// Copyright 2017 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;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.analysis.actions.ActionConstructionContext;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.analysis.config.BuildOptions;
import com.google.devtools.build.lib.collect.nestedset.NestedSet;
import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
import com.google.devtools.build.lib.collect.nestedset.Order;
import com.google.devtools.build.lib.packages.RuleErrorConsumer;
import com.google.devtools.build.lib.rules.cpp.CcToolchainFeatures.FeatureConfiguration;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.util.regex.Pattern;
import javax.annotation.Nullable;

/** Handles creation of CppCompileAction used to compile linkstamp sources. */
public class CppLinkstampCompileHelper {

  /**
   * Creates {@link CppCompileAction} to compile linkstamp source
   *
   * @param inputsForInvalidation: see {@link CppCompileAction#inputsForInvalidation}
   */
  public static CppCompileAction createLinkstampCompileAction(
      RuleErrorConsumer ruleErrorConsumer,
      ActionConstructionContext actionConstructionContext,
      @Nullable Artifact grepIncludes,
      BuildConfiguration configuration,
      Artifact sourceFile,
      Artifact outputFile,
      NestedSet<Artifact> compilationInputs,
      NestedSet<Artifact> nonCodeInputs,
      NestedSet<Artifact> inputsForInvalidation,
      ImmutableList<Artifact> buildInfoHeaderArtifacts,
      Iterable<String> additionalLinkstampDefines,
      CcToolchainProvider ccToolchainProvider,
      boolean codeCoverageEnabled,
      CppConfiguration cppConfiguration,
      String fdoBuildStamp,
      FeatureConfiguration featureConfiguration,
      boolean needsPic,
      String labelReplacement,
      String outputReplacement,
      CppSemantics semantics) {
    CppCompileActionBuilder builder =
        new CppCompileActionBuilder(
                actionConstructionContext, grepIncludes, ccToolchainProvider, configuration)
            .addMandatoryInputs(compilationInputs)
            .setVariables(
                getVariables(
                    ruleErrorConsumer,
                    sourceFile,
                    outputFile,
                    labelReplacement,
                    outputReplacement,
                    additionalLinkstampDefines,
                    buildInfoHeaderArtifacts,
                    featureConfiguration,
                    configuration.getOptions(),
                    cppConfiguration,
                    ccToolchainProvider,
                    needsPic,
                    fdoBuildStamp,
                    codeCoverageEnabled))
            .setFeatureConfiguration(featureConfiguration)
            .setSourceFile(sourceFile)
            .setSemantics(semantics)
            .setOutputs(outputFile, null)
            .setInputsForInvalidation(inputsForInvalidation)
            .setBuiltinIncludeFiles(buildInfoHeaderArtifacts)
            .addMandatoryInputs(nonCodeInputs)
            .setShareable(true)
            .setShouldScanIncludes(false)
            .setActionName(CppActionNames.LINKSTAMP_COMPILE);
    semantics.finalizeCompileActionBuilder(
        configuration, featureConfiguration, builder, ruleErrorConsumer);
    return builder.buildOrThrowIllegalStateException();
  }

  private static NestedSet<String> computeAllLinkstampDefines(
      String labelReplacement,
      String outputReplacement,
      Iterable<String> additionalLinkstampDefines,
      CcToolchainProvider ccToolchainProvider,
      String fdoBuildStamp,
      boolean codeCoverageEnabled) {
    String labelPattern = Pattern.quote("${LABEL}");
    String outputPathPattern = Pattern.quote("${OUTPUT_PATH}");
    ImmutableList.Builder<String> defines =
        ImmutableList.<String>builder()
            .add("GPLATFORM=\"" + ccToolchainProvider.getToolchainIdentifier() + "\"")
            .add("BUILD_COVERAGE_ENABLED=" + (codeCoverageEnabled ? "1" : "0"))
            // G3_TARGET_NAME is a C string literal that normally contain the label of the target
            // being linked.  However, they are set differently when using shared native deps. In
            // that case, a single .so file is shared by multiple targets, and its contents cannot
            // depend on which target(s) were specified on the command line.  So in that case we
            // have to use the (obscure) name of the .so file instead, or more precisely the path of
            // the .so file relative to the workspace root.
            .add("G3_TARGET_NAME=\"${LABEL}\"")
            // G3_BUILD_TARGET is a C string literal containing the output of this
            // link.  (An undocumented and untested invariant is that G3_BUILD_TARGET is the
            // location of the executable, either absolutely, or relative to the directory part of
            // BUILD_INFO.)
            .add("G3_BUILD_TARGET=\"${OUTPUT_PATH}\"")
            .addAll(additionalLinkstampDefines);

