[java_common.compile] Always generate a source jar.

[Rolling forward https://github.com/bazelbuild/bazel/commit/c4e128e2c6d8cacaeba034d6a3195796d50f1745]

java_common.compile doesn't generate the output source jar when a source jar is
the only input for the compilation. This is wrong because the source jar can
include APT generated sources. It is also inconsistent with java_library and
leads to inconsistent Skylark rules where a declared output will not always have a
generating action.

This new behavior is guarded by a new flag --incompatible_generate_javacommon_source_jar.

RELNOTES: None.
PiperOrigin-RevId: 202648346

2 files changed, 57 insertions, 0 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
index fc30103bb6..4a8e303a50 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/SkylarkSemanticsConsistencyTest.java
@@ -130,6 +130,7 @@ public class SkylarkSemanticsConsistencyTest {
         "--incompatible_disallow_legacy_javainfo=" + rand.nextBoolean(),
         "--incompatible_disallow_old_style_args_add=" + rand.nextBoolean(),
         "--incompatible_disallow_slash_operator=" + rand.nextBoolean(),
+        "--incompatible_generate_javacommon_source_jar=" + rand.nextBoolean(),
         "--incompatible_new_actions_api=" + rand.nextBoolean(),
         "--incompatible_no_support_tools_in_action_inputs=" + rand.nextBoolean(),
         "--incompatible_package_name_is_a_function=" + rand.nextBoolean(),
@@ -157,6 +158,7 @@ public class SkylarkSemanticsConsistencyTest {
         .incompatibleDisallowLegacyJavaInfo(rand.nextBoolean())
         .incompatibleDisallowOldStyleArgsAdd(rand.nextBoolean())
         .incompatibleDisallowSlashOperator(rand.nextBoolean())
+        .incompatibleGenerateJavaCommonSourceJar(rand.nextBoolean())
         .incompatibleNewActionsApi(rand.nextBoolean())
         .incompatibleNoSupportToolsInActionInputs(rand.nextBoolean())
         .incompatiblePackageNameIsAFunction(rand.nextBoolean())
diff --git a/src/test/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiTest.java b/src/test/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiTest.java
index c5956c0021..cd5eaf171c 100644
--- a/src/test/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiTest.java
+++ b/src/test/java/com/google/devtools/build/lib/rules/java/JavaSkylarkApiTest.java
@@ -605,6 +605,61 @@ public class JavaSkylarkApiTest extends BuildViewTestCase {
   }
 
   @Test
+  public void testJavaCommonCompileWithOnlyOneSourceJarWithIncompatibleFlag() throws Exception {
+    writeBuildFileForJavaToolchain();
+    setSkylarkSemanticsOptions("--incompatible_generate_javacommon_source_jar=true");
+    scratch.file(
+        "java/test/BUILD",
+        "load(':custom_rule.bzl', 'java_custom_library')",
+        "java_custom_library(",
+        "  name = 'custom',",
+        "  srcs = ['myjar-src.jar'],",
+        ")");
+    scratch.file(
+        "java/test/custom_rule.bzl",
+        "def _impl(ctx):",
+        "  output_jar = ctx.actions.declare_file('lib' + ctx.label.name + '.jar')",
+        "  compilation_provider = java_common.compile(",
+        "    ctx,",
+        "    source_jars = ctx.files.srcs,",
+        "    output = output_jar,",
+        "    javac_opts = java_common.default_javac_opts(",
+        "        ctx, java_toolchain_attr = '_java_toolchain'),",
+        "    java_toolchain = ctx.attr._java_toolchain,",
+        "    host_javabase = ctx.attr._host_javabase",
+        "  )",
+        "  return struct(",
+        "    files = depset([output_jar]),",
+        "    providers = [compilation_provider]",
+        "  )",
+        "java_custom_library = rule(",
+        "  implementation = _impl,",
+        "  outputs = {",
+        "    'my_output': 'lib%{name}.jar'",
+        "  },",
+        "  attrs = {",
+        "    'srcs': attr.label_list(allow_files=['.jar']),",
+        "    '_java_toolchain': attr.label(default = Label('//java/com/google/test:toolchain')),",
+        "    '_host_javabase': attr.label(",
+        "        default = Label('" + HOST_JAVA_RUNTIME_LABEL + "'))",
+        "  },",
+        "  fragments = ['java']",
+        ")");
+
+    ConfiguredTarget configuredTarget = getConfiguredTarget("//java/test:custom");
+    JavaInfo info = configuredTarget.get(JavaInfo.PROVIDER);
+    SkylarkList<Artifact> sourceJars = info.getSourceJars();
+    assertThat(artifactFilesNames(sourceJars)).containsExactly("libcustom-src.jar");
+    JavaRuleOutputJarsProvider outputJars = info.getOutputJars();
+    assertThat(outputJars.getOutputJars()).hasSize(1);
+    OutputJar outputJar = outputJars.getOutputJars().get(0);
+    assertThat(outputJar.getClassJar().getFilename()).isEqualTo("libcustom.jar");
+    assertThat(outputJar.getSrcJar().getFilename()).isEqualTo("libcustom-src.jar");
+    assertThat(outputJar.getIJar().getFilename()).isEqualTo("libcustom-hjar.jar");
+    assertThat(outputJars.getJdeps().getFilename()).isEqualTo("libcustom.jdeps");
+  }
+
+  @Test
   public void testJavaCommonCompileWithNoSources() throws Exception {
     writeBuildFileForJavaToolchain();
     scratch.file(