From 96f638b98a6e9c6e9078dc6b240ab726017980d6 Mon Sep 17 00:00:00 2001
From: Yann Diorcet <yann.diorcet@xenocs.com>
Date: Thu, 9 Apr 2020 09:54:44 +0200
Subject: [PATCH] Windows MSVC/Clang improvements

---
 CMakeLists.txt     | 26 ++++++++++++++++----------
 zproject_cmake.gsl | 34 ++++++++++++++++++++--------------
 2 files changed, 36 insertions(+), 24 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 02ccbec7..2e3e7392 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,7 +14,11 @@ enable_testing()
 set(SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
 set(CMAKE_EXPORT_COMPILE_COMMANDS 1)
 # Select flags
-SET(CMAKE_C_FLAGS_RELEASE "-O3")
+if(MSVC)
+    SET(CMAKE_C_FLAGS_RELEASE "/O2")
+else()
+    SET(CMAKE_C_FLAGS_RELEASE "-O3")
+endif()
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/builds/cmake/Modules)
 
@@ -59,15 +63,17 @@ file(WRITE "${PROJECT_BINARY_DIR}/platform.h.in" "
 
 configure_file("${PROJECT_BINARY_DIR}/platform.h.in" "${PROJECT_BINARY_DIR}/platform.h")
 
-#The MSVC C compiler is too out of date,
-#so the sources have to be compiled as c++
-if (MSVC)
-    enable_language(CXX)
-    file(GLOB sources "${SOURCE_DIR}/src/*.c")
-    set_source_files_properties(
-        ${sources}
-        PROPERTIES LANGUAGE CXX
-    )
+if (WIN32)
+    #The MSVC C compiler is too out of date,
+    #so the sources have to be compiled as c++
+    if (MSVC AND NOT (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
+        enable_language(CXX)
+        file(GLOB sources "${SOURCE_DIR}/src/*.c")
+        set_source_files_properties(
+            ${sources}
+            PROPERTIES LANGUAGE CXX
+        )
+    endif()
     set(MORE_LIBRARIES ws2_32 Rpcrt4 Iphlpapi)
 endif()
 
diff --git a/zproject_cmake.gsl b/zproject_cmake.gsl
index 7f4202fa..0d053d30 100644
--- a/zproject_cmake.gsl
+++ b/zproject_cmake.gsl
@@ -31,7 +31,11 @@ enable_testing()
 set(SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
 set(CMAKE_EXPORT_COMPILE_COMMANDS 1)
 # Select flags
-SET(CMAKE_C_FLAGS_RELEASE "-O3")
+if(MSVC)
+    SET(CMAKE_C_FLAGS_RELEASE "/O2")
+else()
+    SET(CMAKE_C_FLAGS_RELEASE "-O3")
+endif()
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/builds/cmake/Modules)
 
@@ -105,19 +109,21 @@ file(WRITE "${PROJECT_BINARY_DIR}/platform.h.in" "
 
 configure_file("${PROJECT_BINARY_DIR}/platform.h.in" "${PROJECT_BINARY_DIR}/platform.h")
 
-#The MSVC C compiler is too out of date,
-#so the sources have to be compiled as c++
-if (MSVC)
-    enable_language(CXX)
-.   if project.use_cxx
-    file(GLOB sources "${SOURCE_DIR}/src/*.$(project.source_ext)")
-.   else
-    file(GLOB sources "${SOURCE_DIR}/src/*.$(project.source_ext)")
-.   endif
-    set_source_files_properties(
-        ${sources}
-        PROPERTIES LANGUAGE CXX
-    )
+if (WIN32)
+    #The MSVC C compiler is too out of date,
+    #so the sources have to be compiled as c++
+    if (MSVC AND NOT (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
+        enable_language(CXX)
+.       if project.use_cxx
+        file(GLOB sources "${SOURCE_DIR}/src/*.$(project.source_ext)")
+.       else
+        file(GLOB sources "${SOURCE_DIR}/src/*.$(project.source_ext)")
+.       endif
+        set_source_files_properties(
+            ${sources}
+            PROPERTIES LANGUAGE CXX
+        )
+    endif()
     set(MORE_LIBRARIES ws2_32 Rpcrt4 Iphlpapi)
 endif()