Only call filterDiscoveredHeaders() if include scanning is in effect.

This is a step towards making CppCompileAction work without input discovery.

This works because:

- filterDiscoveredHeaders() is not necessary if we don't discover any
- shouldPruneModules is always false if `shouldScanIncludes` is false (see CppCompileActionBuilder#shouldPruneModules())

RELNOTES: None.
PiperOrigin-RevId: 206721143

1 files changed, 5 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java
index 8c181ec7e4..5143793efa 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java
@@ -437,9 +437,14 @@ public class CppCompileAction extends AbstractAction
   public Iterable<Artifact> discoverInputs(ActionExecutionContext actionExecutionContext)
       throws ActionExecutionException, InterruptedException {
     additionalInputs = findUsedHeaders(actionExecutionContext);
+    if (!shouldScanIncludes) {
+      return additionalInputs;
+    }
+
     if (!shouldScanDotdFiles()) {
       additionalInputs = filterDiscoveredHeaders(actionExecutionContext, additionalInputs);
     }
+
     if (!shouldPruneModules) {
       return additionalInputs;
     }