Integrate the move analyser into duplifier.nim (#521)

* Integrate the move analyser into duplifier.nim

* fixes `ensureMove`

src/hexer/duplifier.nim

@@ -41,6 +41,7 @@ type
     reportLastUse: bool
     typeCache: TypeCache
     tmpCounter: int
+    source: ptr TokenBuf
 
   Expects = enum
     DontCare,
@@ -50,9 +51,9 @@ type
 
 # -------------- helpers ----------------------------------------
 
-proc isLastRead(c: Context; n: Cursor): bool =
-  # XXX We don't have a move analyser yet.
-  false
+proc isLastRead(c: var Context; n: Cursor): bool =
+  var otherUsage = NoLineInfo
+  result = isLastUse(n, c.source[], otherUsage)
 
 const
   ConstructingExprs = {CallX, CallStrLitX, InfixX, PrefixX, CmdX, OconstrX, NewOconstrX,
@@ -606,6 +607,7 @@ proc trEnsureMove(c: var Context; n: var Cursor; e: Expects) =
     let m = "not the last usage of: " & toString(n, false)
     c.dest.buildTree ErrT, info:
       c.dest.add strToken(pool.strings.getOrIncl(m), info)
+  skip n
 
 proc tr(c: var Context; n: var Cursor; e: Expects) =
   if n.kind == Symbol:
@@ -671,9 +673,9 @@ proc tr(c: var Context; n: var Cursor; e: Expects) =
       else:
         trSons c, n, WantNonOwner
 
-proc injectDups*(n: Cursor; lifter: ref LiftingCtx): TokenBuf =
+proc injectDups*(n: Cursor; source: var TokenBuf; lifter: ref LiftingCtx): TokenBuf =
   var c = Context(lifter: lifter, typeCache: createTypeCache(),
-    dest: createTokenBuf(400))
+    dest: createTokenBuf(400), source: addr source)
   c.typeCache.openScope()
   var n = n
   tr(c, n, WantNonOwner)

src/hexer/mover.nim

@@ -233,7 +233,7 @@ when isMainModule:
     while true:
       case result.kind
       of ParLe:
-        if result.exprKind == EnsureMoveX:
+        if result.exprKind == EMoveX:
           inc result
           return result
         inc nested

src/hexer/pipeline.nim

@@ -46,7 +46,7 @@ proc transform*(c: var EContext; n: Cursor; moduleSuffix: string): TokenBuf =
 
   var c2 = beginRead(n1)
   let ctx = createLiftingCtx()
-  var n2 = injectDups(c2, ctx)
+  var n2 = injectDups(c2, n1, ctx)
   endRead(n1)
 
   var c3 = beginRead(n2)