From dcb5a46b7ec8096d3bab8ecde86203bcb1df38bd Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Fri, 26 Jul 2024 07:42:59 -0700
Subject: [PATCH] Add some CMake guards when building the sysroot

* Require that the compiler is Clang, for example gcc and msvc cannot
  compile to WebAssembly.
* Require that the Clang version is above the minimum threshold. Unsure
  what the minimum threshold is at this time so I've set it to 18.0.0
---
 cmake/wasi-sdk-sysroot.cmake | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/cmake/wasi-sdk-sysroot.cmake b/cmake/wasi-sdk-sysroot.cmake
index 6bed7d3..394b562 100644
--- a/cmake/wasi-sdk-sysroot.cmake
+++ b/cmake/wasi-sdk-sysroot.cmake
@@ -5,6 +5,16 @@ if(NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE RelWithDebInfo)
 endif()
 
+if(NOT CMAKE_C_COMPILER_ID MATCHES Clang)
+  message(FATAL_ERROR "C compiler ${CMAKE_C_COMPILER} is not `Clang`, it is ${CMAKE_C_COMPILER_ID}")
+endif()
+
+set(minimum_clang_required 18.0.0)
+
+if(CMAKE_C_COMPILER_VERSION VERSION_LESS ${minimum_clang_required})
+  message(FATAL_ERROR "compiler version ${CMAKE_C_COMPILER_VERSION} is less than the required version ${minimum_clang_required}")
+endif()
+
 find_program(MAKE make REQUIRED)
 
 option(WASI_SDK_DEBUG_PREFIX_MAP "Pass `-fdebug-prefix-map` for built artifacts" ON)