1 files changed, 30 insertions, 8 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainRule.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainRule.java
index 29831acc1c..a7bf17bf51 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainRule.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainRule.java
@@ -30,6 +30,7 @@ import com.google.devtools.build.lib.analysis.TemplateVariableInfo;
 import com.google.devtools.build.lib.analysis.config.HostTransition;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.Attribute.LabelLateBoundDefault;
+import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleClass;
 import com.google.devtools.build.lib.packages.Target;
@@ -40,6 +41,11 @@ import com.google.devtools.build.lib.syntax.Type;
  * Rule definition for compiler definition.
  */
 public final class CcToolchainRule implements RuleDefinition {
+
+  public static final String LIBC_TOP_ATTR = ":libc_top";
+  public static final String FDO_OPTIMIZE_ATTR = ":fdo_optimize";
+  public static final String FDO_PROFILE_ATTR = ":fdo_profile";
+
   /**
    * Determines if the given target is a cc_toolchain or one of its subclasses. New subclasses
    * should be added to this method.
@@ -49,19 +55,31 @@ public final class CcToolchainRule implements RuleDefinition {
     return ruleClass.endsWith("cc_toolchain");
   }
 
-  private static final LabelLateBoundDefault<?> LIBC_TOP =
+  private static Label getLabel(AttributeMap attributes, String attrName, Label defaultValue) {
+    if (attributes.has(attrName, LABEL)) {
+      Label value = attributes.get(attrName, LABEL);
+      if (value != null) {
+        return value;
+      }
+    }
+    return defaultValue;
+  }
+
+  private static final LabelLateBoundDefault<?> LIBC_TOP_VALUE =
       LabelLateBoundDefault.fromTargetConfiguration(
           CppConfiguration.class,
           null,
-          (rule, attributes, cppConfig) -> cppConfig.getSysrootLabel());
+          (rule, attributes, cppConfig) ->
+              // This avoids analyzing the label from the CROSSTOOL if the attribute is set.
+              getLabel(attributes, "libc_top", cppConfig.getSysrootLabel()));
 
-  private static final LabelLateBoundDefault<?> FDO_OPTIMIZE_LABEL =
+  private static final LabelLateBoundDefault<?> FDO_OPTIMIZE_VALUE =
       LabelLateBoundDefault.fromTargetConfiguration(
           CppConfiguration.class,
           null,
           (rule, attributes, cppConfig) -> cppConfig.getFdoOptimizeLabel());
 
-  private static final LabelLateBoundDefault<?> FDO_PROFILE_LABEL =
+  private static final LabelLateBoundDefault<?> FDO_PROFILE_VALUE =
       LabelLateBoundDefault.fromTargetConfiguration(
           CppConfiguration.class,
           null,
@@ -149,13 +167,17 @@ public final class CcToolchainRule implements RuleDefinition {
                         null,
                         (rule, attributes, cppConfig) ->
                             shouldIncludeZipperInToolchain(cppConfig) ? zipper : null)))
-        .add(attr(":libc_top", LABEL).value(LIBC_TOP))
-        .add(attr(":fdo_optimize", LABEL).singleArtifact().value(FDO_OPTIMIZE_LABEL))
+
+        // TODO(b/78578234): Make this the default and remove the late-bound versions.
+        .add(attr("libc_top", LABEL).allowedFileTypes())
+        .add(attr(LIBC_TOP_ATTR, LABEL).value(LIBC_TOP_VALUE))
+
+        .add(attr(FDO_OPTIMIZE_ATTR, LABEL).singleArtifact().value(FDO_OPTIMIZE_VALUE))
         .add(
-            attr(":fdo_profile", LABEL)
+            attr(FDO_PROFILE_ATTR, LABEL)
                 .allowedRuleClasses("fdo_profile")
                 .mandatoryProviders(ImmutableList.of(FdoProfileProvider.PROVIDER.id()))
-                .value(FDO_PROFILE_LABEL))
+                .value(FDO_PROFILE_VALUE))
         .add(
             attr(TransitiveLipoInfoProvider.LIPO_CONTEXT_COLLECTOR, LABEL)
                 .cfg(LipoContextCollectorTransition.INSTANCE)