fixes nim-lang#22354; Wrong C++ codegen for default parameter values …

…in ORC (nim-lang#22819)

fixes nim-lang#22354

It skips `nkHiddenAddr`. No need to hoist `var parameters` without side
effects. Besides, it saves lots of temporary variables in ORC.

compiler/semexprs.nim

@@ -2927,7 +2927,7 @@ proc hoistParamsUsedInDefault(c: PContext, call, letSection, defExpr: var PNode)
   if defExpr.kind == nkSym and defExpr.sym.kind == skParam and defExpr.sym.owner == call[0].sym:
     let paramPos = defExpr.sym.position + 1
 
-    if call[paramPos].kind != nkSym:
+    if call[paramPos].skipAddr.kind != nkSym:
       let hoistedVarSym = newSym(skLet, getIdent(c.graph.cache, genPrefix), c.idgen,
                                  c.p.owner, letSection.info, c.p.owner.options)
       hoistedVarSym.typ = call[paramPos].typ
@@ -2939,7 +2939,7 @@ proc hoistParamsUsedInDefault(c: PContext, call, letSection, defExpr: var PNode)
 
       call[paramPos] = newSymNode(hoistedVarSym) # Refer the original arg to its hoisted sym
 
-    # arg we refer to is a sym, wether introduced by hoisting or not doesn't matter, we simply reuse it
+    # arg we refer to is a sym, whether introduced by hoisting or not doesn't matter, we simply reuse it
     defExpr = call[paramPos]
   else:
     for i in 0..<defExpr.safeLen:

tests/ccgbugs2/tcodegen.nim

@@ -1,28 +1,47 @@
-discard """
-  targets: "c cpp"
-"""
-
-# bug #19094
-type
-  X = object
-    filler: array[2048, int]
-    innerAddress: uint
-
-proc initX(): X =
-  result.innerAddress = cast[uint](result.addr)
-
-proc initXInPlace(x: var X) =
-  x.innerAddress = cast[uint](x.addr)
-
-block: # NRVO1
-  var x = initX()
-  let innerAddress = x.innerAddress
-  let outerAddress = cast[uint](x.addr)
-  doAssert(innerAddress == outerAddress) # [OK]
-
-block: # NRVO2
-  var x: X
-  initXInPlace(x)
-  let innerAddress = x.innerAddress
-  let outerAddress = cast[uint](x.addr)
-  doAssert(innerAddress == outerAddress) # [OK]
+discard """
+  targets: "c cpp"
+"""
+
+# bug #19094
+type
+  X = object
+    filler: array[2048, int]
+    innerAddress: uint
+
+proc initX(): X =
+  result.innerAddress = cast[uint](result.addr)
+
+proc initXInPlace(x: var X) =
+  x.innerAddress = cast[uint](x.addr)
+
+block: # NRVO1
+  var x = initX()
+  let innerAddress = x.innerAddress
+  let outerAddress = cast[uint](x.addr)
+  doAssert(innerAddress == outerAddress) # [OK]
+
+block: # NRVO2
+  var x: X
+  initXInPlace(x)
+  let innerAddress = x.innerAddress
+  let outerAddress = cast[uint](x.addr)
+  doAssert(innerAddress == outerAddress) # [OK]
+
+block: # bug #22354
+  type Object = object
+    foo: int
+
+  proc takeFoo(self: var Object): int =
+    result = self.foo
+    self.foo = 999
+
+  proc doSomething(self: var Object; foo: int = self.takeFoo()) =
+    discard
+
+  proc main() =
+    var obj = Object(foo: 2)
+    obj.doSomething()
+    doAssert obj.foo == 999
+
+
+  main()