Remove AppDomain unload (#20250)

* Remove AppDomain unload

This change removes all code in AppDomain that's related to AppDomain
unloading which is obsolete in CoreCLR. It also removes all calls to the
removed methods.
In few places, I have made the change simpler by taking into account the
fact that there is always just one AppDomain.

3 files changed, 5 insertions, 156 deletions

diff --git a/src/vm/amd64/UMThunkStub.asm b/src/vm/amd64/UMThunkStub.asm
index 123a630880..b7701d8e18 100644
--- a/src/vm/amd64/UMThunkStub.asm
+++ b/src/vm/amd64/UMThunkStub.asm
@@ -18,7 +18,6 @@ extern TheUMEntryPrestubWorker:proc
 extern UMEntryPrestubUnwindFrameChainHandler:proc
 extern UMThunkStubUnwindFrameChainHandler:proc
 extern g_TrapReturningThreads:dword
-extern UM2MDoADCallBack:proc
 extern UMThunkStubRareDisableWorker:proc
 extern ReversePInvokeBadTransition:proc
 
@@ -188,14 +187,6 @@ HaveThread:
 
 InCooperativeMode:
 
-        mov             rax, [r12 + OFFSETOF__Thread__m_pDomain]
-        mov             eax, [rax + OFFSETOF__AppDomain__m_dwId]
-
-        mov             r11d, [METHODDESC_REGISTER + OFFSETOF__UMEntryThunk__m_dwDomainId]
-
-        cmp             rax, r11
-        jne             WrongAppDomain
-
         mov             r11, [METHODDESC_REGISTER + OFFSETOF__UMEntryThunk__m_pUMThunkMarshInfo]
         mov             eax, [r11 + OFFSETOF__UMThunkMarshInfo__m_cbActualArgSize]                      ; stack_args
         test            rax, rax                                                                        ; stack_args
@@ -322,137 +313,7 @@ CopyLoop:
         
         jmp             ArgumentsSetup
 
-
-WrongAppDomain:
-        ;
-        ; home register args to the stack
-        ;
-        mov             [rbp + UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET +  0h], rcx
-        mov             [rbp + UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET +  8h], rdx
-        mov             [rbp + UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET + 10h], r8
-        mov             [rbp + UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET + 18h], r9
-
-        ;
-        ; save off xmm registers
-        ;
-        movdqa          xmmword ptr [rbp + UMThunkStubAMD64_XMM_SAVE_OFFSET +  0h], xmm0
-        movdqa          xmmword ptr [rbp + UMThunkStubAMD64_XMM_SAVE_OFFSET + 10h], xmm1
-        movdqa          xmmword ptr [rbp + UMThunkStubAMD64_XMM_SAVE_OFFSET + 20h], xmm2
-        movdqa          xmmword ptr [rbp + UMThunkStubAMD64_XMM_SAVE_OFFSET + 30h], xmm3
-
-        ;
-        ; call our helper to perform the AD transtion 
-        ;
-        mov             rcx, METHODDESC_REGISTER
-        lea             r8,  [rbp + UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET]
-        mov             rax, [METHODDESC_REGISTER + OFFSETOF__UMEntryThunk__m_pUMThunkMarshInfo]
-        mov             r9d, [rax + OFFSETOF__UMThunkMarshInfo__m_cbActualArgSize]
-        call            UM2MDoADCallBack
-
-        ; restore return value
-        mov             rax,  [rbp + UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET +  0h]
-        movdqa          xmm0, xmmword ptr [rbp + UMThunkStubAMD64_XMM_SAVE_OFFSET +  0h]
-
-        jmp             PostCall
-
 NESTED_END UMThunkStub, _TEXT
 
