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

// Copyright 2014 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 static com.google.devtools.build.lib.packages.Attribute.attr;
import static com.google.devtools.build.lib.packages.BuildType.LABEL;
import static com.google.devtools.build.lib.packages.ImplicitOutputsFunction.fromTemplates;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.ALWAYS_LINK_LIBRARY;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.ALWAYS_LINK_PIC_LIBRARY;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.ARCHIVE;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.ASSEMBLER;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.ASSEMBLER_WITH_C_PREPROCESSOR;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.CPP_HEADER;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.CPP_SOURCE;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.C_SOURCE;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.INTERFACE_SHARED_LIBRARY;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.OBJECT_FILE;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.PIC_ARCHIVE;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.PIC_OBJECT_FILE;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.SHARED_LIBRARY;
import static com.google.devtools.build.lib.rules.cpp.CppFileTypes.VERSIONED_SHARED_LIBRARY;

import com.google.devtools.build.lib.analysis.RuleDefinition;
import com.google.devtools.build.lib.analysis.RuleDefinitionEnvironment;
import com.google.devtools.build.lib.analysis.config.HostTransition;
import com.google.devtools.build.lib.analysis.test.InstrumentedFilesCollector.InstrumentationSpec;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.packages.Attribute.LabelLateBoundDefault;
import com.google.devtools.build.lib.packages.Attribute.LateBoundDefault.Resolver;
import com.google.devtools.build.lib.packages.ImplicitOutputsFunction.SafeImplicitOutputsFunction;
import com.google.devtools.build.lib.packages.RuleClass;
import com.google.devtools.build.lib.packages.RuleClass.Builder.RuleClassType;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
import com.google.devtools.build.lib.util.FileTypeSet;
import com.google.devtools.build.lib.util.OsUtils;

/**
 * Rule class definitions for C++ rules.
 */
public class CppRuleClasses {

  /**
   * Label of a pseudo-filegroup that contains all crosstool and libcfiles for all configurations,
   * as specified on the command-line.
   */
  public static final String CROSSTOOL_LABEL = "//tools/cpp:toolchain";

  public static final LabelLateBoundDefault<?> DEFAULT_MALLOC =
      LabelLateBoundDefault.fromTargetConfiguration(
          CppConfiguration.class, null, (rule, attributes, cppConfig) -> cppConfig.customMalloc());

  public static LabelLateBoundDefault<CppConfiguration> ccToolchainAttribute(
      RuleDefinitionEnvironment env) {
    return LabelLateBoundDefault.fromTargetConfiguration(
        CppConfiguration.class,
        env.getToolsLabel(CROSSTOOL_LABEL),
        CC_TOOLCHAIN_CONFIGURATION_RESOLVER);
  }

  @AutoCodec
  static final Resolver<CppConfiguration, Label> CC_TOOLCHAIN_CONFIGURATION_RESOLVER =
      (rule, attributes, configuration) -> configuration.getRuleProvidingCcToolchainProvider();

  public static LabelLateBoundDefault<CppConfiguration> ccHostToolchainAttribute(
      RuleDefinitionEnvironment env) {
    return LabelLateBoundDefault.fromHostConfiguration(
        CppConfiguration.class,
        env.getToolsLabel(CROSSTOOL_LABEL),
        (rules, attributes, cppConfig) -> cppConfig.getRuleProvidingCcToolchainProvider());
  }

  public static Label ccToolchainTypeAttribute(RuleDefinitionEnvironment env) {
    return env.getToolsLabel(CppHelper.TOOLCHAIN_TYPE_LABEL);
  }

  // Artifacts of these types are discarded from the 'hdrs' attribute in cc rules
  static final FileTypeSet DISALLOWED_HDRS_FILES = FileTypeSet.of(
      ARCHIVE,
      PIC_ARCHIVE,
      ALWAYS_LINK_LIBRARY,
      ALWAYS_LINK_PIC_LIBRARY,
      SHARED_LIBRARY,
      INTERFACE_SHARED_LIBRARY,
      VERSIONED_SHARED_LIBRARY,
      OBJECT_FILE,
      PIC_OBJECT_FILE);

