From 5a8280a7e90319e6ac0641d507158eb3c4628eba Mon Sep 17 00:00:00 2001
From: John Cater <jcater@google.com>
Date: Wed, 31 Jul 2024 07:33:03 -0700
Subject: [PATCH] Add check that NativeAndStarlarkFlags actually contains
 flags.

Part of fixing #23147.

Closes #23157.

PiperOrigin-RevId: 658001205
Change-Id: Ibf85095d66f70ebcf078bd7f6da108bab37746f1
---
 .../lib/analysis/producers/BuildConfigurationKeyProducer.java | 2 +-
 .../build/lib/skyframe/config/NativeAndStarlarkFlags.java     | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/producers/BuildConfigurationKeyProducer.java b/src/main/java/com/google/devtools/build/lib/analysis/producers/BuildConfigurationKeyProducer.java
index d1560741b1361f..dd043672944300 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/producers/BuildConfigurationKeyProducer.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/producers/BuildConfigurationKeyProducer.java
@@ -201,7 +201,7 @@ private StateMachine finishConfigurationKeyProcessing(BuildConfigurationKey newC
   private BuildConfigurationKey applyFlagsForOptions(BuildOptions options)
       throws OptionsParsingException {
     // Does the target platform provide any flags?
-    if (this.platformFlags != null) {
+    if (this.platformFlags != null && !this.platformFlags.isEmpty()) {
       OptionsParsingResult parsingResult = platformFlags.parse();
       BuildOptions updatedOptions = options.applyParsingResult(parsingResult);
       return BuildConfigurationKey.create(updatedOptions);
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/config/NativeAndStarlarkFlags.java b/src/main/java/com/google/devtools/build/lib/skyframe/config/NativeAndStarlarkFlags.java
index b605b83874df4c..97fbdb15444ede 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/config/NativeAndStarlarkFlags.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/config/NativeAndStarlarkFlags.java
@@ -64,6 +64,10 @@ public static Builder builder() {
   @Nullable
   abstract RepositoryMapping repoMapping();
 
+  public boolean isEmpty() {
+    return nativeFlags().isEmpty() && starlarkFlags().isEmpty();
+  }
+
   public OptionsParsingResult parse() throws OptionsParsingException {
     OptionsParser parser =
         OptionsParser.builder()