Jump directly to exit on error and eliminate the stop variable

bitdefender · Aug 26, 2024 · 5577520 · 5577520
1 parent c611c8a
commit 5577520
Showing 1 changed file with 13 additions and 18 deletions.
diff --git a/bddisasm/bdx86_decoder.c b/bddisasm/bdx86_decoder.c
@@ -3341,13 +3341,12 @@ NdFindInstruction(
     NDSTATUS status;
     const ND_TABLE *pTable;
     ND_IDBE *pIns;
-    ND_BOOL stop, redf2, redf3;
+    ND_BOOL redf2, redf3;
     ND_UINT32 nextOpcode;
 
     // pre-init
     status = ND_STATUS_SUCCESS;
     pIns = (ND_IDBE *)ND_NULL;
-    stop = ND_FALSE;
     nextOpcode = 0;
     redf2 = redf3 = ND_FALSE;
 
@@ -3379,22 +3378,22 @@ NdFindInstruction(
         break;
     }
 
-    while ((!stop) && (ND_NULL != pTable))
+    while (ND_NULL != pTable)
     {
         switch (pTable->Type)
         {
         case ND_ILUT_INSTRUCTION:
             // We've found the leaf entry, which is an instruction - we can leave.
             pIns = (ND_IDBE *)(((ND_TABLE_INSTRUCTION *)pTable)->Instruction);
-            stop = ND_TRUE;
+            goto success;
             break;
 
         case ND_ILUT_OPCODE:
             // We need an opcode to keep going.
             status = NdFetchOpcode(Instrux, Code, Instrux->Length, Size);
             if (!ND_SUCCESS(status))
             {
-                stop = ND_TRUE;
+                goto cleanup_and_exit;
                 break;
             }
 
@@ -3409,7 +3408,7 @@ NdFindInstruction(
                 status = NdFetchModrmSibDisplacement(Instrux, Code, Instrux->Length, Size);
                 if (!ND_SUCCESS(status))
                 {
-                    stop = ND_TRUE;
+                    goto cleanup_and_exit;
                     break;
                 }
             }
@@ -3418,7 +3417,7 @@ NdFindInstruction(
             status = NdFetchOpcode(Instrux, Code, Instrux->Length, Size);
             if (!ND_SUCCESS(status))
             {
-                stop = ND_TRUE;
+                goto cleanup_and_exit;
                 break;
             }
 
@@ -3433,7 +3432,7 @@ NdFindInstruction(
                 status = NdFetchModrmSibDisplacement(Instrux, Code, Instrux->Length, Size);
                 if (!ND_SUCCESS(status))
                 {
-                    stop = ND_TRUE;
+                    goto cleanup_and_exit;
                     break;
                 }
             }
@@ -3450,7 +3449,7 @@ NdFindInstruction(
                 status = NdFetchModrmSibDisplacement(Instrux, Code, Instrux->Length, Size);
                 if (!ND_SUCCESS(status))
                 {
-                    stop = ND_TRUE;
+                    goto cleanup_and_exit;
                     break;
                 }
             }
@@ -3467,7 +3466,7 @@ NdFindInstruction(
                 status = NdFetchModrmSibDisplacement(Instrux, Code, Instrux->Length, Size);
                 if (!ND_SUCCESS(status))
                 {
-                    stop = ND_TRUE;
+                    goto cleanup_and_exit;
                     break;
                 }
             }
@@ -3658,7 +3657,7 @@ NdFindInstruction(
                     status = NdFetchModrmSibDisplacement(Instrux, Code, Instrux->Length, Size);
                     if (!ND_SUCCESS(status))
                     {
-                        stop = ND_TRUE;
+                        goto cleanup_and_exit;
                         break;
                     }
                 }
@@ -3717,24 +3716,20 @@ NdFindInstruction(
 
         default:
             status = ND_STATUS_INTERNAL_ERROR;
-            stop = ND_TRUE;
+            goto cleanup_and_exit;
             break;
         }
     }
 
-    // Error - leave now.
-    if (!ND_SUCCESS(status))
-    {
-        goto cleanup_and_exit;
-    }
-
     // No encoding found - leave now.
     if (ND_NULL == pIns)
     {
         status = ND_STATUS_INVALID_ENCODING;
         goto cleanup_and_exit;
     }
 
+success:
+
     // Bingo! Valid instruction found for the encoding. If Modrm is needed and we didn't fetch it - do it now.
     if ((pIns->Attributes & ND_FLAG_MODRM) && (!Instrux->HasModRm))
     {