Expose C++ action names to Skylark

This cl adds Skylark constants allowing users to specify which C++ action they
want for the feature configuration Skylark API.  This is done by exposing a
Skylark file at @bazel_tools//tools/cpp:action_names.bzl.

Skylark api to the C++ toolchain doc:
https://docs.google.com/document/d/1g91BWJITcYw_X-VxsDC0VgUn5E9g0kRBGoBSpoO41gA/edit#.

Progress on #4571.

RELNOTES: None.
PiperOrigin-RevId: 199596778

src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java

@@ -110,17 +110,17 @@ public void collectMetadataArtifacts(Iterable<Artifact> objectFiles,
 
   public static final ImmutableSet<String> ALL_COMPILE_ACTIONS =
       ImmutableSet.of(
-          CppCompileAction.C_COMPILE,
-          CppCompileAction.CPP_COMPILE,
-          CppCompileAction.CPP_HEADER_PARSING,
-          CppCompileAction.CPP_HEADER_PREPROCESSING,
-          CppCompileAction.CPP_MODULE_COMPILE,
-          CppCompileAction.CPP_MODULE_CODEGEN,
-          CppCompileAction.ASSEMBLE,
-          CppCompileAction.PREPROCESS_ASSEMBLE,
-          CppCompileAction.CLIF_MATCH,
-          CppCompileAction.LINKSTAMP_COMPILE,
-          CppCompileAction.CC_FLAGS_MAKE_VARIABLE_ACTION_NAME);
+          CppActionNames.C_COMPILE,
+          CppActionNames.CPP_COMPILE,
+          CppActionNames.CPP_HEADER_PARSING,
+          CppActionNames.CPP_HEADER_PREPROCESSING,
+          CppActionNames.CPP_MODULE_COMPILE,
+          CppActionNames.CPP_MODULE_CODEGEN,
+          CppActionNames.ASSEMBLE,
+          CppActionNames.PREPROCESS_ASSEMBLE,
+          CppActionNames.CLIF_MATCH,
+          CppActionNames.LINKSTAMP_COMPILE,
+          CppActionNames.CC_FLAGS_MAKE_VARIABLE);
 
   public static final ImmutableSet<String> ALL_LINK_ACTIONS =
       ImmutableSet.of(
@@ -132,7 +132,7 @@ public void collectMetadataArtifacts(Iterable<Artifact> objectFiles,
       ImmutableSet.of(Link.LinkTargetType.STATIC_LIBRARY.getActionName());
 
   public static final ImmutableSet<String> ALL_OTHER_ACTIONS =
-      ImmutableSet.of(CppCompileAction.STRIP_ACTION_NAME);
+      ImmutableSet.of(CppActionNames.STRIP);
 
   /** Action configs we request to enable. */
   public static final ImmutableSet<String> DEFAULT_ACTION_CONFIGS =
@@ -971,8 +971,7 @@ public static String computeCcFlags(RuleContext ruleContext, TransitiveInfoColle
         (CcToolchainProvider) toolchain.get(ToolchainInfo.PROVIDER);
     FeatureConfiguration featureConfiguration =
         CcCommon.configureFeaturesOrReportRuleError(ruleContext, toolchainProvider);
-    if (!featureConfiguration.actionIsConfigured(
-        CppCompileAction.CC_FLAGS_MAKE_VARIABLE_ACTION_NAME)) {
+    if (!featureConfiguration.actionIsConfigured(CppActionNames.CC_FLAGS_MAKE_VARIABLE)) {
       return null;
     }
 
@@ -981,7 +980,7 @@ public static String computeCcFlags(RuleContext ruleContext, TransitiveInfoColle
         Joiner.on(" ")
             .join(
                 featureConfiguration.getCommandLine(
-                    CppCompileAction.CC_FLAGS_MAKE_VARIABLE_ACTION_NAME, buildVariables));
+                    CppActionNames.CC_FLAGS_MAKE_VARIABLE, buildVariables));
     String oldCcFlags = "";
     TemplateVariableInfo templateVariableInfo =
         toolchain.get(TemplateVariableInfo.PROVIDER);