    if (fdoBuildStamp != null) {
      defines.add(CppConfiguration.FDO_STAMP_MACRO + "=\"" + fdoBuildStamp + "\"");
    }

    return NestedSetBuilder.wrap(
        Order.STABLE_ORDER,
        Iterables.transform(
            defines.build(),
            define ->
                define
                    .replaceAll(labelPattern, labelReplacement)
                    .replaceAll(outputPathPattern, outputReplacement)));
  }

  private static CcToolchainVariables getVariables(
      RuleErrorConsumer ruleErrorConsumer,
      Artifact sourceFile,
      Artifact outputFile,
      String labelReplacement,
      String outputReplacement,
      Iterable<String> additionalLinkstampDefines,
      ImmutableList<Artifact> buildInfoHeaderArtifacts,
      FeatureConfiguration featureConfiguration,
      BuildOptions buildOptions,
      CppConfiguration cppConfiguration,
      CcToolchainProvider ccToolchainProvider,
      boolean needsPic,
      String fdoBuildStamp,
      boolean codeCoverageEnabled) {
    // TODO(b/34761650): Remove all this hardcoding by separating a full blown compile action.
    Preconditions.checkArgument(
        featureConfiguration.actionIsConfigured(CppActionNames.LINKSTAMP_COMPILE));

    return CompileBuildVariables.setupVariablesOrReportRuleError(
        ruleErrorConsumer,
        featureConfiguration,
        ccToolchainProvider,
        buildOptions,
        cppConfiguration,
        sourceFile.getExecPathString(),
        outputFile.getExecPathString(),
        /* gcnoFile= */ null,
        /* isUsingFission= */ false,
        /* dwoFile= */ null,
        /* ltoIndexingFile= */ null,
        buildInfoHeaderArtifacts.stream()
            .map(Artifact::getExecPathString)
            .collect(ImmutableList.toImmutableList()),
        CcCompilationHelper.getCoptsFromOptions(cppConfiguration, sourceFile.getExecPathString()),
        /* cppModuleMap= */ null,
        needsPic,
        /* fakeOutputFile= */ null,
        fdoBuildStamp,
        /* dotdFileExecPath= */ null,
        /* variablesExtensions= */ ImmutableList.of(),
        /* additionalBuildVariables= */ ImmutableMap.of(),
        /* directModuleMaps= */ ImmutableList.of(),
        /* includeDirs= */ NestedSetBuilder.create(Order.STABLE_ORDER, PathFragment.create(".")),
        /* quoteIncludeDirs= */ NestedSetBuilder.emptySet(Order.STABLE_ORDER),
        /* systemIncludeDirs= */ NestedSetBuilder.emptySet(Order.STABLE_ORDER),
        /* frameworkIncludeDirs= */ NestedSetBuilder.emptySet(Order.STABLE_ORDER),
        computeAllLinkstampDefines(
            labelReplacement,
            outputReplacement,
            additionalLinkstampDefines,
            ccToolchainProvider,
            fdoBuildStamp,
            codeCoverageEnabled),
        /* localDefines= */ ImmutableList.of());
  }
}