fixes#25007
```nim
proc setLengthSeqUninit(s: PGenericSeq, typ: PNimType, newLen: int, isTrivial: bool): PGenericSeq {.
compilerRtl.} =
```
In this added function, only the line `zeroMem(dataPointer(result,
elemAlign, elemSize, newLen), (result.len-%newLen) *% elemSize)` is
removed from `proc setLengthSeqV2` when enlarging a sequence.
JS and VM versions simply use `setLen`.
(cherry picked from commit 611b8bbf67)
fixes#19728
don't zero-filling memory for "trivial types" without destructor in
refc. I tested locally with internal apis.
(cherry picked from commit b421d0f8ee)
fixes#25265;
fixes#23453
`(addr deref (ptr object))` generated weak typedesc before, which causes
problems for old GCC versions. As a bonus, by generating a typedesc for
`deref (ptr object)`, it also fixes#23453
(cherry picked from commit 92468e99f7)
fixes#17571
Objects in the VM are represented as object constructor nodes that
contain every single field, including ones in different case branches.
This is so that every field has a unique invariant index in the object
constructor that can be written to and read from. However when
converting this node back into semantic code, fields from inactive case
branches can remain in the constructor which causes bad codegen,
generating assignments to fields from other case branches.
To fix this, fields from inactive branches are now detected in
`semmacrosanity.annotateType` (called in `fixupTypeAfterEval`) and
marked to prevent the codegen of their assignments. In #24441 these
fields were excluded from the resulting node, but this causes issues
when the node is directly supposed to go back into the VM, for example
as `const` values. I don't know if this is the only case where this
happens, so I wasn't sure about how to keep that implementation working.
(cherry picked from commit 75b512bc6a)
closes https://github.com/nim-lang/RFCs/issues/554
Adds a symmetric difference operation to the language bitset type. This
maps to a simple `xor` operation on the backend and thus is likely
faster than the current alternatives, namely `(a - b) + (b - a)` or `a +
b - a * b`. The compiler VM implementation of bitsets already
implemented this via `symdiffSets` but it was never used.
The standalone binary operation is added to `setutils`, named
`symmetricDifference` in line with [hash
sets](https://nim-lang.org/docs/sets.html#symmetricDifference%2CHashSet%5BA%5D%2CHashSet%5BA%5D).
An operator version `-+-` and an in-place version like `toggle` as
described in the RFC are also added, implemented as trivial sugar.
(cherry picked from commit ae9287c4f3)
fixes#24319
`byRefLoc` (`mapType`) requires the Loc `a` to have the right type.
Without `lfEnforceDeref`, it produces the wrong type for `deref (var
array)`, which may come from `mitems`.
(cherry picked from commit 0347536ff2)
fixes#24274
The code in the `if` branch replaces the current destination `d` with a
new one. But the location `d` can be an assignment location, in which
case the provided expression isn't generated. To fix this, don't trigger
this code for when the location already exists. An alternative would be
to call `putIntoDest` in this case as is done below.
(cherry picked from commit 9c85f4fd07)
refs #24032, split from #24036
Conversion from variables of range types or base types of range types to
the other are now considered mutable for `var` params, similar to how
distinct types are mutable when converted to their base type or vice
versa. There are 2 main differences:
1. Conversions from base types to range types need to emit
`nkChckRange`, which is not generated for things like tuple/object
fields.
2. Range types can still correspond to different types in the backend
when nested in other types, such as `set[range[3..5]]` vs
`set[range[0..5]]`.
Since the convertibility check for `var` params and a check whether to
emit a no-op for `nkConv` (and now also `nkChckRange`) so that the
output is still addressable both use `sameType`, we accomplish this by
adding a new flag to `sameType` that ignores range types, but only when
they're not nested in other types. The implementation for this might be
flawed, I didn't include children of some metatypes as "nested in other
types", but stuff like `tyGenericInst` params are respected.
ref #20653
```nim
Error* = object
case kind*: ErrorType
of ErrorA:
discard
of ErrorB:
discard
```
For an object variants without fields, it shouldn't generate empty
brackets for default values since there are no fields at all in case
branches.
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.
`reset`, `wasMoved` and `move` doesn't support primitive types, which
generate `null` for these types. It is now produce `x = default(...)` in
the backend. Ideally it should be done by ast2ir in the future
fixes#22597
```nim
proc autoToOpenArray*[T](s: Slice[T]): openArray[T] =
echo "here twice"
result = toOpenArray(s.p, s.first, s.last)
```
For functions returning openarray types, `fixupCall` creates a temporary
variable to store the return value: `let tmp = autoToOpenArray()`. But
`genOpenArrayConv` cannot handle openarray assignements with side
effects. It should have stored the right part of the assignment first
instead of calling the right part twice.
Theoretical Benefits / Plans:
- Typed assembler-like language.
- Allows for a CPS transformation.
- Can replace the existing C backend by a new C backend.
- Can replace the VM.
- Can do more effective "not nil" checking and static array bounds
checking.
- Can be used instead of the DFA.
- Easily translatable to LLVM.
- Reasonably easy to produce native code from.
- Tiny memory consumption. No pointers, no cry.
**In very early stages of development.**
Todo:
- [x] Map Nim types to IR types.
- [ ] Map Nim AST to IR instructions:
- [x] Map bitsets to bitops.
- [ ] Implement string cases.
- [ ] Implement range and index checks.
- [x] Implement `default(T)` builtin.
- [x] Implement multi string concat.
- [ ] Write some analysis passes.
- [ ] Write a backend.
- [x] Integrate into the compilation pipeline.
