fix rust bindings build on windows (#1584)

Refine rust bindings.

CMakeLists.txt

@@ -3,6 +3,18 @@
 
 cmake_minimum_required(VERSION 3.1)
 
+if(MSVC)
+    if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.15")
+        # set all policies to max supported by actual running cmake version
+        # mainly want the following:
+        # CMP0091: prevent msvcrt flags being added to default CMAKE_<LANG>_FLAGS_<CONFIG>
+        # CMP0092: prevent warning flags being added to default CMAKE_<LANG>_FLAGS
+        cmake_policy(VERSION ${CMAKE_VERSION})
+    else()
+        message(FATAL_ERROR "please update cmake")
+    endif()
+endif()
+
 # Workaround to fix wrong compiler on macos.
 if(APPLE AND NOT CMAKE_C_COMPILER)
     set(CMAKE_C_COMPILER "/usr/bin/cc")
@@ -12,13 +24,16 @@ endif()
 set(PROJECT_IS_TOP_LEVEL OFF)
 if(CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
     set(PROJECT_IS_TOP_LEVEL ON)
-    
+
     # Enable folder support
     set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 endif()
 
 project(unicorn C)
 
+# mainline qemu mostly just uses compiler default
+set(CMAKE_C_STANDARD 11)
+
 set(UNICORN_VERSION_MAJOR 2)
 set(UNICORN_VERSION_MINOR 0)
 set(UNICORN_VERSION_PATCH 0)
@@ -63,6 +78,7 @@ if(MSVC)
     else()
         message(FATAL_ERROR "Neither WIN64 or WIN32!")
     endif()
+
     add_compile_options(
         -Dinline=__inline
         -D__func__=__FUNCTION__
@@ -71,22 +87,30 @@ if(MSVC)
         ${MSVC_FLAG}
         /I${CMAKE_CURRENT_SOURCE_DIR}/qemu/tcg/i386
     )
+
     # Disable some warnings
-    add_compile_options(
-        /wd4018
-        /wd4098
-        /wd4244
-        /wd4267
-    )
-    if(CMAKE_BUILD_TYPE STREQUAL "Debug")
-        string(REPLACE "/ZI" "/Zi" CMAKE_C_FLAGS_DEBUG ${CMAKE_C_FLAGS_DEBUG})
+    add_compile_options($<$<COMPILE_LANGUAGE:C>:/wd4018>)
+    add_compile_options($<$<COMPILE_LANGUAGE:C>:/wd4098>)
+    add_compile_options($<$<COMPILE_LANGUAGE:C>:/wd4244>)
+    add_compile_options($<$<COMPILE_LANGUAGE:C>:/wd4267>)
+
+    # handle msvcrt setting being passed in CMAKE_C_FLAGS
+    if(DEFINED CMAKE_MSVC_RUNTIME_LIBRARY)
+        # do not support other methods of setting this (it would be more conformant, tho)
+        message(FATAL_ERROR "please set msvcrt via CMAKE_C_FLAGS")
     endif()
-    # default use the multithread, static version of the run-time library.
-    option(UNICORN_STATIC_MSVCRT "Embed static runtime library" ${PROJECT_IS_TOP_LEVEL})
-    if(UNICORN_STATIC_MSVCRT)
-        string(REPLACE "/MD" "/MT" CMAKE_C_FLAGS_DEBUG ${CMAKE_C_FLAGS_DEBUG})
-        string(REPLACE "/MD" "/MT" CMAKE_C_FLAGS_RELEASE ${CMAKE_C_FLAGS_RELEASE})
+    if(CMAKE_C_FLAGS MATCHES "[/-]MTd")
+        set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreadedDebug")
+    elseif(CMAKE_C_FLAGS MATCHES "[/-]MDd")
+        set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreadedDebugDLL")
+    elseif(CMAKE_C_FLAGS MATCHES "[/-]MT")
+        set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded")
+    elseif(CMAKE_C_FLAGS MATCHES "[/-]MD")
+        set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreadedDLL")
     endif()
+
+    # prevent the arg from occurring more than once (not a big deal, just to keep tidy)
+    string(REGEX REPLACE "[/-]M[TD]d?" "" CMAKE_C_FLAGS ${CMAKE_C_FLAGS})
 else()
     if(MINGW)
         execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpmachine
@@ -1181,7 +1205,7 @@ if(UNICORN_TRACER)
     target_compile_options(unicorn PRIVATE -DUNICORN_TRACER)
 endif()
 
-target_compile_options(unicorn-common PRIVATE 
+target_compile_options(unicorn-common PRIVATE
     ${UNICORN_COMPILE_OPTIONS}
 )