fixes #488

compiler/semexprs.nim

@@ -1290,6 +1290,7 @@ proc newAnonSym(kind: TSymKind, info: TLineInfo,
 proc semExpandToAst(c: PContext, n: PNode): PNode =
   var macroCall = n[1]
   var expandedSym = expectMacroOrTemplateCall(c, macroCall)
+  if expandedSym.kind == skError: return n
 
   macroCall.sons[0] = newSymNode(expandedSym, macroCall.info)
   markUsed(n, expandedSym)

tests/compile/tmacrostmt.nim

@@ -15,3 +15,12 @@ else:
   return tkUnknown
   
 case_token: inc i
+
+#bug #488
+
+macro foo: stmt =
+  var exp = newCall("whatwhat", newIntLitNode(1))
+  if compiles(getAst(exp)): return exp
+  else: echo "Does not compute!"
+
+foo()