fix for template redefinition. test cases added.

compiler/astalgo.nim

@@ -567,6 +567,19 @@ proc StrTableRawInsert(data: var TSymSeq, n: PSym) =
   assert(data[h] == nil)
   data[h] = n
 
+proc SymTabReplaceRaw(data: var TSymSeq, prevSym: PSym, newSym: PSym) =
+  assert prevSym.name.h == newSym.name.h
+  var h: THash = prevSym.name.h and high(data)
+  while data[h] != nil:
+    if data[h] == prevSym:
+      data[h] = newSym
+      return
+    h = nextTry(h, high(data))
+  assert false
+ 
+proc SymTabReplace*(t: var TStrTable, prevSym: PSym, newSym: PSym) =
+  SymTabReplaceRaw(t.data, prevSym, newSym)
+
 proc StrTableEnlarge(t: var TStrTable) = 
   var n: TSymSeq
   newSeq(n, len(t.data) * growthFactor)

compiler/semexprs.nim

@@ -1269,7 +1269,6 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
     if s != nil: 
       case s.kind
       of skMacro:
-        echo c.filename
         if c.filename.endsWith("hello.nim") and sfImmediate notin s.flags:
           result = semDirectOp(c, n, flags)
         else:

compiler/semtempl.nim

@@ -191,14 +191,10 @@ proc semTemplateDef(c: PContext, n: PNode): PNode =
   result = n
   if n.sons[bodyPos].kind == nkEmpty: 
     LocalError(n.info, errImplOfXexpected, s.name.s)
-  var proto = SearchForProc(c, s, c.tab.tos-2) # -2 because we have a scope
-                                               # open for parameters
+  let curScope = c.tab.tos - 2 # -2 because we have a scope open for parameters
+  var proto = SearchForProc(c, s, curScope)
   if proto == nil:
-    # add identifier of template as a last step to not allow recursive templates:  
     addInterfaceOverloadableSymAt(c, s, c.tab.tos - 2)
   else:
-    # overwrite template
-    proto.info = s.info
-    proto.ast = s.ast
-    proto.typ = s.typ
-    proto.flags = s.flags
+    SymTabReplace(c.tab.stack[curScope], proto, s)
+

tests/compile/tredef.nim

@@ -0,0 +1,29 @@
+template foo(a: int, b: string) = nil
+foo(1, "test")
+
+proc bar(a: int, b: string) = nil
+bar(1, "test")
+
+template foo(a: int, b: string) = bar(a, b)
+foo(1, "test")
+
+block:
+  proc bar(a: int, b: string) = nil
+  template foo(a: int, b: string) = nil
+  foo(1, "test")
+  bar(1, "test")
+  
+proc baz =
+  proc foo(a: int, b: string) = nil
+  proc foo(b: string) =
+    template bar(a: int, b: string) = nil
+    bar(1, "test")
+    
+  foo("test")
+
+  block:
+    proc foo(b: string) = nil
+    foo("test")
+    foo(1, "test")
+
+baz()

tests/reject/tprocredef.nim

@@ -0,0 +1,9 @@
+discard """
+  file: "tprocredef.nim"
+  line: 8
+  errormsg: "redefinition of \'foo\'"
+"""
+
+proc foo(a: int, b: string) = nil
+proc foo(a: int, b: string) = nil
+

tests/run/toverl2.nim

@@ -1,6 +1,6 @@
 discard """
   file: "toverl2.nim"
-  output: "true012"
+  output: "true012innertrue"
 """
 # Test new overloading resolution rules
 
@@ -14,14 +14,20 @@ iterator toverl2(x: int): int =
   while res < x: 
     yield res
     inc(res)
-    
+
 var
   pp: proc (x: bool): string = toverl2
+
 stdout.write(pp(true))
+
 for x in toverl2(3): 
   stdout.write(toverl2(x))
+
+block:
+  proc toverl2(x: int): string = return "inner"
+  stdout.write(toverl2(5))
+  stdout.write(true)
+
 stdout.write("\n")
-#OUT true012
-
-
+#OUT true012innertrue
 

tests/run/tunittests.nim

@@ -1,2 +1,2 @@
-import uclosures
+import uclosures, utemplates
 

tests/run/utemplates.nim

@@ -0,0 +1,32 @@
+import unittest
+
+template t(a: int): expr = "int"
+template t(a: string): expr = "string"
+
+test "templates can be overloaded":
+  check t(10) == "int"
+  check t("test") == "string"
+
+test "previous definitions can be further overloaded or hidden in local scopes":
+  template t(a: bool): expr = "bool"
+
+  check t(true) == "bool"
+  check t(10) == "int"
+  
+  template t(a: int): expr = "inner int"
+  check t(10) == "inner int"
+  check t("test") == "string"
+
+test "templates can be redefined multiple times":
+  template customAssert(cond: bool, msg: string): stmt =
+    if not cond: fail(msg)
+
+  template assertion_failed(body: stmt) =
+    template fail(msg: string): stmt = body
+
+  assertion_failed: check msg == "first fail path"
+  customAssert false, "first fail path"
+
+  assertion_failed: check msg == "second fail path"  
+  customAssert false, "second fail path"
+