Remove target libcTop label from CppOptions

the value of the flag seems to be no longer used

PiperOrigin-RevId: 792662960
Change-Id: I1057b4fb5e837a74c051967740b3eb3d5b0ff6fd

Author: mai93

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

@@ -790,29 +790,6 @@ public boolean shareNativeDepsStarlark(StarlarkThread thread) throws EvalExcepti
     return shareNativeDeps();
   }
 
-  /**
-   * Returns the value of the libc top-level directory (--grte_top) as specified on the command line
-   */
-  @Nullable
-  @StarlarkConfigurationField(
-      name = "target_libc_top_DO_NOT_USE_ONLY_FOR_CC_TOOLCHAIN",
-      doc = "DO NOT USE")
-  public Label getTargetLibcTopLabel() {
-    if (!isToolConfigurationDoNotUseWillBeRemovedFor129045294) {
-      // This isn't for a platform-enabled C++ toolchain (legacy C++ toolchains evaluate in the
-      // target configuration while platform-enabled toolchains evaluate in the exec configuration).
-      // targetLibcTopLabel is only intended for platform-enabled toolchains and can cause errors
-      // otherwise.
-      //
-      // For example: if a legacy-configured toolchain inherits a --grte_top pointing to an Android
-      // runtime alias that select()s on a target Android CPU and an iOS dep changes the CPU to an
-      // iOS CPU, the alias resolution fails. Legacy toolchains should read --grte_top through
-      // libcTopLabel (which changes along with the iOS CPU change), not this.
-      return null;
-    }
-    return cppOptions.targetLibcTopLabel;
-  }
-
   public boolean dontEnableHostNonhost() {
     return cppOptions.dontEnableHostNonhost;
   }

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

@@ -15,14 +15,12 @@
 
 import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableSet;
-import com.google.devtools.build.lib.actions.ActionAnalysisMetadata;
 import com.google.devtools.build.lib.analysis.config.CompilationMode;
 import com.google.devtools.build.lib.analysis.config.CoreOptionConverters.EmptyToNullLabelConverter;
 import com.google.devtools.build.lib.analysis.config.CoreOptionConverters.LabelConverter;
 import com.google.devtools.build.lib.analysis.config.FragmentOptions;
 import com.google.devtools.build.lib.analysis.config.PerLabelOptions;
 import com.google.devtools.build.lib.cmdline.Label;
-import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.rules.cpp.CppConfiguration.DynamicMode;
 import com.google.devtools.build.lib.rules.cpp.CppConfiguration.StripMode;
 import com.google.devtools.common.options.Converter;
@@ -82,10 +80,7 @@ public static class LibcTopLabelConverter implements Converter<Label> {
     @Nullable
     @Override
     public Label convert(String input, Object conversionContext) throws OptionsParsingException {
-      if (input.equals(TARGET_LIBC_TOP_NOT_YET_SET)) {
-        return Label.createUnvalidated(
-            PackageIdentifier.EMPTY_PACKAGE_ID, TARGET_LIBC_TOP_NOT_YET_SET);
-      } else if (input.equals("default")) {
+      if (input.equals("default")) {
         // This is needed for defining config_setting() values, the syntactic form
         // of which must be a String, to match absence of a --grte_top option.
         // "--grte_top=default" works on the command-line too,
@@ -693,42 +688,6 @@ public Label getMemProfProfileLabel() {
               + "for the exec configuration.")
   public Label hostLibcTopLabel;
 
