From 57742cb02b04ea973ff702b42a7e380decd4048f Mon Sep 17 00:00:00 2001
From: Ellie Hermaszewska <ellieh@nvidia.com>
Date: Thu, 11 Jul 2024 19:52:44 +0800
Subject: [PATCH] Statically link MSVC runtime (#4613)

* Statically link MSVC runtime

* Statically link MSVC runtime for llvm
---
 CMakeLists.txt         | 1 +
 CMakePresets.json      | 5 ++++-
 external/build-llvm.sh | 4 ++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 415343050d..1dd289a8dd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,6 +21,7 @@ set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
 if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.25")
     cmake_policy(SET CMP0141 NEW)
 endif()
+cmake_policy(SET CMP0091 NEW)
 
 # Don't use absolute paths to the build tree in RPATH, this makes the build
 # tree relocatable
diff --git a/CMakePresets.json b/CMakePresets.json
index 7e0697afbe..08f85a37fb 100644
--- a/CMakePresets.json
+++ b/CMakePresets.json
@@ -10,7 +10,10 @@
       "name": "default",
       "description": "Default build using Ninja Multi-Config generator",
       "generator": "Ninja Multi-Config",
-      "binaryDir": "${sourceDir}/build"
+      "binaryDir": "${sourceDir}/build",
+      "cacheVariables": {
+        "CMAKE_MSVC_RUNTIME_LIBRARY": "MultiThreaded$<$<CONFIG:Debug>:Debug>"
+      }
     },
     {
       "name": "msvc-base",
diff --git a/external/build-llvm.sh b/external/build-llvm.sh
index 142d30ee2f..95302a742b 100755
--- a/external/build-llvm.sh
+++ b/external/build-llvm.sh
@@ -109,6 +109,10 @@ cmake_arguments_for_slang=(
   -DLLVM_ENABLE_PROJECTS=clang
   "-DLLVM_TARGETS_TO_BUILD=X86;ARM;AArch64"
   -DLLVM_BUILD_TOOLS=0
+  # Get LLVM to use the static linked version of the msvc runtime
+  "-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded$<$<CONFIG:Debug>:Debug>"
+  "-DLLVM_USE_CRT_RELEASE=MT"
+  "-DLLVM_USE_CRT_DEBUG=MTd"
 )
 build_dir=$source_dir/build
 mkdir -p "$build_dir"