Use ToolchainTypeRequirement in ToolchainContext and related classes.

Part of Optional Toolchains (bazelbuild#14726).

src/main/java/com/google/devtools/build/lib/analysis/BUILD

@@ -985,6 +985,7 @@ java_library(
     name = "resolved_toolchain_context",
     srcs = ["ResolvedToolchainContext.java"],
     deps = [
+        ":config/toolchain_type_requirement",
         ":template_variable_info",
         ":toolchain_context",
         "//src/main/java/com/google/devtools/build/lib/analysis/platform",
@@ -1091,6 +1092,7 @@ java_library(
     name = "toolchain_context",
     srcs = ["ToolchainContext.java"],
     deps = [
+        ":config/toolchain_type_requirement",
         "//src/main/java/com/google/devtools/build/lib/analysis/platform",
         "//src/main/java/com/google/devtools/build/lib/cmdline",
         "//src/main/java/com/google/devtools/build/lib/skyframe:toolchain_context_key",
@@ -2296,6 +2298,7 @@ java_library(
     name = "starlark/starlark_toolchain_context",
     srcs = ["starlark/StarlarkToolchainContext.java"],
     deps = [
+        ":config/toolchain_type_requirement",
         ":resolved_toolchain_context",
         "//src/main/java/com/google/devtools/build/lib/analysis/platform",
         "//src/main/java/com/google/devtools/build/lib/cmdline",

src/main/java/com/google/devtools/build/lib/analysis/ResolvedToolchainContext.java

@@ -86,7 +86,7 @@ public static ResolvedToolchainContext load(
         unloadedToolchainContext.key(),
         unloadedToolchainContext.executionPlatform(),
         unloadedToolchainContext.targetPlatform(),
-        unloadedToolchainContext.requiredToolchainTypes(),
+        unloadedToolchainContext.toolchainTypes(),
         unloadedToolchainContext.resolvedToolchainLabels(),
         // this:
         targetDescription,

src/main/java/com/google/devtools/build/lib/analysis/ToolchainContext.java

@@ -14,8 +14,8 @@
 package com.google.devtools.build.lib.analysis;
 
 import com.google.common.collect.ImmutableSet;
+import com.google.devtools.build.lib.analysis.config.ToolchainTypeRequirement;
 import com.google.devtools.build.lib.analysis.platform.PlatformInfo;
-import com.google.devtools.build.lib.analysis.platform.ToolchainTypeInfo;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.skyframe.ToolchainContextKey;
 
@@ -31,7 +31,7 @@ public interface ToolchainContext {
   PlatformInfo targetPlatform();
 
   /** Returns the toolchain types that were requested. */
-  ImmutableSet<ToolchainTypeInfo> requiredToolchainTypes();
+  ImmutableSet<ToolchainTypeRequirement> toolchainTypes();
 
   /** Returns the labels of the specific toolchains being used. */
   ImmutableSet<Label> resolvedToolchainLabels();

src/main/java/com/google/devtools/build/lib/analysis/config/ToolchainTypeRequirement.java

@@ -62,6 +62,9 @@ public static ToolchainTypeRequirement strictest(
    */
   public abstract boolean mandatory();
 
+  /** Returns a new Builder to copy this ToolchainTypeRequirement. */
+  public abstract Builder toBuilder();
+
   /** A builder for a new {@link ToolchainTypeRequirement}. */
   @AutoValue.Builder
   public interface Builder {

src/main/java/com/google/devtools/build/lib/analysis/starlark/StarlarkToolchainContext.java

@@ -17,6 +17,7 @@
 
 import com.google.auto.value.AutoValue;
 import com.google.devtools.build.lib.analysis.ResolvedToolchainContext;
+import com.google.devtools.build.lib.analysis.config.ToolchainTypeRequirement;
 import com.google.devtools.build.lib.analysis.platform.ToolchainInfo;
 import com.google.devtools.build.lib.analysis.platform.ToolchainTypeInfo;
 import com.google.devtools.build.lib.cmdline.Label;
@@ -110,8 +111,8 @@ public ToolchainInfo getIndex(
           "In %s, toolchain type %s was requested but only types [%s] are configured",
           toolchainContext().targetDescription(),
           toolchainTypeLabel,
-          toolchainContext().requiredToolchainTypes().stream()
-              .map(ToolchainTypeInfo::typeLabel)
+          toolchainContext().toolchainTypes().stream()
+              .map(ToolchainTypeRequirement::toolchainType)
               .map(Label::toString)
               .collect(joining(", ")));
     }

src/main/java/com/google/devtools/build/lib/skyframe/BUILD

@@ -2726,6 +2726,7 @@ java_library(
     deps = [
         ":toolchain_context_key",
         ":unloaded_toolchain_context",
+        "//src/main/java/com/google/devtools/build/lib/analysis:config/toolchain_type_requirement",
         "//src/main/java/com/google/devtools/build/lib/analysis/platform",
         "//src/main/java/com/google/devtools/build/lib/cmdline",
         "//src/main/java/com/google/devtools/build/skyframe:skyframe-objects",

src/main/java/com/google/devtools/build/lib/skyframe/RegisteredToolchainsCycleReporter.java

