PCH: No repeated path for internal generated PCH files

Fixes: #19952

Source/cmGeneratorTarget.cxx

@@ -3360,14 +3360,8 @@ std::string cmGeneratorTarget::GetPchHeader(const std::string& config,
         this->GetGlobalGenerator()->FindGeneratorTarget(pchReuseFrom);
     }
 
-    if (this->GetGlobalGenerator()->IsMultiConfig()) {
-      filename = cmStrCat(
-        generatorTarget->LocalGenerator->GetCurrentBinaryDirectory(), "/");
-    } else {
-      // For GCC we need to have the header file .h[xx]
-      // next to the .h[xx].gch file
-      filename = generatorTarget->ObjectDirectory;
-    }
+    filename = cmStrCat(
+      generatorTarget->LocalGenerator->GetCurrentBinaryDirectory(), "/");
 
     const std::map<std::string, std::string> languageToExtension = {
       { "C", ".h" },

Source/cmLocalGenerator.cxx

@@ -3123,6 +3123,14 @@ std::string cmLocalGenerator::GetObjectFileNameWithoutTarget(
     const char* pchExtension = source.GetProperty("PCH_EXTENSION");
     if (pchExtension) {
       customOutputExtension = pchExtension;
+
+      // Make sure that for the CMakeFiles/<target>.dir/cmake_pch.h|xx.c|xx
+      // source file, we don't end up having
+      // CMakeFiles/<target>.dir/CMakeFiles/<target>.dir/cmake_pch.h|xx.pch
+      cmsys::RegularExpression var("(CMakeFiles/[^/]+.dir/)");
+      while (var.find(objectName)) {
+        objectName.erase(var.start(), var.end() - var.start());
+      }
     }
 
     // Remove the source extension if it is to be replaced.

Tests/RunCMake/PrecompileHeaders/DisabledPch-check.cmake

@@ -1,10 +1,5 @@
-if (NOT RunCMake_GENERATOR_IS_MULTI_CONFIG)
-  set(foo_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foo.dir/CMakeFiles/foo.dir/cmake_pch.h")
-  set(foobar_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/CMakeFiles/foobar.dir/cmake_pch.h")
-else()
-  set(foo_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foo.dir/cmake_pch.h")
-  set(foobar_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.h")
-endif()
+set(foo_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foo.dir/cmake_pch.h")
+set(foobar_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.h")
 
 if (NOT EXISTS ${foo_pch_header})
   set(RunCMake_TEST_FAILED "Generated foo pch header ${foo_pch_header} does not exist")

Tests/RunCMake/PrecompileHeaders/PchInterface-check.cmake

@@ -1,10 +1,5 @@
-if (NOT RunCMake_GENERATOR_IS_MULTI_CONFIG)
-  set(foo_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foo.dir/CMakeFiles/foo.dir/cmake_pch.h")
-  set(foobar_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/CMakeFiles/foobar.dir/cmake_pch.h")
-else()
-  set(foo_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foo.dir/cmake_pch.h")
-  set(foobar_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.h")
-endif()
+set(foo_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foo.dir/cmake_pch.h")
+set(foobar_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.h")
 
 if (NOT EXISTS ${foo_pch_header})
   set(RunCMake_TEST_FAILED "Generated foo pch header ${foo_pch_header} does not exist")

Tests/RunCMake/PrecompileHeaders/PchMultilanguage-check.cmake

@@ -1,10 +1,5 @@
-if (NOT RunCMake_GENERATOR_IS_MULTI_CONFIG)
-  set(foobar_pch_h_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/CMakeFiles/foobar.dir/cmake_pch.h")
-  set(foobar_pch_hxx_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/CMakeFiles/foobar.dir/cmake_pch.hxx")
-else()
-  set(foobar_pch_h_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.h")
-  set(foobar_pch_hxx_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.hxx")
-endif()
+set(foobar_pch_h_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.h")
+set(foobar_pch_hxx_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/foobar.dir/cmake_pch.hxx")
 
 if (NOT EXISTS ${foobar_pch_h_header})
   set(RunCMake_TEST_FAILED "Generated foobar C pch header ${foobar_pch_h_header} does not exist")

Tests/RunCMake/PrecompileHeaders/PchPrologueEpilogue-check.cmake

@@ -1,8 +1,4 @@
-if (NOT RunCMake_GENERATOR_IS_MULTI_CONFIG)
-  set(main_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/main.dir/CMakeFiles/main.dir/cmake_pch.hxx")
-else()
-  set(main_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/main.dir/cmake_pch.hxx")
-endif()
+set(main_pch_header "${RunCMake_TEST_BINARY_DIR}/CMakeFiles/main.dir/cmake_pch.hxx")
 
 file(STRINGS ${main_pch_header} main_pch_header_strings)
 string(REGEX MATCH "#pragma warning\\(push, 0\\).*#include.*pch.h.*#pragma warning\\(pop\\)" matched_code ${main_pch_header_strings})