CcToolchainAttributesProvider is never actually used as a ToolchainIn…

…fo provider.

Tested with Bazel downstream: https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/1894 (only failures also happen in the nightly).

PiperOrigin-RevId: 355635392

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

@@ -25,6 +25,7 @@
 import com.google.devtools.build.lib.analysis.RunfilesProvider;
 import com.google.devtools.build.lib.analysis.TemplateVariableInfo;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
+import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
 import com.google.devtools.build.lib.cmdline.Label;
 import java.io.Serializable;
 import java.util.HashMap;
@@ -81,8 +82,10 @@ public ConfiguredTarget create(RuleContext ruleContext)
     if (!CppHelper.useToolchainResolution(ruleContext)) {
       // This is not a platforms-backed build, let's provide CcToolchainAttributesProvider
       // and have cc_toolchain_suite select one of its toolchains and create CcToolchainProvider
-      // from its attributes.
-      return ruleConfiguredTargetBuilder.build();
+      // from its attributes. We also need to provide a do-nothing ToolchainInfo.
+      return ruleConfiguredTargetBuilder
+          .addNativeDeclaredProvider(new ToolchainInfo(ImmutableMap.of("cc", "dummy cc toolchain")))
+          .build();
     }
 
     // This is a platforms-backed build, we will not analyze cc_toolchain_suite at all, and we are

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

@@ -18,7 +18,6 @@
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.actions.Actions;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.analysis.Allowlist;
@@ -30,24 +29,24 @@
 import com.google.devtools.build.lib.analysis.PackageSpecificationProvider;
 import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
-import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
 import com.google.devtools.build.lib.cmdline.Label;
 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.BuildType;
 import com.google.devtools.build.lib.packages.BuiltinProvider;
+import com.google.devtools.build.lib.packages.Info;
 import com.google.devtools.build.lib.packages.License;
+import com.google.devtools.build.lib.packages.NativeInfo;
 import com.google.devtools.build.lib.packages.Type;
 import com.google.devtools.build.lib.rules.cpp.CcToolchain.AdditionalBuildVariablesComputer;
-import net.starlark.java.syntax.Location;
 
 /**
  * Provider encapsulating all the information from the cc_toolchain rule that affects creation of
  * {@link CcToolchainProvider}
  */
 // TODO(adonovan): rename s/Provider/Info/.
-public class CcToolchainAttributesProvider extends ToolchainInfo implements HasCcToolchainLabel {
+public class CcToolchainAttributesProvider extends NativeInfo implements HasCcToolchainLabel {
 
   public static final BuiltinProvider<CcToolchainAttributesProvider> PROVIDER =
       new BuiltinProvider<CcToolchainAttributesProvider>(
@@ -106,7 +105,7 @@ public CcToolchainAttributesProvider(
       RuleContext ruleContext,
       boolean isAppleToolchain,
       AdditionalBuildVariablesComputer additionalBuildVariablesComputer) {
-    super(ImmutableMap.of(), Location.BUILTIN);
+    super();
     this.ccToolchainLabel = ruleContext.getLabel();
     this.toolchainIdentifier = ruleContext.attributes().get("toolchain_identifier", Type.STRING);
     if (ruleContext.getFragment(CppConfiguration.class).removeCpuCompilerCcToolchainAttributes()
@@ -221,6 +220,11 @@ public CcToolchainAttributesProvider(
             ruleContext, CcToolchain.LOOSE_HEADER_CHECK_ALLOWLIST);
   }
 
+  @Override
+  public BuiltinProvider<CcToolchainAttributesProvider> getProvider() {
+    return PROVIDER;
+  }
+
   public String getCpu() {
     return cpu;
   }
@@ -468,6 +472,6 @@ private static NestedSet<Artifact> fullInputsForLink(
  * CcToolchainProvider}.
  */
 // TODO(b/113849758): Remove once behavior is migrated.
-interface HasCcToolchainLabel {
+interface HasCcToolchainLabel extends Info {
   Label getCcToolchainLabel();
 }

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

@@ -28,6 +28,7 @@
 import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.BuildType;
+import com.google.devtools.build.lib.packages.BuiltinProvider;
 import java.util.Map;
 
 /**
@@ -60,6 +61,9 @@ public ConfiguredTarget create(RuleContext ruleContext)
       ccToolchainProvider =
           selectCcToolchain(
               CcToolchainProvider.class,
+              // TOOD(b/17906781): Change this to CcToolchainProvider when CcToolchainProvider isn't
+              // a subclass of ToolchainInfo.
+              ToolchainInfo.PROVIDER,
               ruleContext,
               transformedCpu,
               compiler,
@@ -70,6 +74,7 @@ public ConfiguredTarget create(RuleContext ruleContext)
       CcToolchainAttributesProvider selectedAttributes =
           selectCcToolchain(
               CcToolchainAttributesProvider.class,
+              CcToolchainAttributesProvider.PROVIDER,
               ruleContext,
               transformedCpu,
               compiler,
@@ -107,14 +112,16 @@ public ConfiguredTarget create(RuleContext ruleContext)
 
   private <T extends HasCcToolchainLabel> T selectCcToolchain(
       Class<T> clazz,
+      // TOOD(b/17906781): Change the type to T when CcToolchainprovider has its own provider type.
+      BuiltinProvider<?> providerType,
       RuleContext ruleContext,
       String cpu,
       String compiler,
       Label selectedCcToolchain)
       throws RuleErrorException {
     T selectedAttributes = null;
     for (TransitiveInfoCollection dep : ruleContext.getPrerequisiteMap("toolchains").values()) {
-      T attributes = clazz.cast(dep.get(ToolchainInfo.PROVIDER));
+      T attributes = clazz.cast(dep.get(providerType));
       if (attributes != null && attributes.getCcToolchainLabel().equals(selectedCcToolchain)) {
         selectedAttributes = attributes;
         break;