Rules created by Skylark macros now have values for the attributes generator_name and generator_function.

Additionally, both Skylark macros and build extensions set the attribute generator_location in order to store the name of the file where generator_function was defined.

--
MOS_MIGRATED_REVID=101458757

3 files changed, 51 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java b/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
index 48887ddf1b..bb615d8b92 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BaseRuleClasses.java
@@ -205,6 +205,7 @@ public class BaseRuleClasses {
             .nonconfigurable("low-level attribute, used in TargetUtils without configurations"))
         .add(attr("generator_name", STRING).undocumented("internal"))
         .add(attr("generator_function", STRING).undocumented("internal"))
+        .add(attr("generator_location", STRING).undocumented("internal"))
         .add(attr("testonly", BOOLEAN).value(testonlyDefault)
             .nonconfigurable("policy decision: rules testability should be consistent"))
         .add(attr("features", STRING_LIST).orderIndependent())
diff --git a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleClassFunctions.java b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleClassFunctions.java
index 6cdb75fb5c..b1c48d4dd3 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleClassFunctions.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/SkylarkRuleClassFunctions.java
@@ -321,14 +321,37 @@ public class SkylarkRuleClassFunctions {
         }
         RuleClass ruleClass = builder.build(ruleClassName);
         PackageContext pkgContext = (PackageContext) env.lookup(PackageFactory.PKG_CONTEXT);
-        return RuleFactory.createAndAddRule(
-            pkgContext, ruleClass, (Map<String, Object>) args[0], ast);
+        return RuleFactory.createAndAddRule(pkgContext, ruleClass,
+            addGeneratorAttributesForMacros((Map<String, Object>) args[0], env), ast);
       } catch (InvalidRuleException | NameConflictException | NoSuchVariableException e) {
         throw new EvalException(ast.getLocation(), e.getMessage());
       }
     }
 
     /**
+     * If the current rule was created by a macro, this method sets the appropriate values for the
+     * attributes generator_{name, function, location} and returns a map of all attribute values.
+     *
+     * <p>Otherwise, the specified map of arguments is returned without any changes.
+     */
+    private Map<String, Object> addGeneratorAttributesForMacros(
+        Map<String, Object> args, Environment env) {
+      ImmutableList<BaseFunction> stackTrace = env.getStackTrace();
+      if (stackTrace.isEmpty()) {
+        // If there was a macro, it would be on the stack.
+        return args;
+      }
+
+      BaseFunction generator = stackTrace.get(0); // BaseFunction
+      ImmutableMap.Builder<String, Object> builder = ImmutableMap.builder();
+      builder.putAll(args);
+      builder.put("generator_name", args.get("name"));
+      builder.put("generator_function", generator.getName());
+      builder.put("generator_location", generator.getLocationPathAndLine());
+      return builder.build();
+    }
+
+    /**
      * Export a RuleFunction from a Skylark file with a given name.
      */
     void export(PathFragment skylarkFile, String ruleClassName) {
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java b/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java
index 816110097b..7574e1fe4e 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BaseFunction.java
@@ -21,7 +21,9 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Ordering;
 import com.google.common.collect.Sets;
 import com.google.devtools.build.lib.events.Location;
+import com.google.devtools.build.lib.events.Location.LineAndColumn;
 import com.google.devtools.build.lib.packages.Type.ConversionException;
+import com.google.devtools.build.lib.vfs.PathFragment;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -569,4 +571,27 @@ public abstract class BaseFunction {
   public int hashCode() {
     return Objects.hash(name, location);
   }
+
+  /**
+   * Returns the location (filename:line) of the BaseFunction's definition.
+   *
+   * <p>If such a location is not defined, this method returns an empty string.
+   */
+  public String getLocationPathAndLine() {
+    if (location == null) {
+      return "";
+    }
+
+    StringBuilder builder = new StringBuilder();
+    PathFragment path = location.getPath();
+    if (path != null) {
+      builder.append(path.getPathString());
+    }
+
+    LineAndColumn position = location.getStartLineAndColumn();
+    if (position != null) {
+      builder.append(":").append(position.getLine());
+    }
+    return builder.toString();
+  }
 }