From 5289584168c1428c4b3720b537c7ae4e0c2338ec Mon Sep 17 00:00:00 2001
From: Xi Ge <xi_ge@apple.com>
Date: Tue, 9 Dec 2025 14:29:08 -0800
Subject: [PATCH] PrebuiltModules: exclude discovered package interface when
 generating prebuilt modules

We never intend to build package Swift textual interfaces because they are only used for
intra-package module loading.

rdar://166174634
---
 Sources/SwiftDriver/Jobs/PrebuiltModulesJob.swift | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/Sources/SwiftDriver/Jobs/PrebuiltModulesJob.swift b/Sources/SwiftDriver/Jobs/PrebuiltModulesJob.swift
index 86b3b46dc..67b023ce3 100644
--- a/Sources/SwiftDriver/Jobs/PrebuiltModulesJob.swift
+++ b/Sources/SwiftDriver/Jobs/PrebuiltModulesJob.swift
@@ -529,10 +529,16 @@ public struct SDKPrebuiltModuleInputsCollector {
   }
 
   private func sanitizeInterfaceMap(_ map: [String: [PrebuiltModuleInput]]) -> [String: [PrebuiltModuleInput]] {
-    return map.filter {
+    return map.compactMapValues { inputs in
+      // Filter out .package.swiftinterface files
+      return inputs.filter { input in
+        !(input.path.file.extension == "swiftinterface" &&
+          input.path.file.basenameWithoutExt.hasSuffix(".package"))
+      }
+    }.filter { key, value in
       // Remove modules without associated .swiftinterface files and diagnose.
-      if $0.value.isEmpty {
-        diagEngine.emit(.warning("\($0.key) has no associated .swiftinterface files"),
+      if value.isEmpty {
+        diagEngine.emit(.warning("\(key) has no associated .swiftinterface files"),
                         location: nil)
         return false
       }