Support compiling on mingw (no exception handling)

CMakeLists.txt

@@ -114,12 +114,12 @@ set(libBlocksRuntime_COMPATIBILITY_HDRS
 set(libobjc_CXX_SRCS
 	selector_table.cc
 	)
-# Windows does not use DWARF EH
-if (WIN32)
+# Windows does not use DWARF EH, except when using the GNU ABI (MinGW)
+if (WIN32 AND NOT MINGW)
 	list(APPEND libobjc_CXX_SRCS eh_win32_msvc.cc)
 else ()
 	list(APPEND libobjc_C_SRCS eh_personality.c)
-endif (WIN32)
+endif (WIN32 AND NOT MINGW)
 
 find_package(tsl-robin-map)
 
@@ -132,7 +132,7 @@ if (NOT tls-robin-map_FOUND)
 	FetchContent_MakeAvailable(robinmap)
 endif()
 
-if (WIN32)
+if (WIN32 AND NOT MINGW)
 	set(OLD_ABI_COMPAT_DEFAULT false)
 else()
 	set(OLD_ABI_COMPAT_DEFAULT true)
@@ -189,7 +189,7 @@ if(WIN32)
 endif()
 
 
-if (MSVC)
+if (WIN32 AND NOT MINGW)
 	set(ASSEMBLER ${CMAKE_ASM_COMPILER} CACHE STRING "Assembler to use with Visual Studio (must be gcc / clang!)")
 	message(STATUS "Using custom build commands to work around CMake bugs")
 	message(STATUS "ASM compiler: ${ASSEMBLER}")
@@ -210,7 +210,7 @@ endif()
 
 
 
-if (WIN32)
+if (WIN32 AND NOT MINGW)
 	message(STATUS "Using MSVC-compatible exception model")
 else ()
 	separate_arguments(EH_PERSONALITY_FLAGS NATIVE_COMMAND ${CMAKE_CXX_FLAGS})
@@ -234,7 +234,7 @@ target_sources(objc PRIVATE ${libobjc_CXX_SRCS})
 include(FindThreads)
 target_link_libraries(objc Threads::Threads)
 # Link against ntdll.dll for RtlRaiseException
-if (WIN32)
+if (WIN32 AND NOT MINGW)
 	target_link_libraries(objc ntdll.dll)
 endif()
 

common.S

@@ -10,3 +10,9 @@
 #define TYPE_DIRECTIVE(symbol, symboltype)
 #endif
 
+#if defined(_MSC_VER) && defined(__i386__)
+#define STRINGIFY(a) #a
+#define EXPORT_SYMBOL(symbol) .ascii  " " STRINGIFY(/EXPORT:_##symbol)
+#else
+#define EXPORT_SYMBOL(symbol) .ascii  " /EXPORT:" #symbol
+#endif

eh_personality.c

@@ -550,25 +550,29 @@ static inline _Unwind_Reason_Code internal_objc_personality(int version,
 		}
 	}
 
-	_Unwind_SetIP(context, (unsigned long)action.landing_pad);
+	_Unwind_SetIP(context, (uintptr_t)action.landing_pad);
 	_Unwind_SetGR(context, __builtin_eh_return_data_regno(0), 
-			(unsigned long)(isNew ? exceptionObject : object));
+			(uintptr_t)(isNew ? exceptionObject : object));
 	_Unwind_SetGR(context, __builtin_eh_return_data_regno(1), selector);
 
 	DEBUG_LOG("Installing context, selector %d\n", (int)selector);
 	get_thread_data()->cxxCaughtException = NO;
 	return _URC_INSTALL_CONTEXT;
 }
 
+OBJC_PUBLIC
 BEGIN_PERSONALITY_FUNCTION(__gnu_objc_personality_v0)
 	return internal_objc_personality(version, actions, exceptionClass,
 			exceptionObject, context, NO);
 }
+
+OBJC_PUBLIC
 BEGIN_PERSONALITY_FUNCTION(__gnustep_objc_personality_v0)
 	return internal_objc_personality(version, actions, exceptionClass,
 			exceptionObject, context, YES);
 }
 
+OBJC_PUBLIC
 BEGIN_PERSONALITY_FUNCTION(__gnustep_objcxx_personality_v0)
 #ifndef NO_OBJCXX
 	if (cxx_exception_class == 0)
@@ -584,11 +588,11 @@ BEGIN_PERSONALITY_FUNCTION(__gnustep_objcxx_personality_v0)
 		}
 		// We now have two copies of the _Unwind_Exception object (which stores
 		// state for the unwinder) in flight.  Make sure that they're in sync.
-		COPY_EXCEPTION(ex->cxx_exception, exceptionObject)
+		COPY_EXCEPTION(ex->cxx_exception, exceptionObject);
 		exceptionObject = ex->cxx_exception;
 		exceptionClass = cxx_exception_class;
 		int ret = CALL_PERSONALITY_FUNCTION(__gxx_personality_v0);
-		COPY_EXCEPTION(exceptionObject, ex->cxx_exception)
+		COPY_EXCEPTION(exceptionObject, ex->cxx_exception);
 		if (ret == _URC_INSTALL_CONTEXT)
 		{
 			get_thread_data()->cxxCaughtException = YES;
@@ -599,7 +603,7 @@ BEGIN_PERSONALITY_FUNCTION(__gnustep_objcxx_personality_v0)
 	return CALL_PERSONALITY_FUNCTION(__gxx_personality_v0);
 }
 
