Introduce --enabled_toolchain_types, which when set to the cpp toolchain causes the cc_toolchain dependency of cc targets to be selected using the platforms/toolchains constraint solving system.

PiperOrigin-RevId: 169250621

4 files changed, 44 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainProvider.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainProvider.java
index 8fc5075c46..74aa13de0b 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainProvider.java
@@ -124,7 +124,7 @@ public final class CcToolchainProvider extends ToolchainInfo {
       ImmutableMap<String, String> environment,
       ImmutableList<PathFragment> builtInIncludeDirectories,
       @Nullable PathFragment sysroot) {
-    super(ImmutableMap.<String, Object>of(), Location.BUILTIN);
+    super(ImmutableMap.of(), Location.BUILTIN);
     this.cppConfiguration = cppConfiguration;
     this.crosstool = Preconditions.checkNotNull(crosstool);
     this.crosstoolMiddleman = Preconditions.checkNotNull(crosstoolMiddleman);
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
index 4133decc06..fa0f18f287 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfiguration.java
@@ -41,6 +41,7 @@ import com.google.devtools.build.lib.packages.OutputFile;
 import com.google.devtools.build.lib.packages.Target;
 import com.google.devtools.build.lib.rules.cpp.CppActionConfigs.CppPlatform;
 import com.google.devtools.build.lib.rules.cpp.CppConfigurationLoader.CppConfigurationParameters;
+import com.google.devtools.build.lib.rules.cpp.CrosstoolConfigurationLoader.CrosstoolFile;
 import com.google.devtools.build.lib.rules.cpp.transitions.ContextCollectorOwnerTransition;
 import com.google.devtools.build.lib.rules.cpp.transitions.DisableLipoTransition;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
@@ -225,6 +226,7 @@ public class CppConfiguration extends BuildConfiguration.Fragment {
   }
 
   private final Label crosstoolTop;
+  private final CrosstoolFile crosstoolFile;
   private final String hostSystemName;
   private final String compiler;
   // TODO(lberki): desiredCpu *should* be always the same as targetCpu, except that we don't check
@@ -336,6 +338,7 @@ public class CppConfiguration extends BuildConfiguration.Fragment {
     this.targetLibc = toolchain.getTargetLibc();
     this.targetOS = toolchain.getCcTargetOs();
     this.crosstoolTop = params.crosstoolTop;
+    this.crosstoolFile = params.crosstoolFile;
     this.ccToolchainLabel = params.ccToolchainLabel;
     this.stlLabel = params.stlLabel;
     this.compilationMode = params.commonOptions.compilationMode;
@@ -834,6 +837,11 @@ public class CppConfiguration extends BuildConfiguration.Fragment {
     return toolchainIdentifier;
   }
 
+  /** Returns the contents of the CROSSTOOL for this configuration. */
+  public CrosstoolFile getCrosstoolFile() {
+    return crosstoolFile;
+  }
+
   /**
    * Returns the path of the crosstool.
    */
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java
index b334b10923..73f3b1b6ea 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppConfigurationLoader.java
@@ -83,6 +83,7 @@ public class CppConfigurationLoader implements ConfigurationFragmentFactory {
    */
   public static class CppConfigurationParameters {
     protected final CrosstoolConfig.CToolchain toolchain;
+    protected final CrosstoolConfigurationLoader.CrosstoolFile crosstoolFile;
     protected final String cacheKeySuffix;
     protected final BuildConfiguration.Options commonOptions;
     protected final CppOptions cppOptions;
@@ -94,6 +95,7 @@ public class CppConfigurationLoader implements ConfigurationFragmentFactory {
 
     CppConfigurationParameters(
         CrosstoolConfig.CToolchain toolchain,
+        CrosstoolConfigurationLoader.CrosstoolFile crosstoolFile,
         String cacheKeySuffix,
         BuildOptions buildOptions,
         Path fdoZip,
@@ -102,6 +104,7 @@ public class CppConfigurationLoader implements ConfigurationFragmentFactory {
         Label stlLabel,
         Label sysrootLabel) {
       this.toolchain = toolchain;
+      this.crosstoolFile = crosstoolFile;
       this.cacheKeySuffix = cacheKeySuffix;
       this.commonOptions = buildOptions.get(BuildConfiguration.Options.class);
       this.cppOptions = buildOptions.get(CppOptions.class);
@@ -224,6 +227,7 @@ public class CppConfigurationLoader implements ConfigurationFragmentFactory {
 
     return new CppConfigurationParameters(
         toolchain,
+        file,
         file.getMd5(),
         options,
         fdoZip,
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
index 7c48a9ff3a..aff9c39e18 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
@@ -27,9 +27,11 @@ import com.google.devtools.build.lib.actions.MiddlemanFactory;
 import com.google.devtools.build.lib.analysis.AnalysisUtils;
 import com.google.devtools.build.lib.analysis.FileProvider;
 import com.google.devtools.build.lib.analysis.MakeVariableSupplier;
+import com.google.devtools.build.lib.analysis.PlatformConfiguration;
 import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
 import com.google.devtools.build.lib.analysis.RuleContext;
 import com.google.devtools.build.lib.analysis.StaticallyLinkedMarkerProvider;
+import com.google.devtools.build.lib.analysis.ToolchainContext.ResolvedToolchainProviders;
 import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
 import com.google.devtools.build.lib.analysis.actions.CustomCommandLine;
 import com.google.devtools.build.lib.analysis.actions.SpawnAction;
@@ -328,6 +330,35 @@ public class CppHelper {
    */
   public static CcToolchainProvider getToolchain(RuleContext ruleContext,
       TransitiveInfoCollection dep) {
+    Label toolchainType;
+    // TODO(b/65835260): Remove this conditional once j2objc can learn the toolchain type.
+    if (ruleContext.attributes().has(CcToolchain.CC_TOOLCHAIN_TYPE_ATTRIBUTE_NAME)) {
+      toolchainType =
+          ruleContext.attributes().get(CcToolchain.CC_TOOLCHAIN_TYPE_ATTRIBUTE_NAME, LABEL);
+    } else {
+      toolchainType = null;
+    }
+
+    if (toolchainType != null
+        && ruleContext
+            .getFragment(PlatformConfiguration.class)
+            .getEnabledToolchainTypes()
+            .contains(toolchainType)) {
+      return getToolchainFromPlatformConstraints(ruleContext, toolchainType);
+    }
+    return getToolchainFromCrosstoolTop(ruleContext, dep);
+  }
+
+  private static CcToolchainProvider getToolchainFromPlatformConstraints(
+      RuleContext ruleContext, Label toolchainType) {
+    ResolvedToolchainProviders providers =
+        (ResolvedToolchainProviders)
+            ruleContext.getToolchainContext().getResolvedToolchainProviders();
+    return (CcToolchainProvider) providers.getForToolchainType(toolchainType);
+  }
+
+  private static CcToolchainProvider getToolchainFromCrosstoolTop(
+      RuleContext ruleContext, TransitiveInfoCollection dep) {
     // TODO(bazel-team): Consider checking this generally at the attribute level.
     if ((dep == null) || (dep.get(ToolchainInfo.PROVIDER) == null)) {
       ruleContext.ruleError("The selected C++ toolchain is not a cc_toolchain rule");