Invoke javac using the API, instead of main()

This unifies the test and production javac invocations. Location arguments
(e.g. classpath, sources) are now set programatically from Paths, instead
of going through string args.

The classloader masking plugin is now just a custom filemanager, since javac
uses the same context for the entire compilation and we don't need a plugin
to carry it across annotation processing rounds.

--
PiperOrigin-RevId: 144110025
MOS_MIGRATED_REVID=144110025

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractJavaBuilder.java

@@ -17,6 +17,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
 import com.google.common.io.Files;
+import com.google.devtools.build.buildjar.javac.BlazeJavacArguments;
 import com.google.devtools.build.buildjar.javac.BlazeJavacMain;
 import com.google.devtools.build.buildjar.javac.JavacRunner;
 import com.google.devtools.build.buildjar.javac.plugins.BlazeJavaCompilerPlugin;
@@ -60,8 +61,10 @@ public Result compileJavaLibrary(final JavaLibraryBuildRequest build, final Prin
         new JavacRunner() {
           @Override
           public Result invokeJavac(
-              ImmutableList<BlazeJavaCompilerPlugin> plugins, String[] args, PrintWriter output) {
-            return new BlazeJavacMain(output, plugins).compile(args);
+              ImmutableList<BlazeJavaCompilerPlugin> plugins,
+              BlazeJavacArguments arguments,
+              PrintWriter output) {
+            return new BlazeJavacMain(output, plugins).compile(arguments);
           }
         };
     Result result = compileSources(build, javacRunner, err);

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/AbstractLibraryBuilder.java

@@ -34,7 +34,7 @@
  *
  * <p>Implements common functionality like source files preparation and output jar creation.
  */
-public abstract class AbstractLibraryBuilder extends CommonJavaLibraryProcessor {
+public abstract class AbstractLibraryBuilder {
 
   /**
    * Prepares a compilation run. This involves cleaning up temporary directories and writing the

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BUILD

@@ -37,6 +37,7 @@ java_library(
         ":invalid_command_line_exception",
         ":javac_options",
         "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/plugins",
+        "//third_party:auto_value",
         "//third_party:guava",
         "//third_party:jsr305",
         "//third_party/java/jdk/langtools:javac",
@@ -63,7 +64,6 @@ java_library(
         ":javac_options",
         "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/jarhelper",
         "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/plugins",
-        "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/plugins:classloader",
         "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/plugins:dependency",
         "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/plugins:errorprone",
         "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/javac/plugins:processing",

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/BazelJavaBuilder.java

@@ -19,7 +19,6 @@
 import com.google.devtools.build.buildjar.instrumentation.JacocoInstrumentationProcessor;
 import com.google.devtools.build.buildjar.javac.JavacOptions;
 import com.google.devtools.build.buildjar.javac.plugins.BlazeJavaCompilerPlugin;
-import com.google.devtools.build.buildjar.javac.plugins.classloader.ClassLoaderMaskingPlugin;
 import com.google.devtools.build.buildjar.javac.plugins.dependency.DependencyModule;
 import com.google.devtools.build.buildjar.javac.plugins.errorprone.ErrorPronePlugin;
 import com.google.devtools.build.lib.worker.WorkerProtocol.WorkRequest;
@@ -133,7 +132,6 @@ public static JavaLibraryBuildRequest parse(List<String> args)
       throws IOException, InvalidCommandLineException {
     OptionsParser optionsParser = new OptionsParser(args);
     ImmutableList.Builder<BlazeJavaCompilerPlugin> plugins = ImmutableList.builder();
-    plugins.add(new ClassLoaderMaskingPlugin());
 
     // Support for -extra_checks:off was removed from ErrorPronePlugin, but Bazel still needs it,
     // so we'll emulate support for this here by handling the flag ourselves and not loading the

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/JavaLibraryBuildRequest.java

@@ -14,11 +14,20 @@
 
 package com.google.devtools.build.buildjar;
 
