Disallow Skylark implicit outputs from referencing attributes

that use 'select': fail with a clean user error rather than
crashing.

Rule outputs are "special" in that they need to be defined before
select statements can be evaluated (e.g. before the analysis
phase begins).

--
MOS_MIGRATED_REVID=98000760

1 files changed, 9 insertions, 7 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/packages/ImplicitOutputsFunction.java b/src/main/java/com/google/devtools/build/lib/packages/ImplicitOutputsFunction.java
index 61ffea55d8..b05082ade0 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/ImplicitOutputsFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/ImplicitOutputsFunction.java
@@ -86,14 +86,16 @@ public abstract class ImplicitOutputsFunction {
     public ImmutableMap<String, String> calculateOutputs(AttributeMap map) throws EvalException {
       Map<String, Object> attrValues = new HashMap<>();
       for (String attrName : map.getAttributeNames()) {
-        // TODO(bazel-team): support configurable attributes - which value would we want to
-        // pass on to the child outputs function? Maybe implicit output functions shouldn't
-        // have access to configurable values (makes them too complicated?). Maybe they
-        // should have *full* access (gives them the most power?).
-        Object value = map.get(attrName, map.getAttributeType(attrName));
-        attrValues.put(attrName, value == null ? Environment.NONE : value);
+        Type<?> attrType = map.getAttributeType(attrName);
+        // Don't include configurable attributes: we don't know which value they might take
+        // since we don't yet have a build configuration.
+        if (!map.isConfigurable(attrName, attrType)) {
+          Object value = map.get(attrName, attrType);
+          attrValues.put(attrName, value == null ? Environment.NONE : value);
+        }
       }
-      ClassObject attrs = new SkylarkClassObject(attrValues, "No such attribute '%s'");
+      ClassObject attrs = new SkylarkClassObject(attrValues, "Attribute '%s' either doesn't exist "
+          + "or uses a select() (i.e. could have multiple values)");
       try {
         ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
         for (Map.Entry<String, String> entry : castMap(callback.call(attrs),