fixes #293

6 files changed, 29 insertions, 13 deletions

diff --git a/compiler/ast.nim b/compiler/ast.nim
index 82a20c312..fc21235bc 100755
--- a/compiler/ast.nim
+++ b/compiler/ast.nim
@@ -1,7 +1,7 @@
 #
 #
 #           The Nimrod Compiler
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2013 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
diff --git a/compiler/evals.nim b/compiler/evals.nim
index 5623f7955..4b42f5ada 100755
--- a/compiler/evals.nim
+++ b/compiler/evals.nim
@@ -1,7 +1,7 @@
 #
 #
 #           The Nimrod Compiler
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2013 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
@@ -319,7 +319,7 @@ proc evalVar(c: PEvalContext, n: PNode): PNode =
       else:
         if x.kind notin {nkEmpty..nkNilLit}:
           discardSons(x)
-          for i in countup(0, sonsLen(result) - 1): addSon(x, result.sons[i])
+          for j in countup(0, sonsLen(result) - 1): addSon(x, result.sons[j])
   result = emptyNode
 
 proc aliasNeeded(n: PNode, flags: TEvalFlags): bool = 
diff --git a/compiler/msgs.nim b/compiler/msgs.nim
index 16603a9a8..9858b1b9e 100755
--- a/compiler/msgs.nim
+++ b/compiler/msgs.nim
@@ -1,7 +1,7 @@
 #
 #
 #           The Nimrod Compiler
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2013 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
diff --git a/compiler/renderer.nim b/compiler/renderer.nim
index c8ee66e03..48a190ec1 100755
--- a/compiler/renderer.nim
+++ b/compiler/renderer.nim
@@ -1,7 +1,7 @@
 #
 #
 #           The Nimrod Compiler
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2013 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
@@ -753,8 +753,7 @@ proc doParamsAux(g: var TSrcGen, params: PNode) =
 
 proc gsub(g: var TSrcGen, n: PNode, c: TContext) = 
   if isNil(n): return
-  var 
-    L: int
+  var
     a: TContext
   if n.comment != nil: pushCom(g, n)
   case n.kind                 # atoms:
@@ -1096,7 +1095,7 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext) =
     incl(a.flags, rfInConstExpr)
     gsection(g, n, a, tkConst, "const")
   of nkVarSection, nkLetSection:
-    L = sonsLen(n)
+    var L = sonsLen(n)
     if L == 0: return
     if n.kind == nkVarSection: putWithSpace(g, tkVar, "var")
     else: putWithSpace(g, tkLet, "let")
diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
index d78112ee5..c86e3eb91 100755
--- a/compiler/semstmts.nim
+++ b/compiler/semstmts.nim
@@ -172,11 +172,16 @@ proc fitRemoveHiddenConv(c: PContext, typ: Ptype, n: PNode): PNode =
     changeType(result, typ)
 
 proc findShadowedVar(c: PContext, v: PSym): PSym =
-  for i in countdown(c.tab.tos - 2, 0):
+  for i in countdown(c.tab.tos - 2, ModuleTablePos+1):
     let shadowed = StrTableGet(c.tab.stack[i], v.name)
     if shadowed != nil and shadowed.kind in skLocalVars:
       return shadowed
 
+proc identWithin(n: PNode, s: PIdent): bool =
+  for i in 0 .. n.safeLen-1:
+    if identWithin(n.sons[i], s): return true
+  result = n.kind == nkSym and n.sym.name.id == s.id
+
 proc semIdentDef(c: PContext, n: PNode, kind: TSymKind): PSym =
   if isTopLevel(c): 
     result = semIdentWithPragma(c, kind, n, {sfExported})
@@ -239,7 +244,10 @@ proc semVarOrLet(c: PContext, n: PNode, symkind: TSymKind): PNode =
           let shadowed = findShadowedVar(c, v)
           if shadowed != nil:
             shadowed.flags.incl(sfShadowed)
-            Message(a.info, warnShadowIdent, v.name.s)
+            # a shadowed variable is an error unless it appears on the right
+            # side of the '=':
+            if warnShadowIdent in gNotes and not identWithin(def, v.name):
+              Message(a.info, warnShadowIdent, v.name.s)
       if def != nil and def.kind != nkEmpty:
         # this is only needed for the evaluation pass:
         v.ast = def
@@ -368,6 +376,15 @@ proc semForFields(c: PContext, n: PNode, m: TMagic): PNode =
   b.add(ast.emptyNode)
   stmts.add(b)
 
+proc addForVarDecl(c: PContext, v: PSym) =
+  if warnShadowIdent in gNotes:
+    let shadowed = findShadowedVar(c, v)
+    if shadowed != nil:
+      # XXX should we do this here?
+      #shadowed.flags.incl(sfShadowed)
+      Message(v.info, warnShadowIdent, v.name.s)
+  addDecl(c, v)
+
 proc semForVars(c: PContext, n: PNode): PNode =
   result = n
   var length = sonsLen(n)
@@ -383,7 +400,7 @@ proc semForVars(c: PContext, n: PNode): PNode =
       # for an example:
       v.typ = n.sons[length-2].typ
       n.sons[0] = newSymNode(v)
-      if sfGenSym notin v.flags: addDecl(c, v)
+      if sfGenSym notin v.flags: addForVarDecl(c, v)
     else:
       LocalError(n.info, errWrongNumberOfVariables)
   elif length-2 != sonsLen(iter):
@@ -394,7 +411,7 @@ proc semForVars(c: PContext, n: PNode): PNode =
       if getCurrOwner().kind == skModule: incl(v.flags, sfGlobal)
       v.typ = iter.sons[i]
       n.sons[i] = newSymNode(v)
-      if sfGenSym notin v.flags: addDecl(c, v)
+      if sfGenSym notin v.flags: addForVarDecl(c, v)
   Inc(c.p.nestedLoopCounter)
   n.sons[length-1] = SemStmt(c, n.sons[length-1])
   Dec(c.p.nestedLoopCounter)
diff --git a/compiler/semthreads.nim b/compiler/semthreads.nim
index 75621be79..9fc6a54d9 100755
--- a/compiler/semthreads.nim
+++ b/compiler/semthreads.nim
@@ -1,7 +1,7 @@
 #
 #
 #           The Nimrod Compiler
-#        (c) Copyright 2012 Andreas Rumpf
+#        (c) Copyright 2013 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.