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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* Platform specific code to invoke XPCOM methods on native objects */
#include "xptcprivate.h"
#if !defined(LINUX) || !defined(__arm__)
#error "This code is for Linux ARM only. Check that it works on your system, too.\nBeware that this code is highly compiler dependent."
#endif
// Remember that these 'words' are 32bit DWORDS
static PRUint32
invoke_count_words(PRUint32 paramCount, nsXPTCVariant* s)
{
PRUint32 result = 0;
for(PRUint32 i = 0; i < paramCount; i++, s++)
{
if(s->IsPtrData())
{
result++;
continue;
}
switch(s->type)
{
case nsXPTType::T_I8 :
case nsXPTType::T_I16 :
case nsXPTType::T_I32 :
result++;
break;
case nsXPTType::T_I64 :
result+=2;
break;
case nsXPTType::T_U8 :
case nsXPTType::T_U16 :
case nsXPTType::T_U32 :
result++;
break;
case nsXPTType::T_U64 :
result+=2;
break;
case nsXPTType::T_FLOAT :
result++;
break;
case nsXPTType::T_DOUBLE :
result+=2;
break;
case nsXPTType::T_BOOL :
case nsXPTType::T_CHAR :
case nsXPTType::T_WCHAR :
result++;
break;
default:
// all the others are plain pointer types
result++;
break;
}
}
return result;
}
static void
invoke_copy_to_stack(PRUint32* d, PRUint32 paramCount, nsXPTCVariant* s)
{
for(PRUint32 i = 0; i < paramCount; i++, d++, s++)
{
if(s->IsPtrData())
{
*((void**)d) = s->ptr;
continue;
}
switch(s->type)
{
case nsXPTType::T_I8 : *((PRInt8*) d) = s->val.i8; break;
case nsXPTType::T_I16 : *((PRInt16*) d) = s->val.i16; break;
case nsXPTType::T_I32 : *((PRInt32*) d) = s->val.i32; break;
case nsXPTType::T_I64 : *((PRInt64*) d) = s->val.i64; d++; break;
case nsXPTType::T_U8 : *((PRUint8*) d) = s->val.u8; break;
case nsXPTType::T_U16 : *((PRUint16*)d) = s->val.u16; break;
case nsXPTType::T_U32 : *((PRUint32*)d) = s->val.u32; break;
case nsXPTType::T_U64 : *((PRUint64*)d) = s->val.u64; d++; break;
case nsXPTType::T_FLOAT : *((float*) d) = s->val.f; break;
case nsXPTType::T_DOUBLE : *((double*) d) = s->val.d; d++; break;
case nsXPTType::T_BOOL : *((PRBool*) d) = s->val.b; break;
case nsXPTType::T_CHAR : *((char*) d) = s->val.c; break;
case nsXPTType::T_WCHAR : *((wchar_t*) d) = s->val.wc; break;
default:
// all the others are plain pointer types
*((void**)d) = s->val.p;
break;
}
}
}
extern "C" {
struct my_params_struct {
nsISupports* that;
PRUint32 Index;
PRUint32 Count;
nsXPTCVariant* params;
PRUint32 fn_count;
PRUint32 fn_copy;
};
};
XPTC_PUBLIC_API(nsresult)
XPTC_InvokeByIndex(nsISupports* that, PRUint32 methodIndex,
PRUint32 paramCount, nsXPTCVariant* params)
{
PRUint32 result;
struct my_params_struct my_params;
my_params.that = that;
my_params.Index = methodIndex;
my_params.Count = paramCount;
my_params.params = params;
my_params.fn_copy = (PRUint32) &invoke_copy_to_stack;
my_params.fn_count = (PRUint32) &invoke_count_words;
/* This is to call a given method of class that.
* The parameters are in params, the number is in paramCount.
* The routine will issue calls to count the number of words
* required for argument passing and to copy the arguments to
* the stack.
* Since APCS passes the first 3 params in r1-r3, we need to
* load the first three words from the stack and correct the stack
* pointer (sp) in the appropriate way. This means:
*
* 1.) more than 3 arguments: load r1-r3, correct sp and remember No.
* of bytes left on the stack in r4
*
* 2.) <= 2 args: load r1-r3 (we won't be causing a stack overflow I hope),
* restore sp as if nothing had happened and set the marker r4 to zero.
*
* Afterwards sp will be restored using the value in r4 (which is not a temporary register
* and will be preserved by the function/method called according to APCS [ARM Procedure
* Calling Standard]).
*
* !!! IMPORTANT !!!
* This routine makes assumptions about the vtable layout of the c++ compiler. It's implemented
* for arm-linux GNU g++ >= 2.8.1 (including egcs and gcc-2.95.[1-3])!
*
*/
__asm__ __volatile__(
"ldr r1, [%1, #12] \n\t" /* prepare to call invoke_count_words */
"ldr ip, [%1, #16] \n\t" /* r0=paramCount, r1=params */
"ldr r0, [%1, #8] \n\t"
"mov lr, pc \n\t" /* call it... */
"mov pc, ip \n\t"
"mov r4, r0, lsl #2 \n\t" /* This is the amount of bytes needed. */
"sub sp, sp, r4 \n\t" /* use stack space for the args... */
"mov r0, sp \n\t" /* prepare a pointer an the stack */
"ldr r1, [%1, #8] \n\t" /* =paramCount */
"ldr r2, [%1, #12] \n\t" /* =params */
"ldr ip, [%1, #20] \n\t" /* =invoke_copy_to_stack */
"mov lr, pc \n\t" /* copy args to the stack like the */
"mov pc, ip \n\t" /* compiler would. */
"ldr r0, [%1] \n\t" /* =that */
"ldr r1, [r0, #0] \n\t" /* get that->vtable offset */
"ldr r2, [%1, #4] \n\t"
"mov r2, r2, lsl #2 \n\t" /* a vtable_entry(x)=8 + (4 bytes * x) */
#if defined(__GXX_ABI_VERSION) && __GXX_ABI_VERSION >= 100 /* G++ V3 ABI */
"ldr ip, [r1, r2] \n\t" /* get method adress from vtable */
#else /* non G++ V3 ABI */
"add r2, r2, #8 \n\t" /* with this compilers */
"ldr ip, [r1, r2] \n\t" /* get method adress from vtable */
#endif
"cmp r4, #12 \n\t" /* more than 3 arguments??? */
"ldmgtia sp!, {r1, r2, r3}\n\t" /* yes: load arguments for r1-r3 */
"subgt r4, r4, #12 \n\t" /* and correct the stack pointer */
"ldmleia sp, {r1, r2, r3}\n\t" /* no: load r1-r3 from stack */
"addle sp, sp, r4 \n\t" /* and restore stack pointer */
"movle r4, #0 \n\t" /* a mark for restoring sp */
"ldr r0, [%1, #0] \n\t" /* get (self) */
"mov lr, pc \n\t" /* call mathod */
"mov pc, ip \n\t"
"add sp, sp, r4 \n\t" /* restore stack pointer */
"mov %0, r0 \n\t" /* the result... */
: "=r" (result)
: "r" (&my_params)
: "r0", "r1", "r2", "r3", "r4", "ip", "lr", "sp"
);
return result;
}
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