+import com.google.common.base.Joiner;
+import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterables;
+import com.google.devtools.build.buildjar.javac.BlazeJavacArguments;
 import com.google.devtools.build.buildjar.javac.plugins.BlazeJavaCompilerPlugin;
 import com.google.devtools.build.buildjar.javac.plugins.dependency.DependencyModule;
 import com.google.devtools.build.buildjar.javac.plugins.processing.AnnotationProcessingModule;
+import java.io.File;
+import java.io.IOError;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.List;
 import java.util.Map.Entry;
@@ -45,7 +54,7 @@ public final class JavaLibraryBuildRequest {
   private final ImmutableList<String> rootResourceFiles;
 
   private final String classPath;
-
+  private final String bootClassPath;
   private final String extdir;
 
   private final String processorPath;
@@ -142,6 +151,7 @@ public JavaLibraryBuildRequest(
     this.resourceJars = ImmutableList.copyOf(optionsParser.getResourceJars());
     this.rootResourceFiles = ImmutableList.copyOf(optionsParser.getRootResourceFiles());
     this.classPath = optionsParser.getClassPath();
+    this.bootClassPath = optionsParser.getBootClassPath();
     this.extdir = optionsParser.getExtdir();
     this.processorPath = optionsParser.getProcessorPath();
     this.processorNames = optionsParser.getProcessorNames();
@@ -218,6 +228,10 @@ public String getClassPath() {
     return classPath;
   }
 
+  public String getBootClassPath() {
+    return bootClassPath;
+  }
+
   public String getExtdir() {
     return extdir;
   }
@@ -263,4 +277,95 @@ public AnnotationProcessingModule getProcessingModule() {
   public ImmutableList<BlazeJavaCompilerPlugin> getPlugins() {
     return plugins;
   }
+
+  public BlazeJavacArguments toBlazeJavacArguments(final String classPath) {
+    return BlazeJavacArguments.builder()
+        .classPath(toPaths(classPath))
+        .classOutput(Paths.get(getClassDir()))
+        .bootClassPath(
+            ImmutableList.copyOf(Iterables.concat(toPaths(getBootClassPath()), getExtJars())))
+        .javacOptions(makeJavacArguments())
+        .sourceFiles(toPaths(getSourceFiles()))
+        .processors(null)
+        .sourceOutput(getSourceGenDir() != null ? Paths.get(getSourceGenDir()) : null)
+        .processorPath(toPaths(getProcessorPath()))
+        .build();
+  }
+
+  // TODO(cushon): make Bazel pass the individual files instead of inferring a directory and
+  // listing it here
+  List<Path> getExtJars() {
+    if (getExtdir() == null) {
+      return ImmutableList.of();
+    }
+    ImmutableList.Builder<Path> jars = ImmutableList.builder();
+    for (String file : Splitter.on(File.pathSeparatorChar).split(getExtdir())) {
+      try {
+        Path path = Paths.get(file);
+        if (Files.isDirectory(path)) {
+          Files.list(path).forEach(jars::add);
+        } else {
+          jars.add(path);
+        }
+      } catch (IOException e) {
+        throw new IOError(e);
+      }
+    }
+    return jars.build();
+  }
+
+  static ImmutableList<Path> toPaths(List<String> files) {
+    if (files == null) {
+      return ImmutableList.of();
+    }
+    ImmutableList.Builder<Path> result = ImmutableList.builder();
+    for (String e : files) {
+      result.add(Paths.get(e));
+    }
+    return result.build();
+  }
+
+  static ImmutableList<Path> toPaths(String classPath) {
+    if (classPath == null) {
+      return ImmutableList.of();
+    }
+    ImmutableList.Builder<Path> result = ImmutableList.builder();
+    for (String e : Splitter.on(File.pathSeparatorChar).split(classPath)) {
+      result.add(Paths.get(e));
+    }
+    return result.build();
+  }
+
+  /** Constructs a command line that can be used for a javac invocation. */
+  ImmutableList<String> makeJavacArguments() {
+    ImmutableList.Builder<String> javacArguments = ImmutableList.builder();
+    javacArguments.addAll(getJavacOpts());
+
+    if (!getProcessors().isEmpty() && !getSourceFiles().isEmpty()) {
+      // ImmutableSet.copyOf maintains order
+      ImmutableSet<String> deduplicatedProcessorNames = ImmutableSet.copyOf(getProcessors());
+      javacArguments.add("-processor");
+      javacArguments.add(Joiner.on(',').join(deduplicatedProcessorNames));
+    } else {
+      // This is necessary because some jars contain discoverable annotation processors that
+      // previously didn't run, and they break builds if the "-proc:none" option is not passed to
+      // javac.
+      javacArguments.add("-proc:none");
+    }
+
+    for (String option : getJavacOpts()) {
+      if (option.startsWith("-J")) { // ignore the VM options.
+        continue;
+      }
+      if (option.equals("-processor") || option.equals("-processorpath")) {
+        throw new IllegalStateException(
+            "Using "
+                + option
+                + " in javacopts is no longer supported."
+                + " Use a java_plugin() rule instead.");
+      }
+    }
+
+    return javacArguments.build();
+  }
 }

