Create experimental flag to include source info in proto descriptors

src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCompileActionBuilder.java

@@ -14,12 +14,12 @@
 
 package com.google.devtools.build.lib.rules.proto;
 
-import static com.google.common.base.Preconditions.checkState;
 import static com.google.common.collect.Iterables.isEmpty;
 import static com.google.devtools.build.lib.collect.nestedset.Order.STABLE_ORDER;
 import static com.google.devtools.build.lib.rules.proto.ProtoCommon.areDepsStrict;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
 import com.google.common.base.Supplier;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -337,7 +337,10 @@ public static void writeDescriptorSet(
     SpawnAction.Builder actions =
         createActions(
             ruleContext,
-            ImmutableList.of(createDescriptorSetToolchain(output.getExecPathString())),
+            ImmutableList.of(
+                createDescriptorSetToolchain(
+                    ruleContext.getFragment(ProtoConfiguration.class),
+                    output.getExecPathString())),
             protoInfo,
             ruleContext.getLabel(),
             ImmutableList.of(output),
@@ -353,7 +356,13 @@ public static void writeDescriptorSet(
     ruleContext.registerAction(actions.build(ruleContext));
   }
 
-  private static ToolchainInvocation createDescriptorSetToolchain(CharSequence outReplacement) {
+  private static ToolchainInvocation createDescriptorSetToolchain(
+      ProtoConfiguration configuration, CharSequence outReplacement) {
+    ImmutableList.Builder<String> protocOpts = ImmutableList.builder();
+    if (configuration.experimentalProtoDescriptorSetsIncludeSourceInfo()) {
+      protocOpts.add("--include_source_info");
+    }
+
     return new ToolchainInvocation(
         "dontcare",
         ProtoLangToolchainProvider.create(
@@ -365,7 +374,8 @@ private static ToolchainInvocation createDescriptorSetToolchain(CharSequence out
             /* pluginExecutable= */ null,
             /* runtime= */ null,
             /* blacklistedProtos= */ NestedSetBuilder.<Artifact>emptySet(STABLE_ORDER)),
-        outReplacement);
+        outReplacement,
+        protocOpts.build());
   }
 
   /** Whether to use exports in the proto compile action. */
@@ -552,6 +562,8 @@ static CustomCommandLine createCommandLineFromToolchains(
             "--plugin=protoc-gen-PLUGIN_%s=%s",
             invocation.name, toolchain.pluginExecutable().getExecutable().getExecPath());
       }
+
+      cmdLine.addAll(invocation.protocOpts);
     }
 
     cmdLine.addAll(protocOpts);
@@ -749,13 +761,23 @@ public static class ToolchainInvocation {
     final String name;
     public final ProtoLangToolchainProvider toolchain;
     final CharSequence outReplacement;
+    final ImmutableList<String> protocOpts;
 
     public ToolchainInvocation(
         String name, ProtoLangToolchainProvider toolchain, CharSequence outReplacement) {
-      checkState(!name.contains(" "), "Name %s should not contain spaces", name);
+      this(name, toolchain, outReplacement, ImmutableList.of());
+    }
+
+    public ToolchainInvocation(
+        String name,
+        ProtoLangToolchainProvider toolchain,
+        CharSequence outReplacement,
+        ImmutableList<String> protocOpts) {
+      Preconditions.checkState(!name.contains(" "), "Name %s should not contain spaces", name);
       this.name = name;
       this.toolchain = toolchain;
       this.outReplacement = outReplacement;
+      this.protocOpts = Preconditions.checkNotNull(protocOpts);
     }
   }
 }

src/main/java/com/google/devtools/build/lib/rules/proto/ProtoConfiguration.java

@@ -81,6 +81,16 @@ public static class Options extends FragmentOptions {
     )
     public boolean experimentalProtoExtraActions;
 
+    @Option(
+      name = "experimental_proto_descriptor_sets_include_source_info",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.OUTPUT_SELECTION,
+      effectTags = {OptionEffectTag.AFFECTS_OUTPUTS, OptionEffectTag.LOADING_AND_ANALYSIS},
+      metadataTags = {OptionMetadataTag.EXPERIMENTAL},
+      help = "Run extra actions for alternative Java api versions in a proto_library."
+    )
+    public boolean experimentalProtoDescriptorSetsIncludeSourceInfo;
+
     @Option(
         name = "proto_compiler",
         defaultValue = "@com_google_protobuf//:protoc",
@@ -208,6 +218,8 @@ public FragmentOptions getHost() {
           loadProtoToolchainForJavaliteFromComGoogleProtobuf;
       host.protoCompiler = protoCompiler;
       host.protocOpts = protocOpts;
+      host.experimentalProtoDescriptorSetsIncludeSourceInfo =
+          experimentalProtoDescriptorSetsIncludeSourceInfo;
       host.experimentalProtoExtraActions = experimentalProtoExtraActions;
       host.protoCompiler = protoCompiler;
       host.protoToolchainForJava = protoToolchainForJava;
@@ -261,6 +273,10 @@ public ImmutableList<String> protocOpts() {
     return protocOpts;
   }
 
+  public boolean experimentalProtoDescriptorSetsIncludeSourceInfo() {
+    return options.experimentalProtoDescriptorSetsIncludeSourceInfo;
+  }
+
   /**
    * Returns true if we will run extra actions for actions that are not run by default. If this
    * is enabled, e.g. all extra_actions for alternative api-versions or language-flavours of a

src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibraryTest.java

@@ -1003,4 +1003,33 @@ public void testMigrationLabelNotRequiredWhenDisabled() throws Exception {
 
     getConfiguredTarget("//a");
   }
+
+  @Test
+  public void testNoExperimentalProtoDescriptorSetsIncludeSourceInfo() throws Exception {
+    scratch.file(
+        "x/BUILD",
+        TestConstants.LOAD_PROTO_LIBRARY,
+        "proto_library(",
+        "    name = 'a_proto',",
+        "    srcs = ['a.proto'],",
+        ")");
+
+    Iterable<String> commandLine = paramFileArgsForAction(getDescriptorWriteAction("//x:a_proto"));
+    assertThat(commandLine).doesNotContain("--include_source_info");
+  }
+
+  @Test
+  public void testExperimentalProtoDescriptorSetsIncludeSourceInfo() throws Exception {
+    useConfiguration("--experimental_proto_descriptor_sets_include_source_info");
+    scratch.file(
+        "x/BUILD",
+        TestConstants.LOAD_PROTO_LIBRARY,
+        "proto_library(",
+        "    name = 'a_proto',",
+        "    srcs = ['a.proto'],",
+        ")");
+
+    Iterable<String> commandLine = paramFileArgsForAction(getDescriptorWriteAction("//x:a_proto"));
+    assertThat(commandLine).contains("--include_source_info");
+  }
 }