Completing the Java sandwich and testing it.

* Unwrapping JavaCompilationArgsProvider from JavaProvider when collecting compile time dependencies artifacts (in addition to JavaCompilationArgsProvider), so that java_library could depend on Skylark rules that return java_common.provider. (this makes java sandwich complete \o/)

* Added a new param (source_files) to java_common.compile to allow compilation of source files in addition to source jars.

* Added a new sourceFiles field to JavaLibraryHelper in order to pass them to JavaCompilationHelper.

* Added a new method (java_common.default_javac_opts) for default Java compilation.

* Added a test for a basic java sandwich.

--
PiperOrigin-RevId: 145064700
MOS_MIGRATED_REVID=145064700

src/main/java/com/google/devtools/build/lib/BUILD

@@ -845,6 +845,7 @@ java_library(
         "rules/java/JavaNeverlinkInfoProvider.java",
         "rules/java/JavaOptions.java",
         "rules/java/JavaPluginInfoProvider.java",
+        "rules/java/JavaProvider.java",
         "rules/java/JavaRuleOutputJarsProvider.java",
         "rules/java/JavaRunfilesProvider.java",
         "rules/java/JavaRuntimeProvider.java",

src/main/java/com/google/devtools/build/lib/rules/java/JavaCommon.java

@@ -29,6 +29,7 @@
 import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.Runfiles;
 import com.google.devtools.build.lib.analysis.RunfilesProvider;
+import com.google.devtools.build.lib.analysis.SkylarkProviders;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
 import com.google.devtools.build.lib.analysis.Util;
@@ -286,14 +287,33 @@ public JavaCompilationArgs collectJavaCompilationArgs(boolean recursive, boolean
    */
   public NestedSet<Artifact> collectCompileTimeDependencyArtifacts(@Nullable Artifact outDeps) {
     NestedSetBuilder<Artifact> builder = NestedSetBuilder.stableOrder();
+    Set<JavaCompilationArgsProvider> addedProviders = new LinkedHashSet<>();
     if (outDeps != null) {
       builder.add(outDeps);
     }
 
     for (JavaCompilationArgsProvider provider : AnalysisUtils.getProviders(
         getExports(ruleContext), JavaCompilationArgsProvider.class)) {
       builder.addTransitive(provider.getCompileTimeJavaDependencyArtifacts());
+      addedProviders.add(provider);
+    }
+
+    // We also check for artifacts in the JavaProvider of the dependencies (might exist when
+    // information is passed from a custom Skylark Java rule).
+    for (SkylarkProviders skylarkProviders : AnalysisUtils.getProviders(
+        getExports(ruleContext), SkylarkProviders.class)) {
+      JavaProvider javaProvider =
+          (JavaProvider) skylarkProviders.getDeclaredProvider(JavaProvider.JAVA_PROVIDER.getKey());
+      if (javaProvider != null) {
+        JavaCompilationArgsProvider compilationArgsProvider =
+            javaProvider.getJavaCompilationArgsProvider();
+        if (!addedProviders.contains(compilationArgsProvider)) {
+          builder.addTransitive(javaProvider
+              .getJavaCompilationArgsProvider().getCompileTimeJavaDependencyArtifacts());
+        }
+      }
     }
+
     return builder.build();
   }
 