  /**
   * The set of instrumented source file types; keep this in sync with the list above. Note that
   * extension-less header files cannot currently be declared, so we cannot collect coverage for
   * those.
   */
  static final InstrumentationSpec INSTRUMENTATION_SPEC = new InstrumentationSpec(
      FileTypeSet.of(CPP_SOURCE, C_SOURCE, CPP_HEADER, ASSEMBLER_WITH_C_PREPROCESSOR,
          ASSEMBLER))
      .withSourceAttributes("srcs", "hdrs")
      .withDependencyAttributes("deps", "data");

  /** Implicit outputs for cc_binary rules. */
  public static final SafeImplicitOutputsFunction CC_BINARY_STRIPPED =
      fromTemplates("%{name}.stripped" + OsUtils.executableExtension());

  // Used for requesting dwp "debug packages".
  public static final SafeImplicitOutputsFunction CC_BINARY_DEBUG_PACKAGE =
      fromTemplates("%{name}.dwp");

  /** Name of the feature that will be exempt from flag filtering when nocopts are used */
  public static final String UNFILTERED_COMPILE_FLAGS_FEATURE_NAME = "unfiltered_compile_flags";

  /**
   * A string constant for the parse_headers feature.
   */
  public static final String PARSE_HEADERS = "parse_headers";

  /**
   * A string constant for the module_maps feature; this is a precondition to the layering_check and
   * header_modules features.
   */
  public static final String MODULE_MAPS = "module_maps";

  /**
   * A string constant for the random_seed feature. This is used by gcc and Clangfor the
   * randomization of symbol names that are in the anonymous namespace but have external linkage.
   */
  public static final String RANDOM_SEED = "random_seed";

  /**
   * A string constant for the dependency_file feature. This feature generates the .d file.
   */
  public static final String DEPENDENCY_FILE = "dependency_file";

  /**
   * A string constant for the module_map_home_cwd feature.
   */
  public static final String MODULE_MAP_HOME_CWD = "module_map_home_cwd";

  /**
   * A string constant for the module_map_without_extern_module feature.
   *
   * <p>This features is a transitional feature; enabling it means that generated module maps
   * will not have "extern module" declarations inside them; instead, the module maps need
   * to be passed via the dependent_module_map_files build variable.
   *
   * <p>This variable is phrased negatively to aid the roll-out: currently, the default is that
   * "extern module" declarations are generated.
   */
  public static final String MODULE_MAP_WITHOUT_EXTERN_MODULE = "module_map_without_extern_module";

  /**
   * A string constant for the layering_check feature.
   */
  public static final String LAYERING_CHECK = "layering_check";

  /** A string constant for the header_modules feature. */
  public static final String HEADER_MODULES = "header_modules";

  /** A string constant for the header_modules_compile feature. */
  public static final String HEADER_MODULE_COMPILE = "header_module_compile";

  /** A string constant for the header_module_codegen feature. */
  public static final String HEADER_MODULE_CODEGEN = "header_module_codegen";

  /**
   * A string constant for the compile_all_modules feature.
   */
  public static final String COMPILE_ALL_MODULES = "compile_all_modules";

  /**
   * A string constant for the exclude_private_headers_in_module_maps feature.
   */
  public static final String EXCLUDE_PRIVATE_HEADERS_IN_MODULE_MAPS =
      "exclude_private_headers_in_module_maps";

  /**
   * A string constant for the use_header_modules feature.
   *
   * <p>This feature is only used during rollout; we expect to default enable this once we
   * have verified that module-enabled compilation is stable enough.
   */
  public static final String USE_HEADER_MODULES = "use_header_modules";

  /**
   * A string constant for the generate_submodules feature.
   *
   * <p>This feature is only used temporarily to make the switch to using submodules easier. With
   * submodules, each header of a cc_library is placed into a submodule of the module generated for
   * the appropriate target. As this influences the layering_check semantics and needs to be synced
   * with a clang release, we want to be able to switch back and forth easily.
   */
  public static final String GENERATE_SUBMODULES = "generate_submodules";

  /**
   * A string constant for the only_doth_headers_in_module_maps.
   *
   * <p>This feature filters any headers without a ".h" suffix from generated module maps.
   */
  public static final String ONLY_DOTH_HEADERS_IN_MODULE_MAPS = "only_doth_headers_in_module_maps";

  /**
   * A string constant for the no_legacy_features feature.
   *
   * <p>If this feature is enabled, Bazel will not extend the crosstool configuration with the
   * default legacy feature set.
   */
  public static final String NO_LEGACY_FEATURES = "no_legacy_features";

