remove deprecated type pragma syntax, fix bugs that required it (#20199)

* remove deprecated pragma syntax from 0.20.0

closes #4651, closes #16653 with a cheap fix for now due to
how early `tfFinal` is set

* remove type pragma between name and generics

* undo removal, try removing bind expression (0.8.14)

* fix test, unremove bind expr

* remove again

* Update changelog.md

Co-authored-by: konsumlamm <44230978+konsumlamm@users.noreply.github.com>

* dependencies @ HEAD & weave test dependencies

* try fix package ci

Co-authored-by: konsumlamm <44230978+konsumlamm@users.noreply.github.com>

compiler/parser.nim

@@ -20,6 +20,8 @@ when isMainModule:
   # Leave a note in grammar.txt that it is generated:
   #| # This file is generated by compiler/parser.nim.
   import pegs
+  when defined(nimPreviewSlimSystem):
+    import std/syncio
   var outp = open("doc/grammar.txt", fmWrite)
   for line in lines("compiler/parser.nim"):
     if line =~ peg" \s* '#| ' {.*}":
@@ -2031,15 +2033,10 @@ proc parseObjectPart(p: var Parser): PNode =
     result = p.emptyNode
 
 proc parseObject(p: var Parser): PNode =
-  #| objectDecl = 'object' pragma? ('of' typeDesc)? COMMENT? objectPart
+  #| objectDecl = 'object' ('of' typeDesc)? COMMENT? objectPart
   result = newNodeP(nkObjectTy, p)
   getTok(p)
-  if p.tok.tokType == tkCurlyDotLe and p.validInd:
-    # Deprecated since v0.20.0
-    parMessage(p, warnDeprecated, "type pragmas follow the type name; this form of writing pragmas is deprecated")
-    result.add(parsePragma(p))
-  else:
-    result.add(p.emptyNode)
+  result.add(p.emptyNode) # compatibility with old pragma node
   if p.tok.tokType == tkOf and p.tok.indent < 0:
     var a = newNodeP(nkOfInherit, p)
     getTok(p)
@@ -2117,39 +2114,24 @@ proc parseTypeClass(p: var Parser): PNode =
 
 proc parseTypeDef(p: var Parser): PNode =
   #|
-  #| typeDef = identWithPragmaDot genericParamList? '=' optInd typeDefAux
-  #|             indAndComment? / identVisDot genericParamList? pragma '=' optInd typeDefAux
+  #| typeDef = identVisDot genericParamList? pragma '=' optInd typeDefAux
   #|             indAndComment?
   result = newNodeP(nkTypeDef, p)
   var identifier = identVis(p, allowDot=true)
   var identPragma = identifier
   var pragma: PNode
   var genericParam: PNode
-  var noPragmaYet = true
-
-  if p.tok.tokType == tkCurlyDotLe:
-    pragma = optPragmas(p)
-    identPragma = newNodeP(nkPragmaExpr, p)
-    identPragma.add(identifier)
-    identPragma.add(pragma)
-    noPragmaYet = false
 
   if p.tok.tokType == tkBracketLe and p.validInd:
-    if not noPragmaYet:
-      # Deprecated since v0.20.0
-      parMessage(p, warnDeprecated, "pragma before generic parameter list is deprecated")
     genericParam = parseGenericParamList(p)
   else:
     genericParam = p.emptyNode
 
-  if noPragmaYet:
-    pragma = optPragmas(p)
-    if pragma.kind != nkEmpty:
-      identPragma = newNodeP(nkPragmaExpr, p)
-      identPragma.add(identifier)
-      identPragma.add(pragma)
-  elif p.tok.tokType == tkCurlyDotLe:
-    parMessage(p, errGenerated, "pragma already present")
+  pragma = optPragmas(p)
+  if pragma.kind != nkEmpty:
+    identPragma = newNodeP(nkPragmaExpr, p)
+    identPragma.add(identifier)
+    identPragma.add(pragma)
 
   result.add(identPragma)
   result.add(genericParam)

compiler/semstmts.nim

@@ -1327,6 +1327,7 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) =
     if s.magic == mNone and a[2].kind == nkEmpty:
       localError(c.config, a.info, errImplOfXexpected % s.name.s)
     if s.magic != mNone: processMagicType(c, s)
+    let oldFlags = s.typ.flags
     if a[1].kind != nkEmpty:
       # We have a generic type declaration here. In generic types,
       # symbol lookup needs to be done here.
@@ -1354,6 +1355,13 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) =
       if body != nil:
         body.sym = s
         body.size = -1 # could not be computed properly
+        if body.kind == tyObject:
+          # add flags applied to generic type to object (nominal) type
+          incl(body.flags, oldFlags)
+          # {.inheritable, final.} is already disallowed, but
+          # object might have been assumed to be final
+          if tfInheritable in oldFlags and tfFinal in body.flags:
+            excl(body.flags, tfFinal)
         s.typ[^1] = body
         if tfCovariant in s.typ.flags:
           checkCovariantParamsUsages(c, s.typ)
@@ -1405,6 +1413,13 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) =
       internalAssert c.config, st.kind in {tyPtr, tyRef}
       internalAssert c.config, st.lastSon.sym == nil
       incl st.flags, tfRefsAnonObj
+      let objTy = st.lastSon
+      # add flags for `ref object` etc to underlying `object`
+      incl(objTy.flags, oldFlags)
+      # {.inheritable, final.} is already disallowed, but
+      # object might have been assumed to be final
+      if tfInheritable in oldFlags and tfFinal in objTy.flags:
+        excl(objTy.flags, tfFinal)
       let obj = newSym(skType, getIdent(c.cache, s.name.s & ":ObjectType"),
                        nextSymId c.idgen, getCurrOwner(c), s.info)
       let symNode = newSymNode(obj)
@@ -1420,8 +1435,8 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) =
       obj.ast[2] = a[2][0]
       if sfPure in s.flags:
         obj.flags.incl sfPure
-      obj.typ = st.lastSon
-      st.lastSon.sym = obj
+      obj.typ = objTy
+      objTy.sym = obj
 
 proc checkForMetaFields(c: PContext; n: PNode) =
   proc checkMeta(c: PContext; n: PNode; t: PType) =