src/main/java/com/google/devtools/build/lib/rules/java/JavaCompilationArgs.java

@@ -17,6 +17,7 @@
 import com.google.auto.value.AutoValue;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.analysis.FileProvider;
+import com.google.devtools.build.lib.analysis.SkylarkProviders;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
@@ -152,6 +153,19 @@ public Builder addTransitiveCompilationArgs(
     public Builder addTransitiveTarget(TransitiveInfoCollection dep, boolean recursive,
         ClasspathType type) {
       JavaCompilationArgsProvider provider = dep.getProvider(JavaCompilationArgsProvider.class);
+      if (provider == null) {
+        // Only look for the JavaProvider when there is no JavaCompilationArgsProvider, else
+        // it would encapsulate the same information.
+        SkylarkProviders skylarkProviders = dep.getProvider(SkylarkProviders.class);
+        if (skylarkProviders != null) {
+          JavaProvider javaProvider =
+              (JavaProvider) skylarkProviders.getDeclaredProvider(
+                  JavaProvider.JAVA_PROVIDER.getKey());
+          if (javaProvider != null) {
+            provider = javaProvider.getJavaCompilationArgsProvider();
+          }
+        }
+      }
       if (provider != null) {
         addTransitiveCompilationArgs(provider, recursive, type);
         return this;

src/main/java/com/google/devtools/build/lib/rules/java/JavaCompilationHelper.java

@@ -23,11 +23,11 @@
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.actions.ParameterFile.ParameterFileType;
 import com.google.devtools.build.lib.analysis.AnalysisEnvironment;
-import com.google.devtools.build.lib.analysis.AnalysisUtils;
 import com.google.devtools.build.lib.analysis.FileProvider;
 import com.google.devtools.build.lib.analysis.FilesToRunProvider;
 import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
 import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.analysis.SkylarkProviders;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.analysis.actions.CustomCommandLine;
 import com.google.devtools.build.lib.analysis.actions.SpawnAction;
@@ -44,6 +44,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.LinkedHashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import javax.annotation.Nullable;
@@ -661,9 +662,41 @@ public void addLibrariesToAttributes(Iterable<? extends TransitiveInfoCollection
 
     JavaClasspathMode classpathMode = getJavaConfiguration().getReduceJavaClasspath();
     if (isStrict() && classpathMode != JavaClasspathMode.OFF) {
-      addDependencyArtifactsToAttributes(
-          attributes, AnalysisUtils.getProviders(deps, JavaCompilationArgsProvider.class));
+      List<JavaCompilationArgsProvider> compilationArgsProviders = new LinkedList<>();
+      for (TransitiveInfoCollection dep : deps) {
+        // First check if there is a JavaCompilationArgsProvider.
+        JavaCompilationArgsProvider provider = dep.getProvider(JavaCompilationArgsProvider.class);
+
+        if (provider == null) {
+          // A target can either have both JavaCompilationArgsProvider and JavaProvider that
+          // encapsulates the same information, or just one of them.
+          provider = getJavaCompilationArgsProviderFromDep(dep);
+        }
+        if (provider != null) {
+          compilationArgsProviders.add(provider);
+        }
+      }
+      addDependencyArtifactsToAttributes(attributes, compilationArgsProviders);
+    }
+  }
+
+  /**
+   * Returns a JavaCompilationArgsProvider fetched from the JavaProvider of the given target.
+   * JavaProvider can be found as a declared provider in SkylarkProviders.
+   */
+  @Nullable
+  private static JavaCompilationArgsProvider getJavaCompilationArgsProviderFromDep(
+      TransitiveInfoCollection target) {
+    SkylarkProviders skylarkProviders = target.getProvider(SkylarkProviders.class);
+    if (skylarkProviders == null) {
+      return null;
+    }
+    JavaProvider javaProvider =
+        (JavaProvider) skylarkProviders.getDeclaredProvider(JavaProvider.JAVA_PROVIDER.getKey());
+    if (javaProvider == null) {
+      return null;
     }
+    return javaProvider.getJavaCompilationArgsProvider();
   }
 
   /**

src/main/java/com/google/devtools/build/lib/rules/java/JavaLibraryHelper.java

@@ -43,6 +43,7 @@ public final class JavaLibraryHelper {
 
   private Artifact output;
   private final List<Artifact> sourceJars = new ArrayList<>();
+  private final List<Artifact> sourceFiles = new ArrayList<>();
 
   /**
    * Contains all the dependencies; these are treated as both compile-time and runtime dependencies.
@@ -90,6 +91,14 @@ public JavaLibraryHelper addDep(JavaCompilationArgsProvider provider) {
     return this;
   }
 
