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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* Implement shared vtbl methods. */
#include "xptcprivate.h"
#include "xptiprivate.h"
#ifdef __GNUC__
/* This tells gcc3.4+ not to optimize away symbols.
* @see http://gcc.gnu.org/gcc-3.4/changes.html
*/
#define DONT_DROP_OR_WARN __attribute__((used))
#else
/* This tells older gccs not to warn about unused vairables.
* @see http://docs.freebsd.org/info/gcc/gcc.info.Variable_Attributes.html
*/
#define DONT_DROP_OR_WARN __attribute__((unused))
#endif
/* Specify explicitly a symbol for this function, don't try to guess the c++ mangled symbol. */
static nsresult PrepareAndDispatch(nsXPTCStubBase* self, uint32_t methodIndex, uint32_t* args) asm("_PrepareAndDispatch")
DONT_DROP_OR_WARN;
static nsresult ATTRIBUTE_USED
PrepareAndDispatch(nsXPTCStubBase* self, uint32_t methodIndex, uint32_t* args)
{
#define PARAM_BUFFER_COUNT 16
nsXPTCMiniVariant paramBuffer[PARAM_BUFFER_COUNT];
nsXPTCMiniVariant* dispatchParams = nullptr;
const nsXPTMethodInfo* info;
uint8_t paramCount;
uint8_t i;
nsresult result = NS_ERROR_FAILURE;
NS_ASSERTION(self,"no self");
self->mEntry->GetMethodInfo(uint16_t(methodIndex), &info);
paramCount = info->GetParamCount();
// setup variant array pointer
if(paramCount > PARAM_BUFFER_COUNT)
dispatchParams = new nsXPTCMiniVariant[paramCount];
else
dispatchParams = paramBuffer;
NS_ASSERTION(dispatchParams,"no place for params");
if (!dispatchParams)
return NS_ERROR_OUT_OF_MEMORY;
uint32_t* ap = args;
for(i = 0; i < paramCount; i++, ap++)
{
const nsXPTParamInfo& param = info->GetParam(i);
const nsXPTType& type = param.GetType();
nsXPTCMiniVariant* dp = &dispatchParams[i];
if(param.IsOut() || !type.IsArithmetic())
{
dp->val.p = (void*) *ap;
continue;
}
// else
switch(type)
{
case nsXPTType::T_I8 : dp->val.i8 = *((int8_t*) ap); break;
case nsXPTType::T_I16 : dp->val.i16 = *((int16_t*) ap); break;
case nsXPTType::T_I32 : dp->val.i32 = *((int32_t*) ap); break;
case nsXPTType::T_I64 : dp->val.i64 = *((int64_t*) ap); ap++; break;
case nsXPTType::T_U8 : dp->val.u8 = *((uint8_t*) ap); break;
case nsXPTType::T_U16 : dp->val.u16 = *((uint16_t*)ap); break;
case nsXPTType::T_U32 : dp->val.u32 = *((uint32_t*)ap); break;
case nsXPTType::T_U64 : dp->val.u64 = *((uint64_t*)ap); ap++; break;
case nsXPTType::T_FLOAT : dp->val.f = *((float*) ap); break;
case nsXPTType::T_DOUBLE : dp->val.d = *((double*) ap); ap++; break;
case nsXPTType::T_BOOL : dp->val.b = *((bool*) ap); break;
case nsXPTType::T_CHAR : dp->val.c = *((char*) ap); break;
case nsXPTType::T_WCHAR : dp->val.wc = *((wchar_t*) ap); break;
default:
NS_ERROR("bad type");
break;
}
}
result = self->mOuter->CallMethod((uint16_t)methodIndex, info, dispatchParams);
if(dispatchParams != paramBuffer)
delete [] dispatchParams;
return result;
}
/*
* This is our shared stub.
*
* r0 = Self.
*
* The Rules:
* We pass an (undefined) number of arguments into this function.
* The first 3 C++ arguments are in r1 - r3, the rest are built
* by the calling function on the stack.
*
* We are allowed to corrupt r0 - r3, ip, and lr.
*
* Other Info:
* We pass the stub number in using `ip'.
*
* Implementation:
* - We save r1 to r3 inclusive onto the stack, which will be
* immediately below the caller saved arguments.
* - setup r2 (PrepareAndDispatch's args pointer) to point at
* the base of all these arguments
* - Save LR (for the return address)
* - Set r1 (PrepareAndDispatch's methodindex argument) from ip
* - r0 is passed through (self)
* - Call PrepareAndDispatch
* - When the call returns, we return by loading the PC off the
* stack, and undoing the stack (one instruction)!
*
*/
__asm__ ("\n\
.text \n\
.align 2 \n\
SharedStub: \n\
stmfd sp!, {r1, r2, r3} \n\
mov r2, sp \n\
str lr, [sp, #-4]! \n\
mov r1, ip \n\
bl _PrepareAndDispatch \n\
ldr pc, [sp], #16");
/*
* Create sets of stubs to call the SharedStub.
* We don't touch the stack here, nor any registers, other than IP.
* IP is defined to be corruptable by a called function, so we are
* safe to use it.
*
* This will work with or without optimisation.
*/
/*
* Note : As G++3 ABI contains the length of the functionname in the
* mangled name, it is difficult to get a generic assembler mechanism like
* in the G++ 2.95 case.
* Create names would be like :
* _ZN14nsXPTCStubBase5Stub9Ev
* _ZN14nsXPTCStubBase6Stub13Ev
* _ZN14nsXPTCStubBase7Stub144Ev
* Use the assembler directives to get the names right...
*/
#define STUB_ENTRY(n) \
__asm__( \
".section \".text\"\n" \
" .align 2\n" \
" .iflt ("#n" - 10)\n" \
" .globl _ZN14nsXPTCStubBase5Stub"#n"Ev\n" \
" .type _ZN14nsXPTCStubBase5Stub"#n"Ev,#function\n" \
"_ZN14nsXPTCStubBase5Stub"#n"Ev:\n" \
" .else\n" \
" .iflt ("#n" - 100)\n" \
" .globl _ZN14nsXPTCStubBase6Stub"#n"Ev\n" \
" .type _ZN14nsXPTCStubBase6Stub"#n"Ev,#function\n" \
"_ZN14nsXPTCStubBase6Stub"#n"Ev:\n" \
" .else\n" \
" .iflt ("#n" - 1000)\n" \
" .globl _ZN14nsXPTCStubBase7Stub"#n"Ev\n" \
" .type _ZN14nsXPTCStubBase7Stub"#n"Ev,#function\n" \
"_ZN14nsXPTCStubBase7Stub"#n"Ev:\n" \
" .else\n" \
" .err \"stub number "#n"> 1000 not yet supported\"\n" \
" .endif\n" \
" .endif\n" \
" .endif\n" \
" mov ip, #"#n"\n" \
" b SharedStub\n\t");
#if 0
/*
* This part is left in as comment : this is how the method definition
* should look like.
*/
#define STUB_ENTRY(n) \
nsresult nsXPTCStubBase::Stub##n () \
{ \
__asm__ ( \
" mov ip, #"#n"\n" \
" b SharedStub\n\t"); \
return 0; /* avoid warnings */ \
}
#endif
#define SENTINEL_ENTRY(n) \
nsresult nsXPTCStubBase::Sentinel##n() \
{ \
NS_ERROR("nsXPTCStubBase::Sentinel called"); \
return NS_ERROR_NOT_IMPLEMENTED; \
}
#include "xptcstubsdef.inc"
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