-;
-; EXTERN_C void __stdcall UM2MThunk_WrapperHelper(
-;       void *pThunkArgs,               ; rcx
-;       int argLen,                     ; rdx
-;       void *pAddr,                    ; r8            // not used
-;       UMEntryThunk *pEntryThunk,      ; r9
-;       Thread *pThread);               ; [entry_sp + 28h]
-;
-NESTED_ENTRY UM2MThunk_WrapperHelper, _TEXT
-
-
-UM2MThunk_WrapperHelper_STACK_FRAME_SIZE = 0
-
-; number of integer registers saved in prologue
-UM2MThunk_WrapperHelper_NUM_REG_PUSHES = 3
-UM2MThunk_WrapperHelper_STACK_FRAME_SIZE = UM2MThunk_WrapperHelper_STACK_FRAME_SIZE + (UM2MThunk_WrapperHelper_NUM_REG_PUSHES * 8)
-
-UM2MThunk_WrapperHelper_CALLEE_SCRATCH_SIZE = SIZEOF_MAX_OUTGOING_ARGUMENT_HOMES
-UM2MThunk_WrapperHelper_STACK_FRAME_SIZE = UM2MThunk_WrapperHelper_STACK_FRAME_SIZE + UM2MThunk_WrapperHelper_CALLEE_SCRATCH_SIZE
-
-; Ensure that rsp remains 16-byte aligned
-if ((UM2MThunk_WrapperHelper_STACK_FRAME_SIZE + 8) MOD 16) ne 0        ; +8 for caller-pushed return address
-UM2MThunk_WrapperHelper_STACK_FRAME_SIZE = UM2MThunk_WrapperHelper_STACK_FRAME_SIZE + 8
-endif
-
-UM2MThunk_WrapperHelper_FRAME_OFFSET = UM2MThunk_WrapperHelper_CALLEE_SCRATCH_SIZE
-UM2MThunk_WrapperHelper_FIXED_STACK_ALLOC_SIZE = UM2MThunk_WrapperHelper_STACK_FRAME_SIZE - (UM2MThunk_WrapperHelper_NUM_REG_PUSHES * 8)
-
-        push_nonvol_reg rsi
-        push_nonvol_reg rdi
-        push_nonvol_reg rbp
-        alloc_stack     UM2MThunk_WrapperHelper_FIXED_STACK_ALLOC_SIZE
-        set_frame       rbp, UM2MThunk_WrapperHelper_FRAME_OFFSET
-        END_PROLOGUE
-
-        ;
-        ; We are in cooperative mode and in the correct domain. 
-        ; The host has also been notified that we've entered the 
-        ; runtime.  All we have left to do is to copy the stack, 
-        ; setup the register args and then call the managed target
-        ;
-
-        test            rdx, rdx
-        jg              CopyStackArgs
-
-ArgumentsSetup:
-        mov             METHODDESC_REGISTER, r9
-
-        mov             rsi, rcx                ; rsi <- pThunkArgs
-        mov             rcx, [rsi +  0h]
-        mov             rdx, [rsi +  8h]
-        mov             r8,  [rsi + 10h]
-        mov             r9,  [rsi + 18h]
-
-        movdqa          xmm0, xmmword ptr [rsi + UMThunkStubAMD64_XMM_SAVE_OFFSET - UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET +  0h]
-        movdqa          xmm1, xmmword ptr [rsi + UMThunkStubAMD64_XMM_SAVE_OFFSET - UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET + 10h]
-        movdqa          xmm2, xmmword ptr [rsi + UMThunkStubAMD64_XMM_SAVE_OFFSET - UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET + 20h]
-        movdqa          xmm3, xmmword ptr [rsi + UMThunkStubAMD64_XMM_SAVE_OFFSET - UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET + 30h]
-
-        mov             rax, [METHODDESC_REGISTER + OFFSETOF__UMEntryThunk__m_pUMThunkMarshInfo]      ; rax <- UMThunkMarshInfo*
-        mov             rax, [rax + OFFSETOF__UMThunkMarshInfo__m_pILStub]                              ; rax <- Stub*
-        call            rax
-
-        ; make sure we don't trash the return value
-        mov             [rsi + 0h], rax
-        movdqa          xmmword ptr [rsi + UMThunkStubAMD64_XMM_SAVE_OFFSET - UMThunkStubAMD64_ARGUMENTS_STACK_HOME_OFFSET +  0h], xmm0
-
-        lea             rsp, [rbp - UM2MThunk_WrapperHelper_FRAME_OFFSET + UM2MThunk_WrapperHelper_FIXED_STACK_ALLOC_SIZE]
-        pop             rbp
-        pop             rdi
-        pop             rsi
-        ret
-        
-
-CopyStackArgs:
-        ; rdx = cbStackArgs (with 20h for register args subtracted out already)
-        ; rcx = pSrcArgStack
-
-        sub             rsp, rdx
-        and             rsp, -16
-
-        mov             r8, rcx
-        
-        lea             rsi, [rcx + SIZEOF_MAX_OUTGOING_ARGUMENT_HOMES]
-        lea             rdi, [rsp + UM2MThunk_WrapperHelper_CALLEE_SCRATCH_SIZE]
-
-        mov             rcx, rdx
-        shr             rcx, 3
-        
-        rep movsq
-        
-        mov             rcx, r8
-        
-        jmp             ArgumentsSetup
-        
-NESTED_END UM2MThunk_WrapperHelper, _TEXT
-
         end
 
