commit b712f335a945c81a6b77fd48e96103ff09c8967b
author brandjon <brandjon@google.com> Sat Apr 29 16:03:32 2017 +0200
committer Vladimir Moskva <vladmos@google.com> Sun Apr 30 23:14:25 2017 +0200
tree b8ac0e5aa200cf19717aa22e51cb9abc457be572
parent e7fe50aa727df9ef0a3d37fa258d017971035515

Make Skylark interpreter read Skylark command-line flags

This is the second of two CLs for making command line options able to affect the Skylark interpreter. For the main kinds of evaluation contexts -- package loading, .bzl loading, rule analysis, aspect analysis, and computed defaults -- the SkylarkSemanticsOptions object is retrieved from Skyframe and passed along to the Environment builder. For other contexts such as tests, default values of builtin functions, and standalone Skylark, flags are currently not processed.

In the future, we may want to split into separate files the options that affect "pure" Skylark vs the options that affect Bazel-flavored Skylark. One possibility is to subclass SkylarkSemanticsOptions into SkylarkBazelSemanticsOptions, and go through an indirection in SkylarkUtils.

We could also pass SkylarkSemanticsOptions to the parser, to support --incompatible_* changes that alter Skylark's syntax. I don't think that's needed at the moment.

RELNOTES: None
PiperOrigin-RevId: 154628391

src/main/java/com/google/devtools/build/lib/syntax/Environment.java

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
index 9ac4789..6550ca2 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
@@ -27,6 +27,7 @@
 import com.google.devtools.build.lib.util.Pair;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.util.SpellChecker;
+import com.google.devtools.common.options.Options;
 import java.io.Serializable;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -306,6 +307,11 @@
   private final Frame dynamicFrame;
 
   /**
+   * The semantics options that affect how Skylark code is evaluated.
+   */
+  private final SkylarkSemanticsOptions semantics;
+
+  /**
    * An EventHandler for errors and warnings. This is not used in the BUILD language,
    * however it might be used in Skylark code called from the BUILD language, so shouldn't be null.
    */
@@ -472,6 +478,7 @@
   private Environment(
       Frame globalFrame,
       Frame dynamicFrame,
+      SkylarkSemanticsOptions semantics,
       EventHandler eventHandler,
       Map<String, Extension> importedExtensions,
       @Nullable String fileContentHashCode,
@@ -481,6 +488,7 @@
     this.dynamicFrame = Preconditions.checkNotNull(dynamicFrame);
     Preconditions.checkArgument(globalFrame.mutability().isMutable());
     Preconditions.checkArgument(dynamicFrame.mutability().isMutable());
+    this.semantics = semantics;
     this.eventHandler = eventHandler;
     this.importedExtensions = importedExtensions;
     this.phase = phase;
@@ -496,6 +504,7 @@
     private final Mutability mutability;
     private Phase phase = Phase.ANALYSIS;
     @Nullable private Frame parent;
+    @Nullable private SkylarkSemanticsOptions semantics;
     @Nullable private EventHandler eventHandler;
     @Nullable private Map<String, Extension> importedExtensions;
     @Nullable private String fileContentHashCode;
@@ -527,6 +536,11 @@
       return this;
     }
 
+    public Builder setSemantics(SkylarkSemanticsOptions semantics) {
+      this.semantics = semantics;
+      return this;
+    }
+
     /** Sets an EventHandler for errors and warnings. */
     public Builder setEventHandler(EventHandler eventHandler) {
       Preconditions.checkState(this.eventHandler == null);
@@ -555,12 +569,16 @@
       }
       Frame globalFrame = new Frame(mutability, parent);
       Frame dynamicFrame = new Frame(mutability, null);
+      if (semantics == null) {
+        semantics = Options.getDefaults(SkylarkSemanticsOptions.class);
+      }
       if (importedExtensions == null) {
         importedExtensions = ImmutableMap.of();
       }
       return new Environment(
           globalFrame,
           dynamicFrame,
+          semantics,
           eventHandler,
           importedExtensions,
           fileContentHashCode,
@@ -723,6 +741,10 @@
     return knownGlobalVariables != null && knownGlobalVariables.contains(varname);
   }
 
+  public SkylarkSemanticsOptions getSemantics() {
+    return semantics;
+  }
+
   public void handleEvent(Event event) {
     eventHandler.handle(event);
   }