From f61c64cd1cac7c9a6ec93d63647f332a5915da13 Mon Sep 17 00:00:00 2001
From: Ben Boeckel <ben.boeckel@kitware.com>
Date: Mon, 4 Dec 2023 08:43:25 -0500
Subject: cmLocalGenerator: prevent scanning of PCH source files

---
 Source/cmLocalGenerator.cxx | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index fe8d502..caac535 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2706,6 +2706,9 @@ void cmLocalGenerator::AddPchDependencies(cmGeneratorTarget* target)
 
         auto* pch_sf = this->Makefile->GetOrCreateSource(
           pchSource, false, cmSourceFileLocationKind::Known);
+        // PCH sources should never be scanned as they cannot contain C++
+        // module references.
+        pch_sf->SetProperty("CXX_SCAN_FOR_MODULES", "0");
 
         if (!this->GetGlobalGenerator()->IsXcode()) {
           if (!ReuseFrom) {
-- 
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