diff --git a/src/vm/amd64/asmconstants.h b/src/vm/amd64/asmconstants.h
index cadc10ac56..1af07860ce 100644
--- a/src/vm/amd64/asmconstants.h
+++ b/src/vm/amd64/asmconstants.h
@@ -147,22 +147,22 @@ ASMCONSTANTS_C_ASSERT(OFFSETOF__Thread__m_pFrame
 ASMCONSTANTS_C_ASSERT(OFFSETOF__Thread__m_State
                     == offsetof(Thread, m_State));
 
-#define               OFFSETOF__Thread__m_pDomain                   0x20
+#define               OFFSETOF__Thread__m_pDomain                   0x18
 ASMCONSTANTS_C_ASSERT(OFFSETOF__Thread__m_pDomain
                     == offsetof(Thread, m_pDomain));
 
-#define               OFFSETOF__Thread__m_dwLockCount               0x28
+#define               OFFSETOF__Thread__m_dwLockCount               0x20
 ASMCONSTANTS_C_ASSERT(OFFSETOF__Thread__m_dwLockCount
                     == offsetof(Thread, m_dwLockCount));
 
-#define               OFFSETOF__Thread__m_ThreadId                  0x2C
+#define               OFFSETOF__Thread__m_ThreadId                  0x24
 ASMCONSTANTS_C_ASSERT(OFFSETOF__Thread__m_ThreadId
                     == offsetof(Thread, m_ThreadId));
 
-#define               OFFSET__Thread__m_alloc_context__alloc_ptr 0x60
+#define               OFFSET__Thread__m_alloc_context__alloc_ptr 0x58
 ASMCONSTANTS_C_ASSERT(OFFSET__Thread__m_alloc_context__alloc_ptr == offsetof(Thread, m_alloc_context) + offsetof(gc_alloc_context, alloc_ptr));
 
-#define               OFFSET__Thread__m_alloc_context__alloc_limit 0x68
+#define               OFFSET__Thread__m_alloc_context__alloc_limit 0x60
 ASMCONSTANTS_C_ASSERT(OFFSET__Thread__m_alloc_context__alloc_limit == offsetof(Thread, m_alloc_context) + offsetof(gc_alloc_context, alloc_limit));
 
 #define               OFFSETOF__gc_alloc_context__alloc_ptr 0x0
diff --git a/src/vm/amd64/umthunkstub.S b/src/vm/amd64/umthunkstub.S
index 3e60bedb3f..834f0ca0f8 100644
--- a/src/vm/amd64/umthunkstub.S
+++ b/src/vm/amd64/umthunkstub.S
@@ -196,15 +196,3 @@ LOCAL_LABEL(WrongAppDomain):
 #endif
 
 NESTED_END UMThunkStub, _TEXT
-
-//
-// EXTERN_C void __stdcall UM2MThunk_WrapperHelper(
-//       void *pThunkArgs,               // rdi
-//       int argLen,                     // rsi
-//       void *pAddr,                    // rdx            // not used
-//       UMEntryThunk *pEntryThunk,      // rcx
-//       Thread *pThread);               // r8
-//
-NESTED_ENTRY UM2MThunk_WrapperHelper, _TEXT, NoHandler
-        int3
-NESTED_END UM2MThunk_WrapperHelper, _TEXT