try destructor fix

compiler/liftdestructors.nim

@@ -1276,6 +1276,10 @@ proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInf
   ## The later 'injectdestructors' pass depends on it.
   if orig == nil or {tfCheckedForDestructor, tfHasMeta} * orig.flags != {}: return
   incl orig.flags, tfCheckedForDestructor
+  # for user defined generic destructors:
+  let origRoot = genericRoot(orig)
+  if origRoot != nil:
+    incl origRoot.flags, tfCheckedForDestructor
 
   let skipped = orig.skipTypes({tyGenericInst, tyAlias, tySink})
   if isEmptyContainer(skipped) or skipped.kind == tyStatic: return

compiler/semstmts.nim

@@ -2035,14 +2035,27 @@ proc canonType(c: PContext, t: PType): PType =
   else:
     result = t
 
-proc prevDestructor(c: PContext; prevOp: PSym; obj: PType; info: TLineInfo) =
-  var msg = "cannot bind another '" & prevOp.name.s & "' to: " & typeToString(obj)
-  if sfOverridden notin prevOp.flags:
+proc prevDestructor(c: PContext; op: TTypeAttachedOp; prevOp: PSym; obj: PType; info: TLineInfo) =
+  var msg = "cannot bind another '" & AttachedOpToStr[op] & "' to: " & typeToString(obj)
+  if prevOp == nil:
+    # happens if the destructor was implicitly constructed for a specific instance,
+    # not the entire generic type
+    msg.add "; previous declaration was constructed implicitly"
+  elif sfOverridden notin prevOp.flags:
     msg.add "; previous declaration was constructed here implicitly: " & (c.config $ prevOp.info)
   else:
     msg.add "; previous declaration was here: " & (c.config $ prevOp.info)
   localError(c.config, info, errGenerated, msg)
 
+proc checkedForDestructor(t: PType): bool =
+  if tfCheckedForDestructor in t.flags:
+    return true
+  # maybe another instance was instantiated, marking the generic root:
+  let root = genericRoot(t)
+  if root != nil and tfCheckedForDestructor in root.flags:
+    return true
+  result = false
+
 proc whereToBindTypeHook(c: PContext; t: PType): PType =
   result = t
   while true:
@@ -2076,10 +2089,10 @@ proc bindDupHook(c: PContext; s: PSym; n: PNode; op: TTypeAttachedOp) =
       let ao = getAttachedOp(c.graph, obj, op)
       if ao == s:
         discard "forward declared destructor"
-      elif ao.isNil and tfCheckedForDestructor notin obj.flags:
+      elif ao.isNil and not checkedForDestructor(obj):
         setAttachedOp(c.graph, c.module.position, obj, op, s)
       else:
-        prevDestructor(c, ao, obj, n.info)
+        prevDestructor(c, op, ao, obj, n.info)
       noError = true
       if obj.owner.getModule != s.getModule:
         localError(c.config, n.info, errGenerated,
@@ -2123,10 +2136,10 @@ proc bindTypeHook(c: PContext; s: PSym; n: PNode; op: TTypeAttachedOp) =
       let ao = getAttachedOp(c.graph, obj, op)
       if ao == s:
         discard "forward declared destructor"
-      elif ao.isNil and tfCheckedForDestructor notin obj.flags:
+      elif ao.isNil and not checkedForDestructor(obj):
         setAttachedOp(c.graph, c.module.position, obj, op, s)
       else:
-        prevDestructor(c, ao, obj, n.info)
+        prevDestructor(c, op, ao, obj, n.info)
       noError = true
       if obj.owner.getModule != s.getModule:
         localError(c.config, n.info, errGenerated,
@@ -2217,10 +2230,10 @@ proc semOverride(c: PContext, s: PSym, n: PNode) =
         let ao = getAttachedOp(c.graph, obj, k)
         if ao == s:
           discard "forward declared op"
-        elif ao.isNil and tfCheckedForDestructor notin obj.flags:
+        elif ao.isNil and not checkedForDestructor(obj):
           setAttachedOp(c.graph, c.module.position, obj, k, s)
         else:
-          prevDestructor(c, ao, obj, n.info)
+          prevDestructor(c, k, ao, obj, n.info)
         if obj.owner.getModule != s.getModule:
           localError(c.config, n.info, errGenerated,
             "type bound operation `" & name & "` can be defined only in the same module with its type (" & obj.typeToString() & ")")

tests/destructor/tinvalid_rebind.nim

@@ -1,8 +1,7 @@
 discard """
-disabled: true
 joinable: false
 cmd: "nim check $file"
-errormsg: "cannot bind another '=destroy' to: Foo; previous declaration was constructed here implicitly: tinvalid_rebind.nim(12, 7)"
+errormsg: "cannot bind another '=destroy' to: Foo; previous declaration was constructed implicitly"
 line: 14
 """
 

tests/destructor/tinvalid_rebind_nonempty.nim

@@ -1,9 +1,8 @@
 discard """
-disabled: true
 joinable: false
 cmd: "nim check $file"
-errormsg: "cannot bind another '=destroy' to: Foo; previous declaration was constructed here implicitly: tinvalid_rebind.nim(12, 7)"
-line: 14
+errormsg: "cannot bind another '=destroy' to: Foo; previous declaration was constructed implicitly"
+line: 15
 """
 
 type