michael@0: /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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: #include <stdio.h>
michael@0: 
michael@0: typedef unsigned nsresult;
michael@0: typedef unsigned uint32_t;
michael@0: typedef unsigned nsXPCVariant;
michael@0: 
michael@0: 
michael@0: #if defined(WIN32)
michael@0: #define NS_IMETHOD virtual nsresult __stdcall
michael@0: #define NS_IMETHODIMP nsresult __stdcall
michael@0: #else
michael@0: #define NS_IMETHOD virtual nsresult
michael@0: #define NS_IMETHODIMP nsresult
michael@0: #endif
michael@0: 
michael@0: 
michael@0: class base{
michael@0: public:
michael@0:   NS_IMETHOD ignored() = 0;
michael@0: };
michael@0: 
michael@0: class foo : public base {
michael@0: public:
michael@0:   NS_IMETHOD callme1(int i, int j) = 0;
michael@0:   NS_IMETHOD callme2(int i, int j) = 0;
michael@0:   NS_IMETHOD callme3(int i, int j) = 0;
michael@0: };
michael@0: 
michael@0: class bar : public foo{
michael@0: public:
michael@0:   NS_IMETHOD ignored();
michael@0:   NS_IMETHOD callme1(int i, int j);
michael@0:   NS_IMETHOD callme2(int i, int j);
michael@0:   NS_IMETHOD callme3(int i, int j);
michael@0: };
michael@0: 
michael@0: /*
michael@0: class baz : public base {
michael@0: public:
michael@0:   NS_IMETHOD ignored();
michael@0:   NS_IMETHOD callme1();
michael@0:   NS_IMETHOD callme2();
michael@0:   NS_IMETHOD callme3();
michael@0:   void setfoo(foo* f) {other = f;}
michael@0: 
michael@0:   foo* other;
michael@0: };
michael@0: NS_IMETHODIMP baz::ignored(){return 0;}
michael@0: */
michael@0: 
michael@0: NS_IMETHODIMP bar::ignored(){return 0;}
michael@0: 
michael@0: NS_IMETHODIMP bar::callme1(int i, int j)
michael@0: {
michael@0:   printf("called bar::callme1 with: %d %d\n", i, j);
michael@0:   return 5;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP bar::callme2(int i, int j)
michael@0: {
michael@0:   printf("called bar::callme2 with: %d %d\n", i, j);
michael@0:   return 5;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP bar::callme3(int i, int j)
michael@0: {
michael@0:   printf("called bar::callme3 with: %d %d\n", i, j);
michael@0:   return 5;
michael@0: }
michael@0: 
michael@0: void docall(foo* f, int i, int j){
michael@0:   f->callme1(i, j); 
michael@0: }
michael@0: 
michael@0: /***************************************************************************/
michael@0: #if defined(WIN32)
michael@0: 
michael@0: static uint32_t __stdcall
michael@0: invoke_count_words(uint32_t paramCount, nsXPCVariant* s)
michael@0: {
michael@0:     return paramCount;
michael@0: }    
michael@0: 
michael@0: static void __stdcall
michael@0: invoke_copy_to_stack(uint32_t* d, uint32_t paramCount, nsXPCVariant* s)
michael@0: {
michael@0:     for(uint32_t i = 0; i < paramCount; i++, d++, s++)
michael@0:     {
michael@0:         *((uint32_t*)d) = *((uint32_t*)s);
michael@0:     }
michael@0: }
michael@0: 
michael@0: static nsresult __stdcall
michael@0: DoInvoke(void* that, uint32_t index,
michael@0:          uint32_t paramCount, nsXPCVariant* params)
michael@0: {
michael@0:     __asm {
michael@0:         push    params
michael@0:         push    paramCount
michael@0:         call    invoke_count_words  // stdcall, result in eax
michael@0:         shl     eax,2               // *= 4
michael@0:         sub     esp,eax             // make space for params
michael@0:         mov     edx,esp
michael@0:         push    params
michael@0:         push    paramCount
michael@0:         push    edx
michael@0:         call    invoke_copy_to_stack // stdcall
michael@0:         mov     ecx,that            // instance in ecx
michael@0:         push    ecx                 // push this
michael@0:         mov     edx,[ecx]           // vtable in edx
michael@0:         mov     eax,index
michael@0:         shl     eax,2               // *= 4
michael@0:         add     edx,eax
michael@0:         call    [edx]               // stdcall, i.e. callee cleans up stack.