+  /**
+   * Adds the given source files to be compiled.
+   */
+  public JavaLibraryHelper addSourceFiles(Iterable<Artifact> sourceFiles) {
+    Iterables.addAll(this.sourceFiles, sourceFiles);
+    return this;
+  }
+
   public JavaLibraryHelper addAllDeps(
       Iterable<JavaCompilationArgsProvider> providers) {
     Iterables.addAll(deps, providers);
@@ -131,6 +140,7 @@ public JavaCompilationArgs build(
     Preconditions.checkState(output != null, "must have an output file; use setOutput()");
     JavaTargetAttributes.Builder attributes = new JavaTargetAttributes.Builder(semantics);
     attributes.addSourceJars(sourceJars);
+    attributes.addSourceFiles(sourceFiles);
     addDepsToAttributes(attributes);
     attributes.setStrictJavaDeps(strictDepsMode);
     attributes.setRuleKind(ruleContext.getRule().getRuleClass());

src/main/java/com/google/devtools/build/lib/rules/java/JavaSkylarkCommon.java

@@ -16,9 +16,11 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.analysis.ConfiguredTarget;
 import com.google.devtools.build.lib.analysis.MiddlemanProvider;
+import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration.StrictDepsMode;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
@@ -56,11 +58,20 @@ public SkylarkClassObjectConstructor getJavaProvider() {
     mandatoryPositionals = 1,
     parameters = {
       @Param(
-        name = "source_jars",
+          name = "source_jars",
+          positional = false,
+          named = true,
+          type = SkylarkList.class,
+          generic1 = Artifact.class,
+          defaultValue = "[]"
+      ),
+      @Param(
+        name = "source_files",
         positional = false,
         named = true,
         type = SkylarkList.class,
-        generic1 = Artifact.class
+        generic1 = Artifact.class,
+        defaultValue = "[]"
       ),
       @Param(name = "output", positional = false, named = true, type = Artifact.class),
       @Param(
@@ -101,6 +112,7 @@ public SkylarkClassObjectConstructor getJavaProvider() {
   public JavaProvider createJavaCompileAction(
       SkylarkRuleContext skylarkRuleContext,
       SkylarkList<Artifact> sourceJars,
+      SkylarkList<Artifact> sourceFiles,
       Artifact outputJar,
       SkylarkList<String> javacOpts,
       SkylarkList<JavaProvider> deps,
@@ -111,7 +123,9 @@ public JavaProvider createJavaCompileAction(
         new JavaLibraryHelper(skylarkRuleContext.getRuleContext())
             .setOutput(outputJar)
             .addSourceJars(sourceJars)
+            .addSourceFiles(sourceFiles)
             .setJavacOpts(javacOpts);
+
     helper.addAllDeps(getJavaCompilationArgsProviders(deps));
     helper.setCompilationStrictDepsMode(getStrictDepsMode(strictDepsMode));
     MiddlemanProvider hostJavabaseProvider = hostJavabase.getProvider(MiddlemanProvider.class);
@@ -131,6 +145,27 @@ public JavaProvider createJavaCompileAction(
     return new JavaProvider(helper.buildCompilationArgsProvider(artifacts, true));
   }
 
+  @SkylarkCallable(
+      name = "default_javac_opts",
+      // This function is experimental for now.
+      documented = false,
+      // There's only one mandatory positional,the Skylark context
+      mandatoryPositionals = 1,
+      parameters = {
+        @Param(name = "java_toolchain_attr", positional = false, named = true, type = String.class)
+      }
+  )
+  public static List<String> getDefaultJavacOpts(
+      SkylarkRuleContext skylarkRuleContext, String javaToolchainAttr) {
+    RuleContext ruleContext = skylarkRuleContext.getRuleContext();
+    ConfiguredTarget javaToolchainConfigTarget =
+        (ConfiguredTarget) checkNotNull(skylarkRuleContext.getAttr().getValue(javaToolchainAttr));
+    JavaToolchainProvider toolchain =
+        checkNotNull(javaToolchainConfigTarget.getProvider(JavaToolchainProvider.class));
+    return ImmutableList.copyOf(Iterables.concat(
+        toolchain.getJavacOptions(), ruleContext.getTokenizedStringListAttr("javacopts")));
+  }
+
   @SkylarkCallable(
     name = "merge",
     // We have one positional argument: the list of providers to merge.

