bazel syntax: delete SkylarkUtils

The Phase is now recorded in lib.packages.BazelStarlarkContext.
It is now always explicit whereas, before, failure to set it
caused it to assume a default of ANALYSIS.

In SkylarkRepositoryFunction, the "fetch" thread now uses
phase=LOADING where before it has none (=ANALYSIS), which
I suspect was an oversight.
PiperOrigin-RevId: 285236359

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

@@ -59,8 +59,6 @@
 import com.google.devtools.build.lib.syntax.ClassObject;
 import com.google.devtools.build.lib.syntax.Module;
 import com.google.devtools.build.lib.syntax.Mutability;
-import com.google.devtools.build.lib.syntax.SkylarkUtils;
-import com.google.devtools.build.lib.syntax.SkylarkUtils.Phase;
 import com.google.devtools.build.lib.syntax.StarlarkSemantics;
 import com.google.devtools.build.lib.syntax.StarlarkThread;
 import com.google.devtools.build.lib.syntax.StarlarkThread.Extension;
@@ -819,14 +817,14 @@ public StarlarkThread createRuleClassStarlarkThread(
             .build();
 
     new BazelStarlarkContext(
+            BazelStarlarkContext.Phase.LOADING,
             toolsRepository,
             configurationFragmentMap,
             repoMapping,
             new SymbolGenerator<>(fileLabel),
             /* analysisRuleLabel= */ null)
         .storeInThread(thread);
 
-    SkylarkUtils.setPhase(thread, Phase.LOADING);
     return thread;
   }
 

src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkAttr.java

@@ -51,7 +51,6 @@
 import com.google.devtools.build.lib.syntax.Printer;
 import com.google.devtools.build.lib.syntax.Sequence;
 import com.google.devtools.build.lib.syntax.SkylarkType;
-import com.google.devtools.build.lib.syntax.SkylarkUtils;
 import com.google.devtools.build.lib.syntax.Starlark;
 import com.google.devtools.build.lib.syntax.StarlarkFunction;
 import com.google.devtools.build.lib.syntax.StarlarkThread;
@@ -458,7 +457,7 @@ public Descriptor intAttribute(
       StarlarkThread thread)
       throws EvalException {
     // TODO(bazel-team): Replace literal strings with constants.
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.int", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.int");
     return createAttrDescriptor(
         "int",
         EvalUtils.<String, Object>optionMap(
@@ -477,7 +476,7 @@ public Descriptor stringAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.string", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.string");
     return createAttrDescriptor(
         "string",
         EvalUtils.<String, Object>optionMap(
@@ -503,7 +502,7 @@ public Descriptor labelAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.label", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.label");
     try {
       ImmutableAttributeFactory attribute =
           createAttributeFactory(
@@ -550,7 +549,7 @@ public Descriptor stringListAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.string_list", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.string_list");
     return createAttrDescriptor(
         "string_list",
         EvalUtils.<String, Object>optionMap(
@@ -578,7 +577,7 @@ public Descriptor intListAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.int_list", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.int_list");
     return createAttrDescriptor(
         "int_list",
         EvalUtils.<String, Object>optionMap(
@@ -612,7 +611,7 @@ public Descriptor labelListAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.label_list", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.label_list");
     Dict<String, Object> kwargs =
         EvalUtils.<String, Object>optionMap(
             thread,
@@ -661,8 +660,7 @@ public Descriptor labelKeyedStringDictAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(
-        thread, "attr.label_keyed_string_dict", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.label_keyed_string_dict");
     Dict<String, Object> kwargs =
         EvalUtils.<String, Object>optionMap(
             thread,
@@ -705,7 +703,7 @@ public Descriptor labelKeyedStringDictAttribute(
   public Descriptor boolAttribute(
       Boolean defaultO, String doc, Boolean mandatory, FuncallExpression ast, StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.bool", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.bool");
     return createAttrDescriptor(
         "bool",
         EvalUtils.<String, Object>optionMap(
@@ -719,7 +717,7 @@ public Descriptor boolAttribute(
   public Descriptor outputAttribute(
       Object defaultO, String doc, Boolean mandatory, FuncallExpression ast, StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.output", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.output");
 
     return createNonconfigurableAttrDescriptor(
         "output",
@@ -740,7 +738,7 @@ public Descriptor outputListAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.output_list", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.output_list");
 