src/main/java/com/google/devtools/build/lib/rules/cpp/CppActionNames.java

@@ -0,0 +1,75 @@
+// Copyright 2018 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.rules.cpp;
+
+/** Class holding constants for all C++ action names */
+public class CppActionNames {
+
+  /** A string constant used to compute CC_FLAGS make variable value */
+  public static final String CC_FLAGS_MAKE_VARIABLE = "cc-flags-make-variable";
+  /** A string constant for the strip action name. */
+  public static final String STRIP = "strip";
+  /** A string constant for the linkstamp-compile action. */
+  public static final String LINKSTAMP_COMPILE = "linkstamp-compile";
+  /** A string constant for the c compilation action. */
+  public static final String C_COMPILE = "c-compile";
+  /** A string constant for the c++ compilation action. */
+  public static final String CPP_COMPILE = "c++-compile";
+  /** A string constant for the c++ module compile action. */
+  public static final String CPP_MODULE_CODEGEN = "c++-module-codegen";
+  /** A string constant for the objc compilation action. */
+  public static final String OBJC_COMPILE = "objc-compile";
+  /** A string constant for the objc++ compile action. */
+  public static final String OBJCPP_COMPILE = "objc++-compile";
+  /** A string constant for the c++ header parsing. */
+  public static final String CPP_HEADER_PARSING = "c++-header-parsing";
+  /** A string constant for the c++ header preprocessing. */
+  public static final String CPP_HEADER_PREPROCESSING = "c++-header-preprocessing";
+  /**
+   * A string constant for the c++ module compilation action. Note: currently we don't support C
+   * module compilation.
+   */
+  public static final String CPP_MODULE_COMPILE = "c++-module-compile";
+  /** A string constant for the assembler actions. */
+  public static final String ASSEMBLE = "assemble";
+
+  public static final String PREPROCESS_ASSEMBLE = "preprocess-assemble";
+  /**
+   * A string constant for the clif actions. Bazel enables different features of the toolchain based
+   * on the name of the action. This name enables the clif_matcher feature, which switches the
+   * "compiler" to the clif_matcher and adds some additional arguments as described in the CROSSTOOL
+   * file.
+   */
+  public static final String CLIF_MATCH = "clif-match";
+
+  /** Name of the action producing static library. */
+  public static final String CPP_LINK_STATIC_LIBRARY = "c++-link-static-library";
+  /** Name of the action producing dynamic library from cc_library. */
+  public static final String CPP_LINK_NODEPS_DYNAMIC_LIBRARY = "c++-link-nodeps-dynamic-library";
+  /** Name of the action producing dynamic library from cc_binary. */
+  public static final String CPP_LINK_DYNAMIC_LIBRARY = "c++-link-dynamic-library";
+  /** Name of the action producing executable binary. */
+  public static final String CPP_LINK_EXECUTABLE = "c++-link-executable";
+  /** Name of the objc action producing static library */
+  public static final String OBJC_ARCHIVE = "objc-archive";
+  /** Name of the objc action producing dynamic library */
+  public static final String OBJC_FULLY_LINK = "objc-fully-link";
+  /** Name of the objc action producing objc executable binary */
+  public static final String OBJC_EXECUTABLE = "objc-executable";
+  /** Name of the objc action producing objc++ executable binary */
+  public static final String OBJCPP_EXECUTABLE = "objc++-executable";
+
+  public static final String LTO_INDEXING = "lto-indexing";
+  public static final String LTO_BACKEND = "lto-backend";
+}

src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java

@@ -93,69 +93,6 @@ public class CppCompileAction extends AbstractAction
   private static final int VALIDATION_DEBUG = 0;  // 0==none, 1==warns/errors, 2==all
   private static final boolean VALIDATION_DEBUG_WARN = VALIDATION_DEBUG >= 1;
 