src/test/shell/bazel/bazel_java_test.sh

@@ -158,5 +158,121 @@ EOF
   expect_log "testTest was run"
 }
 
+function test_basic_java_sandwich() {
+  mkdir -p java/com/google/sandwich
+  cd java/com/google/sandwich
+
+  touch BUILD A.java B.java C.java Main.java java_custom_library.bzl
+
+  cat > BUILD << EOF
+load(':java_custom_library.bzl', 'java_custom_library')
+
+java_binary(
+  name = "Main",
+  srcs = ["Main.java"],
+  deps = [":top"]
+)
+
+java_library(
+  name = "top",
+  srcs = ["A.java"],
+  deps = [":middle"]
+)
+
+java_custom_library(
+  name = "middle",
+  srcs = ["B.java"],
+  deps = [":bottom"]
+)
+
+java_library(
+  name = "bottom",
+  srcs = ["C.java"]
+)
+EOF
+
+  cat > C.java << EOF
+package com.google.sandwich;
+class C {
+  public void printC() {
+    System.out.println("Message from C");
+  }
+}
+EOF
+
+  cat > B.java << EOF
+package com.google.sandwich;
+class B {
+  C myObject;
+  public void printB() {
+    System.out.println("Message from B");
+    myObject = new C();
+    myObject.printC();
+  }
+}
+EOF
+
+  cat > A.java << EOF
+package com.google.sandwich;
+class A {
+  B myObject;
+  public void printA() {
+    System.out.println("Message from A");
+    myObject = new B();
+    myObject.printB();
+  }
+}
+EOF
+
+  cat > Main.java << EOF
+package com.google.sandwich;
+class Main {
+  public static void main(String[] args) {
+    A myObject = new A();
+    myObject.printA();
+  }
+}
+EOF
+
+  cat > java_custom_library.bzl << EOF
+def _impl(ctx):
+  deps = [dep[java_common.provider] for dep in ctx.attr.deps]
+  deps_provider = java_common.merge(deps)
+
+  output_jar = ctx.new_file("lib" + ctx.label.name + ".jar")
+
+  compilation_provider = java_common.compile(
+    ctx,
+    source_files = ctx.files.srcs,
+    output = output_jar,
+    javac_opts = java_common.default_javac_opts(ctx, java_toolchain_attr = "_java_toolchain"),
+    deps = deps,
+    strict_deps = "ERROR",
+    java_toolchain = ctx.attr._java_toolchain,
+    host_javabase = ctx.attr._host_javabase
+  )
+  result = java_common.merge([deps_provider, compilation_provider])
+  return struct(
+    files = set([output_jar]),
+    providers = [result]
+  )
+
+java_custom_library = rule(
+  implementation = _impl,
+  attrs = {
+    "srcs": attr.label_list(allow_files=True),
+    "deps": attr.label_list(),
+    "_java_toolchain": attr.label(default = Label("@bazel_tools//tools/jdk:toolchain")),
+    "_host_javabase": attr.label(default = Label("//tools/defaults:jdk"))
+  },
+  fragments = ["java"]
+)
+EOF
+
+  $PRODUCT_NAME run :Main > $TEST_log || fail "Java sandwich build failed"
+  expect_log "Message from A"
+  expect_log "Message from B"
+  expect_log "Message from C"
+}
 
 run_suite "Java integration tests"