     return createAttrDescriptor(
         "output_list",
@@ -769,7 +767,7 @@ public Descriptor stringDictAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.string_dict", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.string_dict");
     return createAttrDescriptor(
         "string_dict",
         EvalUtils.<String, Object>optionMap(
@@ -797,7 +795,7 @@ public Descriptor stringListDictAttribute(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.string_list_dict", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.string_list_dict");
     return createAttrDescriptor(
         "string_list_dict",
         EvalUtils.<String, Object>optionMap(
@@ -819,7 +817,7 @@ public Descriptor stringListDictAttribute(
   public Descriptor licenseAttribute(
       Object defaultO, String doc, Boolean mandatory, FuncallExpression ast, StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "attr.license", ast.getLocation());
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("attr.license");
     return createNonconfigurableAttrDescriptor(
         "license",
         EvalUtils.<String, Object>optionMap(

src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleClassFunctions.java

@@ -89,7 +89,6 @@
 import com.google.devtools.build.lib.syntax.Printer;
 import com.google.devtools.build.lib.syntax.Sequence;
 import com.google.devtools.build.lib.syntax.SkylarkType;
-import com.google.devtools.build.lib.syntax.SkylarkUtils;
 import com.google.devtools.build.lib.syntax.Starlark;
 import com.google.devtools.build.lib.syntax.StarlarkFunction;
 import com.google.devtools.build.lib.syntax.StarlarkThread;
@@ -297,9 +296,9 @@ public BaseFunction rule(
       FuncallExpression ast,
       StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(thread, "rule", ast.getLocation());
-
     BazelStarlarkContext bazelContext = BazelStarlarkContext.from(thread);
+    bazelContext.checkLoadingOrWorkspacePhase("rule");
+
     // analysis_test=true implies test=true.
     test |= Boolean.TRUE.equals(analysisTest);
 
@@ -644,7 +643,7 @@ public String getName() {
     public Object call(Object[] args, FuncallExpression astForLocation, StarlarkThread thread)
         throws EvalException, InterruptedException, ConversionException {
       Location loc = astForLocation.getLocation();
-      SkylarkUtils.checkLoadingPhase(thread, getName(), loc);
+      BazelStarlarkContext.from(thread).checkLoadingPhase(getName());
       if (ruleClass == null) {
         throw new EvalException(loc, "Invalid rule class hasn't been exported by a bzl file");
       }

src/main/java/com/google/devtools/build/lib/analysis/skylark/SkylarkRuleConfiguredTargetUtil.java

@@ -102,12 +102,12 @@ public static ConfiguredTarget buildRule(
           StarlarkThread.builder(mutability)
               .setSemantics(starlarkSemantics)
               .setEventHandler(ruleContext.getAnalysisEnvironment().getEventHandler())
-              .build(); // NB: loading phase functions are not available: this is analysis already,
-      // so we do *not* setLoadingPhase().
+              .build();
 
       new BazelStarlarkContext(
+              BazelStarlarkContext.Phase.ANALYSIS,
               toolsRepository,
-              /* fragmentNameToClass= */ null,
+              /*fragmentNameToClass=*/ null,
               ruleContext.getTarget().getPackage().getRepositoryMapping(),
               ruleContext.getSymbolGenerator(),
               ruleContext.getLabel())

src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryFunction.java

@@ -130,11 +130,12 @@ public RepositoryDirectoryValue.Builder fetch(
       // The fetch phase does not need the tools repository
       // or the fragment map because it happens before analysis.
       new BazelStarlarkContext(
-              /* toolsRepository = */ null,
-              /* fragmentNameToClass = */ null,
+              BazelStarlarkContext.Phase.LOADING, // ("fetch")
+              /*toolsRepository=*/ null,
+              /*fragmentNameToClass=*/ null,
               rule.getPackage().getRepositoryMapping(),
               new SymbolGenerator<>(key),
-              /* analysisRuleLabel= */ null)
+              /*analysisRuleLabel=*/ null)
           .storeInThread(thread);
 
