The Tor Browser: xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp@b8a032363ba2

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

     1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 /* Implement shared vtbl methods. */

     8 #include "xptcprivate.h"

     9 #include "xptiprivate.h"

    11 #ifndef WIN32

    12 #error "This code is for Win32 only"

    13 #endif

    15 extern "C" {

    17 #ifndef __GNUC__

    18 static

    19 #endif

    20 nsresult __stdcall

    21 PrepareAndDispatch(nsXPTCStubBase* self, uint32_t methodIndex,

    22                    uint32_t* args, uint32_t* stackBytesToPop)

    23 {

    24 #define PARAM_BUFFER_COUNT     16

    26     nsXPTCMiniVariant paramBuffer[PARAM_BUFFER_COUNT];

    27     nsXPTCMiniVariant* dispatchParams = nullptr;

    28     const nsXPTMethodInfo* info = nullptr;

    29     uint8_t paramCount;

    30     uint8_t i;

    31     nsresult result = NS_ERROR_FAILURE;

    33     // If anything fails before stackBytesToPop can be set then

    34     // the failure is completely catastrophic!

    36     NS_ASSERTION(self,"no self");

    38     self->mEntry->GetMethodInfo(uint16_t(methodIndex), &info);

    39     NS_ASSERTION(info,"no method info");

    41     paramCount = info->GetParamCount();

    43     // setup variant array pointer

    44     if(paramCount > PARAM_BUFFER_COUNT)

    45         dispatchParams = new nsXPTCMiniVariant[paramCount];

    46     else

    47         dispatchParams = paramBuffer;

    48     NS_ASSERTION(dispatchParams,"no place for params");

    50     uint32_t* ap = args;

    51     for(i = 0; i < paramCount; i++, ap++)

    52     {

    53         const nsXPTParamInfo& param = info->GetParam(i);

    54         const nsXPTType& type = param.GetType();

    55         nsXPTCMiniVariant* dp = &dispatchParams[i];

    57         if(param.IsOut() || !type.IsArithmetic())

    58         {

    59             dp->val.p = (void*) *ap;

    60             continue;

    61         }

    62         // else

    63         switch(type)

    64         {

    65         case nsXPTType::T_I8     : dp->val.i8  = *((int8_t*)  ap);       break;

    66         case nsXPTType::T_I16    : dp->val.i16 = *((int16_t*) ap);       break;

    67         case nsXPTType::T_I32    : dp->val.i32 = *((int32_t*) ap);       break;

    68         case nsXPTType::T_I64    : dp->val.i64 = *((int64_t*) ap); ap++; break;

    69         case nsXPTType::T_U8     : dp->val.u8  = *((uint8_t*) ap);       break;

    70         case nsXPTType::T_U16    : dp->val.u16 = *((uint16_t*)ap);       break;

    71         case nsXPTType::T_U32    : dp->val.u32 = *((uint32_t*)ap);       break;

    72         case nsXPTType::T_U64    : dp->val.u64 = *((uint64_t*)ap); ap++; break;

    73         case nsXPTType::T_FLOAT  : dp->val.f   = *((float*)   ap);       break;

    74         case nsXPTType::T_DOUBLE : dp->val.d   = *((double*)  ap); ap++; break;

    75         case nsXPTType::T_BOOL   : dp->val.b   = *((bool*)  ap);       break;

    76         case nsXPTType::T_CHAR   : dp->val.c   = *((char*)    ap);       break;

    77         case nsXPTType::T_WCHAR  : dp->val.wc  = *((wchar_t*) ap);       break;

    78         default:

    79             NS_ERROR("bad type");

    80             break;

    81         }

    82     }

    83     *stackBytesToPop = ((uint32_t)ap) - ((uint32_t)args);

    85     result = self->mOuter->CallMethod((uint16_t)methodIndex, info, dispatchParams);

    87     if(dispatchParams != paramBuffer)

    88         delete [] dispatchParams;

    90     return result;

    91 }

    93 } // extern "C"

    95 // declspec(naked) is broken in gcc

    96 #ifndef __GNUC__

    97 static

    98 __declspec(naked)

    99 void SharedStub(void)