-id objc_begin_catch(struct _Unwind_Exception *exceptionObject)
+OBJC_PUBLIC id objc_begin_catch(struct _Unwind_Exception *exceptionObject)
 {
 	struct thread_data *td = get_thread_data();
 	DEBUG_LOG("Beginning catch %p\n", exceptionObject);
@@ -671,7 +675,7 @@ id objc_begin_catch(struct _Unwind_Exception *exceptionObject)
 	return (id)((char*)exceptionObject + sizeof(struct _Unwind_Exception));
 }
 
-void objc_end_catch(void)
+OBJC_PUBLIC void objc_end_catch(void)
 {
 	struct thread_data *td = get_thread_data_fast();
 	// If this is a boxed foreign exception then the boxing class is
@@ -717,7 +721,7 @@ void objc_end_catch(void)
 	}
 }
 
-void objc_exception_rethrow(struct _Unwind_Exception *e)
+OBJC_PUBLIC void objc_exception_rethrow(struct _Unwind_Exception *e)
 {
 	struct thread_data *td = get_thread_data_fast();
 	// If this is an Objective-C exception, then 

objc/hooks.h

@@ -47,7 +47,7 @@ OBJC_PUBLIC extern struct objc_slot *(*__objc_msg_forward3)(id, SEL) OBJC_DEPREC
  */
 OBJC_PUBLIC extern IMP (*__objc_msg_forward2)(id, SEL);
 
-#ifndef _WIN32
+#ifndef _MSC_VER
 /**
  * Hook defined for handling unhandled exceptions.  If the unwind library
  * reaches the end of the stack without finding a handler then this hook is

objc_msgSend.x86-32.S

@@ -37,7 +37,7 @@
 	test  %eax, %eax
 	jz    5f                             # Nil slot - invoke some kind of forwarding mechanism
 	mov   SLOT_OFFSET(%eax), %ecx
-#ifdef _WIN32
+#ifdef _MSC_VER
 	call  *CDECL(__guard_check_icall_fptr)
 #endif
 	jmp   *%ecx
@@ -62,7 +62,7 @@
 	add   $12, %esp                      # restore the stack
 
 
-#ifdef _WIN32
+#ifdef _MSC_VER
 	mov    %eax, %ecx
 	call  *CDECL(__guard_check_icall_fptr)
 	jmp   *%ecx
@@ -126,7 +126,7 @@ CDECL(objc_msgSend_stret):
 
 #ifdef _WIN32
         .section        .drectve,"yn"
-        .ascii  " /EXPORT:_objc_msgSend"
-        .ascii  " /EXPORT:_objc_msgSend_stret"
-        .ascii  " /EXPORT:_objc_msgSend_fpret"
+		EXPORT_SYMBOL(objc_msgSend)
+		EXPORT_SYMBOL(objc_msgSend_stret)
+		EXPORT_SYMBOL(objc_msgSend_fpret)
 #endif

objc_msgSend.x86-64.S

@@ -193,7 +193,7 @@
 
 12:
 #endif // WITH_TRACING
-#ifdef _WIN64
+#ifdef _MSC_VER
 	mov   %r10, %rax
 	jmp   *__guard_dispatch_icall_fptr(%rip)
 #else
@@ -295,9 +295,11 @@ TYPE_DIRECTIVE(CDECL(objc_msgSend_stret), @function)
 CDECL(objc_msgSend_stret):
 	MSGSEND objc_msgSend_stret, %rdx, %r8
 .section        .drectve,"yn"
-.ascii  " /EXPORT:objc_msgSend"
-.ascii  " /EXPORT:objc_msgSend_fpret"
-.ascii  " /EXPORT:objc_msgSend_stret"
+EXPORT_SYMBOL(objc_msgSend)
+
+EXPORT_SYMBOL(objc_msgSend_fpret)
+
+EXPORT_SYMBOL(objc_msgSend_stret)
 #else
 .globl CDECL(objc_msgSend)
 TYPE_DIRECTIVE(CDECL(objc_msgSend), @function)