-  /** A string constant used to compute CC_FLAGS make variable value */
-  public static final java.lang.String CC_FLAGS_MAKE_VARIABLE_ACTION_NAME =
-      "cc-flags-make-variable";
-
-  /** A string constant for the strip action name. */
-  public static final String STRIP_ACTION_NAME = "strip";
-
-  /** A string constant for the linkstamp-compile action. */
-  public static final String LINKSTAMP_COMPILE = "linkstamp-compile";
-
-  /**
-   * A string constant for the c compilation action.
-   */
-  public static final String C_COMPILE = "c-compile";
-
-  /**
-   * A string constant for the c++ compilation action.
-   */
-  public static final String CPP_COMPILE = "c++-compile";
-
-  /** A string constant for the c++ module compile action. */
-  public static final String CPP_MODULE_CODEGEN = "c++-module-codegen";
-
-  /**
-   * A string constant for the objc compilation action.
-   */
-  public static final String OBJC_COMPILE = "objc-compile";
-
-  /**
-   * A string constant for the objc++ compile action.
-   */
-  public static final String OBJCPP_COMPILE = "objc++-compile";
-
-  /**
-   * A string constant for the c++ header parsing.
-   */
-  public static final String CPP_HEADER_PARSING = "c++-header-parsing";
-
-  /**
-   * A string constant for the c++ header preprocessing.
-   */
-  public static final String CPP_HEADER_PREPROCESSING = "c++-header-preprocessing";
-
-  /**
-   * A string constant for the c++ module compilation action.
-   * Note: currently we don't support C module compilation.
-   */
-  public static final String CPP_MODULE_COMPILE = "c++-module-compile";
-
-  /**
-   * A string constant for the assembler actions.
-   */
-  public static final String ASSEMBLE = "assemble";
-  public static final String PREPROCESS_ASSEMBLE = "preprocess-assemble";
-
-  /**
-   * A string constant for the clif actions. Bazel enables different features of the toolchain based
-   * on the name of the action. This name enables the clif_matcher feature, which switches the
-   * "compiler" to the clif_matcher and adds some additional arguments as described in the CROSSTOOL
-   * file.
-   */
-  public static final String CLIF_MATCH = "clif-match";
-
   protected final Artifact outputFile;
   private final Artifact sourceFile;
   private final NestedSet<Artifact> mandatoryInputs;
@@ -1327,11 +1264,11 @@ public Iterable<Artifact> getInputFilesForExtraAction(
   @Override
   public String getMnemonic() {
     switch (actionName) {
-      case OBJC_COMPILE:
-      case OBJCPP_COMPILE:
+      case CppActionNames.OBJC_COMPILE:
+      case CppActionNames.OBJCPP_COMPILE:
         return "ObjcCompile";
 
-      case LINKSTAMP_COMPILE:
+      case CppActionNames.LINKSTAMP_COMPILE:
         // When compiling shared native deps, e.g. when two java_binary rules have the same set of
         // native dependencies, the CppCompileAction for link stamp data is shared also. This means
         // that out of two CppCompileAction instances, only one is actually executed, which means

src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileActionBuilder.java

@@ -232,37 +232,37 @@ private String getActionName() {
     }
     PathFragment sourcePath = sourceFile.getExecPath();
     if (CppFileTypes.CPP_MODULE_MAP.matches(sourcePath)) {
-      return CppCompileAction.CPP_MODULE_COMPILE;
+      return CppActionNames.CPP_MODULE_COMPILE;
     } else if (CppFileTypes.CPP_HEADER.matches(sourcePath)) {
       // TODO(bazel-team): Handle C headers that probably don't work in C++ mode.
       if (!cppConfiguration.getParseHeadersVerifiesModules()
           && featureConfiguration.isEnabled(CppRuleClasses.PARSE_HEADERS)) {
-        return CppCompileAction.CPP_HEADER_PARSING;
+        return CppActionNames.CPP_HEADER_PARSING;
       } else if (!cppConfiguration.getParseHeadersVerifiesModules()
           && featureConfiguration.isEnabled(CppRuleClasses.PREPROCESS_HEADERS)) {
-        return CppCompileAction.CPP_HEADER_PREPROCESSING;
+        return CppActionNames.CPP_HEADER_PREPROCESSING;
       } else {
         // CcCommon.collectCAndCppSources() ensures we do not add headers to
         // the compilation artifacts unless either 'parse_headers' or
         // 'preprocess_headers' is set.
         throw new IllegalStateException();
       }
     } else if (CppFileTypes.C_SOURCE.matches(sourcePath)) {
-      return CppCompileAction.C_COMPILE;
+      return CppActionNames.C_COMPILE;
     } else if (CppFileTypes.CPP_SOURCE.matches(sourcePath)) {
-      return CppCompileAction.CPP_COMPILE;
+      return CppActionNames.CPP_COMPILE;
     } else if (CppFileTypes.OBJC_SOURCE.matches(sourcePath)) {
-      return CppCompileAction.OBJC_COMPILE;
+      return CppActionNames.OBJC_COMPILE;
     } else if (CppFileTypes.OBJCPP_SOURCE.matches(sourcePath)) {
-      return CppCompileAction.OBJCPP_COMPILE;
+      return CppActionNames.OBJCPP_COMPILE;
     } else if (CppFileTypes.ASSEMBLER.matches(sourcePath)) {
-      return CppCompileAction.ASSEMBLE;
+      return CppActionNames.ASSEMBLE;
     } else if (CppFileTypes.ASSEMBLER_WITH_C_PREPROCESSOR.matches(sourcePath)) {
-      return CppCompileAction.PREPROCESS_ASSEMBLE;
+      return CppActionNames.PREPROCESS_ASSEMBLE;
     } else if (CppFileTypes.CLIF_INPUT_PROTO.matches(sourcePath)) {
-      return CppCompileAction.CLIF_MATCH;
+      return CppActionNames.CLIF_MATCH;
     } else if (CppFileTypes.CPP_MODULE.matches(sourcePath)) {
-      return CppCompileAction.CPP_MODULE_CODEGEN;
+      return CppActionNames.CPP_MODULE_CODEGEN;
     }
     // CcCompilationHelper ensures CppCompileAction only gets instantiated for supported file types.
     throw new IllegalStateException();