       SkylarkRepositoryContext skylarkRepositoryContext =

src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryModule.java

@@ -26,6 +26,7 @@
 import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
 import com.google.devtools.build.lib.events.Location;
 import com.google.devtools.build.lib.packages.AttributeValueSource;
+import com.google.devtools.build.lib.packages.BazelStarlarkContext;
 import com.google.devtools.build.lib.packages.Package;
 import com.google.devtools.build.lib.packages.Package.NameConflictException;
 import com.google.devtools.build.lib.packages.PackageFactory;
@@ -47,10 +48,8 @@
 import com.google.devtools.build.lib.syntax.Identifier;
 import com.google.devtools.build.lib.syntax.Printer;
 import com.google.devtools.build.lib.syntax.Sequence;
-import com.google.devtools.build.lib.syntax.SkylarkUtils;
 import com.google.devtools.build.lib.syntax.Starlark;
 import com.google.devtools.build.lib.syntax.StarlarkFunction;
-import com.google.devtools.build.lib.syntax.StarlarkSemantics;
 import com.google.devtools.build.lib.syntax.StarlarkThread;
 import java.util.Map;
 
@@ -70,16 +69,15 @@ public BaseFunction repositoryRule(
       Boolean remotable,
       String doc,
       FuncallExpression ast,
-      StarlarkThread funcallThread)
+      StarlarkThread thread)
       throws EvalException {
-    SkylarkUtils.checkLoadingOrWorkspacePhase(funcallThread, "repository_rule", ast.getLocation());
-    StarlarkSemantics semantics = funcallThread.getSemantics();
+    BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase("repository_rule");
     // We'll set the name later, pass the empty string for now.
     RuleClass.Builder builder = new RuleClass.Builder("", RuleClassType.WORKSPACE, true);
 
     builder.addOrOverrideAttribute(attr("$local", BOOLEAN).defaultValue(local).build());
     builder.addOrOverrideAttribute(attr("$configure", BOOLEAN).defaultValue(configure).build());
-    if (semantics.experimentalRepoRemoteExec()) {
+    if (thread.getSemantics().experimentalRepoRemoteExec()) {
       builder.addOrOverrideAttribute(attr("$remotable", BOOLEAN).defaultValue(remotable).build());
       BaseRuleClasses.execPropertiesAttribute(builder);
     }
@@ -99,8 +97,7 @@ public BaseFunction repositoryRule(
     }
     builder.setConfiguredTargetFunction(implementation);
     builder.setRuleDefinitionEnvironmentLabelAndHashCode(
-        (Label) funcallThread.getGlobals().getLabel(),
-        funcallThread.getTransitiveContentHashCode());
+        (Label) thread.getGlobals().getLabel(), thread.getTransitiveContentHashCode());
     builder.setWorkspaceOnly();
     return new RepositoryRuleFunction(builder, ast.getLocation());
   }

src/main/java/com/google/devtools/build/lib/packages/BazelStarlarkContext.java

@@ -19,11 +19,19 @@
 import com.google.devtools.build.lib.analysis.RuleDefinitionContext;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.RepositoryName;
+import com.google.devtools.build.lib.syntax.EvalException;
 import com.google.devtools.build.lib.syntax.StarlarkThread;
 import javax.annotation.Nullable;
 
 /** Contextual information associated with each Starlark thread created by Bazel. */
-public class BazelStarlarkContext implements RuleDefinitionContext, Label.HasRepoMapping {
+public final class BazelStarlarkContext implements RuleDefinitionContext, Label.HasRepoMapping {
+
+  /** The phase to which this Starlark thread belongs. */
+  public enum Phase {
+    WORKSPACE,
+    LOADING,
+    ANALYSIS
+  }
 
   /** Return the Bazel information associated with the specified Starlark thread. */
   public static BazelStarlarkContext from(StarlarkThread thread) {
@@ -36,13 +44,15 @@ public void storeInThread(StarlarkThread thread) {
     thread.setThreadLocal(Label.HasRepoMapping.class, this);
   }
 
+  private final Phase phase;
   private final String toolsRepository;
   @Nullable private final ImmutableMap<String, Class<?>> fragmentNameToClass;
   private final ImmutableMap<RepositoryName, RepositoryName> repoMapping;
   private final SymbolGenerator<?> symbolGenerator;
   @Nullable private final Label analysisRuleLabel;
 
