bugfix: invoking a generic iterator twice triggers a code gen bug (titer2)

compiler/sem.nim

@@ -14,7 +14,7 @@ import
   wordrecg, ropes, msgs, os, condsyms, idents, renderer, types, platform, math, 
   magicsys, parser, nversion, nimsets, semdata, evals, semfold, importer, 
   procfind, lookups, rodread, pragmas, passes, semtypinst, sigmatch, suggest,
-  semthreads, intsets
+  semthreads, intsets, transf
 
 proc semPass*(): TPass
 # implementation
@@ -138,8 +138,8 @@ proc addCodeForGenerics(c: PContext, n: PNode) =
     var it = c.generics.sons[i].sons[1]
     if it.kind != nkSym: InternalError("addCodeForGenerics")
     var prc = it.sym
-    if (prc.kind in {skProc, skMethod, skConverter}) and (prc.magic == mNone): 
+    if prc.kind in {skProc, skMethod, skConverter} and prc.magic == mNone: 
-      if (prc.ast == nil) or (prc.ast.sons[codePos] == nil): 
+      if prc.ast == nil or prc.ast.sons[codePos] == nil: 
         InternalError(prc.info, "no code for " & prc.name.s)
       addSon(n, prc.ast)
   c.lastGenericIdx = sonsLen(c.generics)

compiler/seminst.nim

@@ -105,6 +105,9 @@ proc generateInstance(c: PContext, fn: PSym, pt: TIdTable,
         addResult(c, result.typ.sons[0], n.info)
         addResultNode(c, n)
       n.sons[codePos] = semStmtScope(c, n.sons[codePos])
+      if fn.kind == skIterator:
+        # XXX Bad hack for tests/titer2:
+        n.sons[codePos] = transform(c.module, n.sons[codePos])
       popProcCon(c)
       #echo "code instantiated ", result.name.s
   else:

compiler/transf.nim

@@ -472,6 +472,7 @@ proc transformFor(c: PTransf, n: PNode): PTransNode =
   # generate access statements for the parameters (unless they are constant)
   # put mapping from formal parameters to actual parameters
   if n.kind != nkForStmt: InternalError(n.info, "transformFor")
+  #echo "transforming: ", renderTree(n)
   result = newTransNode(nkStmtList, n.info, 0)
   var length = sonsLen(n)
   var loopBody = transformLoopBody(c, n.sons[length-1])
@@ -480,14 +481,13 @@ proc transformFor(c: PTransf, n: PNode): PTransNode =
     addVar(v, copyTree(n.sons[i])) # declare new vars
   add(result, v.ptransNode)
   var call = n.sons[length - 2]
-  if (call.kind != nkCall) or (call.sons[0].kind != nkSym): 
+  if call.kind != nkCall or call.sons[0].kind != nkSym:
     InternalError(call.info, "transformFor")
   
   var newC = newTransCon(call.sons[0].sym)
   newC.forStmt = n
   newC.forLoopBody = loopBody
-  if (newC.owner.kind != skIterator): 
+  if newC.owner.kind != skIterator: InternalError(call.info, "transformFor") 
-    InternalError(call.info, "transformFor") 
   # generate access statements for the parameters (unless they are constant)
   pushTransCon(c, newC)
   for i in countup(1, sonsLen(call) - 1): 
@@ -512,6 +512,8 @@ proc transformFor(c: PTransf, n: PNode): PTransNode =
   dec(c.inlining)
   popInfoContext()
   popTransCon(c)
+  #echo "transformed: ", renderTree(n)
+  
 
 proc getMagicOp(call: PNode): TMagic = 
   if call.sons[0].kind == nkSym and
@@ -660,7 +662,7 @@ proc transformCall(c: PTransf, n: PNode): PTransNode =
           inc(j)
       add(result, transform(c, a))
     if len(result) == 2: result = result[1]
-  elif (n.sons[0].kind == nkSym) and (n.sons[0].sym.kind == skMethod): 
+  elif n.sons[0].kind == nkSym and n.sons[0].sym.kind == skMethod: 
     # use the dispatcher for the call:
     result = methodCall(transformSons(c, n).pnode).ptransNode
   else:

tests/accept/compile/titer2.nim

@@ -19,15 +19,15 @@ iterator mycountup(a, b: int): int =
     yield res
     inc(res)
 
+when true:
   iterator pairs*[A, B](t: TTable[A, B]): tuple[key: A, val: B] =
     ## iterates over any (key, value) pair in the table `t`.
-  var h = 0
+    for h in mycountup(0, high(t.data)):
-  while h <= high(t.data):
       var k = t.data[h].key
       if t.data[h].slot == seFilled: yield (k, t.data[h].val)
-    inc(h)
+else:
-  
+  iterator pairs*(t: TTable[int, string]): tuple[key: int, val: string] =
-  when false:
+    ## iterates over any (key, value) pair in the table `t`.
     for h in mycountup(0, high(t.data)):
       var k = t.data[h].key
       if t.data[h].slot == seFilled: yield (k, t.data[h].val)

todo.txt

@@ -1,10 +1,10 @@
 High priority (version 0.8.12)
 ==============================
-- bug: invoking a generic iterator twice triggers a code gen bug (titer2)
+* implement write access to ``s[i]`` for macros
 * implement message passing built-ins
 * add --deadlock_prevention:on|off switch? timeout for locks?
 * built-in serialization
-
+* test encodings.nim on windows
 
 
 version 0.9.0
@@ -43,7 +43,6 @@ version 0.9.XX
   is hard because of partial evaluation --> symbol files will fix this as
   a side effect
 - EcmaScript needs a new and better code gen: simply adapt the C code gen to it
-- generalized case statement (requires better transf)
 - tlastmod returns wrong results on BSD (Linux, MacOS X: works)
 - nested tuple unpacking
 - 'nimrod def': does not always work?
@@ -99,6 +98,7 @@ Version 2
     var x = myProc() # checks myProc() initializes every pointer explicitely
     
 - the two other parsers
+- generalized case statement (requires better transf)
 - rethink the syntax: distinction between expr and stmt is unfortunate; 
   indentation handling is quite complex too; problem with exception handling
   is that often the scope of ``try`` is wrong and apart from that ``try`` is