fixes move sideeffects issues [backport] (#22439)

* fixes move sideeffects issues [backport]

* fix openarray

* fixes openarray

compiler/ccgexprs.nim

@@ -2310,9 +2310,21 @@ proc genMove(p: BProc; n: PNode; d: var TLoc) =
  if op == nil:
  resetLoc(p, a)
  else:
- let addrExp = makeAddr(n[1], p.module.idgen)
- let wasMovedCall = newTreeI(nkCall, n.info, newSymNode(op), addrExp)
- genCall(p, wasMovedCall, d)
+ var b = initLocExpr(p, newSymNode(op))
+ case skipTypes(a.t, abstractVar+{tyStatic}).kind
+ of tyOpenArray, tyVarargs: # todo fixme generated `wasMoved` hooks for
+ # openarrays, but it probably shouldn't?
+ var s: string
+ if reifiedOpenArray(a.lode):
+ if a.t.kind in {tyVar, tyLent}:
+ s = "$1->Field0, $1->Field1" % [rdLoc(a)]
+ else:
+ s = "$1.Field0, $1.Field1" % [rdLoc(a)]
+ else:
+ s = "$1, $1Len_0" % [rdLoc(a)]
+ linefmt(p, cpsStmts, "$1($2);$n", [rdLoc(b), s])
+ else:
+ linefmt(p, cpsStmts, "$1($2);$n", [rdLoc(b), byRefLoc(p, a)])
  else:
  let flags = if not canMove(p, n[1], d): {needToCopy} else: {}
  genAssignment(p, d, a, flags)

tests/destructor/tmove.nim

@@ -0,0 +1,18 @@
+discard """
+ targets: "c cpp"
+"""
+
+block:
+ var called = 0
+
+ proc bar(a: var int): var int =
+ inc called
+ result = a
+
+ proc foo =
+ var a = 2
+ var s = move bar(a)
+ doAssert called == 1
+ doAssert s == 2
+
+ foo()