/*
 * win32-exception.c: Win32 SEH filter.
 *
 * (C) 2002 Ximian, Inc.
 */

#include "win32-exception.h"

#ifdef PLATFORM_WIN32

#include <glib.h>


LONG CALLBACK seh_handler(EXCEPTION_POINTERS* ep);

static MonoW32ExceptionHandler fpe_handler;
static MonoW32ExceptionHandler ill_handler;
static MonoW32ExceptionHandler segv_handler;

static LPTOP_LEVEL_EXCEPTION_FILTER old_handler;

#define W32_SEH_COPY_CONTEXT \
	sctx->eax = ctx->Eax;\
	sctx->ebx = ctx->Ebx;\
	sctx->ecx = ctx->Ecx;\
	sctx->edx = ctx->Edx;\
	sctx->ebp = ctx->Ebp;\
	sctx->esp = ctx->Esp;\
	sctx->esi = ctx->Esi;\
	sctx->edi = ctx->Edi;\
	sctx->eip = ctx->Eip;

#define W32_SEH_HANDLE_EX(_ex) \
	if (_ex##_handler) _ex##_handler((int)sctx)

/*
 * Unhandled Exception Filter
 * Top-level per-process exception handler.
 */
LONG CALLBACK seh_handler(EXCEPTION_POINTERS* ep)
{
	EXCEPTION_RECORD* er;
	CONTEXT* ctx;
	struct sigcontext* sctx;
	LONG res;

	res = EXCEPTION_CONTINUE_SEARCH;

	er = ep->ExceptionRecord;
	ctx = ep->ContextRecord;
	sctx = g_malloc(sizeof(struct sigcontext));
	W32_SEH_COPY_CONTEXT

	switch (er->ExceptionCode) {
	case EXCEPTION_ACCESS_VIOLATION:
		W32_SEH_HANDLE_EX(segv);
		break;
	case EXCEPTION_ILLEGAL_INSTRUCTION:
		W32_SEH_HANDLE_EX(ill);
		break;
	case EXCEPTION_INT_DIVIDE_BY_ZERO:
	case EXCEPTION_INT_OVERFLOW:
	case EXCEPTION_FLT_DIVIDE_BY_ZERO:
	case EXCEPTION_FLT_OVERFLOW:
	case EXCEPTION_FLT_UNDERFLOW:
	case EXCEPTION_FLT_INEXACT_RESULT:
		W32_SEH_HANDLE_EX(fpe);
		break;
	default:
		break;
	}

	return res;
}

void win32_seh_init()
{
	old_handler = SetUnhandledExceptionFilter(seh_handler);
}

void win32_seh_cleanup()
{
	if (old_handler) SetUnhandledExceptionFilter(old_handler);
}

void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
{
	switch (type) {
	case SIGFPE:
		fpe_handler = handler;
		break;
	case SIGILL:
		ill_handler = handler;
		break;
	case SIGSEGV:
		segv_handler = handler;
		break;
	default:
		break;
	}
}

#endif /* PLATFORM_WIN32 */