add cmake option MI_WIN_REDIRECT to be able to explicitly disable linking with mimalloc-redirect on windows; always OFF on ARM, fixes issue microsoft#591 and microsoft#590

Author: daanx

CMakeLists.txt

@@ -15,6 +15,7 @@ option(MI_USE_CXX           "Use the C++ compiler to compile the library (instea
 option(MI_SEE_ASM           "Generate assembly files" OFF)
 option(MI_OSX_INTERPOSE     "Use interpose to override standard malloc on macOS" ON)
 option(MI_OSX_ZONE          "Use malloc zone to override standard malloc on macOS" ON) 
+option(MI_WIN_REDIRECT      "Use redirection module ('mimalloc-redirect') on Windows if compiling mimalloc as a DLL" ON)
 option(MI_LOCAL_DYNAMIC_TLS "Use slightly slower, dlopen-compatible TLS mechanism (Unix)" OFF)
 option(MI_BUILD_SHARED      "Build shared library" ON)
 option(MI_BUILD_STATIC      "Build static library" ON)
@@ -105,6 +106,19 @@ if(MI_OVERRIDE)
   endif()
 endif()
 
+if(WIN32)
+  if (MI_WIN_REDIRECT)
+    if (MSVC_C_ARCHITECTURE_ID MATCHES "ARM")
+      message(STATUS "Cannot use redirection on Windows ARM (MI_WIN_REDIRECT=OFF)")
+      set(MI_WIN_REDIRECT OFF)
+    endif()
+  endif()
+  if (NOT MI_WIN_REDIRECT)
+    # use a negative define for backward compatibility
+    list(APPEND mi_defines MI_WIN_NOREDIRECT=1)
+  endif()
+endif()
+
 if(MI_SECURE)
   message(STATUS "Set full secure build (MI_SECURE=ON)")
   list(APPEND mi_defines MI_SECURE=4)
@@ -323,8 +337,8 @@ if(MI_BUILD_SHARED)
       $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
       $<INSTALL_INTERFACE:${mi_install_incdir}>
   )
-  if(WIN32)
-    # On windows copy the mimalloc redirection dll too.
+  if(WIN32 AND MI_WIN_REDIRECT)
+    # On windows, link and copy the mimalloc redirection dll too.
     if(CMAKE_SIZEOF_VOID_P EQUAL 4)
       set(MIMALLOC_REDIRECT_SUFFIX "32")
     else()

src/init.c

@@ -463,7 +463,7 @@ mi_decl_nodiscard bool mi_is_redirected(void) mi_attr_noexcept {
 }
 
 // Communicate with the redirection module on Windows
-#if defined(_WIN32) && defined(MI_SHARED_LIB)
+#if defined(_WIN32) && defined(MI_SHARED_LIB) && !defined(MI_WIN_NOREDIRECT)
 #ifdef __cplusplus
 extern "C" {
 #endif