From e50441ab33d1b287a89ad4e2d795c80b7f8077c0 Mon Sep 17 00:00:00 2001
From: zah <zahary@gmail.com>
Date: Thu, 26 Mar 2020 10:26:19 +0200
Subject: [PATCH] Fix typeSym.getImpl for ref types (#13752)

* Fix typeSym.getImpl for ref types

* Fix a codegen issue affecting the test suite of nim-beacon-chain

* Fix tests/stdlib/tjsonmacro

To understand the fix better it may help to take a look
at the history of the replaced code.

The nil check that is removed in this commit was introduced
in another fix that failed to identify the root cause of the
issue - namely that we allow an object type to exist for which
no ast is present:

https://github.com/nim-lang/Nim/pull/9601/files

The original intention of the code is more obvious here:

https://github.com/nim-lang/Nim/pull/9538/files
---
 compiler/ccgexprs.nim        |  2 +-
 compiler/semstmts.nim        |  2 +-
 compiler/vmdeps.nim          |  8 ++--
 tests/macros/tmacrotypes.nim | 84 +++++++++++++++++++++++++++++++++++-
 4 files changed, 88 insertions(+), 8 deletions(-)

diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index e1561ae12b..fcedcf001e 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -2950,7 +2950,7 @@ proc genBracedInit(p: BProc, n: PNode; isConst: bool): Rope =
       else:
         internalError(p.config, n.info, "node has no type")
     else:
-      ty = skipTypes(n.typ, abstractInstOwned).kind
+      ty = skipTypes(n.typ, abstractInstOwned + {tyStatic}).kind
     case ty
     of tySet:
       var cs: TBitSet
diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
index 6b01e241ba..5232c5706c 100644
--- a/compiler/semstmts.nim
+++ b/compiler/semstmts.nim
@@ -1279,12 +1279,12 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) =
       incl st.flags, tfRefsAnonObj
       let obj = newSym(skType, getIdent(c.cache, s.name.s & ":ObjectType"),
                               getCurrOwner(c), s.info)
+      obj.ast = a
       if sfPure in s.flags:
         obj.flags.incl sfPure
       obj.typ = st.lastSon
       st.lastSon.sym = obj
 
-
 proc checkForMetaFields(c: PContext; n: PNode) =
   proc checkMeta(c: PContext; n: PNode; t: PType) =
     if t != nil and t.isMetaType and tfGenericTypeParam notin t.flags:
diff --git a/compiler/vmdeps.nim b/compiler/vmdeps.nim
index 79d49698a3..7cfba046ab 100644
--- a/compiler/vmdeps.nim
+++ b/compiler/vmdeps.nim
@@ -159,10 +159,10 @@ proc mapTypeToAstX(cache: IdentCache; t: PType; info: TLineInfo;
   of tyObject:
     if inst:
       result = newNodeX(nkObjectTy)
-      if t.sym.ast != nil:
-        result.add t.sym.ast[2][0].copyTree  # copy object pragmas
-      else:
-        result.add newNodeI(nkEmpty, info)
+      var objectDef = t.sym.ast[2]
+      if objectDef.kind == nkRefTy:
+        objectDef = objectDef[0]
+      result.add objectDef[0].copyTree  # copy object pragmas
       if t[0] == nil:
         result.add newNodeI(nkEmpty, info)
       else:  # handle parent object
diff --git a/tests/macros/tmacrotypes.nim b/tests/macros/tmacrotypes.nim
index 8cf93a5932..cfc4ef7fb7 100644
--- a/tests/macros/tmacrotypes.nim
+++ b/tests/macros/tmacrotypes.nim
@@ -4,11 +4,40 @@ void; ntyVoid; void; void
 int; ntyInt; int; int
 proc (); ntyProc; proc[void]; proc ()
 voidProc; ntyProc; proc[void]; proc ()
+listing fields for ObjType
+a: string
+b: int
+listing fields for ObjRef
+skipping ref type
+a: string
+b: int
+listing fields for RefType
+skipping ref type
+a: int
+b: float
+listing fields for typeof(a)
+skipping ref type
+a: string
+b: int
+listing fields for typeof(b)
+skipping ref type
+a: string
+b: int
+listing fields for typeof(c)
+skipping ref type
+a: int
+b: float
+listing fields for typeof(x)
+a: string
+b: int
+listing fields for typeof(x)
+a: int
+b: float
 typeDesc[range[1 .. 5]]; ntyTypeDesc; typeDesc[range[1, 5]]; typeDesc[range[1 .. 5]]
 typeDesc[range]; ntyTypeDesc; typeDesc[range[T]]; typeDesc[range]'''
 """
 
-import macros
+import macros, typetraits
 
 macro checkType(ex: typed): untyped =
   echo ex.getTypeInst.repr, "; ", ex.typeKind, "; ", ex.getType.repr, "; ", ex.getTypeImpl.repr
@@ -17,7 +46,6 @@ macro checkProcType(fn: typed): untyped =
   let fn_sym = if fn.kind == nnkProcDef: fn[0] else: fn
   echo fn_sym, "; ", fn_sym.typeKind, "; ", fn_sym.getType.repr, "; ", fn_sym.getTypeImpl.repr
 
-
 proc voidProc = echo "hello"
 proc intProc(a: int, b: float): int {.checkProcType.} = 10
 
@@ -26,6 +54,58 @@ checkType(intProc(10, 20.0))
 checkType(voidProc)
 checkProcType(voidProc)
 
+macro listFields(T: typed) =
+  echo "listing fields for ", repr(T)
+  let inputExprType = getType(T)
+
+  var objType = inputExprType[1]
+  if objType.kind == nnkBracketExpr and objType.len > 1:
+    if ((objType[0].kind == nnkRefTy) or
+        (objType[0].kind == nnkSym and eqIdent(objType[0], "ref"))):
+      echo "skipping ref type"
+      objType = objType[1]
+
+  let typeAst = objType.getImpl
+
+  var objectDef = typeAst[2]
+  if objectDef.kind == nnkRefTy:
+    objectDef = objectDef[0]
+
+  let recList = objectDef[2]
+  for rec in recList:
+    echo $rec[0], ": ", $rec[1]
+
+type
+  ObjType* = object of RootObj
+    a: string
+    b: int
+
+  ObjRef = ref ObjType
+
+  RefType* = ref object of RootObj
+    a: int
+    b: float
+
+listFields ObjType
+listFields ObjRef
+listFields RefType
+
+let
+  a = new ObjType
+  b = new ObjRef
+  c = new RefType
+
+listFields typeOf(a)
+listFields typeOf(b)
+listFields typeOf(c)
+
+proc genericProc(x: object) =
+  listFields typeOf(x)
+
+genericProc a[]
+genericProc b[]
+genericProc c[]
+
 # bug #10548
 block:
   var c {.compileTime.} = 0