  /**
   * A string constant for the legacy_compile_flags feature. If this feature is present in the
   * toolchain, and the toolchain doesn't specify no_legacy_features, bazel will move
   * legacy_compile_flags before other features from {@link CppActionConfigs}.
   */
  public static final String LEGACY_COMPILE_FLAGS = "legacy_compile_flags";

  /**
   * A string constant for the default_compile_flags feature. If this feature is present in the
   * toolchain, and the toolchain doesn't specify no_legacy_features, bazel will move
   * default_compile_flags before other features from {@link CppActionConfigs}.
   */
  public static final String DEFAULT_COMPILE_FLAGS = "default_compile_flags";

  /**
   * A string constant for the feature that makes us build per-object debug info files.
   */
  public static final String PER_OBJECT_DEBUG_INFO = "per_object_debug_info";

  /**
   * A string constant for the PIC feature.
   *
   * <p>If this feature is active (currently it cannot be switched off) and PIC compilation is
   * requested, the "pic" build variable will be defined with an empty string as its value.
   */
  public static final String PIC = "pic";

  /** A string constant for a feature that indicates that the toolchain can produce PIC objects. */
  public static final String SUPPORTS_PIC = "supports_pic";

  /**
   * A string constant for the feature the represents preprocessor defines.
   */
  public static final String PREPROCESSOR_DEFINES = "preprocessor_defines";

  /** A string constant for the includes feature. */
  public static final String INCLUDES = "includes";

  /**
   * A string constant for the include_paths feature.
   */
  public static final String INCLUDE_PATHS = "include_paths";

  /** A string constant for the feature signalling static linking mode. */
  public static final String STATIC_LINKING_MODE = "static_linking_mode";

  /** A string constant for the feature signalling dynamic linking mode. */
  public static final String DYNAMIC_LINKING_MODE = "dynamic_linking_mode";

  /**
   * A string constant for the ThinLTO feature.
   */
  public static final String THIN_LTO = "thin_lto";

  /*
   * A string constant for allowing implicit ThinLTO enablement for AFDO.
   */
  public static final String AUTOFDO_IMPLICIT_THINLTO = "autofdo_implicit_thinlto";

  /*
   * A string constant for enabling ThinLTO for AFDO implicitly.
   */
  public static final String ENABLE_AFDO_THINLTO = "enable_afdo_thinlto";

  /*
   * A string constant for enabling ThinLTO for FDO implicitly.
   */
  public static final String ENABLE_FDO_THINLTO = "enable_fdo_thinlto";

  /*
   * A string constant for enabling ThinLTO for XFDO implicitly.
   */
  public static final String ENABLE_XFDO_THINLTO = "enable_xbinaryfdo_thinlto";

  /**
   * A string constant for allowing use of shared LTO backend actions for linkstatic tests building
   * with ThinLTO.
   */
  public static final String THIN_LTO_LINKSTATIC_TESTS_USE_SHARED_NONLTO_BACKENDS =
      "thin_lto_linkstatic_tests_use_shared_nonlto_backends";

  /**
   * A string constant for allowing use of shared LTO backend actions for all linkstatic links
   * building with ThinLTO.
   */
  public static final String THIN_LTO_ALL_LINKSTATIC_USE_SHARED_NONLTO_BACKENDS =
      "thin_lto_all_linkstatic_use_shared_nonlto_backends";

  /**
   * A string constant for the PDB file generation feature, should only be used for toolchains
   * targeting Windows that include a linker producing PDB files
   */
  public static final String GENERATE_PDB_FILE = "generate_pdb_file";

  /**
   * A string constant for a feature that automatically exporting symbols on Windows. Bazel
   * generates a DEF file for object files of a cc_library, then use it at linking time. This
   * feature should only be used for toolchains targeting Windows, and the toolchain should support
   * using DEF files for exporting symbols.
   */
  public static final String WINDOWS_EXPORT_ALL_SYMBOLS = "windows_export_all_symbols";

  /** A string constant for a feature to disable WINDOWS_EXPORT_ALL_SYMBOLS. */
  public static final String NO_WINDOWS_EXPORT_ALL_SYMBOLS = "no_windows_export_all_symbols";

