fixes#24806
Blocks don't merge symbols that are used before destruction to the
parent scope, which causes `wasMoved; destroy` to elide incorrectly
(cherry picked from commit 73aeac81d1)
ref https://github.com/nim-lang/Nim/pull/24686
With this PR
```nim
import std/streams
proc foo() =
var name = newStringStream("2r2")
raise newException(ValueError, "sh")
try:
foo()
except:
discard
echo 123
```
this example no longer leaks
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
(cherry picked from commit 510ac84518)
fixes#24626
`createTypeboundOps` in sempass2 is called when generating destructors
for types including for explicit destructor calls, however it blocks
destructors from getting generated in a `nodestroy` proc. This causes
issues when a destructor is explicitly called in a `nodestroy` proc. To
fix this, allow destructors to get generated only for explicit
destructor calls in nodestroy procs.
(cherry picked from commit 793baf34ff)
fixes#22479, fixes#24374, depends on #24429 and #24430
When instantiating generic types which directly have nominal types
(object, distinct, ref/ptr object but not enums[^1]) as their values,
the nominal type is now copied (in the case of ref objects, its child as
well) so that it receives a fresh ID and `typeInst` field. Previously
this only happened if it contained any generic types in its structure,
as is the case for all other types.
This solves #22479 and #24374 by virtue of the IDs being unique, which
is what destructors check for. Technically types containing generic
param fields work for the same reason. There is also the benefit that
the `typeInst` field is correct. However issues like #22445 aren't
solved because the compiler still uses structural object equality checks
for inheritance etc. which could be removed in a later PR.
Also fixes a pre-existing issue where destructors bound to object types
with generic fields would not error when attempting to define a user
destructor after the fact, but the error message doesn't show where the
implicit destructor was created now since it was only created for
another instance. To do this, a type flag is used that marks the generic
type symbol when a generic instance has a destructor created. Reusing
`tfCheckedForDestructor` for this doesn't work.
Maybe there is a nicer design that isn't an overreliance on the ID
mechanism, but the shortcomings of `tyGenericInst` are too ingrained in
the compiler to use for this. I thought about maybe adding something
like `tyNominalGenericInst`, but it's really much easier if the nominal
type itself directly contains the information of its generic parameters,
or at least its "symbol", which the design is heading towards.
[^1]: See [this
test](21420d8b09/lib/std/enumutils.nim (L102))
in enumutils. The field symbols `b0`/`b1` always have the uninstantiated
type `B` because enum fields don't expect to be generic, so no generic
instance of `B` matches its own symbols. Wouldn't expect anyone to use
generic enums but maybe someone does.
(cherry picked from commit 05c74d6844)
fixes#24402
```nim
iterator myPairsInline*[T](twoDarray: seq[seq[T]]): (int, seq[T]) {.inline.} =
for indexValuePair in twoDarray.pairs:
yield indexValuePair
proc innerTestTotalMem() =
var my2dArray: seq[seq[int32]] = @[]
# fill with some data...
for i in 0'i32..100:
var z = @[i, i+1]
my2dArray.add z
for oneDindex, innerArray in myPairsInline(my2dArray):
discard
innerTestTotalMem()
```
In `for oneDindex, innerArray in myPairsInline(my2dArray)`, `oneDindex`
and `innerArray` becomes `cursors` because they satisfy the criterion of
`isSimpleIteratorVar`. On the one hand, it is not correct to have them
point to the temporary generated by tuple unpacking, which left the
memory of the temporary uncleaned up. On the other hand, we don't need
to generate a temporary for a symbol node when unpacking the tuple.
