Implement incompatible_enable_proto_toolchain_resolution

The flag also make proto toolchain related flags a no-op when enabled.

PiperOrigin-RevId: 566186339
Change-Id: If4ddafa4e8ba4cdf9e7b3d564c5fc72ab764c7ac

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

@@ -32,6 +32,7 @@
 import com.google.devtools.common.options.OptionEffectTag;
 import com.google.devtools.common.options.OptionMetadataTag;
 import java.util.List;
+import javax.annotation.Nullable;
 import net.starlark.java.annot.StarlarkMethod;
 import net.starlark.java.eval.EvalException;
 import net.starlark.java.eval.StarlarkThread;
@@ -45,6 +46,16 @@ public class ProtoConfiguration extends Fragment implements ProtoConfigurationAp
 
   /** Command line options. */
   public static class Options extends FragmentOptions {
+    @Option(
+        name = "incompatible_enable_proto_toolchain_resolution",
+        defaultValue = "false",
+        documentationCategory = OptionDocumentationCategory.TOOLCHAIN,
+        effectTags = {OptionEffectTag.LOADING_AND_ANALYSIS},
+        metadataTags = {OptionMetadataTag.INCOMPATIBLE_CHANGE},
+        help =
+            "If true, proto lang rules use toolchain resolution to find the toolchain. The flags"
+                + " proto_compiler and proto_toolchain_for_* are a no-op.")
+    public boolean enableProtoToolchainResolution;
 
     @Option(
         name = "protocopt",
@@ -56,13 +67,12 @@ public static class Options extends FragmentOptions {
     public List<String> protocOpts;
 
     @Option(
-      name = "experimental_proto_extra_actions",
-      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."
-    )
+        name = "experimental_proto_extra_actions",
+        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 experimentalProtoExtraActions;
 
     @Option(
@@ -165,6 +175,7 @@ public static class Options extends FragmentOptions {
     @Override
     public FragmentOptions getExec() {
       Options exec = (Options) super.getExec();
+      exec.enableProtoToolchainResolution = enableProtoToolchainResolution;
       exec.protoCompiler = protoCompiler;
       exec.protocOpts = protocOpts;
       exec.experimentalProtoDescriptorSetsIncludeSourceInfo =
@@ -185,10 +196,12 @@ public FragmentOptions getExec() {
   private final ImmutableList<String> protocOpts;
   private final ImmutableList<String> ccProtoLibraryHeaderSuffixes;
   private final ImmutableList<String> ccProtoLibrarySourceSuffixes;
+  private final boolean enableProtoToolchainResolution;
   private final Options options;
 
   public ProtoConfiguration(BuildOptions buildOptions) {
     Options options = buildOptions.get(Options.class);
+    this.enableProtoToolchainResolution = options.enableProtoToolchainResolution;
     this.protocOpts = ImmutableList.copyOf(options.protocOpts);
     this.ccProtoLibraryHeaderSuffixes = ImmutableList.copyOf(options.ccProtoLibraryHeaderSuffixes);
     this.ccProtoLibrarySourceSuffixes = ImmutableList.copyOf(options.ccProtoLibrarySourceSuffixes);
@@ -219,8 +232,8 @@ public boolean 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
+   * 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
    * proto_library target are run.
    */
   public boolean runExperimentalProtoExtraActions() {
@@ -231,40 +244,65 @@ public boolean runExperimentalProtoExtraActions() {
       name = "proto_compiler",
       doc = "Label for the proto compiler.",
       defaultLabel = ProtoConstants.DEFAULT_PROTOC_LABEL)
+  @Nullable
   public Label protoCompiler() {
-    return options.protoCompiler;
+    if (enableProtoToolchainResolution) {
+      return null;
+    } else {
+      return options.protoCompiler;
+    }
   }
 
   @StarlarkConfigurationField(
       name = "proto_toolchain_for_java",
       doc = "Label for the java proto toolchains.",
       defaultLabel = ProtoConstants.DEFAULT_JAVA_PROTO_LABEL)
+  @Nullable
   public Label protoToolchainForJava() {
-    return options.protoToolchainForJava;
+    if (enableProtoToolchainResolution) {
+      return null;
+    } else {
+      return options.protoToolchainForJava;
+    }
   }
 
   @StarlarkConfigurationField(
       name = "proto_toolchain_for_j2objc",
       doc = "Label for the j2objc toolchains.",
       defaultLabel = ProtoConstants.DEFAULT_J2OBJC_PROTO_LABEL)
+  @Nullable
   public Label protoToolchainForJ2objc() {
-    return options.protoToolchainForJ2objc;
+    if (enableProtoToolchainResolution) {
+      return null;
+    } else {
+      return options.protoToolchainForJ2objc;
+    }
   }
 
   @StarlarkConfigurationField(
       name = "proto_toolchain_for_java_lite",
       doc = "Label for the java lite proto toolchains.",
       defaultLabel = ProtoConstants.DEFAULT_JAVA_LITE_PROTO_LABEL)
+  @Nullable
   public Label protoToolchainForJavaLite() {
-    return options.protoToolchainForJavaLite;
+    if (enableProtoToolchainResolution) {
+      return null;
+    } else {
+      return options.protoToolchainForJavaLite;
+    }
   }
 
   @StarlarkConfigurationField(
       name = "proto_toolchain_for_cc",
       doc = "Label for the cc proto toolchains.",
       defaultLabel = ProtoConstants.DEFAULT_CC_PROTO_LABEL)
+  @Nullable
   public Label protoToolchainForCc() {
-    return options.protoToolchainForCc;
+    if (enableProtoToolchainResolution) {
+      return null;
+    } else {
+      return options.protoToolchainForCc;
+    }
   }
 
   @StarlarkMethod(name = "strict_proto_deps", useStarlarkThread = true, documented = false)