Merge pull request #2031 from reactormonk/high-cstring

Fixes #2030

compiler/semexprs.nim

@@ -306,7 +306,7 @@ proc semLowHigh(c: PContext, n: PNode, m: TMagic): PNode =
     var typ = skipTypes(n.sons[1].typ, abstractVarRange +
                                        {tyTypeDesc, tyFieldAccessor})
     case typ.kind
-    of tySequence, tyString, tyOpenArray, tyVarargs: 
+    of tySequence, tyString, tyCString, tyOpenArray, tyVarargs: 
       n.typ = getSysType(tyInt)
     of tyArrayConstr, tyArray: 
       n.typ = typ.sons[0] # indextype

compiler/semfold.nim

@@ -665,8 +665,8 @@ proc getConstExpr(m: PSym, n: PNode): PNode =
       of mLow: 
         result = newIntNodeT(firstOrd(n.sons[1].typ), n)
       of mHigh: 
-        if  skipTypes(n.sons[1].typ, abstractVar).kind notin
-            {tyOpenArray, tyVarargs, tySequence, tyString}:
+        if skipTypes(n.sons[1].typ, abstractVar).kind notin
+            {tySequence, tyString, tyCString, tyOpenArray, tyVarargs}:
           result = newIntNodeT(lastOrd(skipTypes(n[1].typ, abstractVar)), n)
         else:
           var a = getArrayConstr(m, n.sons[1])

compiler/vmgen.nim

@@ -893,7 +893,8 @@ proc genMagic(c: PCtx; n: PNode; dest: var TDest) =
   of mHigh:
     if dest < 0: dest = c.getTemp(n.typ)
     let tmp = c.genx(n.sons[1])
-    if n.sons[1].typ.skipTypes(abstractVar-{tyTypeDesc}).kind == tyString:
+    case n.sons[1].typ.skipTypes(abstractVar-{tyTypeDesc}).kind:
+    of tyString, tyCString:
       c.gABI(n, opcLenStr, dest, tmp, 1)
     else:
       c.gABI(n, opcLenSeq, dest, tmp, 1)

tests/exprs/thighCString.nim

@@ -0,0 +1,6 @@
+discard """
+  output: "5"
+"""
+let test = cstring("foobar")
+
+echo high(test)