,0 +1,13 @@
+<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/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.eclipse.tycho.it</groupId>
+		<artifactId>javac.parent</artifactId>
+		<version>1.0.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>simple</artifactId>
+
+	<packaging>eclipse-plugin</packaging>
+
+</project>
diff --git a/tycho-its/projects/tycho-compiler-plugin/javac/simple/src/Test.java b/tycho-its/projects/tycho-compiler-plugin/javac/simple/src/Test.java
@@ -0,0 +1,19 @@
+/*******************************************************************************
+ * Copyright (c) 2012 SAP AG and others.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     SAP AG - initial API and implementation
+ *******************************************************************************/
+
+public class Test
+{
+    public static void main(String[] args) {
+        int a = 0;
+    }
+}
diff --git a/tycho-its/src/test/java/org/eclipse/tycho/test/CompilerPluginTest.java b/tycho-its/src/test/java/org/eclipse/tycho/test/CompilerPluginTest.java
@@ -0,0 +1,30 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Christoph Läubrich and others.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Christoph Läubrich - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.tycho.test;
+
+import org.apache.maven.it.Verifier;
+import org.junit.Test;
+
+/**
+ * Test for the tycho-compiler-plugin
+ */
+public class CompilerPluginTest extends AbstractTychoIntegrationTest {
+
+	@Test
+	public void testJavac() throws Exception {
+		Verifier verifier = getVerifier("tycho-compiler-plugin/javac", true, true);
+		verifier.executeGoal("compile");
+		verifier.verifyErrorFreeLog();
+	}
+
+}