introduce --newruntime switch for the upcoming destructors and move semantics

compiler/commands.nim

@@ -666,6 +666,10 @@ proc processSwitch(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     expectArg(switch, arg, pass, info)
     if config != nil:
       config.cppDefine(arg)
+  of "newruntime":
+    expectNoArg(switch, arg, pass, info)
+    newDestructors = true
+    defineSymbol("nimNewRuntime")
   else:
     if strutils.find(switch, '.') >= 0: options.setConfigVar(switch, arg)
     else: invalidCmdLineOption(pass, switch, info)

compiler/destroyer.nim

@@ -290,4 +290,4 @@ proc injectDestructorCalls*(owner: PSym; n: PNode): PNode =
   else:
     result.add body
 
-  echo "transformed into: ", result
+  #echo "transformed into: ", result

compiler/options.nim

@@ -14,7 +14,6 @@ const
   hasTinyCBackend* = defined(tinyc)
   useEffectSystem* = true
   useWriteTracking* = false
-  newDestructors* = defined(nimV2)
   hasFFI* = defined(useFFI)
   newScopeForIf* = true
   useCaas* = not defined(noCaas)
@@ -145,6 +144,7 @@ var
   isServing*: bool = false
   gNoNimblePath* = false
   gExperimentalMode*: bool
+  newDestructors*: bool
 
 proc importantComments*(): bool {.inline.} = gCmd in {cmdDoc, cmdIdeTools}
 proc usesNativeGC*(): bool {.inline.} = gSelectedGC >= gcRefc

compiler/semexprs.nim

@@ -1383,7 +1383,7 @@ proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
           typeMismatch(n.info, lhs.typ, rhs.typ)
 
     n.sons[1] = fitNode(c, le, rhs, n.info)
-    when not newDestructors:
+    if not newDestructors:
       if tfHasAsgn in lhs.typ.flags and not lhsIsResult and
           mode != noOverloadedAsgn:
         return overloadedAsgn(c, lhs, n.sons[1])

compiler/semstmts.nim

@@ -100,7 +100,7 @@ proc semProc(c: PContext, n: PNode): PNode
 include semdestruct
 
 proc semDestructorCheck(c: PContext, n: PNode, flags: TExprFlags) {.inline.} =
-  when not newDestructors:
+  if not newDestructors:
     if efAllowDestructor notin flags and
         n.kind in nkCallKinds+{nkObjConstr,nkBracket}:
       if instantiateDestructor(c, n.typ) != nil:
@@ -608,7 +608,7 @@ proc semVarOrLet(c: PContext, n: PNode, symkind: TSymKind): PNode =
         if def.kind == nkPar: v.ast = def[j]
         setVarType(v, tup.sons[j])
         b.sons[j] = newSymNode(v)
-      when not newDestructors: addDefer(c, result, v)
+      if not newDestructors: addDefer(c, result, v)
       checkNilable(v)
       if sfCompileTime in v.flags: hasCompileTime = true
   if hasCompileTime: vm.setupCompileTimeVar(c.module, c.cache, result)
@@ -1278,9 +1278,8 @@ proc semOverride(c: PContext, s: PSym, n: PNode) =
   case s.name.s.normalize
   of "destroy", "=destroy":
     doDestructorStuff(c, s, n)
-    when not newDestructors:
+    if not newDestructors and not experimentalMode(c):
-      if not experimentalMode(c):
+      localError n.info, "use the {.experimental.} pragma to enable destructors"
-        localError n.info, "use the {.experimental.} pragma to enable destructors"
     incl(s.flags, sfUsed)
   of "deepcopy", "=deepcopy":
     if s.typ.len == 2 and

compiler/transf.nim

@@ -43,7 +43,7 @@ type
     inlining: int            # > 0 if we are in inlining context (copy vars)
     nestedProcs: int         # > 0 if we are in a nested proc
     contSyms, breakSyms: seq[PSym]  # to transform 'continue' and 'break'
-    deferDetected, tooEarly: bool
+    deferDetected, tooEarly, needsDestroyPass: bool
   PTransf = ref TTransfContext
 
 proc newTransNode(a: PNode): PTransNode {.inline.} =
@@ -780,7 +780,8 @@ proc transform(c: PTransf, n: PNode): PTransNode =
                   nkBlockStmt, nkBlockExpr}:
       oldDeferAnchor = c.deferAnchor
       c.deferAnchor = n
-
+  if n.typ != nil and tfHasAsgn in n.typ.flags:
+    c.needsDestroyPass = true
   case n.kind
   of nkSym:
     result = transformSym(c, n)
@@ -972,7 +973,7 @@ proc transformBody*(module: PSym, n: PNode, prc: PSym): PNode =
     #result = liftLambdas(prc, result)
     incl(result.flags, nfTransf)
     when useEffectSystem: trackProc(prc, result)
-    if prc.kind == skFunc:
+    if c.needsDestroyPass and newDestructors:
       result = injectDestructorCalls(prc, result)
     #if prc.name.s == "testbody":
     #  echo renderTree(result)
@@ -989,6 +990,8 @@ proc transformStmt*(module: PSym, n: PNode): PNode =
     when useEffectSystem: trackTopLevelStmt(module, result)
     #if n.info ?? "temp.nim":
     #  echo renderTree(result, {renderIds})
+    if c.needsDestroyPass and newDestructors:
+      result = injectDestructorCalls(module, result)
 
 proc transformExpr*(module: PSym, n: PNode): PNode =
   if nfTransf in n.flags:
@@ -998,3 +1001,5 @@ proc transformExpr*(module: PSym, n: PNode): PNode =
     result = processTransf(c, n, module)
     liftDefer(c, result)
     incl(result.flags, nfTransf)
+    if c.needsDestroyPass and newDestructors:
+      result = injectDestructorCalls(module, result)