Patch for https://github.com/llvm/llvm-project/tree/release/15.x

0001-CMake-Prevent-uncachable-calls-with-ccache-on-Windows.patch

From fa1d9a34232137d7a6db6a01735a9d4bf690d4a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Gr=C3=A4nitz?= <stefan.graenitz@gmail.com>
Date: Thu, 16 Mar 2023 14:42:45 +0100
Subject: [PATCH] [CMake] Prevent uncachable calls with ccache on Windows

---
 llvm/CMakeLists.txt | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index db207e3328be..51b5e4311f83 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -207,6 +207,31 @@ if(LLVM_CCACHE_BUILD)
   endif()
 endif()
 
+if (WIN32)
+  if (CMAKE_C_COMPILER_LAUNCHER)
+    # Ccache has no support for /Zi, all calls will be rejected as uncacheable.
+    # Fall back to /Z7 instead in order to exploit the cache.
+    foreach(var_to_update
+      CMAKE_C_FLAGS
+      CMAKE_C_FLAGS_DEBUG
+      CMAKE_C_FLAGS_RELWITHDEBINFO)
+      string(REGEX REPLACE "(^| )/Z[i7I]($| )" " /Z7 "
+            "${var_to_update}" "${${var_to_update}}")
+    endforeach()
+  endif()
+  if (CMAKE_CXX_COMPILER_LAUNCHER)
+    # Ccache has no support for /Zi, all calls will be rejected as uncacheable.
+    # Fall back to /Z7 instead in order to exploit the cache.
+    foreach(var_to_update
+      CMAKE_CXX_FLAGS
+      CMAKE_CXX_FLAGS_DEBUG
+      CMAKE_CXX_FLAGS_RELWITHDEBINFO)
+      string(REGEX REPLACE "(^| )/Z[i7I]($| )" " /Z7 "
+            "${var_to_update}" "${${var_to_update}}")
+    endforeach()
+  endif()
+endif()
+
 set(LLVM_EXTERNAL_PROJECT_BUILD_TOOL_ARGS "" CACHE STRING
   "Optional arguments for the native tool used in CMake --build invocations for external projects.")
 mark_as_advanced(LLVM_EXTERNAL_PROJECT_BUILD_TOOL_ARGS)
-- 
2.38.1.windows.1