/*
 * Wine exception handling
 *
 * Copyright (c) 1999 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#ifndef __WINE_WINE_EXCEPTION_H
#define __WINE_WINE_EXCEPTION_H

#include <setjmp.h>
#include <windef.h>
#include <winternl.h>
#include <excpt.h>

/* The following definitions allow using exceptions in Wine and Winelib code
 *
 * They should be used like this:
 *
 * __TRY
 * {
 *     do some stuff that can raise an exception
 * }
 * __EXCEPT(filter_func,param)
 * {
 *     handle the exception here
 * }
 * __ENDTRY
 *
 * or
 *
 * __TRY
 * {
 *     do some stuff that can raise an exception
 * }
 * __FINALLY(finally_func,param)
 *
 * The filter_func must be defined with the WINE_EXCEPTION_FILTER
 * macro, and return one of the EXCEPTION_* code; it can use
 * GetExceptionInformation and GetExceptionCode to retrieve the
 * exception info.
 *
 * The finally_func must be defined with the WINE_FINALLY_FUNC macro.
 *
 * Warning: inside a __TRY or __EXCEPT block, 'break' or 'continue' statements
 *          break out of the current block. You cannot use 'return', 'goto'
 *          or 'longjmp' to leave a __TRY block, as this will surely crash.
 *          You can use them to leave a __EXCEPT block though.
 *
 * -- AJ
 */

/* Define this if you want to use your compiler built-in __try/__except support.
 * This is only useful when compiling to a native Windows binary, as the built-in
 * compiler exceptions will most certainly not work under Winelib.
 */
#ifdef USE_COMPILER_EXCEPTIONS

#define __TRY __try
#define __EXCEPT(func) __except((func)(GetExceptionInformation()))
#define __FINALLY(func) __finally { (func)(!AbnormalTermination()); }
#define __ENDTRY /*nothing*/
#define __EXCEPT_PAGE_FAULT __except(GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION)
#define __EXCEPT_ALL __except(EXCEPTION_EXECUTE_HANDLER)

#else  /* USE_COMPILER_EXCEPTIONS */

#ifndef __GNUC__
#define __attribute__(x) /* nothing */
#endif

#if defined(__MINGW32__) || defined(__CYGWIN__)
#define sigjmp_buf jmp_buf
#define sigsetjmp(buf,sigs) setjmp(buf)
#define siglongjmp(buf,val) longjmp(buf,val)
#endif

#define __TRY \
    do { __WINE_FRAME __f; \
         int __first = 1; \
         for (;;) if (!__first) \
         { \
             do {

#define __EXCEPT(func) \
             } while(0); \
             __wine_pop_frame( &__f.frame ); \
             break; \
         } else { \
             __f.frame.Handler = __wine_exception_handler; \
             __f.u.filter = (func); \
             if (sigsetjmp( __f.jmp, 0 )) { \
                 const __WINE_FRAME * const __eptr __attribute__((unused)) = &__f; \
                 do {

/* convenience handler for page fault exceptions */
#define __EXCEPT_PAGE_FAULT \
             } while(0); \
             __wine_pop_frame( &__f.frame ); \
             break; \
         } else { \
             __f.frame.Handler = __wine_exception_handler_page_fault; \
             if (sigsetjmp( __f.jmp, 0 )) { \
                 const __WINE_FRAME * const __eptr __attribute__((unused)) = &__f; \
                 do {

/* convenience handler for all exception */
#define __EXCEPT_ALL \
             } while(0); \
             __wine_pop_frame( &__f.frame ); \
             break; \
         } else { \
             __f.frame.Handler = __wine_exception_handler_all; \
             if (sigsetjmp( __f.jmp, 0 )) { \
                 const __WINE_FRAME * const __eptr __attribute__((unused)) = &__f; \
                 do {

#define __ENDTRY \
                 } while (0); \
                 break; \
             } \
             __wine_push_frame( &__f.frame ); \
             __first = 0; \
         } \
    } while (0);

#define __FINALLY(func) \
             } while(0); \
             __wine_pop_frame( &__f.frame ); \
             (func)(1); \
             break; \
         } else { \
             __f.frame.Handler = __wine_finally_handler; \
             __f.u.finally_func = (func); \
             __wine_push_frame( &__f.frame ); \
             __first = 0; \
         } \
    } while (0);


typedef LONG (CALLBACK *__WINE_FILTER)(PEXCEPTION_POINTERS);
typedef void (CALLBACK *__WINE_FINALLY)(BOOL);

#define GetExceptionInformation() (__eptr)
#define GetExceptionCode()        (__eptr->ExceptionRecord->ExceptionCode)
#define AbnormalTermination()     (!__normal)

typedef struct __tagWINE_FRAME
{
    EXCEPTION_REGISTRATION_RECORD frame;
    union
    {
        /* exception data */
        __WINE_FILTER filter;
        /* finally data */
        __WINE_FINALLY finally_func;
    } u;
    sigjmp_buf jmp;
    /* hack to make GetExceptionCode() work in handler */
    DWORD ExceptionCode;
    const struct __tagWINE_FRAME *ExceptionRecord;
} __WINE_FRAME;

