/*
 * ARM signal handling routines
 *
 * Copyright 2002 Marcus Meissner, SuSE Linux AG
 * Copyright 2010-2013, 2015 André Hentschel
 *
 * 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
 */

#ifdef __arm__

#include "config.h"
#include "wine/port.h"

#include <assert.h>
#include <signal.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#define NONAMELESSUNION
#define NONAMELESSSTRUCT
#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "winternl.h"
#include "wine/exception.h"
#include "ntdll_misc.h"
#include "wine/debug.h"
#include "winnt.h"

WINE_DEFAULT_DEBUG_CHANNEL(seh);


/*******************************************************************
 *         is_valid_frame
 */
static inline BOOL is_valid_frame( void *frame )
{
    if ((ULONG_PTR)frame & 3) return FALSE;
    return (frame >= NtCurrentTeb()->Tib.StackLimit &&
            (void **)frame < (void **)NtCurrentTeb()->Tib.StackBase - 1);
}


/**************************************************************************
 *		__chkstk (NTDLL.@)
 *
 * Incoming r4 contains words to allocate, converting to bytes then return
 */
__ASM_GLOBAL_FUNC( __chkstk, "lsl r4, r4, #2\n\t"
                             "bx lr" )

/***********************************************************************
 *		RtlCaptureContext (NTDLL.@)
 */
/* FIXME: Use the Stack instead of the actual register values */
__ASM_STDCALL_FUNC( RtlCaptureContext, 4,
                    ".arm\n\t"
                    "stmib r0, {r0-r12}\n\t"   /* context->R0..R12 */
                    "mov r1, #0x0200000\n\t"   /* CONTEXT_ARM */
                    "add r1, r1, #0x3\n\t"     /* CONTEXT_FULL */
                    "str r1, [r0]\n\t"         /* context->ContextFlags */
                    "str SP, [r0, #0x38]\n\t"  /* context->Sp */
                    "str LR, [r0, #0x3c]\n\t"  /* context->Lr */
                    "str PC, [r0, #0x40]\n\t"  /* context->Pc */
                    "mrs r1, CPSR\n\t"
                    "str r1, [r0, #0x44]\n\t"  /* context->Cpsr */
                    "bx lr"
                    )


/***********************************************************************
 *           set_cpu_context
 *
 * Set the new CPU context.
 */
void DECLSPEC_HIDDEN set_cpu_context( const CONTEXT *context );
__ASM_GLOBAL_FUNC( set_cpu_context,
                   ".arm\n\t"
                   "ldr r2, [r0, #0x44]\n\t"  /* context->Cpsr */
                   "tst r2, #0x20\n\t"        /* thumb? */
                   "ldr r1, [r0, #0x40]\n\t"  /* context->Pc */
                   "orrne r1, r1, #1\n\t"     /* Adjust PC according to thumb */
                   "biceq r1, r1, #1\n\t"     /* Adjust PC according to arm */
                   "msr CPSR_f, r2\n\t"
                   "ldr lr, [r0, #0x3c]\n\t"  /* context->Lr */
                   "ldr sp, [r0, #0x38]\n\t"  /* context->Sp */
                   "push {r1}\n\t"
                   "ldmib r0, {r0-r12}\n\t"   /* context->R0..R12 */
                   "pop {pc}" )


/**********************************************************************
 *           call_stack_handlers
 *
 * Call the stack handlers chain.
 */
static NTSTATUS call_stack_handlers( EXCEPTION_RECORD *rec, CONTEXT *context )
{
    EXCEPTION_REGISTRATION_RECORD *frame, *dispatch, *nested_frame;
    DWORD res;

    frame = NtCurrentTeb()->Tib.ExceptionList;
    nested_frame = NULL;
    while (frame != (EXCEPTION_REGISTRATION_RECORD*)~0UL)
    {
        /* Check frame address */
        if (!is_valid_frame( frame ))
        {
            rec->ExceptionFlags |= EH_STACK_INVALID;
            break;
        }

        /* Call handler */
        TRACE( "calling handler at %p code=%x flags=%x\n",
               frame->Handler, rec->ExceptionCode, rec->ExceptionFlags );
        res = frame->Handler( rec, frame, context, &dispatch );
        TRACE( "handler at %p returned %x\n", frame->Handler, res );

        if (frame == nested_frame)
        {
            /* no longer nested */
            nested_frame = NULL;
            rec->ExceptionFlags &= ~EH_NESTED_CALL;
        }

        switch(res)
        {
        case ExceptionContinueExecution:
            if (!(rec->ExceptionFlags & EH_NONCONTINUABLE)) return STATUS_SUCCESS;
            return STATUS_NONCONTINUABLE_EXCEPTION;
        case ExceptionContinueSearch:
            break;
        case ExceptionNestedException:
            if (nested_frame < dispatch) nested_frame = dispatch;
            rec->ExceptionFlags |= EH_NESTED_CALL;
            break;
        default:
            return STATUS_INVALID_DISPOSITION;
        }
        frame = frame->Prev;
    }
    return STATUS_UNHANDLED_EXCEPTION;
}


/*******************************************************************
 *		KiUserExceptionDispatcher (NTDLL.@)
 */
NTSTATUS WINAPI KiUserExceptionDispatcher( EXCEPTION_RECORD *rec, CONTEXT *context )
{
    NTSTATUS status;
    DWORD c;