@@ -85,7 +85,7 @@ public boolean maybeReportCycle(
           }
           if (input.argument() instanceof SingleToolchainResolutionKey) {
             Label toolchainType =
-                ((SingleToolchainResolutionKey) input.argument()).toolchainTypeLabel();
+                ((SingleToolchainResolutionKey) input.argument()).toolchainType().toolchainType();
             return String.format("toolchain type %s", toolchainType);
           }
           if (input.argument() instanceof ToolchainContextKey) {

src/main/java/com/google/devtools/build/lib/skyframe/SingleToolchainResolutionFunction.java

@@ -23,6 +23,7 @@
 import com.google.devtools.build.lib.analysis.PlatformConfiguration;
 import com.google.devtools.build.lib.analysis.config.BuildConfigurationValue;
 import com.google.devtools.build.lib.analysis.config.ConfigMatchingProvider;
+import com.google.devtools.build.lib.analysis.config.ToolchainTypeRequirement;
 import com.google.devtools.build.lib.analysis.platform.ConstraintCollection;
 import com.google.devtools.build.lib.analysis.platform.ConstraintSettingInfo;
 import com.google.devtools.build.lib.analysis.platform.DeclaredToolchainInfo;
@@ -84,11 +85,11 @@ public SkyValue compute(SkyKey skyKey, Environment env)
         key.debugTarget()
             || configuration
                 .getFragment(PlatformConfiguration.class)
-                .debugToolchainResolution(key.toolchainTypeLabel());
+                .debugToolchainResolution(key.toolchainType().toolchainType());
 
     // Find the right one.
     return resolveConstraints(
-        key.toolchainTypeLabel(),
+        key.toolchainType(),
         key.availableExecutionPlatformKeys(),
         key.targetPlatformKey(),
         toolchains.registeredToolchains(),
@@ -103,7 +104,7 @@ public SkyValue compute(SkyKey skyKey, Environment env)
    */
   @Nullable
   private static SingleToolchainResolutionValue resolveConstraints(
-      Label toolchainTypeLabel,
+      ToolchainTypeRequirement toolchainType,
       List<ConfiguredTargetKey> availableExecutionPlatformKeys,
       ConfiguredTargetKey targetPlatformKey,
       ImmutableList<DeclaredToolchainInfo> toolchains,
@@ -135,13 +136,15 @@ private static SingleToolchainResolutionValue resolveConstraints(
     // check whether a platform has already been seen during processing.
     Set<ConfiguredTargetKey> platformKeysSeen = new HashSet<>();
     ImmutableMap.Builder<ConfiguredTargetKey, Label> builder = ImmutableMap.builder();
-    ToolchainTypeInfo toolchainType = null;
+    ToolchainTypeInfo toolchainTypeInfo = null;
 
     // Pre-filter for the correct toolchain type. This simplifies the loop and makes debugging
     // toolchain resolution much, much easier.
     ImmutableList<DeclaredToolchainInfo> filteredToolchains =
         toolchains.stream()
-            .filter(toolchain -> toolchain.toolchainType().typeLabel().equals(toolchainTypeLabel))
+            .filter(
+                toolchain ->
+                    toolchain.toolchainType().typeLabel().equals(toolchainType.toolchainType()))
             .collect(toImmutableList());
 
     for (DeclaredToolchainInfo toolchain : filteredToolchains) {
@@ -155,7 +158,7 @@ private static SingleToolchainResolutionValue resolveConstraints(
         debugMessage(
             eventHandler,
             "    Type %s: %s platform %s: Rejected toolchain %s; mismatching config settings: %s",
-            toolchainTypeLabel,
+            toolchainType.toolchainType(),
             "target",
             targetPlatform.label(),
             toolchain.toolchainLabel(),
@@ -169,7 +172,7 @@ private static SingleToolchainResolutionValue resolveConstraints(
           toolchain.targetConstraints(),
           "target",
           targetPlatform,
-          toolchainTypeLabel,
+          toolchainType,
           toolchain.toolchainLabel())) {
         continue;
       }
@@ -187,19 +190,19 @@ private static SingleToolchainResolutionValue resolveConstraints(
             toolchain.execConstraints(),
             "execution",
             executionPlatform,
-            toolchainTypeLabel,
+            toolchainType,
             toolchain.toolchainLabel())) {
           continue;
         }
 
         debugMessage(
             eventHandler,
             "  Type %s: target platform %s: execution %s: Selected toolchain %s",
-            toolchainTypeLabel,
+            toolchainType.toolchainType(),
             targetPlatform.label(),
             executionPlatformKey.getLabel(),
             toolchain.toolchainLabel());
-        toolchainType = toolchain.toolchainType();
+        toolchainTypeInfo = toolchain.toolchainType();
         builder.put(executionPlatformKey, toolchain.toolchainLabel());
         platformKeysSeen.add(executionPlatformKey);
       }
@@ -210,13 +213,12 @@ private static SingleToolchainResolutionValue resolveConstraints(
       debugMessage(
           eventHandler,
           "  Type %s: target platform %s: No toolchains found.",
-          toolchainTypeLabel,
+          toolchainType.toolchainType(),
           targetPlatform.label());
-      throw new ToolchainResolutionFunctionException(
-          new NoToolchainFoundException(toolchainTypeLabel));
+      throw new ToolchainResolutionFunctionException(new NoToolchainFoundException(toolchainType));
     }
 