objcxx_eh.cc

@@ -218,7 +218,7 @@ namespace gnustep
 		/**
 		 * Superclass for the type info for Objective-C exceptions.
 		 */
-		struct __objc_type_info : std::type_info
+		struct OBJC_PUBLIC __objc_type_info : std::type_info
 		{
 			/**
 			 * Constructor that sets the name.
@@ -266,7 +266,7 @@ namespace gnustep
 		/**
 		 * Singleton type info for the `id` type.
 		 */
-		struct __objc_id_type_info : __objc_type_info
+		struct OBJC_PUBLIC __objc_id_type_info : __objc_type_info
 		{
 			/**
 			 * The `id` type is mangled to `@id`, which is not a valid mangling
@@ -278,7 +278,7 @@ namespace gnustep
 			                        void **obj,
 			                        unsigned outer) const;
 		};
-		struct __objc_class_type_info : __objc_type_info
+		struct OBJC_PUBLIC __objc_class_type_info : __objc_type_info
 		{
 			virtual ~__objc_class_type_info();
 			virtual bool __do_catch(const type_info *thrownType,

unwind-itanium.h

@@ -79,22 +79,26 @@ struct _Unwind_Exception
   {
     uint64_t exception_class;
     _Unwind_Exception_Cleanup_Fn exception_cleanup;
+#ifdef __SEH__
+    uintptr_t private_[6];
+#else
     uintptr_t private_1;
     uintptr_t private_2;
+#endif
   } __attribute__((__aligned__));
 
 extern _Unwind_Reason_Code _Unwind_RaiseException (struct _Unwind_Exception *);
 extern _Unwind_Reason_Code _Unwind_ForcedUnwind (struct _Unwind_Exception *,
 						 _Unwind_Stop_Fn, void *);
 extern void _Unwind_Resume (struct _Unwind_Exception *);
 extern void _Unwind_DeleteException (struct _Unwind_Exception *);
-extern unsigned long _Unwind_GetGR (struct _Unwind_Context *, int);
-extern void _Unwind_SetGR (struct _Unwind_Context *, int, unsigned long);
-extern unsigned long _Unwind_GetIP (struct _Unwind_Context *);
-extern unsigned long _Unwind_GetIPInfo (struct _Unwind_Context *, int *);
-extern void _Unwind_SetIP (struct _Unwind_Context *, unsigned long);
-extern unsigned long _Unwind_GetLanguageSpecificData (struct _Unwind_Context*);
-extern unsigned long _Unwind_GetRegionStart (struct _Unwind_Context *);
+extern uintptr_t _Unwind_GetGR (struct _Unwind_Context *, int);
+extern void _Unwind_SetGR (struct _Unwind_Context *, int, uintptr_t);
+extern uintptr_t _Unwind_GetIP (struct _Unwind_Context *);
+extern uintptr_t _Unwind_GetIPInfo (struct _Unwind_Context *, int *);
+extern void _Unwind_SetIP (struct _Unwind_Context *, uintptr_t);
+extern uintptr_t _Unwind_GetLanguageSpecificData (struct _Unwind_Context*);
+extern uintptr_t _Unwind_GetRegionStart (struct _Unwind_Context *);
 
 #ifdef _GNU_SOURCE
 
@@ -115,17 +119,17 @@ extern _Unwind_Reason_Code
 
 /* See http://gcc.gnu.org/ml/gcc-patches/2003-09/msg00154.html for why
    _Unwind_GetBSP() exists.  */
-extern unsigned long _Unwind_GetBSP (struct _Unwind_Context *);
+extern uintptr_t _Unwind_GetBSP (struct _Unwind_Context *);
 
 /* Return the "canonical frame address" for the given context.
    This is used by NPTL... */
-extern unsigned long _Unwind_GetCFA (struct _Unwind_Context *);
+extern uintptr_t _Unwind_GetCFA (struct _Unwind_Context *);
 
 /* Return the base-address for data references.  */
-extern unsigned long _Unwind_GetDataRelBase (struct _Unwind_Context *);
+extern uintptr_t _Unwind_GetDataRelBase (struct _Unwind_Context *);
 
 /* Return the base-address for text references.  */
-extern unsigned long _Unwind_GetTextRelBase (struct _Unwind_Context *);
+extern uintptr_t _Unwind_GetTextRelBase (struct _Unwind_Context *);
 
 /* Call _Unwind_Trace_Fn once for each stack-frame, without doing any
    cleanup.  The first frame for which the callback is invoked is the
@@ -164,12 +168,21 @@ _Unwind_Reason_Code name(int version,\
 
 #define CALL_PERSONALITY_FUNCTION(name) name(version, actions, exceptionClass, exceptionObject, context)
 
+#ifdef __SEH__
+#define COPY_EXCEPTION(dst, src) \
+  do {                                                                 \
+    memcpy((dst)->private_, (src)->private_, sizeof((src)->private_)); \
+  } while(0)
+#else
 #define COPY_EXCEPTION(dst, src) \
-  (dst)->private_1 = (src)->private_1; \
-  (dst)->private_2 = (src)->private_2;
+  do {                                   \
+    (dst)->private_1 = (src)->private_1; \
+    (dst)->private_2 = (src)->private_2; \
+  } while(0)
+#endif
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* _UNWIND_H */
+#endif /* _UNWIND_H */