Changeset 97868 in vbox for trunk/src/VBox/Runtime/common

Timestamp:

Dec 27, 2022 12:29:36 AM (2 years ago)

Author:

vboxsync

Message:

IPRT/nocrt: Added the NLG bits to the 32-bit (x86) exception handler support code for whatever its worth. bugref:10261 ticketref:21303

File:

• trunk/src/VBox/Runtime/common/compiler/vcc/except-x86-vcc-asm.asm (modified) (10 diffs)

trunk/src/VBox/Runtime/common/compiler/vcc/except-x86-vcc-asm.asm

@@ -41 +41 @@
 ;*********************************************************************************************************************************
 %include "iprt/asmdefs.mac"
+
+
+;*********************************************************************************************************************************
+;*  Defined Constants And Macros                                                                                                 *
+;*********************************************************************************************************************************
+
+;; @def WITH_NLG_STUFF
+; Enabled NLG debugger hooks/whatever - no idea how it's used.
+;
+; So far vsdebugeng.manimpl.dll in the VS2019 remote debugger directory is the
+; only component with any _NLG_ strings in it.  Could not find any references
+; to _NLG_ in windbg.
+%define WITH_NLG_STUFF 1
 
 
@@ -97 +110 @@
 safeseh _rtVccEh4DoLocalUnwindHandler@16
 
+%ifdef WITH_NLG_STUFF
+BEGINDATA
+GLOBALNAME_RAW __NLG_Destination, data, hidden
+        dd      019930520h
+        dd      0
+        dd      0
+        dd      0
+%endif
+
 
 BEGINCODE
+
+%ifdef WITH_NLG_STUFF
+
+;;
+; Some VS debugger interface, I think.
+;
+; @param        EDX     Notification code.
+; @uses         EBP, EAX & ECX are preserved.  This differs from other implementation,
+;               but simplifies the calling code.
+;
+ALIGNCODE(32)
+GLOBALNAME_RAW __NLG_Notify, function, hidden
+        ;
+        ; Save registers.
+        ;
+        push    eax
+        push    ecx
+        push    ebp
+        push    ebx
+
+
+        ;
+        ; ECX = notification code.
+        ; EBX = __NLG_Destination
+        ;
+        mov     ecx, edx                    ; Originally held in ECX, so moving it there for now.
+        mov     ebx, __NLG_Destination
+
+__NLG_Go:
+        ;
+        ; Save info to __NLG_Destination and the stack (same layout).
+        ;
+        mov     [ebx + 0ch], ebp
+        push    ebp
+        mov     [ebx + 08h], ecx
+        push    ecx
+        mov     [ebx + 04h], eax
+        push    eax
+
+        ;
+        ; This is presumably the symbol the debugger hooks on to as the string
+        ; "__NLG_Dispatch" was found in vsdebugeng.manimpl.dll in VS2019.
+        ;
+global __NLG_Dispatch
+__NLG_Dispatch:
+
+        ; Drop the info structure from the stack.
+        add     esp, 4*3
+
+        ;
+        ; Restore registers and drop the parameter as we return.
+        ;
+        ; Note! This may sabotage attempts by the debugger to modify the state...
+        ;       But that can be fixed once we know this is a requirement. Just
+        ;       keep things simple for the caller for now.
+        ;
+        pop     ebx
+        pop     ebp
+        pop     ecx
+        pop     eax
+        ret
+
+;;
+; NLG call + return2.
+;
+; The "__NLG_Return2" symbol was observed in several vsdebugeng.manimpl.dll
+; strings in VS2019.
+;
+ALIGNCODE(4)
+GLOBALNAME_RAW __NLG_Call, function, hidden
+        call    eax
+
+global __NLG_Return2
+__NLG_Return2:
+        ret
+
+%endif
+
+
 ;;
 ; Calls the filter sub-function for a __finally statement.
@@ -108 +209 @@
 ; @param    pbFrame     [ebp + 10h]
 ;
+ALIGNCODE(64)
 BEGINPROC   rtVccEh4DoFinally
         push    ebp
@@ -115 +217 @@
         push    esi
 
-        ;; @todo we're not calling __NLG_Notify nor NLG_Call, which may perhaps confuse debuggers or something...
-
         xor     edi, edi
         xor     esi, esi
+%ifndef WITH_NLG_STUFF
         xor     edx, edx
+%endif
         xor     ebx, ebx
 
@@ -126 +228 @@
         mov     ebp, [ebp + 10h]            ; pbFrame
 
+%ifdef WITH_NLG_STUFF
+        mov     edx, 101h
+        call    __NLG_Notify
+        xor     edx, edx
+
+        call    __NLG_Call
+%else
         call    eax
+%endif
 
         pop     esi
@@ -144 +254 @@
 ; @param    pbFrame     [ebp + 0ch]
 ;
+ALIGNCODE(32)
 BEGINPROC   rtVccEh4DoFiltering
         push    ebp
@@ -175 +286 @@
 ; @param    pbFrame     [ebp + 0ch]
 ;
+ALIGNCODE(32)
 BEGINPROC   rtVccEh4JumpToHandler
         ;
@@ -183 +295 @@
         mov     ebp, [esp + 1 * 4 + 4]      ; pbFrame
 
-%if 0
+%ifdef WITH_NLG_STUFF
+        ;
+        ; Notify VS debugger/whatever.
+        ;
         mov     eax, esi
-        push    1
-        call    NAME(_NLG_Notify)
+        mov     edx, 1
+        call    __NLG_Notify
 %endif
 
@@ -202 +317 @@
 
 
-
 ;;
 ; This does global unwinding via RtlUnwind.
@@ -211 +325 @@
 ; @param    pXcptRegRec [ebp + 0ch]
 ;
+ALIGNCODE(32)
 BEGINPROC   rtVccEh4DoGlobalUnwind
         push    ebp