   /**
+   * @param phase the phase to which this Starlark thread belongs
    * @param toolsRepository the name of the tools repository, such as "@bazel_tools"
    * @param fragmentNameToClass a map from configuration fragment name to configuration fragment
    *     class, such as "apple" to AppleConfiguration.class
@@ -56,22 +66,30 @@ public void storeInThread(StarlarkThread thread) {
   // analysis, workspace, implicit outputs, computed defaults, etc), perhaps by splitting these into
   // separate structs, exactly one of which is populated (plus the common fields). And eliminate
   // SkylarkUtils.Phase.
+  // TODO(adonovan): move PackageFactory.PackageContext in here, for loading-phase threads.
   // TODO(adonovan): add a PackageIdentifier here, for use by the Starlark Label function.
   // TODO(adonovan): is there any reason not to put the entire RuleContext in this thread, for
   // analysis threads?
   public BazelStarlarkContext(
+      Phase phase,
       String toolsRepository,
       @Nullable ImmutableMap<String, Class<?>> fragmentNameToClass,
       ImmutableMap<RepositoryName, RepositoryName> repoMapping,
       SymbolGenerator<?> symbolGenerator,
       @Nullable Label analysisRuleLabel) {
+    this.phase = phase;
     this.toolsRepository = toolsRepository;
     this.fragmentNameToClass = fragmentNameToClass;
     this.repoMapping = repoMapping;
     this.symbolGenerator = Preconditions.checkNotNull(symbolGenerator);
     this.analysisRuleLabel = analysisRuleLabel;
   }
 
+  /** Returns the phase to which this Starlark thread belongs. */
+  public Phase getPhase() {
+    return phase;
+  }
+
   /** Returns the name of the tools repository, such as "@bazel_tools". */
   @Override
   public String getToolsRepository() {
@@ -105,4 +123,28 @@ public SymbolGenerator<?> getSymbolGenerator() {
   public Label getAnalysisRuleLabel() {
     return analysisRuleLabel;
   }
+
+  /**
+   * Checks that the Starlark thread is in the loading or the workspace phase.
+   *
+   * @param function name of a function that requires this check
+   */
+  public void checkLoadingOrWorkspacePhase(String function) throws EvalException {
+    if (phase == Phase.ANALYSIS) {
+      throw new EvalException(
+          null, "'" + function + "' cannot be called during the analysis phase");
+    }
+  }
+
+  /**
+   * Checks that the current StarlarkThread is in the loading phase.
+   *
+   * @param function name of a function that requires this check
+   */
+  public void checkLoadingPhase(String function) throws EvalException {
+    if (phase != Phase.LOADING) {
+      throw new EvalException(
+          null, "'" + function + "' can only be called during the loading phase");
+    }
+  }
 }

src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java

@@ -56,8 +56,6 @@
 import com.google.devtools.build.lib.syntax.NoneType;
 import com.google.devtools.build.lib.syntax.ParserInput;
 import com.google.devtools.build.lib.syntax.Printer;
-import com.google.devtools.build.lib.syntax.SkylarkUtils;
-import com.google.devtools.build.lib.syntax.SkylarkUtils.Phase;
 import com.google.devtools.build.lib.syntax.Starlark;
 import com.google.devtools.build.lib.syntax.StarlarkFile;
 import com.google.devtools.build.lib.syntax.StarlarkSemantics;
@@ -605,7 +603,7 @@ public NoneType callImpl(
         throw new EvalException(null, "unexpected positional arguments");
       }
       Location loc = call != null ? call.getLocation() : Location.BUILTIN;
-      SkylarkUtils.checkLoadingOrWorkspacePhase(thread, ruleClass.getName(), loc);
+      BazelStarlarkContext.from(thread).checkLoadingOrWorkspacePhase(ruleClass.getName());
       try {
         addRule(getContext(thread, loc), kwargs, loc, thread);
       } catch (RuleFactory.InvalidRuleException | Package.NameConflictException e) {
@@ -1004,14 +1002,14 @@ public Package.Builder evaluateBuildFile(
               .setEventHandler(eventHandler)
               .setImportedExtensions(imports)
               .build();
-      SkylarkUtils.setPhase(thread, Phase.LOADING);
 
       // TODO(adonovan): save this as a field in BazelSkylarkContext.
-      // It needn't be a third thread-local.
+      // It needn't be a second thread-local.
       thread.setThreadLocal(
           PackageContext.class, new PackageContext(pkgBuilder, globber, eventHandler));
 
       new BazelStarlarkContext(
+              BazelStarlarkContext.Phase.LOADING,
               ruleClassProvider.getToolsRepository(),
               /*fragmentNameToClass=*/ null,
               repositoryMapping,