Implement GenericComCallStub

jkotas · jkotas · commit 21865ee3f987 · 2024-09-20T09:14:16.000-07:00
diff --git a/src/coreclr/vm/comtoclrcall.h b/src/coreclr/vm/comtoclrcall.h
@@ -325,12 +325,6 @@ class ComCallMethodDesc
         return -COMMETHOD_PREPAD;
     }
 
-    static DWORD GetOffsetOfMethodDesc()
-    {
-        LIMITED_METHOD_CONTRACT;
-        return ((DWORD) offsetof(class ComCallMethodDesc, m_pMD));
-    }
-
     //get call sig
     PCCOR_SIGNATURE GetSig(DWORD *pcbSigSize = NULL)
     {
diff --git a/src/coreclr/vm/dllimportcallback.h b/src/coreclr/vm/dllimportcallback.h
@@ -308,12 +308,6 @@ class UMEntryThunk
         RETURN m_pMD;
     }
 
-    static DWORD GetOffsetOfMethodDesc()
-    {
-        LIMITED_METHOD_CONTRACT;
-        return offsetof(class UMEntryThunk, m_pMD);
-    }
-
     static DWORD GetCodeOffset()
     {
         LIMITED_METHOD_CONTRACT;
diff --git a/src/coreclr/vm/frames.h b/src/coreclr/vm/frames.h
@@ -1820,20 +1820,6 @@ class UnmanagedToManagedFrame : public Frame
         return m_pvDatum;
     }
 
-    static int GetOffsetOfDatum()
-    {
-        LIMITED_METHOD_CONTRACT;
-        return offsetof(UnmanagedToManagedFrame, m_pvDatum);
-    }
-
-#ifdef TARGET_X86
-    static int GetOffsetOfCalleeSavedRegisters()
-    {
-        LIMITED_METHOD_CONTRACT;
-        return offsetof(UnmanagedToManagedFrame, m_calleeSavedRegisters);
-    }
-#endif
-
     int GetFrameType()
     {
         LIMITED_METHOD_DAC_CONTRACT;
diff --git a/src/coreclr/vm/i386/asmconstants.h b/src/coreclr/vm/i386/asmconstants.h
@@ -212,6 +212,8 @@ ASMCONSTANTS_C_ASSERT(OFFSETOF__FrameHandlerExRecord__m_pEntryFrame == offsetof(
 #define STACK_OVERWRITE_BARRIER_VALUE 0xabcdefab
 #endif
 
+#define COMMETHOD_PREPAD_ASM  8
+ASMCONSTANTS_C_ASSERT(COMMETHOD_PREPAD_ASM == COMMETHOD_PREPAD)
 #endif
 
 #define CLRToCOMCallMethodDesc__m_pCLRToCOMCallInfo DBG_FRE(0x20, 0xC)
diff --git a/src/coreclr/vm/i386/asmhelpers.asm b/src/coreclr/vm/i386/asmhelpers.asm
@@ -46,6 +46,7 @@ EXTERN _TheUMEntryPrestubWorker@4:PROC
 
 ifdef FEATURE_COMINTEROP
 EXTERN _CLRToCOMWorker@8:PROC
+EXTERN _COMToCLRWorker@4:PROC
 endif
 
 EXTERN _ExternalMethodFixupWorker@16:PROC
@@ -1237,7 +1238,40 @@ _GenericCLRToCOMCallStub@0 proc public
 _GenericCLRToCOMCallStub@0 endp
 
 _GenericComCallStub@0 proc public
-    int 3
+    ; push ebp-frame
+    push        ebp
+    mov         ebp,esp
+
+    ; save CalleeSavedRegisters
+    push        ebx
+    push        esi
+    push        edi
+
+    push        eax         ; datum
+    sub         esp, 3*4    ; next, vtable, gscookie
+
+    lea         eax, [esp+4]
+
+    push        eax
+    call        _COMToCLRWorker@4
+
+    add         esp, 3*4
+
+    ; pop the MethodDesc*
+    pop         ecx
+
+    ; pop CalleeSavedRegisters
+    pop         edi
+    pop         esi
+    pop         ebx
+    pop         ebp
+
+    sub         ecx, COMMETHOD_PREPAD_ASM
+    jmp         ecx
+
+    ; This will never be executed. It is just to help out stack-walking logic
+    ; which disassembles the epilog to unwind the stack.
+    ret
 
 _GenericComCallStub@0 endp
 

Original file line number	Diff line number	Diff line change
`@@ -325,12 +325,6 @@ class ComCallMethodDesc`
`325`	`325`	`return -COMMETHOD_PREPAD;`
`326`	`326`	`}`
`327`	`327`
`328`		`- static DWORD GetOffsetOfMethodDesc()`
`329`		`- {`
`330`		`- LIMITED_METHOD_CONTRACT;`
`331`		`- return ((DWORD) offsetof(class ComCallMethodDesc, m_pMD));`
`332`		`- }`
`333`		`-`
`334`	`328`	`//get call sig`
`335`	`329`	`PCCOR_SIGNATURE GetSig(DWORD *pcbSigSize = NULL)`
`336`	`330`	`{`
Original file line number	Diff line number	Diff line change
`@@ -308,12 +308,6 @@ class UMEntryThunk`
`308`	`308`	`RETURN m_pMD;`
`309`	`309`	`}`
`310`	`310`
`311`		`- static DWORD GetOffsetOfMethodDesc()`
`312`		`- {`
`313`		`- LIMITED_METHOD_CONTRACT;`
`314`		`- return offsetof(class UMEntryThunk, m_pMD);`
`315`		`- }`
`316`		`-`
`317`	`311`	`static DWORD GetCodeOffset()`
`318`	`312`	`{`
`319`	`313`	`LIMITED_METHOD_CONTRACT;`