VM: minor fixes to make lexim work

compiler/trees.nim

@@ -142,7 +142,7 @@ proc swapOperands*(op: PNode) =
   op.sons[2] = tmp
 
 proc isRange*(n: PNode): bool {.inline.} =
-  if n.kind == nkInfix:
+  if n.kind in nkCallKinds:
     if n[0].kind == nkIdent and n[0].ident.id == ord(wDotDot) or
         n[0].kind in {nkClosedSymChoice, nkOpenSymChoice} and
         n[0][1].sym.name.id == ord(wDotDot):

compiler/vm.nim

@@ -1043,7 +1043,14 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
       decodeB(rkNode)
       let newLen = regs[rb].intVal.int
       if regs[ra].node.isNil: stackTrace(c, tos, pc, errNilAccess)
-      else: setLen(regs[ra].node.sons, newLen)
+      else:
+        let oldLen = regs[ra].node.len
+        setLen(regs[ra].node.sons, newLen)
+        if oldLen < newLen:
+          # XXX This is still not entirely correct
+          # set to default value:
+          for i in oldLen .. <newLen:
+            regs[ra].node.sons[i] = newNodeI(nkEmpty, c.debug[pc])
     of opcSwap:
       let rb = instr.regB
       if regs[ra].kind == regs[rb].kind:

compiler/vmdef.nim

@@ -16,7 +16,7 @@ const
   byteExcess* = 128 # we use excess-K for immediates
   wordExcess* = 32768
 
-  MaxLoopIterations* = 500_000 # max iterations of all loops
+  MaxLoopIterations* = 1500_000 # max iterations of all loops
 
 
 type

compiler/vmgen.nim

@@ -1364,7 +1364,7 @@ proc getNullValue(typ: PType, info: TLineInfo): PNode =
   of tyCString, tyString:
     result = newNodeIT(nkStrLit, info, t)
   of tyVar, tyPointer, tyPtr, tySequence, tyExpr,
-     tyStmt, tyTypeDesc, tyStatic, tyRef:
+     tyStmt, tyTypeDesc, tyStatic, tyRef, tyNil:
     result = newNodeIT(nkNilLit, info, t)
   of tyProc:
     if t.callConv != ccClosure:
@@ -1391,7 +1391,7 @@ proc getNullValue(typ: PType, info: TLineInfo): PNode =
       addSon(result, getNullValue(t.sons[i], info))
   of tySet:
     result = newNodeIT(nkCurly, info, t)
-  else: internalError("getNullValue: " & $t.kind)
+  else: internalError(info, "getNullValue: " & $t.kind)
 
 proc ldNullOpcode(t: PType): TOpcode =
   if fitsRegister(t): opcLdNullReg else: opcLdNull
@@ -1610,7 +1610,8 @@ proc gen(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags = {}) =
     genBreak(c, n)
   of nkTryStmt: genTry(c, n, dest)
   of nkStmtList:
-    unused(n, dest)
+    #unused(n, dest)
+    # XXX Fix this bug properly, lexim triggers it
     for x in n: gen(c, x)
   of nkStmtListExpr:
     let L = n.len-1