   100 {

   101     __asm {

   102         push ebp            // set up simple stack frame

   103         mov  ebp, esp       // stack has: ebp/vtbl_index/retaddr/this/args

   104         push ecx            // make room for a ptr

   105         lea  eax, [ebp-4]   // pointer to stackBytesToPop

   106         push eax

   107         lea  eax, [ebp+12]  // pointer to args

   108         push eax

   109         push ecx            // vtbl_index

   110         mov  eax, [ebp+8]   // this

   111         push eax

   112         call PrepareAndDispatch

   113         mov  edx, [ebp+4]   // return address

   114         mov  ecx, [ebp-4]   // stackBytesToPop

   115         add  ecx, 8         // for 'this' and return address

   116         mov  esp, ebp

   117         pop  ebp

   118         add  esp, ecx       // fix up stack pointer

   119         jmp  edx            // simulate __stdcall return

   120     }

   121 }

   123 // these macros get expanded (many times) in the file #included below

   124 #define STUB_ENTRY(n) \

   125 __declspec(naked) nsresult __stdcall nsXPTCStubBase::Stub##n() \

   126 { __asm mov ecx, n __asm jmp SharedStub }

   128 #else

   130 asm(".text\n\t"

   131     ".align     4\n\t"

   132     "SharedStub:\n\t"

   133     "push       %ebp\n\t"

   134     "mov        %esp, %ebp\n\t"

   135     "push       %ecx\n\t"

   136     "lea        -4(%ebp), %eax\n\t"

   137     "push       %eax\n\t"

   138     "lea        12(%ebp), %eax\n\t"

   139     "push       %eax\n\t"

   140     "push       %ecx\n\t"

   141     "movl       8(%ebp), %eax\n\t"

   142     "push       %eax\n\t"

   143     "call       _PrepareAndDispatch@16\n\t"

   144     "mov        4(%ebp), %edx\n\t"

   145     "mov        -4(%ebp), %ecx\n\t"

   146     "add        $8, %ecx\n\t"

   147     "mov        %ebp, %esp\n\t"

   148     "pop        %ebp\n\t"

   149     "add        %ecx, %esp\n\t"

   150     "jmp        *%edx"

   151 );

   153 #define STUB_ENTRY(n) \

   154 asm(".text\n\t" \

   155     ".align     4\n\t" \

   156     ".if	" #n " < 10\n\t" \

   157     ".globl     __ZN14nsXPTCStubBase5Stub" #n "Ev@4\n\t" \

   158     ".def       __ZN14nsXPTCStubBase5Stub" #n "Ev@4; \n\t" \

   159     ".scl       3\n\t" \

   160     ".type      46\n\t" \

   161     ".endef\n\t" \

   162     "__ZN14nsXPTCStubBase5Stub" #n "Ev@4:\n\t" \

   163     ".elseif	" #n " < 100\n\t" \

   164     ".globl     __ZN14nsXPTCStubBase6Stub" #n "Ev@4\n\t" \

   165     ".def       __ZN14nsXPTCStubBase6Stub" #n "Ev@4\n\t" \

   166     ".scl       3\n\t" \

   167     ".type      46\n\t" \

   168     ".endef\n\t" \

   169     "__ZN14nsXPTCStubBase6Stub" #n "Ev@4:\n\t" \

   170     ".elseif    " #n " < 1000\n\t" \

   171     ".globl     __ZN14nsXPTCStubBase7Stub" #n "Ev@4\n\t" \

   172     ".def       __ZN14nsXPTCStubBase7Stub" #n "Ev@4\n\t" \

   173     ".scl       3\n\t" \

   174     ".type      46\n\t" \

   175     ".endef\n\t" \

   176     "__ZN14nsXPTCStubBase7Stub" #n "Ev@4:\n\t" \

   177     ".else\n\t" \

   178     ".err	\"stub number " #n " >= 1000 not yet supported\"\n\t" \

   179     ".endif\n\t" \

   180     "mov $" #n ", %ecx\n\t" \

   181     "jmp SharedStub");

   183 #endif /* __GNUC__ */

   185 #define SENTINEL_ENTRY(n) \

   186 nsresult __stdcall nsXPTCStubBase::Sentinel##n() \

   187 { \

   188     NS_ERROR("nsXPTCStubBase::Sentinel called"); \

   189     return NS_ERROR_NOT_IMPLEMENTED; \

   190 }

   192 #ifdef _MSC_VER

   193 #pragma warning(disable : 4035) // OK to have no return value

   194 #endif

   195 #include "xptcstubsdef.inc"

   196 #ifdef _MSC_VER

   197 #pragma warning(default : 4035) // restore default

   198 #endif

   200 void

   201 #ifdef __GNUC__

   202 __cdecl

   203 #endif

   204 xptc_dummy()

   205 {

   206 }

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