    TRACE( "code=%x flags=%x addr=%p pc=%08x tid=%04x\n",
           rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
           context->Pc, GetCurrentThreadId() );
    for (c = 0; c < rec->NumberParameters; c++)
        TRACE( " info[%d]=%08lx\n", c, rec->ExceptionInformation[c] );

    if (rec->ExceptionCode == EXCEPTION_WINE_STUB)
    {
        if (rec->ExceptionInformation[1] >> 16)
            MESSAGE( "wine: Call from %p to unimplemented function %s.%s, aborting\n",
                     rec->ExceptionAddress,
                     (char*)rec->ExceptionInformation[0], (char*)rec->ExceptionInformation[1] );
        else
            MESSAGE( "wine: Call from %p to unimplemented function %s.%ld, aborting\n",
                     rec->ExceptionAddress,
                     (char*)rec->ExceptionInformation[0], rec->ExceptionInformation[1] );
    }
    else
    {
        TRACE( " r0=%08x r1=%08x r2=%08x r3=%08x r4=%08x r5=%08x\n",
               context->R0, context->R1, context->R2, context->R3, context->R4, context->R5 );
        TRACE( " r6=%08x r7=%08x r8=%08x r9=%08x r10=%08x r11=%08x\n",
               context->R6, context->R7, context->R8, context->R9, context->R10, context->R11 );
        TRACE( " r12=%08x sp=%08x lr=%08x pc=%08x cpsr=%08x\n",
               context->R12, context->Sp, context->Lr, context->Pc, context->Cpsr );
    }

    if (call_vectored_handlers( rec, context ) == EXCEPTION_CONTINUE_EXECUTION)
        NtContinue( context, FALSE );

    if ((status = call_stack_handlers( rec, context )) == STATUS_SUCCESS)
        NtContinue( context, FALSE );

    if (status != STATUS_UNHANDLED_EXCEPTION) RtlRaiseStatus( status );
    return NtRaiseException( rec, context, FALSE );
}


/***********************************************************************
 *            RtlUnwind  (NTDLL.@)
 */
void WINAPI RtlUnwind( void *endframe, void *target_ip, EXCEPTION_RECORD *rec, void *retval )
{
    CONTEXT context;
    EXCEPTION_RECORD record;
    EXCEPTION_REGISTRATION_RECORD *frame, *dispatch;
    DWORD res;

    RtlCaptureContext( &context );
    context.R0 = (DWORD)retval;

    /* build an exception record, if we do not have one */
    if (!rec)
    {
        record.ExceptionCode    = STATUS_UNWIND;
        record.ExceptionFlags   = 0;
        record.ExceptionRecord  = NULL;
        record.ExceptionAddress = (void *)context.Pc;
        record.NumberParameters = 0;
        rec = &record;
    }

    rec->ExceptionFlags |= EH_UNWINDING | (endframe ? 0 : EH_EXIT_UNWIND);

    TRACE( "code=%x flags=%x\n", rec->ExceptionCode, rec->ExceptionFlags );

    /* get chain of exception frames */
    frame = NtCurrentTeb()->Tib.ExceptionList;
    while ((frame != (EXCEPTION_REGISTRATION_RECORD*)~0UL) && (frame != endframe))
    {
        /* Check frame address */
        if (endframe && ((void*)frame > endframe))
            raise_status( STATUS_INVALID_UNWIND_TARGET, rec );

        if (!is_valid_frame( frame )) raise_status( STATUS_BAD_STACK, rec );

        /* Call handler */
        TRACE( "calling handler at %p code=%x flags=%x\n",
               frame->Handler, rec->ExceptionCode, rec->ExceptionFlags );
        res = frame->Handler(rec, frame, &context, &dispatch);
        TRACE( "handler at %p returned %x\n", frame->Handler, res );

        switch(res)
        {
        case ExceptionContinueSearch:
            break;
        case ExceptionCollidedUnwind:
            frame = dispatch;
            break;
        default:
            raise_status( STATUS_INVALID_DISPOSITION, rec );
            break;
        }
        frame = __wine_pop_frame( frame );
    }
}


/***********************************************************************
 *		RtlRaiseException (NTDLL.@)
 */
void WINAPI RtlRaiseException( EXCEPTION_RECORD *rec )
{
    CONTEXT context;

    RtlCaptureContext( &context );
    rec->ExceptionAddress = (LPVOID)context.Pc;
    RtlRaiseStatus( NtRaiseException( rec, &context, TRUE ));
}

/*************************************************************************
 *             RtlCaptureStackBackTrace (NTDLL.@)
 */
USHORT WINAPI RtlCaptureStackBackTrace( ULONG skip, ULONG count, PVOID *buffer, ULONG *hash )
{
    FIXME( "(%d, %d, %p, %p) stub!\n", skip, count, buffer, hash );
    return 0;
}

/**********************************************************************
 *              DbgBreakPoint   (NTDLL.@)
 */
void WINAPI DbgBreakPoint(void)
{
     kill(getpid(), SIGTRAP);
}

/**********************************************************************
 *              DbgUserBreakPoint   (NTDLL.@)
 */
void WINAPI DbgUserBreakPoint(void)
{
     kill(getpid(), SIGTRAP);
}

/**********************************************************************
 *           NtCurrentTeb   (NTDLL.@)
 */
TEB * WINAPI NtCurrentTeb(void)
{
    return unix_funcs->NtCurrentTeb();
}

#endif  /* __arm__ */