-  /** See {@link #targetLibcTopLabel} documentation. * */
-  private static final String TARGET_LIBC_TOP_NOT_YET_SET = "TARGET LIBC TOP NOT YET SET";
-
-  /**
-   * This is a fake option used to pass data from target configuration to the exec configuration.
-   * It's a horrible hack that will be removed once toolchain-transitions are implemented.
-   *
-   * <p>We want to make sure this stays bound to the top-level configuration (as opposed to a
-   * configuration that comes out of a transition). Otherwise we risk multiple exec configurations
-   * writing to the same path and creating C++ action conflicts (C++ actions can not be shared
-   * across configurations: see {@link ActionAnalysisMetadata#isShareable}).
-   *
-   * <p>To accomplish this, we initialize this to a special value that means "I haven't been set
-   * yet" and use {@link #getNormalized} to rewrite it to {@link #libcTopLabel} <b>only</b> from
-   * that default. Blaze always evaluates top-level configurations first, so they'll trigger this.
-   * But no followup transitions can.
-   *
-   * <p>It's not sufficient to use null for the default. That wouldn't handle the case of the
-   * top-level {@link #libcTopLabel} being null and {@link
-   * com.google.devtools.build.lib.rules.android.AndroidConfiguration.Options#androidLibcTopLabel}
-   * being non-null.
-   */
-  // TODO(b/129045294): Remove once toolchain-transitions are implemented.
-  @Option(
-      name = "target libcTop label",
-      defaultValue = TARGET_LIBC_TOP_NOT_YET_SET,
-      documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
-      converter = LibcTopLabelConverter.class,
-      effectTags = {
-        OptionEffectTag.LOSES_INCREMENTAL_STATE,
-        OptionEffectTag.AFFECTS_OUTPUTS,
-        OptionEffectTag.LOADING_AND_ANALYSIS
-      },
-      metadataTags = {OptionMetadataTag.INTERNAL})
-  public Label targetLibcTopLabel;
-
   @Option(
       name = "experimental_inmemory_dotd_files",
       defaultValue = "true",
@@ -1041,20 +1000,4 @@ public Label getMemProfProfileLabel() {
       metadataTags = {OptionMetadataTag.EXPERIMENTAL},
       help = "If enabled, a Starlark version of compiling is used.")
   public boolean experimentalStarlarkCompiling;
-
-  /** See {@link #targetLibcTopLabel} documentation. * */
-  @Override
-  public FragmentOptions getNormalized() {
-    CppOptions newOptions = (CppOptions) this.clone();
-    boolean changed = false;
-    if (targetLibcTopLabel != null
-        && targetLibcTopLabel.getName().equals(TARGET_LIBC_TOP_NOT_YET_SET)) {
-      newOptions.targetLibcTopLabel = libcTopLabel;
-      changed = true;
-    }
-    if (changed) {
-      return newOptions;
-    }
-    return this;
-  }
 }

src/main/starlark/builtins_bzl/common/builtin_exec_platforms.bzl

@@ -293,7 +293,6 @@ bazel_fragments["CppOptions"] = fragment(
         "//command_line_option:host_per_file_copt",
         "//command_line_option:host_grte_top",
         "//command_line_option:host_linkopt",
-        "//command_line_option:target libcTop label",
         "//command_line_option:experimental_link_static_libraries_once",
         "//command_line_option:experimental_cc_implementation_deps",
         "//command_line_option:experimental_cpp_modules",

src/main/starlark/builtins_bzl/common/cc/cc_toolchain.bzl

@@ -81,7 +81,6 @@ def _attributes(ctx):
         grep_includes = _single_file(ctx, "_grep_includes")
 
     latebound_libc = _latebound_libc(ctx, "libc_top", "_libc_top")
-    latebound_target_libc = _latebound_libc(ctx, "libc_top", "_target_libc_top")
 
     all_files = _files(ctx, "all_files")
     return struct(
@@ -115,9 +114,7 @@ def _attributes(ctx):
         coverage_files = _files(ctx, "coverage_files") or all_files,
         compiler_files_without_includes = _files(ctx, "compiler_files_without_includes"),
         libc = _files(ctx, latebound_libc),
-        target_libc = _files(ctx, latebound_target_libc),
         libc_top_label = _label(ctx, latebound_libc),
-        target_libc_top_label = _label(ctx, latebound_target_libc),
         if_so_builder = ctx.file._interface_library_builder,
         allowlist_for_layering_check = _package_specification_provider(ctx, "disabling_parse_headers_and_layering_check_allowed"),
         build_info_files = _provider(ctx.attr._build_info_translator, OutputGroupInfo),
@@ -335,9 +332,6 @@ The label of the rule providing <code>cc_toolchain_config_info</code>.""",
             allow_single_file = True,
             cfg = "exec",
         ),
-        "_target_libc_top": attr.label(
-            default = configuration_field(fragment = "cpp", name = "target_libc_top_DO_NOT_USE_ONLY_FOR_CC_TOOLCHAIN"),
-        ),
         "_whitelist_disabling_parse_headers_and_layering_check_allowed": attr.label(
             default = "@" + semantics.get_repo() + "//tools/build_defs/cc/whitelists/parse_headers_and_layering_check:disabling_parse_headers_and_layering_check_allowed",
             providers = [PackageSpecificationInfo],