Non-var destructors become the default

changelog.md

@@ -3,6 +3,7 @@
 
 ## Changes affecting backward compatibility
 
+- Non-var destructors become the default. Use `-d:nimLegacyVarDestructor` to emulate old behaviors.
 
 ## Standard library additions and changes
 

compiler/liftdestructors.nim

@@ -40,7 +40,7 @@ template asink*(t: PType): PSym = getAttachedOp(c.g, t, attachedSink)
 
 proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode)
 proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator; isDistinct = false): PSym
+              info: TLineInfo; idgen: IdGenerator): PSym
 
 proc createTypeBoundOps*(g: ModuleGraph; c: PContext; orig: PType; info: TLineInfo;
                          idgen: IdGenerator)
@@ -1063,9 +1063,7 @@ proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
   assert typ.kind == tyDistinct
   let baseType = typ.elementType
   if getAttachedOp(g, baseType, kind) == nil:
-    # TODO: fixme `isDistinct` is a fix for #23552; remove it after
-    # `-d:nimPreviewNonVarDestructor` becomes the default
-    discard produceSym(g, c, baseType, kind, info, idgen, isDistinct = true)
+    discard produceSym(g, c, baseType, kind, info, idgen)
   result = getAttachedOp(g, baseType, kind)
   setAttachedOp(g, idgen.module, typ, kind, result)
 
@@ -1104,7 +1102,7 @@ proc symDupPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttache
   incl result.flags, sfGeneratedOp
 
 proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator; isDiscriminant = false; isDistinct = false): PSym =
+              info: TLineInfo; idgen: IdGenerator; isDiscriminant = false): PSym =
   if kind == attachedDup:
     return symDupPrototype(g, typ, owner, kind, info, idgen)
 
@@ -1115,7 +1113,7 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
                    idgen, result, info)
 
   if kind == attachedDestructor and g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc} and
-     ((g.config.isDefined("nimPreviewNonVarDestructor") and not isDiscriminant) or (typ.kind in {tyRef, tyString, tySequence} and not isDistinct)):
+      not g.config.isDefined("nimLegacyVarDestructor") and not isDiscriminant:
     dest.typ = typ
   else:
     dest.typ = makeVarType(typ.owner, typ, idgen)
@@ -1157,13 +1155,13 @@ proc genTypeFieldCopy(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   body.add newAsgnStmt(xx, yy)
 
 proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator; isDistinct = false): PSym =
+              info: TLineInfo; idgen: IdGenerator): PSym =
   if typ.kind == tyDistinct:
     return produceSymDistinctType(g, c, typ, kind, info, idgen)
 
   result = getAttachedOp(g, typ, kind)
   if result == nil:
-    result = symPrototype(g, typ, typ.owner, kind, info, idgen, isDistinct = isDistinct)
+    result = symPrototype(g, typ, typ.owner, kind, info, idgen)
 
   var a = TLiftCtx(info: info, g: g, kind: kind, c: c, asgnForType: typ, idgen: idgen,
                    fn: result)

compiler/nim.cfg

@@ -9,7 +9,6 @@ define:nimPreviewSlimSystem
 define:nimPreviewCstringConversion
 define:nimPreviewProcConversion
 define:nimPreviewRangeDefault
-define:nimPreviewNonVarDestructor
 threads:off
 
 #import:"$projectpath/testability"

lib/system.nim

@@ -365,7 +365,7 @@ proc arrPut[I: Ordinal;T,S](a: T; i: I;
 const arcLikeMem = defined(gcArc) or defined(gcAtomicArc) or defined(gcOrc)
 
 
-when defined(nimAllowNonVarDestructor) and arcLikeMem and defined(nimPreviewNonVarDestructor):
+when defined(nimAllowNonVarDestructor) and arcLikeMem and not defined(nimLegacyVarDestructor):
   proc `=destroy`*[T](x: T) {.inline, magic: "Destroy".} =
     ## Generic `destructor`:idx: implementation that can be overridden.
     discard
@@ -374,15 +374,7 @@ else:
     ## Generic `destructor`:idx: implementation that can be overridden.
     discard
 
-  when defined(nimAllowNonVarDestructor) and arcLikeMem:
-    proc `=destroy`*(x: string) {.inline, magic: "Destroy", enforceNoRaises.} =
-      discard
 
-    proc `=destroy`*[T](x: seq[T]) {.inline, magic: "Destroy".} =
-      discard
-
-    proc `=destroy`*[T](x: ref T) {.inline, magic: "Destroy".} =
-      discard
 
 when defined(nimHasDup):
   proc `=dup`*[T](x: T): T {.inline, magic: "Dup".} =

tests/arc/thard_alignment.nim

@@ -1,6 +1,6 @@
 discard """
 disabled: "arm64"
-cmd: "nim c --mm:arc -u:nimPreviewNonVarDestructor $file"
+cmd: "nim c --mm:arc -d:nimLegacyVarDestructor $file"
 output: "y"
 """
 

tests/config.nims

@@ -40,7 +40,6 @@ switch("define", "nimPreviewFloatRoundtrip")
 switch("define", "nimPreviewJsonutilsHoleyEnum")
 switch("define", "nimPreviewHashRef")
 switch("define", "nimPreviewRangeDefault")
-switch("define", "nimPreviewNonVarDestructor")
 
 switch("warningAserror", "UnnamedBreak")
 when not defined(testsConciseTypeMismatch):

tests/destructor/tdistinctseq.nim

@@ -1,5 +1,5 @@
 discard """
-  matrix: "-u:nimPreviewNonVarDestructor;"
+  matrix: "-d:nimLegacyVarDestructor;"
 """
 type DistinctSeq* = distinct seq[int]