  /** A string constant for a feature to copy dynamic libraries to the binary's directory. */
  public static final String COPY_DYNAMIC_LIBRARIES_TO_BINARY = "copy_dynamic_libraries_to_binary";

  /** A string constant for a feature to statically link MSVCRT info on Windows. */
  public static final String STATIC_LINK_MSVCRT = "static_link_msvcrt";

  /** A string constant for a feature to statically link MSVCRT without debug info on Windows. */
  public static final String STATIC_LINK_MSVCRT_NO_DEBUG = "static_link_msvcrt_no_debug";

  /** A string constant for a feature to dynamically link MSVCRT without debug info on Windows. */
  public static final String DYNAMIC_LINK_MSVCRT_NO_DEBUG = "dynamic_link_msvcrt_no_debug";

  /** A string constant for a feature to statically link MSVCRT with debug info on Windows. */
  public static final String STATIC_LINK_MSVCRT_DEBUG = "static_link_msvcrt_debug";

  /** A string constant for a feature to dynamically link MSVCRT with debug info on Windows. */
  public static final String DYNAMIC_LINK_MSVCRT_DEBUG = "dynamic_link_msvcrt_debug";

  /** A string constant for a feature to statically link the C++ runtimes. */
  public static final String STATIC_LINK_CPP_RUNTIMES = "static_link_cpp_runtimes";

  /**
   * A string constant for a feature that indicates we are using a toolchain building for Windows.
   */
  public static final String TARGETS_WINDOWS = "targets_windows";

  /**
   * A string constant for a feature that indicates we are using a toolchain building for Windows.
   */
  public static final String SUPPORTS_INTERFACE_SHARED_LIBRARIES =
      "supports_interface_shared_libraries";

  /**
   * A string constant for no_stripping feature, if it's specified, then no strip action config is
   * needed, instead the stripped binary will simply be a symlink (or a copy on Windows) of the
   * original binary.
   */
  public static final String NO_STRIPPING = "no_stripping";

  /** A string constant for /showIncludes parsing feature, should only be used for MSVC toolchain */
  public static final String PARSE_SHOWINCLUDES = "parse_showincludes";

  /*
   * A string constant for the fdo_instrument feature.
   */
  public static final String FDO_INSTRUMENT = "fdo_instrument";

  /**
   * A string constant for the fdo_optimize feature.
   */
  public static final String FDO_OPTIMIZE = "fdo_optimize";

  /**
   * A string constant for the cache prefetch hints feature.
   */
  public static final String FDO_PREFETCH_HINTS = "fdo_prefetch_hints";

  /**
   * A string constant for the autofdo feature.
   */
  public static final String AUTOFDO = "autofdo";

  /** A string constant for the xbinaryfdo feature. */
  public static final String XBINARYFDO = "xbinaryfdo";

  /**
   * A string constant for the coverage feature.
   */
  public static final String COVERAGE = "coverage";

  /** Produce artifacts for coverage in llvm coverage mapping format. */
  public static final String LLVM_COVERAGE_MAP_FORMAT = "llvm_coverage_map_format";

  /** Produce artifacts for coverage in gcc coverage mapping format. */
  public static final String GCC_COVERAGE_MAP_FORMAT = "gcc_coverage_map_format";

  /** A string constant for the match-clif action. */
  public static final String MATCH_CLIF = "match_clif";

  /** A string constant for is_cc_fake_binary feature. */
  public static final String IS_CC_FAKE_BINARY = "is_cc_fake_binary";

  /** A feature marking that the toolchain can use --start-lib/--end-lib flags */
  public static final String SUPPORTS_START_END_LIB = "supports_start_end_lib";

  /**
   * A feature marking that the toolchain can produce binaries that load shared libraries at
   * runtime.
   */
  public static final String SUPPORTS_DYNAMIC_LINKER = "supports_dynamic_linker";

  /** Ancestor for all rules that do include scanning. */
  public static final class CcIncludeScanningRule implements RuleDefinition {
    @Override
    public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
      return builder
          .add(
              attr("$grep_includes", LABEL)
                  .cfg(HostTransition.INSTANCE)
                  .value(env.getToolsLabel("//tools/cpp:grep-includes")))
          .build();
    }

    @Override
    public Metadata getMetadata() {
      return RuleDefinition.Metadata.builder()
          .name("$cc_include_scanning_rule")
          .type(RuleClassType.ABSTRACT)
          .build();
    }
  }
}