From ee657c95175c7338a5a8a28654482bab33b74129 Mon Sep 17 00:00:00 2001
From: Cristian Adam <cristian.adam@gmail.com>
Date: Thu, 8 Oct 2026 17:36:43 +0200
Subject: [PATCH] cmLocalGenerator: Use cached real paths for implicit include
 directories

Include directories requested by the user that are also implicit
include directories were resolved with an uncached real path lookup for
every target and configuration.  Use the cached lookup of the global
generator, as for the other include directories, and clear that cache
on every configure.
---
 Source/cmGlobalGenerator.cxx | 1 +
 Source/cmLocalGenerator.cxx  | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index ec681a6500..c8ab360e44 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -2604,6 +2604,7 @@ void cmGlobalGenerator::ClearGeneratorMembers()
   this->RuleHashes.clear();
   this->DirectoryContentMap.clear();
   this->ExistingSourceFiles.clear();
+  this->RealPaths.clear();
   this->XcFrameworkPListContentMap.clear();
   this->BinaryDirectories.clear();
   this->GeneratedFiles.clear();
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 6b8995d70a..330d9a5a29 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -1544,7 +1544,8 @@ std::vector<BT<std::string>> cmLocalGenerator::GetIncludeDirectoriesImplicit(
   if (!stripImplicitDirs) {
     // Append implicit directories that were requested by the user only
     for (BT<std::string> const& udr : userDirs) {
-      if (cm::contains(implicitSet, cmSystemTools::GetRealPath(udr.Value))) {
+      if (cm::contains(implicitSet,
+                       this->GlobalGenerator->GetRealPath(udr.Value))) {
         emitBT(udr);
       }
     }