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