/* -*- 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/. */ /* Platform specific code to invoke XPCOM methods on native objects */ #include "xptcprivate.h" // Remember that these 'words' are 32bit DWORDS static uint32_t invoke_count_words(uint32_t paramCount, nsXPTCVariant* s) { uint32_t result = 0; for(uint32_t 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(uint32_t* d, uint32_t paramCount, nsXPTCVariant* s) { for(uint32_t i = 0; i < paramCount; i++, d++, s++) { if(s->IsPtrData()) { *((void**)d) = s->ptr; continue; } switch(s->type) { case nsXPTType::T_I8 : *((int8_t*) d) = s->val.i8; break; case nsXPTType::T_I16 : *((int16_t*) d) = s->val.i16; break; case nsXPTType::T_I32 : *((int32_t*) d) = s->val.i32; break; case nsXPTType::T_I64 : *((int64_t*) d) = s->val.i64; d++; break; case nsXPTType::T_U8 : *((uint8_t*) d) = s->val.u8; break; case nsXPTType::T_U16 : *((uint16_t*)d) = s->val.u16; break; case nsXPTType::T_U32 : *((uint32_t*)d) = s->val.u32; break; case nsXPTType::T_U64 : *((uint64_t*)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 : *((bool*) 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; uint32_t Index; uint32_t Count; nsXPTCVariant* params; uint32_t fn_count; uint32_t fn_copy; }; } EXPORT_XPCOM_API(nsresult) NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex, uint32_t paramCount, nsXPTCVariant* params) { uint32_t 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 = (uint32_t) &invoke_copy_to_stack; my_params.fn_count = (uint32_t) &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])! * */ #ifdef __GNUC__ __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) */ "ldr ip, [r1, r2] \n\t" /* get method adress from vtable */ "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), "m" (my_params) : "r0", "r1", "r2", "r3", "r4", "ip", "lr", "sp" ); #else #error "Unsupported compiler. Use g++ >= 2.8 for OpenBSD/arm." #endif /* G++ >= 2.8 */ return result; }