mirror of
https://github.com/nim-lang/Nim.git
synced 2026-09-17 18:44:53 +00:00
e927887b7e
Supersedes #26120 (https://github.com/nim-lang/Nim/pull/26120), which fixed the reported case but left the `tfShallow` half of the same condition open. Since #25860 array literals are materialized into temporaries so that `lent` results keep valid backing storage. In an async proc such a temporary is lifted into the closure environment, and the environment is filled with an `nkFastAsgn`, i.e. without `needToCopy`. `genGenericAsgn` then emitted `genericShallowAssign` from the static const array, and for the `string` elements that ends in `unsureAsgnRef` -> `incRef(usrToCell(literal))` on memory that has no GC header: proc f() {.async.} = for ip in ["::1", "2001:db8::", "::"]: await sleepAsync(1) `OnStatic` sources must therefore always take the `genericAssign` path. Note that the guard has to dominate the `tfShallow` test as well, not just the `needToCopy` one: a `{.shallow.}` destination assigned from a `const` crashes in exactly the same way. This is the precedence `genOptAsgnTuple` and `genOptAsgnObject` already use, so `genGenericAsgn` now agrees with its two siblings instead of contradicting them. refc only; the other GCs do not reference count in `unsureAsgnRef`. Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
33 lines
817 B
Nim
33 lines
817 B
Nim
discard """
|
|
matrix: "--mm:refc; --mm:orc"
|
|
output: '''aaaeee
|
|
["p", "q", "r"]'''
|
|
"""
|
|
|
|
# A `{.shallow.}` destination type must not shortcut the deep copy when the
|
|
# source is static data: `genericShallowAssign` would `incRef` the string
|
|
# literals, which have no GC header. `genOptAsgnTuple`/`genOptAsgnObject`
|
|
# already give `OnStatic` priority over `tfShallow`; `genGenericAsgn` has to
|
|
# agree with them.
|
|
|
|
type
|
|
Obj {.shallow.} = object
|
|
a, b, c, d, e: string # asgnComplexity > 4, so genGenericAsgn is used
|
|
ShallowArray {.shallow.} = array[3, string]
|
|
Holder = ref object
|
|
o: Obj
|
|
a: ShallowArray
|
|
|
|
const
|
|
c1 = Obj(a: "aaa", b: "bbb", c: "ccc", d: "ddd", e: "eee")
|
|
ca: ShallowArray = ["p", "q", "r"]
|
|
|
|
proc main =
|
|
var h = Holder()
|
|
h.o = c1
|
|
h.a = ca
|
|
echo h.o.a, h.o.e
|
|
echo h.a
|
|
|
|
main()
|