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Fix #14325 (#17308)

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* Fix #14325
* Refactor and fix
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Clyybber 2021-03-11 14:03:25 +01:00 • committed by GitHub
commit 3cbc80045d
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3 changed files with 41 additions and 32 deletions
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52
compiler/ccgexprs.nim
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@ -2577,40 +2577,32 @@ proc upConv(p: BProc, n: PNode, d: var TLoc) =
[getTypeDesc(p.module, dest), addrLoc(p.config, a)], a.storage)
proc downConv(p: BProc, n: PNode, d: var TLoc) =
if p.module.compileToCpp:
discard getTypeDesc(p.module, skipTypes(n[0].typ, abstractPtrs))
expr(p, n[0], d) # downcast does C++ for us
else:
var dest = skipTypes(n.typ, abstractPtrs)
var arg = n[0]
while arg.kind == nkObjDownConv: arg = arg[0]
var arg = n[0]
while arg.kind == nkObjDownConv: arg = arg[0]
var src = skipTypes(arg.typ, abstractPtrs)
discard getTypeDesc(p.module, src)
let dest = skipTypes(n.typ, abstractPtrs)
let src = skipTypes(arg.typ, abstractPtrs)
discard getTypeDesc(p.module, src)
let isRef = skipTypes(arg.typ, abstractInstOwned).kind in {tyRef, tyPtr, tyVar, tyLent}
if isRef and d.k == locNone and n.typ.skipTypes(abstractInstOwned).kind in {tyRef, tyPtr} and n.isLValue:
# it can happen that we end up generating '&&x->Sup' here, so we pack
# the '&x->Sup' into a temporary and then those address is taken
# (see bug #837). However sometimes using a temporary is not correct:
# init(TFigure(my)) # where it is passed to a 'var TFigure'. We test
# this by ensuring the destination is also a pointer:
var a: TLoc
initLocExpr(p, arg, a)
var r = rdLoc(a)
let isRef = skipTypes(arg.typ, abstractInstOwned).kind in {tyRef, tyPtr, tyVar, tyLent}
if isRef:
r.add("->Sup")
else:
r.add(".Sup")
putIntoDest(p, d, n,
"(*(($1*) (&($2))))" % [getTypeDesc(p.module, n.typ), rdLoc(a)], a.storage)
elif p.module.compileToCpp:
# C++ implicitly downcasts for us
expr(p, arg, d)
else:
var a: TLoc
initLocExpr(p, arg, a)
var r = rdLoc(a) & (if isRef: "->Sup" else: ".Sup")
for i in 2..abs(inheritanceDiff(dest, src)): r.add(".Sup")
if isRef:
# it can happen that we end up generating '&&x->Sup' here, so we pack
# the '&x->Sup' into a temporary and then those address is taken
# (see bug #837). However sometimes using a temporary is not correct:
# init(TFigure(my)) # where it is passed to a 'var TFigure'. We test
# this by ensuring the destination is also a pointer:
if d.k == locNone and skipTypes(n.typ, abstractInstOwned).kind in {tyRef, tyPtr, tyVar, tyLent}:
getTemp(p, n.typ, d)
linefmt(p, cpsStmts, "$1 = &$2;$n", [rdLoc(d), r])
else:
r = "&" & r
putIntoDest(p, d, n, r, a.storage)
else:
putIntoDest(p, d, n, r, a.storage)
putIntoDest(p, d, n, if isRef: "&" & r else: r, a.storage)
proc exprComplexConst(p: BProc, n: PNode, d: var TLoc) =
let t = n.typ