The Tor Browser: xpcom/reflect/xptcall/src/md/test/invoke

xpcom/reflect/xptcall/src/md/test/invoke_test.cpp@b8a032363ba2 (annotated)

xpcom/reflect/xptcall/src/md/test/invoke_test.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

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

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xpcom/reflect/xptcall/src/md/test/invoke_test.cpp@b8a032363ba2 (annotated)

xpcom/reflect/xptcall/src/md/test/invoke_test.cpp