error message for accidental use of macro (#10490)

* error message for accidental use of macro

compiler/semstmts.nim

@@ -448,10 +448,14 @@ proc semVarOrLet(c: PContext, n: PNode, symkind: TSymKind): PNode =
     var def: PNode = c.graph.emptyNode
     if a.sons[length-1].kind != nkEmpty:
       def = semExprWithType(c, a.sons[length-1], {efAllowDestructor})
-      if def.typ.kind == tyTypeDesc and c.p.owner.kind != skMacro:
+      if def.typ.kind == tyProc and def.kind == nkSym and def.sym.kind == skMacro:
+        localError(c.config, def.info, "cannot assign macro symbol to variable here. Forgot to invoke the macro with '()'?")
+        def.typ = errorType(c)
+      elif def.typ.kind == tyTypeDesc and c.p.owner.kind != skMacro:
         # prevent the all too common 'var x = int' bug:
         localError(c.config, def.info, "'typedesc' metatype is not valid here; typed '=' instead of ':'?")
         def.typ = errorType(c)
+
       if typ != nil:
         if typ.isMetaType:
           def = inferWithMetatype(c, typ, def)
@@ -583,7 +587,10 @@ proc semConst(c: PContext, n: PNode): PNode =
       localError(c.config, a.sons[length-1].info, errConstExprExpected)
       continue
 
-    if def.typ.kind == tyTypeDesc and c.p.owner.kind != skMacro:
+    if def.typ.kind == tyProc and def.kind == nkSym and def.sym.kind == skMacro:
+        localError(c.config, def.info, "cannot assign macro symbol to constant here. Forgot to invoke the macro with '()'?")
+        def.typ = errorType(c)
+    elif def.typ.kind == tyTypeDesc and c.p.owner.kind != skMacro:
       # prevent the all too common 'const x = int' bug:
       localError(c.config, def.info, "'typedesc' metatype is not valid here; typed '=' instead of ':'?")
       def.typ = errorType(c)

tests/errmsgs/t10489_a.nim

@@ -0,0 +1,9 @@
+discard """
+errormsg: "cannot assign macro symbol to variable here"
+line: 9
+"""
+
+macro m(body: untyped): untyped =
+  body
+
+let x1 = m

tests/errmsgs/t10489_b.nim

@@ -0,0 +1,9 @@
+discard """
+errormsg: "cannot assign macro symbol to constant here"
+line: 9
+"""
+
+macro m(body: untyped): untyped =
+  body
+
+const x2 = m