michael@0:     }
michael@0: }
michael@0: 
michael@0: #else
michael@0: /***************************************************************************/
michael@0: // just Linux_x86 now. Add other later...
michael@0: 
michael@0: static uint32_t 
michael@0: invoke_count_words(uint32_t paramCount, nsXPCVariant* s)
michael@0: {
michael@0:     return paramCount;
michael@0: }    
michael@0: 
michael@0: static void 
michael@0: invoke_copy_to_stack(uint32_t* d, uint32_t paramCount, nsXPCVariant* s)
michael@0: {
michael@0:     for(uint32_t i = 0; i < paramCount; i++, d++, s++)
michael@0:     {
michael@0:         *((uint32_t*)d) = *((uint32_t*)s);
michael@0:     }
michael@0: }
michael@0: 
michael@0: static nsresult
michael@0: DoInvoke(void* that, uint32_t index,
michael@0:          uint32_t paramCount, nsXPCVariant* params)
michael@0: {
michael@0:     uint32_t result;
michael@0:     void* fn_count = invoke_count_words;
michael@0:     void* fn_copy = invoke_copy_to_stack;
michael@0: 
michael@0:  __asm__ __volatile__(
michael@0:     "pushl %4\n\t"
michael@0:     "pushl %3\n\t"
michael@0:     "movl  %5, %%eax\n\t"
michael@0:     "call  *%%eax\n\t"       /* count words */
michael@0:     "addl  $0x8, %%esp\n\t"
michael@0:     "shl   $2, %%eax\n\t"    /* *= 4 */
michael@0:     "subl  %%eax, %%esp\n\t" /* make room for params */
michael@0:     "movl  %%esp, %%edx\n\t"
michael@0:     "pushl %4\n\t"
michael@0:     "pushl %3\n\t"
michael@0:     "pushl %%edx\n\t"
michael@0:     "movl  %6, %%eax\n\t"
michael@0:     "call  *%%eax\n\t"       /* copy params */
michael@0:     "addl  $0xc, %%esp\n\t"
michael@0:     "movl  %1, %%ecx\n\t"
michael@0:     "pushl %%ecx\n\t"
michael@0:     "movl  (%%ecx), %%edx\n\t"
michael@0:     "movl  %2, %%eax\n\t"   /* function index */
michael@0:     "shl   $2, %%eax\n\t"   /* *= 4 */
michael@0:     "addl  $8, %%eax\n\t"   /* += 8 */
michael@0:     "addl  %%eax, %%edx\n\t"
michael@0:     "call  *(%%edx)\n\t"    /* safe to not cleanup esp */
michael@0:     "movl  %%eax, %0"
michael@0:     : "=g" (result)         /* %0 */
michael@0:     : "g" (that),           /* %1 */
michael@0:       "g" (index),          /* %2 */
michael@0:       "g" (paramCount),     /* %3 */
michael@0:       "g" (params),         /* %4 */
michael@0:       "g" (fn_count),       /* %5 */
michael@0:       "g" (fn_copy)         /* %6 */
michael@0:     : "ax", "cx", "dx", "memory" 
michael@0:     );
michael@0:   
michael@0:   return result;
michael@0: }    
michael@0: 
michael@0: #endif
michael@0: /***************************************************************************/
michael@0: 
michael@0: int main()
michael@0: {
michael@0:   nsXPCVariant params1[2] = {1,2};
michael@0:   nsXPCVariant params2[2] = {2,4};
michael@0:   nsXPCVariant params3[2] = {3,6};
michael@0: 
michael@0:   foo* a = new bar();
michael@0: 
michael@0: //  printf("calling via C++...\n");
michael@0: //  docall(a, 12, 24);
michael@0: 
michael@0:   printf("calling via ASM...\n");
michael@0:   DoInvoke(a, 1, 2, params1);
michael@0:   DoInvoke(a, 2, 2, params2);
michael@0:   DoInvoke(a, 3, 2, params3);
michael@0: 
michael@0:   return 0;
michael@0: }