From 4df2949c07a15bc7ff0dd4df5d7cc2b1a8501a91 Mon Sep 17 00:00:00 2001
From: WeijunDeng <dwjchn@gmail.com>
Date: Tue, 14 Oct 2025 16:28:03 +0800
Subject: [PATCH] [Incremental Builds]When a file changed, do not affect nodes
 that have a fingerprint and have not changed.

---
 .../ModuleDependencyGraphParts/Tracer.swift              | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Sources/SwiftDriver/IncrementalCompilation/ModuleDependencyGraphParts/Tracer.swift b/Sources/SwiftDriver/IncrementalCompilation/ModuleDependencyGraphParts/Tracer.swift
index 6bd8fc8f9..8d91c139c 100644
--- a/Sources/SwiftDriver/IncrementalCompilation/ModuleDependencyGraphParts/Tracer.swift
+++ b/Sources/SwiftDriver/IncrementalCompilation/ModuleDependencyGraphParts/Tracer.swift
@@ -86,6 +86,15 @@ extension ModuleDependencyGraph.Tracer {
 
     // If this use also provides something, follow it
     for use in graph.nodeFinder.uses(of: definition) {
+      if (definition.key.aspect == .interface) {
+        // .swift or .swiftmodule
+        if case .sourceFileProvide(name: _) = definition.key.designator {
+          if use.keyAndFingerprint.fingerprint != nil {
+            // When a file changed, do not affect nodes that have a fingerprint and have not changed.
+            continue
+          }
+        }
+      }
       collectNextPreviouslyUntracedDependent(of: use)
     }
     traceDeparture(pathLengthAfterArrival);