fix restoring RBX

adjust for other vcruntime lib/dll versions

Author: rainers

src/ldc/eh/win32.d

@@ -362,8 +362,9 @@ void msvc_eh_terminate() nothrow
             cmp RAX, 1;
             jle L_term;
 
-            // update stack and IP so we just continue in __FrameUnwindHandler
-            // TODO: check DLL versions of MS runtime
+            // update stack and IP so we just continue in __FrameUnwindHandler
+            // NOTE: these checks can fail if you have breakpoints set at
+            //       the respective code locations
             mov RAX,[RSP+8];            // get return address
             cmp byte ptr[RAX], 0xEB;    // jmp?
             jne noJump;
@@ -373,52 +374,64 @@ void msvc_eh_terminate() nothrow
             cmp byte ptr[RAX], 0xE8;    // call abort?
             jne L_term;
             add RAX,5;
-            mov EDX,[RAX];
+            mov EDX,[RAX];
             mov RBX, 0xFFFFFF;
             and RDX, RBX;
             cmp RDX, 0xC48348;          // add ESP,nn
-            je L_addESP_found;
-            cmp DX, 0xCC90;             // nop; int3;
-            jne L_term;
-            mov RDX, 0x28;              // release build of vcruntimelib
-            jmp L_retTerminate;
-
+            je L_addESP_found;
+            cmp DX, 0xCC90;             // nop; int3;
+            jne L_term;
+            mov RDX, 0x28;              // release build of vcruntimelib
+            jmp L_retTerminate;
+
         L_addESP_found:
             movzx RDX,byte ptr[RAX+3];  // read nn
 
             cmp byte ptr [RAX+4], 0xC3; // ret?
             jne L_term;
-
+
         L_retTerminate:
             lea RDX,[RSP+RDX+0x10];     // RSP before returning from terminate()
 
-            mov RAX,[RDX];              // return address inside __FrameUnwindHandler
+            mov RAX,[RDX];              // return address inside __FrameUnwindHandler
 
-            cmp byte ptr [RAX-19], 0xEB; // skip back to default jump inside "switch" (debug build)
-            je L_switchFound;
-
-            mov RBX, 0xc48348c0333048ff; // dec [rax+30h]; xor eax,eax; add rsp,nn
+            cmp byte ptr [RAX-19], 0xEB; // skip back to default jump inside "switch" (libvcruntimed.lib)
+            je L_switchFound;
+
+            cmp byte ptr [RAX-20], 0xEB; // skip back to default jump inside "switch" (vcruntime140d.dll)
+            je L_switchFound2;
+
+            mov RBX, 0xc48348c0333048ff; // dec [rax+30h]; xor eax,eax; add rsp,nn (libvcruntime.lib)
             cmp RBX,[RAX-0x18];
+            je L_retFound;
+
+            cmp RBX,[RAX+0x29];          // dec [rax+30h]; xor eax,eax; add rsp,nn (vcruntime140.dll)
             jne L_term;
-
-            lea RAX, [RAX-19];
-            jmp L_xorSkipped;
-
+
+            lea RAX, [RAX+0x2F];
+            jmp L_xorSkipped;
+
+        L_retFound:
+            lea RAX, [RAX-19];
+            jmp L_xorSkipped;
+
+        L_switchFound2:
+            dec RAX;
         L_switchFound:
             movsx RBX, byte ptr [RAX-18]; // follow jump
             lea RAX, [RAX+RBX-17];
 
             cmp word ptr[RAX],0xC033;   // xor EAX,EAX?
             jne L_term;
 
-            add RAX,2;
+            add RAX,2;
         L_xorSkipped:
-            pop RBX;
+            mov RBX,[RDX-8]; // restore RBX (pushed inside terminate())
             lea RSP,[RDX+8];
             push RAX;       // new return after setting return value in __frameUnwindHandler
-
-            call __processing_throw;
-            mov [RAX], 1;
+
+            call __processing_throw;
+            mov [RAX], 1;
 
             //add RSP,0x68; // TODO: needs to be verified for different CRT builds
             mov RAX,1;      // return EXCEPTION_EXECUTE_HANDLER