test transformClosureIterator

compiler/ast.nim

@@ -116,6 +116,16 @@ proc `transformedBody=`*(s: PSym, val: PNode) {.inline.} =
   if s.state == Partial: loadSym(s)
   s.transformedBodyImpl = val
 
+proc closureBody*(s: PSym): PNode {.inline.} =
+  if s.state == Partial: loadSym(s)
+  result = s.closureBodyImpl
+
+proc `closureBody=`*(s: PSym, val: PNode) {.inline.} =
+  #assert s.state != Sealed
+  # Make an exception here for this misfeature...
+  if s.state == Partial: loadSym(s)
+  s.closureBodyImpl = val
+
 proc guard*(s: PSym): PSym {.inline.} =
   if s.state == Partial: loadSym(s)
   result = s.guardImpl

compiler/astdef.nim

@@ -705,6 +705,7 @@ type
       #procInstCache*: seq[PInstantiation]
       gcUnsafetyReasonImpl*: PSym  # for better error messages regarding gcsafe
       transformedBodyImpl*: PNode  # cached body after transf pass
+      closureBodyImpl*: PNode      # cached body after closure conversion
     of skLet, skVar, skField, skForVar:
       guardImpl*: PSym
       bitsizeImpl*: int

compiler/cgen.nim

@@ -1285,6 +1285,9 @@ proc genProcBody(p: BProc; procBody: PNode) =
     p.blocks[0].sections[cpsInit].addAssignmentWithValue("nimErr_"):
       p.blocks[0].sections[cpsInit].addCall(cgsymValue(p.module, "nimErrorFlag"))
 
+template isIterator(owner: PSym): bool =
+  owner.kind == skIterator and owner.typ.callConv == ccClosure
+
 proc genProcAux*(m: BModule, prc: PSym) =
   var p = newProc(prc, m)
   var header = newBuilder("")
@@ -1297,9 +1300,13 @@ proc genProcAux*(m: BModule, prc: PSym) =
   var returnStmt: Snippet = ""
   assert(prc.ast != nil)
 
-  var procBody = transformBody(m.g.graph, m.idgen, prc, {})
-  if sfInjectDestructors in prc.flags:
-    procBody = injectDestructorCalls(m.g.graph, m.idgen, prc, procBody)
+  var procBody: PNode = nil
+  if isIterator(prc) and prc.closureBody != nil:
+    procBody = prc.closureBody
+  else:
+    procBody = transformBody(m.g.graph, m.idgen, prc, {})
+    if sfInjectDestructors in prc.flags:
+      procBody = injectDestructorCalls(m.g.graph, m.idgen, prc, procBody)
 
   let tmpInfo = prc.info
   discard freshLineInfo(p, prc.info)

compiler/injectdestructors.nim

@@ -1083,6 +1083,10 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
       for i in 0..<n.len:
         result[i] = p(n[i], c, s, mode, inReturn=true)
       s.needsTry = true
+    of nkYieldStmt: # TODO:
+      result = shallowCopy(n)
+      for i in 0..<n.len:
+        result[i] = p(n[i], c, s, mode)
     of nkCast:
       result = shallowCopy(n)
       result[0] = n[0]

compiler/transf.nim

@@ -26,6 +26,8 @@ import
   lowerings, liftlocals,
   modulegraphs, lineinfos
 
+import injectdestructors
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -123,11 +125,16 @@ proc newAsgnStmt(c: PTransf, kind: TNodeKind, le: PNode, ri: PNode; isFirstWrite
 proc transformSymAux(c: PTransf, n: PNode): PNode =
   let s = n.sym
   if s.typ != nil and s.typ.callConv == ccClosure:
+    var body: PNode = nil
     if s.kind in routineKinds:
-      discard transformBody(c.graph, c.idgen, s, {useCache}+c.flags)
+      body = transformBody(c.graph, c.idgen, s, {useCache}+c.flags)
     if s.kind == skIterator:
       if c.tooEarly: return n
-      else: return liftIterSym(c.graph, n, c.idgen, getCurrOwner(c))
+      else:
+        let transformedBody = injectDestructorCalls(c.graph, c.idgen, s, body)
+        let closureBody = transformClosureIterator(c.graph, c.idgen, s, transformedBody)
+        s.closureBody = closureBody
+        return liftIterSym(c.graph, n, c.idgen, getCurrOwner(c))
     elif s.kind in {skProc, skFunc, skConverter, skMethod} and not c.tooEarly:
       # top level .closure procs are still somewhat supported for 'Nake':
       return makeClosure(c.graph, c.idgen, s, nil, n.info)
@@ -1316,8 +1323,6 @@ proc transformBody*(g: ModuleGraph; idgen: IdGenerator; prc: PSym; flags: Transf
     liftDefer(c, result)
     result = liftLocalsIfRequested(prc, result, g.cache, g.config, c.idgen)
 
-    if prc.isIterator:
-      result = g.transformClosureIterator(c.idgen, prc, result)
 
     incl(result.flags, nfTransf)