src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java

@@ -902,14 +902,13 @@ public static void createStripAction(
       return;
     }
 
-    if (!featureConfiguration.actionIsConfigured(CppCompileAction.STRIP_ACTION_NAME)) {
+    if (!featureConfiguration.actionIsConfigured(CppActionNames.STRIP)) {
       context.ruleError("Expected action_config for 'strip' to be configured.");
       return;
     }
 
     Tool stripTool =
-        Preconditions.checkNotNull(
-            featureConfiguration.getToolForAction(CppCompileAction.STRIP_ACTION_NAME));
+        Preconditions.checkNotNull(featureConfiguration.getToolForAction(CppActionNames.STRIP));
     CcToolchainVariables variables =
         new CcToolchainVariables.Builder(toolchain.getBuildVariables())
             .addStringVariable(
@@ -919,8 +918,7 @@ public static void createStripAction(
             .addStringVariable(CcCommon.INPUT_FILE_VARIABLE_NAME, input.getExecPathString())
             .build();
     ImmutableList<String> commandLine =
-        ImmutableList.copyOf(
-            featureConfiguration.getCommandLine(CppCompileAction.STRIP_ACTION_NAME, variables));
+        ImmutableList.copyOf(featureConfiguration.getCommandLine(CppActionNames.STRIP, variables));
     ImmutableMap.Builder<String, String> executionInfoBuilder = ImmutableMap.builder();
     for (String executionRequirement : stripTool.getExecutionRequirements()) {
       executionInfoBuilder.put(executionRequirement, "");

src/main/java/com/google/devtools/build/lib/rules/cpp/CppLinkstampCompileHelper.java

@@ -75,7 +75,7 @@ public static CppCompileAction createLinkstampCompileAction(
             .setBuiltinIncludeFiles(buildInfoHeaderArtifacts)
             .addMandatoryInputs(nonCodeInputs)
             .setCppConfiguration(cppConfiguration)
-            .setActionName(CppCompileAction.LINKSTAMP_COMPILE);
+            .setActionName(CppActionNames.LINKSTAMP_COMPILE);
     semantics.finalizeCompileActionBuilder(ruleContext, builder);
     return builder.buildOrThrowIllegalStateException();
   }
@@ -140,7 +140,7 @@ private static CcToolchainVariables getVariables(
       boolean codeCoverageEnabled) {
     // TODO(b/34761650): Remove all this hardcoding by separating a full blown compile action.
     Preconditions.checkArgument(
-        featureConfiguration.actionIsConfigured(CppCompileAction.LINKSTAMP_COMPILE));
+        featureConfiguration.actionIsConfigured(CppActionNames.LINKSTAMP_COMPILE));
 
     return CompileBuildVariables.setupVariablesOrReportRuleError(
         ruleContext,

src/main/java/com/google/devtools/build/lib/rules/cpp/FakeCppCompileAction.java

@@ -118,7 +118,7 @@ public class FakeCppCompileAction extends CppCompileAction {
         /* additionalIncludeScanningRoots=*/ ImmutableList.of(),
         GUID,
         executionInfo,
-        CppCompileAction.CPP_COMPILE,
+        CppActionNames.CPP_COMPILE,
         cppSemantics,
         cppProvider,
         grepIncludes);