-    return SingleToolchainResolutionValue.create(toolchainType, resolvedToolchainLabels);
+    return SingleToolchainResolutionValue.create(toolchainTypeInfo, resolvedToolchainLabels);
   }
 
   /**
@@ -242,7 +244,7 @@ private static boolean checkConstraints(
       ConstraintCollection toolchainConstraints,
       String platformType,
       PlatformInfo platform,
-      Label toolchainTypeLabel,
+      ToolchainTypeRequirement toolchainType,
       Label toolchainLabel) {
 
     // Check every constraint_setting in either the toolchain or the platform.
@@ -283,7 +285,7 @@ private static boolean checkConstraints(
       debugMessage(
           eventHandler,
           "    Type %s: %s platform %s: Rejected toolchain %s%s%s",
-          toolchainTypeLabel,
+          toolchainType.toolchainType(),
           platformType,
           platform.label(),
           toolchainLabel,
@@ -296,15 +298,17 @@ private static boolean checkConstraints(
 
   /** Used to indicate that a toolchain was not found for the current request. */
   public static final class NoToolchainFoundException extends NoSuchThingException {
-    private final Label missingToolchainTypeLabel;
+    private final ToolchainTypeRequirement missingToolchainType;
 
-    public NoToolchainFoundException(Label missingToolchainTypeLabel) {
-      super(String.format("no matching toolchain found for %s", missingToolchainTypeLabel));
-      this.missingToolchainTypeLabel = missingToolchainTypeLabel;
+    public NoToolchainFoundException(ToolchainTypeRequirement missingToolchainType) {
+      super(
+          String.format(
+              "no matching toolchain found for %s", missingToolchainType.toolchainType()));
+      this.missingToolchainType = missingToolchainType;
     }
 
-    public Label missingToolchainTypeLabel() {
-      return missingToolchainTypeLabel;
+    public ToolchainTypeRequirement missingToolchainType() {
+      return missingToolchainType;
     }
   }
 

src/main/java/com/google/devtools/build/lib/skyframe/SingleToolchainResolutionValue.java

@@ -18,6 +18,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.analysis.config.ToolchainTypeRequirement;
 import com.google.devtools.build.lib.analysis.platform.ToolchainTypeInfo;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.skyframe.SkyFunctionName;
@@ -35,26 +36,22 @@ public abstract class SingleToolchainResolutionValue implements SkyValue {
   // A key representing the input data.
   public static SingleToolchainResolutionKey key(
       BuildConfigurationKey configurationKey,
-      Label toolchainTypeLabel,
+      ToolchainTypeRequirement toolchainType,
       ConfiguredTargetKey targetPlatformKey,
       List<ConfiguredTargetKey> availableExecutionPlatformKeys) {
     return key(
-        configurationKey,
-        toolchainTypeLabel,
-        targetPlatformKey,
-        availableExecutionPlatformKeys,
-        false);
+        configurationKey, toolchainType, targetPlatformKey, availableExecutionPlatformKeys, false);
   }
 
   public static SingleToolchainResolutionKey key(
       BuildConfigurationKey configurationKey,
-      Label toolchainTypeLabel,
+      ToolchainTypeRequirement toolchainType,
       ConfiguredTargetKey targetPlatformKey,
       List<ConfiguredTargetKey> availableExecutionPlatformKeys,
       boolean debugTarget) {
     return SingleToolchainResolutionKey.create(
         configurationKey,
-        toolchainTypeLabel,
+        toolchainType,
         targetPlatformKey,
         availableExecutionPlatformKeys,
         debugTarget);
@@ -71,7 +68,7 @@ public SkyFunctionName functionName() {
 
     abstract BuildConfigurationKey configurationKey();
 
-    public abstract Label toolchainTypeLabel();
+    public abstract ToolchainTypeRequirement toolchainType();
 
     abstract ConfiguredTargetKey targetPlatformKey();
 
@@ -81,13 +78,13 @@ public SkyFunctionName functionName() {
 
     static SingleToolchainResolutionKey create(
         BuildConfigurationKey configurationKey,
-        Label toolchainTypeLabel,
+        ToolchainTypeRequirement toolchainType,
         ConfiguredTargetKey targetPlatformKey,
         List<ConfiguredTargetKey> availableExecutionPlatformKeys,
         boolean debugTarget) {
       return new AutoValue_SingleToolchainResolutionValue_SingleToolchainResolutionKey(
           configurationKey,
-          toolchainTypeLabel,
+          toolchainType,
           targetPlatformKey,
           ImmutableList.copyOf(availableExecutionPlatformKeys),
           debugTarget);