Added cursors in the right places of the async macro.

rayman22201 · Jan 19, 2020 · 39c1131 · disruptek · Jan 20, 2020 · 39c1131
1 parent a5e6707
commit 39c1131
Showing 1 changed file with 12 additions and 10 deletions.
diff --git a/lib/pure/asyncmacro.nim b/lib/pure/asyncmacro.nim
@@ -25,9 +25,8 @@ proc skipStmtList(node: NimNode): NimNode {.compileTime.} =
 template createCb(retFutureSym, iteratorNameSym,
                   strName, identName, futureVarCompletions: untyped) =
   bind finished
-  let retFutUnown = unown retFutureSym
 
-  var nameIterVar = iteratorNameSym
+  var nameIterVar {.cursor.} = iteratorNameSym
   proc identName {.closure.} =
     try:
       if not nameIterVar.finished:
@@ -39,7 +38,7 @@ template createCb(retFutureSym, iteratorNameSym,
             break
 
         if next == nil:
-          if not retFutUnown.finished:
+          if not retFutureSym.finished:
             let msg = "Async procedure ($1) yielded `nil`, are you await'ing a " &
                     "`nil` Future?"
             raise newException(AssertionError, msg % strName)
@@ -50,12 +49,12 @@ template createCb(retFutureSym, iteratorNameSym,
             {.pop.}
     except:
       futureVarCompletions
-      if retFutUnown.finished:
+      if retFutureSym.finished:
         # Take a look at tasyncexceptions for the bug which this fixes.
         # That test explains it better than I can here.
         raise
       else:
-        retFutUnown.fail(getCurrentException())
+        retFutureSym.fail(getCurrentException())
   identName()
 
 template useVar(result: var NimNode, futureVarNode: NimNode, valueReceiver,
@@ -252,6 +251,7 @@ proc asyncSingleProc(prc: NimNode): NimNode {.compileTime.} =
 
   # -> var retFuture = newFuture[T]()
   var retFutureSym = genSym(nskVar, "retFuture")
+  var retFutureCursorSym = genSym(nskVar, "retFutureCursor")
   var subRetType =
     if returnType.kind == nnkEmpty: newIdentNode("void")
     else: baseType
@@ -262,6 +262,8 @@ proc asyncSingleProc(prc: NimNode): NimNode {.compileTime.} =
           newIdentNode("newFuture"),
           subRetType),
       newLit(prcName)))) # Get type from return type of this proc
+  outerProcBody.add newVarStmt(nnkPragmaExpr.newTree(retFutureCursorSym, nnkPragma.newTree(newIdentNode("cursor"))), retFutureSym)
+
 
   # -> iterator nameIter(): FutureBase {.closure.} =
   # ->   {.push warning[resultshadowed]: off.}
@@ -270,7 +272,7 @@ proc asyncSingleProc(prc: NimNode): NimNode {.compileTime.} =
   # ->   <proc_body>
   # ->   complete(retFuture, result)
   var iteratorNameSym = genSym(nskIterator, $prcName & "Iter")
-  var procBody = prc.body.processBody(retFutureSym, subtypeIsVoid,
+  var procBody = prc.body.processBody(retFutureCursorSym, subtypeIsVoid,
                                     futureVarIdents)
   # don't do anything with forward bodies (empty)
   if procBody.kind != nnkEmpty:
@@ -290,10 +292,10 @@ proc asyncSingleProc(prc: NimNode): NimNode {.compileTime.} =
 
       procBody.add(
         newCall(newIdentNode("complete"),
-          retFutureSym, newIdentNode("result"))) # -> complete(retFuture, result)
+          retFutureCursorSym, newIdentNode("result"))) # -> complete(retFuture, result)
     else:
       # -> complete(retFuture)
-      procBody.add(newCall(newIdentNode("complete"), retFutureSym))
+      procBody.add(newCall(newIdentNode("complete"), retFutureCursorSym))
 
     var closureIterator = newProc(iteratorNameSym, [parseExpr("owned(FutureBase)")],
                                   procBody, nnkIteratorDef)
@@ -310,7 +312,7 @@ proc asyncSingleProc(prc: NimNode): NimNode {.compileTime.} =
     # NOTE: The NimAsyncContinueSuffix is checked for in asyncfutures.nim to produce
     # friendlier stack traces:
     var cbName = genSym(nskProc, prcName & NimAsyncContinueSuffix)
-    var procCb = getAst createCb(retFutureSym, iteratorNameSym,
+    var procCb = getAst createCb(retFutureCursorSym, iteratorNameSym,
                          newStrLitNode(prcName),
                          cbName,
                          createFutureVarCompletions(futureVarIdents, nil))
@@ -328,7 +330,7 @@ proc asyncSingleProc(prc: NimNode): NimNode {.compileTime.} =
       result.params[0] = parseExpr("owned(Future[void])")
   if procBody.kind != nnkEmpty:
     result.body = outerProcBody
-  #echo(treeRepr(result))
+  echo(treeRepr(result))
   #if prcName == "recvLineInto":
   #  echo(toStrLit(result))