(cherry picked from commit 21420d8b09)
pre-existing issues:
```nim
block:
type
FooObj = object
data: int
Foo = ref ref FooObj
proc delete(self: Foo) =
echo self.data
var s: Foo
new(s, delete)
```
it crashed with arc/orc in 1.6.x and 2.x.x
```nim
block:
type
Foo = ref int
proc delete(self: Foo) =
echo self[]
var s: Foo
new(s, delete)
```
The simple fix is to add a type restriction for the type `T` for arc/orc
versions
```nim
proc new*[T: object](a: var ref T, finalizer: proc (x: T) {.nimcall.})
```
(cherry picked from commit 2af602a5c8)
fixes#23690
```nim
dest.`:state` = src.`:state`
var :tmp_553651276 = dest.e1.a
`=wasMoved`(dest.e1.a)
dest.e1.a.kind = src.e1.a.kind
case dest.e1.a.kind
of 0:
dest.e1.a.a = src.e1.a.a
of 1:
`=copy`(dest.e1.a.c, src.e1.a.c)
case :tmp_553651276.kind
of 0:
of 1:
`=destroy`(:tmp_553651276.c)
```
`dest.e1.a.kind = src.e1.a.kind` changes the discrimant but it fails to
clear the memory of `dest.e1.a`. Before using hooks for copying, we need
to clear the dest, e.g. `=wasMoved(dest.e1.a.c)`.
```nim
dest.`:state` = src.`:state`
var :tmp_553651276 = dest.e1.a
`=wasMoved`(dest.e1.a)
dest.e1.a.kind = src.e1.a.kind
case dest.e1.a.kind
of 0:
`=wasMoved`(dest.e1.a.a)
dest.e1.a.a = src.e1.a.a
`=wasMoved`(dest.e1.a.b)
of 1:
`=wasMoved`(dest.e1.a.c)
`=copy`(dest.e1.a.c, src.e1.a.c)
case :tmp_553651276.kind
of 0:
of 1:
`=destroy`(:tmp_553651276.c)
```
fixes#23627
```nim
type
TestObj = object of RootObj
TestTestObj = object of RootObj
testo: TestObj
proc `=destroy`(x: TestTestObj) =
echo "Destructor for TestTestObj"
proc testCaseT() =
echo "\nTest Case T"
let tt1 {.used.} = TestTestObj(testo: TestObj())
```
When generating const object fields, it's likely that
we need to generate type infos for the object, which may be an object
with
custom hooks. We need to generate potential consts in the hooks first.
https://github.com/nim-lang/Nim/pull/20433 changed the semantics of
initialization. It should evaluate`BracedInit` first.
fixes#22909
required by https://github.com/nim-lang/Nim/pull/23267
```nim
proc foo: string =
assert false
result = ""
```
In the function `foo`, `assert false` raises an exception, which can
cause `result` to be uninitialized if the default result initialization
is optimized out
fixes#23247closes#23251 (which accounts for why the openarray type is lifted
because ops are lifted for openarray conversions)
related: https://github.com/nim-lang/Nim/pull/18713
It seems to me that openarray doesn't own the data, so it cannot destroy
itself. The same case should be applied to
https://github.com/nim-lang/Nim/issues/19435. It shouldn't be destroyed
even openarray can have a destructor. A cleanup will be followed for
https://github.com/nim-lang/Nim/pull/19723 if it makes sense.
According to https://github.com/nim-lang/Nim/pull/12073, it lifts
destructor for openarray when openarray is sunk into the function, when
means `sink openarray` owns the data and needs to destroy it. In other
cases, destructor shouldn't be lifted for `openarray` in the first place
and it shouldn't destroy the data if it doesn't own it.
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
fixes#22286
ref https://forum.nim-lang.org/t/10642
For backwards compatibilities, we might need to keep the changes under a
preview compiler flag. Let's see how many packags it break.
**TODO** in the following PRs
- [ ] Turn the `var T` destructors warning into an error with
`nimPreviewNonVarDestructor`
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
`{.push overflowChecks: off.}` works in backends. Though it could be
implemented as a magic function.
By inspecting the generated C code, the overflow check is eliminated in
the debug or release mode.
Likewise, the index checking is probably not needed.
* round out tuple unpacking assignment, support underscores
fixes#18710
* fix test messages
* use discard instead of continue
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
* adds documentation for `=wasMoved` and `=dup` hooks and small fixes
* Update doc/destructors.md
* Update doc/destructors.md
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