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/OptionsParser.java

@@ -27,6 +27,7 @@
 import java.util.Deque;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -64,7 +65,7 @@ public final class OptionsParser {
   private final List<String> rootResourceFiles = new ArrayList<>();
 
   private String classPath = "";
-
+  private String bootClassPath;
   private String extdir;
 
   private String processorPath = "";
@@ -107,6 +108,7 @@ private void processCommandlineArgs(Deque<String> argQueue) throws InvalidComman
           // otherwise we have to do something like adding a "--"
           // terminator to the passed arguments.
           collectFlagArguments(javacOpts, argQueue, "--");
+          bootClassPathFromJavacOpts();
           break;
         case "--direct_dependency":
           {
@@ -167,6 +169,9 @@ private void processCommandlineArgs(Deque<String> argQueue) throws InvalidComman
         case "--classpath":
           classPath = getArgument(argQueue, arg);
           break;
+        case "--bootclasspath":
+          bootClassPath = getArgument(argQueue, arg);
+          break;
         case "--processorpath":
           processorPath = getArgument(argQueue, arg);
           break;
@@ -314,6 +319,19 @@ private void addExternalPostProcessor(Deque<String> args, String arg)
     postProcessors.put(processorName, arguments);
   }
 
+  // TODO(cushon): update Blaze to set --bootclasspath directly
+  private void bootClassPathFromJavacOpts() {
+    Iterator<String> it = javacOpts.iterator();
+    while (it.hasNext()) {
+      String curr = it.next();
+      if (curr.equals("-bootclasspath") && it.hasNext()) {
+        it.remove();
+        bootClassPath = it.next();
+        it.remove();
+      }
+    }
+  }
+
   public List<String> getJavacOpts() {
     return javacOpts;
   }
@@ -386,6 +404,10 @@ public String getClassPath() {
     return classPath;
   }
 
+  public String getBootClassPath() {
+    return bootClassPath;
+  }
+
   public String getExtdir() {
     return extdir;
   }

src/java_tools/buildjar/java/com/google/devtools/build/buildjar/ReducedClasspathJavaLibraryBuilder.java

@@ -56,12 +56,15 @@ Result compileSources(JavaLibraryBuildRequest build, JavacRunner javacRunner, Pr
       // class output directory to prevent that from happening.
       compressedClasspath = build.getClassDir();
     }
-    String[] javacArguments = makeJavacArguments(build, compressedClasspath);
 
     // Compile!
     StringWriter javacOutput = new StringWriter();
     PrintWriter javacOutputWriter = new PrintWriter(javacOutput);
-    Result result = javacRunner.invokeJavac(build.getPlugins(), javacArguments, javacOutputWriter);
+    Result result =
+        javacRunner.invokeJavac(
+            build.getPlugins(),
+            build.toBlazeJavacArguments(compressedClasspath),
+            javacOutputWriter);
     javacOutputWriter.close();
 
     // If javac errored out because of missing entries on the classpath, give it another try.
@@ -75,8 +78,9 @@ Result compileSources(JavaLibraryBuildRequest build, JavacRunner javacRunner, Pr
       prepareSourceCompilation(build);
 
       // Fall back to the regular compile, but add extra checks to catch transitive uses
-      javacArguments = makeJavacArguments(build);
-      result = javacRunner.invokeJavac(build.getPlugins(), javacArguments, err);
+      result =
+          javacRunner.invokeJavac(
+              build.getPlugins(), build.toBlazeJavacArguments(build.getClassPath()), err);
     } else {
       err.print(javacOutput.getBuffer());
     }