Use a diagnostic listener, and match diagnostic codes for the reduced classpath heuristic

PiperOrigin-RevId: 185746460

3 files changed, 54 insertions, 19 deletions

diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java
index 99c195d55b..242bee83e5 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbine.java
@@ -47,12 +47,14 @@ import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 import java.util.jar.Attributes;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
-import java.util.regex.Pattern;
 import java.util.zip.ZipOutputStream;
+import javax.tools.Diagnostic;
+import javax.tools.JavaFileObject;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
@@ -233,8 +235,7 @@ public class JavacTurbine implements AutoCloseable {
       }
     }
 
-    if (compileResult == null
-        || (!compileResult.success() && hasRecognizedError(compileResult.output()))) {
+    if (compileResult == null || shouldFallBack(compileResult)) {
       // fall back to transitive classpath
       actualClasspath = originalClasspath;
       requestBuilder.setClassPath(actualClasspath);
@@ -250,6 +251,9 @@ public class JavacTurbine implements AutoCloseable {
           turbineOptions, compileResult.files(), transitive.collectTransitiveDependencies());
       dependencyModule.emitDependencyInformation(actualClasspath, compileResult.success());
     } else {
+      for (Diagnostic<? extends JavaFileObject> diagnostic : compileResult.diagnostics()) {
+        out.println(diagnostic.getMessage(Locale.getDefault()));
+      }
       out.print(compileResult.output());
     }
     return result;
@@ -450,21 +454,33 @@ public class JavacTurbine implements AutoCloseable {
     return fs;
   }
 
-  private static final Pattern MISSING_PACKAGE =
-      Pattern.compile("error: package ([\\p{javaJavaIdentifierPart}\\.]+) does not exist");
-
   /**
    * The compilation failed with an error that may indicate that the reduced class path was too
    * aggressive.
    *
    * <p>WARNING: keep in sync with ReducedClasspathJavaLibraryBuilder.
    */
-  // TODO(cushon): use a diagnostic listener and match known codes instead
-  private static boolean hasRecognizedError(String javacOutput) {
-    return javacOutput.contains("error: cannot access")
-        || javacOutput.contains("error: cannot find symbol")
-        || javacOutput.contains("com.sun.tools.javac.code.Symbol$CompletionFailure")
-        || MISSING_PACKAGE.matcher(javacOutput).find();
+  private static boolean shouldFallBack(JavacTurbineCompileResult result) {
+    if (result.success()) {
+      return false;
+    }
+    for (Diagnostic<? extends JavaFileObject> diagnostic : result.diagnostics()) {
+      String code = diagnostic.getCode();
+      if (code.contains("doesnt.exist")
+          || code.contains("cant.resolve")
+          || code.contains("cant.access")) {
+        return true;
+      }
+      // handle -Xdoclint:reference errors, which don't have a diagnostic code
+      // TODO(cushon): this is locale-dependent
+      if (diagnostic.getMessage(Locale.getDefault()).contains("error: reference not found")) {
+        return true;
+      }
+    }
+    if (result.output().contains("com.sun.tools.javac.code.Symbol$CompletionFailure")) {
+      return true;
+    }
+    return false;
   }
 
   @Override
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompileResult.java b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompileResult.java
index 23cade9224..b066537b9e 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompileResult.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompileResult.java
@@ -15,27 +15,36 @@
 package com.google.devtools.build.java.turbine.javac;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.sun.tools.javac.util.Context;
-import java.io.StringWriter;
+import javax.tools.Diagnostic;
+import javax.tools.JavaFileObject;
 
 /** The output from a {@link JavacTurbineCompiler} compilation. */
 class JavacTurbineCompileResult {
 
+
   enum Status {
     OK, ERROR
   }
 
   private final ImmutableMap<String, byte[]> files;
   private final Status status;
-  private final StringWriter sb;
+  private final String output;
+  private final ImmutableList<Diagnostic<? extends JavaFileObject>> diagnostics;
   private final Context context;
 
   JavacTurbineCompileResult(
-      ImmutableMap<String, byte[]> files, Status status, StringWriter sb, Context context) {
+      ImmutableMap<String, byte[]> files,
+      Status status,
+      String output,
+      ImmutableList<Diagnostic<? extends JavaFileObject>> diagnostics,
+      Context context) {
     this.files = files;
     this.status = status;
-    this.sb = sb;
+    this.output = output;
+    this.diagnostics = diagnostics;
     this.context = context;
   }
 
@@ -46,7 +55,12 @@ class JavacTurbineCompileResult {
 
   /** The stderr from the compilation. */
   String output() {
-    return sb.toString();
+    return output;
+  }
+
+  /** The diagnostics from the compilation. */
+  ImmutableList<Diagnostic<? extends JavaFileObject>> diagnostics() {
+    return diagnostics;
   }
 
   /** The files produced by the compilation. */
diff --git a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompiler.java b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompiler.java
index 6db9b88426..58417f1fbf 100644
--- a/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompiler.java
+++ b/src/java_tools/buildjar/java/com/google/devtools/build/java/turbine/javac/JavacTurbineCompiler.java
@@ -45,6 +45,8 @@ import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Objects;
 import javax.annotation.Nullable;
+import javax.tools.Diagnostic;
+import javax.tools.JavaFileObject;
 import javax.tools.StandardLocation;
 
 /** Performs a javac-based turbine compilation given a {@link JavacTurbineCompileRequest}. */
@@ -55,6 +57,8 @@ public class JavacTurbineCompiler {
     Map<String, byte[]> files = new LinkedHashMap<>();
     Status status;
     StringWriter sw = new StringWriter();
+    ImmutableList.Builder<Diagnostic<? extends JavaFileObject>> diagnostics =
+        ImmutableList.builder();
     Context context = new Context();
 
     try (PrintWriter pw = new PrintWriter(sw)) {
@@ -67,7 +71,7 @@ public class JavacTurbineCompiler {
                 .getTask(
                     pw,
                     fm,
-                    null /*diagnostics*/,
+                    diagnostics::add,
                     request.javacOptions(),
                     ImmutableList.of() /*classes*/,
                     fm.getJavaFileObjectsFromPaths(request.sources()),
@@ -107,7 +111,8 @@ public class JavacTurbineCompiler {
       }
     }
 
-    return new JavacTurbineCompileResult(ImmutableMap.copyOf(files), status, sw, context);
+    return new JavacTurbineCompileResult(
+        ImmutableMap.copyOf(files), status, sw.toString(), diagnostics.build(), context);
   }
 
   /** Mask the annotation processor classpath to avoid version skew. */