From f591b447a7a988ed929fb0da50223395ba0e0ada Mon Sep 17 00:00:00 2001
From: Araq <rumpf_a@web.de>
Date: Tue, 24 Nov 2020 11:32:44 +0100
Subject: [PATCH] fixes #16069; refs
 https://github.com/nim-lang/RFCs/issues/257 [backport:1.2] [backport:1.4]

---
 compiler/ast.nim       |  2 +-
 compiler/ccgexprs.nim  |  1 +
 compiler/semfold.nim   |  1 +
 compiler/transf.nim    |  5 +++++
 compiler/trees.nim     |  2 +-
 tests/vm/tconstobj.nim | 20 +++++++++++++++++++-
 6 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/compiler/ast.nim b/compiler/ast.nim
index c75a149c02e4f..af86d51ddfa88 100644
--- a/compiler/ast.nim
+++ b/compiler/ast.nim
@@ -1122,7 +1122,7 @@ proc safeLen*(n: PNode): int {.inline.} =
 
 proc safeArrLen*(n: PNode): int {.inline.} =
   ## works for array-like objects (strings passed as openArray in VM).
-  if n.kind in {nkStrLit..nkTripleStrLit}:result = n.strVal.len
+  if n.kind in {nkStrLit..nkTripleStrLit}: result = n.strVal.len
   elif n.kind in {nkNone..nkFloat128Lit}: result = 0
   else: result = n.len
 
diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index ec28eb1ec3a1d..ef3ceae62f9a1 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -881,6 +881,7 @@ proc genFieldCheck(p: BProc, e: PNode, obj: Rope, field: PSym) =
               [rdLoc(test), strLit, raiseInstr(p)])
 
 proc genCheckedRecordField(p: BProc, e: PNode, d: var TLoc) =
+  assert e[0].kind == nkDotExpr
   if optFieldCheck in p.options:
     var a: TLoc
     genRecordFieldAux(p, e[0], d, a)
diff --git a/compiler/semfold.nim b/compiler/semfold.nim
index b92895b1928a7..958d8c14e7f52 100644
--- a/compiler/semfold.nim
+++ b/compiler/semfold.nim
@@ -685,6 +685,7 @@ proc getConstExpr(m: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode
   of nkBracketExpr: result = foldArrayAccess(m, n, idgen, g)
   of nkDotExpr: result = foldFieldAccess(m, n, idgen, g)
   of nkCheckedFieldExpr:
+    assert n[0].kind == nkDotExpr
     result = foldFieldAccess(m, n[0], idgen, g)
   of nkStmtListExpr:
     var i = 0
diff --git a/compiler/transf.nim b/compiler/transf.nim
index 42a78c8e31aa0..ae233d3224ff2 100644
--- a/compiler/transf.nim
+++ b/compiler/transf.nim
@@ -1002,6 +1002,11 @@ proc transform(c: PTransf, n: PNode): PNode =
     return n
   of nkExceptBranch:
     result = transformExceptBranch(c, n)
+  of nkCheckedFieldExpr:
+    result = transformSons(c, n)
+    if result[0].kind != nkDotExpr:
+      # simplfied beyond a dot expression --> simplify further.
+      result = result[0]
   else:
     result = transformSons(c, n)
   when false:
diff --git a/compiler/trees.nim b/compiler/trees.nim
index 63459babe0dc4..05c0605953736 100644
--- a/compiler/trees.nim
+++ b/compiler/trees.nim
@@ -211,6 +211,6 @@ proc stupidStmtListExpr*(n: PNode): bool =
 proc dontInlineConstant*(orig, cnst: PNode): bool {.inline.} =
   # symbols that expand to a complex constant (array, etc.) should not be
   # inlined, unless it's the empty array:
-  result = orig.kind == nkSym and
+  result = orig.kind != cnst.kind and
            cnst.kind in {nkCurly, nkPar, nkTupleConstr, nkBracket, nkObjConstr} and
            cnst.len > ord(cnst.kind == nkObjConstr)
diff --git a/tests/vm/tconstobj.nim b/tests/vm/tconstobj.nim
index 93d0e1d7d07fc..7dc20a0ba1fb8 100644
--- a/tests/vm/tconstobj.nim
+++ b/tests/vm/tconstobj.nim
@@ -3,6 +3,7 @@ discard """
 (name: "hello")
 (-1, 0)
 (FirstName: "James", LastName: "Franco")
+[1, 2, 3]
 '''
 """
 
@@ -74,4 +75,21 @@ static: # issue #11861
 
 static: # issue #15662
   proc a(T: typedesc) = echo T.type
-  a((int, int))
\ No newline at end of file
+  a((int, int))
+
+# bug #16069
+type
+  E = enum
+    val1, val2
+  Obj = object
+    case k: E
+    of val1:
+      x: array[3, int]
+    of val2:
+      y: uint32
+
+const
+  foo = [1, 2, 3]
+  arr = Obj(k: val1, x: foo)
+
+echo arr.x