fixes #4555

compiler/lookups.nim

@@ -99,8 +99,11 @@ proc debugScopes*(c: PContext; limit=0) {.deprecated.} =
 
 proc searchInScopes*(c: PContext, s: PIdent, filter: TSymKinds): PSym =
   for scope in walkScopes(c.currentScope):
-    result = strTableGet(scope.symbols, s)
+    var ti: TIdentIter
-    if result != nil and result.kind in filter: return
+    var candidate = initIdentIter(ti, scope.symbols, s)
+    while candidate != nil:
+      if candidate.kind in filter: return candidate
+      candidate = nextIdentIter(ti, scope.symbols)
   result = nil
 
 proc errorSym*(c: PContext, n: PNode): PSym =
@@ -266,13 +269,17 @@ proc lookUp*(c: PContext, n: PNode): PSym =
 
 type
   TLookupFlag* = enum
-    checkAmbiguity, checkUndeclared
+    checkAmbiguity, checkUndeclared, checkModule
 
-proc qualifiedLookUp*(c: PContext, n: PNode, flags = {checkUndeclared}): PSym =
+proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
+  const allExceptModule = {low(TSymKind)..high(TSymKind)}-{skModule,skPackage}
   case n.kind
   of nkIdent, nkAccQuoted:
     var ident = considerQuotedIdent(n)
-    result = searchInScopes(c, ident).skipAlias(n)
+    if checkModule in flags:
+      result = searchInScopes(c, ident).skipAlias(n)
+    else:
+      result = searchInScopes(c, ident, allExceptModule).skipAlias(n)
     if result == nil and checkUndeclared in flags:
       fixSpelling(n, ident, searchInScopes)
       localError(n.info, errUndeclaredIdentifier, ident.s)
@@ -286,7 +293,7 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags = {checkUndeclared}): PSym =
       errorUseQualifier(c, n.info, n.sym)
   of nkDotExpr:
     result = nil
-    var m = qualifiedLookUp(c, n.sons[0], flags*{checkUndeclared})
+    var m = qualifiedLookUp(c, n.sons[0], (flags*{checkUndeclared})+{checkModule})
     if m != nil and m.kind == skModule:
       var ident: PIdent = nil
       if n.sons[1].kind == nkIdent:
@@ -331,7 +338,7 @@ proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
     o.mode = oimDone
   of nkDotExpr:
     o.mode = oimOtherModule
-    o.m = qualifiedLookUp(c, n.sons[0])
+    o.m = qualifiedLookUp(c, n.sons[0], {checkUndeclared, checkModule})
     if o.m != nil and o.m.kind == skModule:
       var ident: PIdent = nil
       if n.sons[1].kind == nkIdent:

compiler/pragmas.nim

@@ -569,7 +569,7 @@ proc deprecatedStmt(c: PContext; pragma: PNode) =
     localError(pragma.info, "list of key:value pairs expected"); return
   for n in pragma:
     if n.kind in {nkExprColonExpr, nkExprEqExpr}:
-      let dest = qualifiedLookUp(c, n[1])
+      let dest = qualifiedLookUp(c, n[1], {checkUndeclared})
       let src = considerQuotedIdent(n[0])
       let alias = newSym(skAlias, src, dest, n[0].info)
       incl(alias.flags, sfExported)
@@ -594,7 +594,7 @@ proc pragmaGuard(c: PContext; it: PNode; kind: TSymKind): PSym =
       # and perform the lookup on demand instead.
       result = newSym(skUnknown, considerQuotedIdent(n), nil, n.info)
   else:
-    result = qualifiedLookUp(c, n)
+    result = qualifiedLookUp(c, n, {checkUndeclared})
 
 proc singlePragma(c: PContext, sym: PSym, n: PNode, i: int,
                   validPragmas: TSpecialWords): bool =

compiler/semexprs.nim

@@ -1107,7 +1107,7 @@ proc builtinFieldAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
   # here at all!
   #if isSymChoice(n.sons[1]): return
 
-  var s = qualifiedLookUp(c, n, {checkAmbiguity, checkUndeclared})
+  var s = qualifiedLookUp(c, n, {checkAmbiguity, checkUndeclared, checkModule})
   if s != nil:
     if s.kind in OverloadableSyms:
       result = symChoice(c, n, s, scClosed)

compiler/semgnrc.nim

@@ -127,7 +127,7 @@ proc fuzzyLookup(c: PContext, n: PNode, flags: TSemGenericFlags,
   assert n.kind == nkDotExpr
   semIdeForTemplateOrGenericCheck(n, ctx.cursorInBody)
 
-  let luf = if withinMixin notin flags: {checkUndeclared} else: {}
+  let luf = if withinMixin notin flags: {checkUndeclared, checkModule} else: {checkModule}
 
   var s = qualifiedLookUp(c, n, luf)
   if s != nil:

compiler/semmagic.nim

@@ -133,7 +133,7 @@ proc semBindSym(c: PContext, n: PNode): PNode =
     return errorNode(c, n)
 
   let id = newIdentNode(getIdent(sl.strVal), n.info)
-  let s = qualifiedLookUp(c, id)
+  let s = qualifiedLookUp(c, id, {checkUndeclared})
   if s != nil:
     # we need to mark all symbols:
     var sc = symChoice(c, id, s, TSymChoiceRule(isMixin.intVal))

compiler/semstmts.nim

@@ -675,7 +675,7 @@ proc typeSectionLeftSidePass(c: PContext, n: PNode) =
     let name = a.sons[0]
     var s: PSym
     if name.kind == nkDotExpr:
-      s = qualifiedLookUp(c, name)
+      s = qualifiedLookUp(c, name, {checkUndeclared, checkModule})
       if s.kind != skType or s.typ.skipTypes(abstractPtrs).kind != tyObject or tfPartial notin s.typ.skipTypes(abstractPtrs).flags:
         localError(name.info, "only .partial objects can be extended")
     else:

compiler/semtempl.nim

@@ -80,7 +80,7 @@ proc semBindStmt(c: PContext, n: PNode, toBind: var IntSet): PNode =
     # the same symbol!
     # This is however not true anymore for hygienic templates as semantic
     # processing for them changes the symbol table...
-    let s = qualifiedLookUp(c, a)
+    let s = qualifiedLookUp(c, a, {checkUndeclared})
     if s != nil:
       # we need to mark all symbols:
       let sc = symChoice(c, n, s, scClosed)

tests/lookups/test.nim

@@ -0,0 +1,17 @@
+# This file needs to be called 'test' nim to provoke a clash
+# with the unittest.test name. Issue #
+
+import unittest, macros
+
+# bug #4555
+
+macro memo(n: untyped): typed =
+  result = n
+
+proc fastFib(n: int): int {.memo.} = 40
+proc fib(n: int): int = 40
+
+suite "memoization":
+  test "recursive function memoization":
+    check fastFib(40) == fib(40)
+