#endif /* USE_COMPILER_EXCEPTIONS */

static inline EXCEPTION_REGISTRATION_RECORD *__wine_push_frame( EXCEPTION_REGISTRATION_RECORD *frame )
{
#if defined(__GNUC__) && defined(__i386__)
    EXCEPTION_REGISTRATION_RECORD *prev;
    __asm__ __volatile__(".byte 0x64\n\tmovl (0),%0"
                         "\n\tmovl %0,(%1)"
                         "\n\t.byte 0x64\n\tmovl %1,(0)"
                         : "=&r" (prev) : "r" (frame) : "memory" );
    return prev;
#else
    NT_TIB *teb = (NT_TIB *)NtCurrentTeb();
    frame->Prev = (void *)teb->ExceptionList;
    teb->ExceptionList = (void *)frame;
    return frame->Prev;
#endif
}

static inline EXCEPTION_REGISTRATION_RECORD *__wine_pop_frame( EXCEPTION_REGISTRATION_RECORD *frame )
{
#if defined(__GNUC__) && defined(__i386__)
    __asm__ __volatile__(".byte 0x64\n\tmovl %0,(0)"
                         : : "r" (frame->Prev) : "memory" );
    return frame->Prev;

#else
    NT_TIB *teb = (NT_TIB *)NtCurrentTeb();
    teb->ExceptionList = (void *)frame->Prev;
    return frame->Prev;
#endif
}

/* Exception handling flags - from OS/2 2.0 exception handling */

/* Win32 seems to use the same flags as ExceptionFlags in an EXCEPTION_RECORD */
#define EH_NONCONTINUABLE   0x01
#define EH_UNWINDING        0x02
#define EH_EXIT_UNWIND      0x04
#define EH_STACK_INVALID    0x08
#define EH_NESTED_CALL      0x10

/* Wine-specific exceptions codes */

#define EXCEPTION_WINE_STUB       0x80000100  /* stub entry point called */
#define EXCEPTION_WINE_ASSERTION  0x80000101  /* assertion failed */

/* unhandled return status from vm86 mode */
#define EXCEPTION_VM86_INTx       0x80000110
#define EXCEPTION_VM86_STI        0x80000111
#define EXCEPTION_VM86_PICRETURN  0x80000112

extern void __wine_enter_vm86( CONTEXT *context );

#ifndef USE_COMPILER_EXCEPTIONS

static inline void DECLSPEC_NORETURN __wine_unwind_frame( EXCEPTION_RECORD *record,
                                                          EXCEPTION_REGISTRATION_RECORD *frame )
{
    __WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;

    /* hack to make GetExceptionCode() work in handler */
    wine_frame->ExceptionCode   = record->ExceptionCode;
    wine_frame->ExceptionRecord = wine_frame;

#if defined(__GNUC__) && defined(__i386__)
    {
        /* RtlUnwind clobbers registers on Windows */
        int dummy1, dummy2, dummy3;
        __asm__ __volatile__("pushl %%ebp\n\t"
                             "pushl %%ebx\n\t"
                             "pushl $0\n\t"
                             "pushl %2\n\t"
                             "pushl $0\n\t"
                             "pushl %1\n\t"
                             "call *%0\n\t"
                             "popl %%ebx\n\t"
                             "popl %%ebp"
                             : "=a" (dummy1), "=S" (dummy2), "=D" (dummy3)
                             : "0" (RtlUnwind), "1" (frame), "2" (record)
                             : "ecx", "edx", "memory" );
    }
#else
    RtlUnwind( frame, 0, record, 0 );
#endif
    __wine_pop_frame( frame );
    siglongjmp( wine_frame->jmp, 1 );
}

static inline DWORD __wine_exception_handler( EXCEPTION_RECORD *record,
                                              EXCEPTION_REGISTRATION_RECORD *frame,
                                              CONTEXT *context,
                                              EXCEPTION_REGISTRATION_RECORD **pdispatcher )
{
    __WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
    EXCEPTION_POINTERS ptrs;

    if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND | EH_NESTED_CALL))
        return ExceptionContinueSearch;

    ptrs.ExceptionRecord = record;
    ptrs.ContextRecord = context;
    switch(wine_frame->u.filter( &ptrs ))
    {
    case EXCEPTION_CONTINUE_SEARCH:
        return ExceptionContinueSearch;
    case EXCEPTION_CONTINUE_EXECUTION:
        return ExceptionContinueExecution;
    case EXCEPTION_EXECUTE_HANDLER:
        break;
    }
    __wine_unwind_frame( record, frame );
}

static inline DWORD __wine_exception_handler_page_fault( EXCEPTION_RECORD *record,
                                                         EXCEPTION_REGISTRATION_RECORD *frame,
                                                         CONTEXT *context,
                                                         EXCEPTION_REGISTRATION_RECORD **pdispatcher )
{
    if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND | EH_NESTED_CALL))
        return ExceptionContinueSearch;
    if (record->ExceptionCode != STATUS_ACCESS_VIOLATION)
        return ExceptionContinueSearch;
    __wine_unwind_frame( record, frame );
}

static inline DWORD __wine_exception_handler_all( EXCEPTION_RECORD *record,
                                                  EXCEPTION_REGISTRATION_RECORD *frame,
                                                  CONTEXT *context,
                                                  EXCEPTION_REGISTRATION_RECORD **pdispatcher )
{
    if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND | EH_NESTED_CALL))
        return ExceptionContinueSearch;
    __wine_unwind_frame( record, frame );
}

static inline DWORD __wine_finally_handler( EXCEPTION_RECORD *record,
                                            EXCEPTION_REGISTRATION_RECORD *frame,
                                            CONTEXT *context,
                                            EXCEPTION_REGISTRATION_RECORD **pdispatcher )
{
    if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
    {
        __WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
        wine_frame->u.finally_func( FALSE );
    }
    return ExceptionContinueSearch;
}

#endif /* USE_COMPILER_EXCEPTIONS */

#endif  /* __WINE_WINE_EXCEPTION_H */
