fixes#23406, closes#23854, closes#23855 (test code of both compiles
but separate issue exists), refs #23432, follows #23411
In generic bodies, previously all regular `nkCall` nodes like `foo(a,
b)` were directly treated as generic statements and delayed immediately,
but other call kinds like `a.foo(b)`, `foo a, b` etc underwent
typechecking before making sure they have to be delayed, as implemented
in #22029. Since the behavior for `nkCall` was slightly buggy (as in
#23406), the behavior for all call kinds is now to call `semTypeExpr`.
However the vast majority of calls in generic bodies out there are
`nkCall`, and while there isn't a difference in the expected behavior,
this exposes many issues with the implementation started in #22029 given
how much more code uses it now. The portion of these issues that CI has
caught are fixed in this PR but it's possible there are more.
1. Deref expressions, dot expressions and calls to dot expressions now
handle and propagate `tyFromExpr`. This is most of the changes in
`semexprs`.
2. For deref expressions to work in `typeof`, a new type flag
`tfNonConstExpr` is added for `tyFromExpr` that calls `semExprWithType`
with `efInTypeof` on the expression instead of `semConstExpr`. This type
flag is set for every `tyFromExpr` type of a node that `prepareNode`
encounters, so that the node itself isn't evaluated at compile time when
just trying to get the type of the node.
3. Unresolved `static` types matching `static` parameters is now treated
the same as unresolved generic types matching `typedesc` parameters in
generic type bodies, it causes a failed match which delays the call
instantiation.
4. `typedesc` parameters now reject all types containing unresolved
generic types like `seq[T]`, not just generic param types by themselves.
(using `containsGenericType`)
5. `semgnrc` now doesn't leave generic param symbols it encounters in
generic type contexts as just identifiers, and instead turns them into
symbol nodes. Normally in generic procs, this isn't a problem since the
generic param symbols will be provided again at instantiation time (and
in fact creating symbol nodes causes issues since `seminst` doesn't
actually instantiate proc body node types).
But generic types can try to be instantiated early in `sigmatch` which
will give an undeclared identifier error when the param is not provided.
Nodes in generic types (specifically in `tyFromExpr` which should be the
only use for `semGenericStmt`) undergo full generic type instantiation
with `prepareNode`, so there is no issue of these symbols remaining as
uninstantiated generic types.
6. `prepareNode` now has more logic for which nodes to avoid
instantiating.
Subscripts and subscripts turned into calls to `[]` by `semgnrc` need to
avoid instantiating the first operand, since it may be a generic body
type like `Generic` in an expression like `Generic[int]`.
Dot expressions cannot instantiate their RHS as it may be a generic proc
symbol or even an undeclared identifier for generic param fields, but
have to instantiate their LHS, so calls and subscripts need to still
instantiate their first node if it's a dot expression.
This logic still isn't perfect and needs the same level of detail as in
`semexprs` for which nodes can be left as "untyped" for overloading/dot
exprs/subscripts to handle, but should handle the majority of cases.
Also the `efDetermineType` requirement for which calls become
`tyFromExpr` is removed and as a result `efDetermineType` is entirely
unused again.
fixes#19848
Not sure why this wasn't the case already. The `if cl.allowMetaTypes:
return` line below for `tyFromExpr` [was added 10 years
ago](d5798b43de).
Hopefully it was just negligence?
fixes#23977
The problem is that for *any* body of a generic declaration,
[semstmts](2e4d344b43/compiler/semstmts.nim (L1610-L1611))
sets the sym of its value to the generic type name, and
[semtypes](2e4d344b43/compiler/semtypes.nim (L2143))
just directly gives the referenced type *specifically* when the
expression is a generic body. I'm blaming `semtypes` here because it's
responsible for the type given but the exact opposite behavior
specifically written in makes me think generating an alias type here
maybe breaks something.
refs https://github.com/nim-lang/Nim/pull/23873#discussion_r1687995060,
fixes#23386, fixes#23385, supersedes #23572
Turns the `nfOpenSym` node flag implemented in #23091 and extended in
#23102 and #23873, into a node kind `nkOpenSym` that forms a unary node
containing either `nkSym` or `nkOpenSymChoice`. Since this affects
macros working on generic proc AST, the node kind is now only generated
when the experimental switch `genericsOpenSym` is enabled, and a new
node flag `nfDisabledOpenSym` is set to the `nkSym` or `nkOpenSymChoice`
when the switch is not enabled so that we can give a warning.
Now that the experimental switch has more reasonable semantics, we
define `nimHasGenericsOpenSym2`.
actually fixes#23865 following up #23873
In the handling of `nkIdent` in `semExpr`, the compiler looks for the
closest symbol with the name and [checks the symbol
kind](6126a0bf46/compiler/semexprs.nim (L3171))
to also consider the overloads if the symbol kind is overloadable. But
it treats the normally overloadable template/macro/module sym kinds the
same as non-overloadable symbols, just calling `semSym` on it. We need
to mirror this behavior in `semOpenSym`; we treat the captured symchoice
as a fresh identifier, so if the symbol we find is a
template/macro/module, we use that symbol immediately as opposed to
waiting for overloads.
fixes#23865
The node flag `nfOpenSym` implemented in #23091 for sym nodes is now
also implemented for open symchoices. This means the intended behavior
is still achieved when multiple overloads are in scope to be captured,
so the issue is fixed. The code for the flag is documented and moved
into a helper proc and the experimental switch is now enabled for the
compiler test suite.
fixes#19819, fixes#23339
Since #22029 `tyFromExpr` does not match anything in overloading, so
generic bodies can know which call expressions to delay until the type
can be evaluated. However generic type invocations also run overloading
to check for generic constraints even in generic bodies. To prevent them
from failing early from the overload not matching, pretend that
`tyFromExpr` matches. This mirrors the behavior of the compiler in more
basic cases like:
```nim
type
Foo[T: int] = object
x: T
Bar[T] = object
y: Foo[T]
```
Unfortunately this case doesn't respect the constraint (#21181, some
other bugs) but `tyFromExpr` should easily use the same principle when
it does.
fixes#23853
Since #22610 generics turns the `Name` in the `GT.Name` expression in
the test code into a sym choice. The problem is when the compiler tries
to instantiate `GT.Name` it also instantiates the sym choice symbols.
`Name` has type `template (E: type ExtensionField)` which contains the
unresolved generic type `ExtensionField`, which the compiler mistakes as
an uninstantiated node, when it's just part of the type of the template.
The compilation of the node itself and hence overloading will handle the
instantiation of the proc, so we avoid instantiating it in `semtypinst`,
similar to how the first nodes of call nodes aren't instantiated.
fixes#3011
In https://github.com/nim-lang/Nim/pull/23532, meta fields that defined
in the object are handled.
In this PR, RefObjectTy is handled as well:
```nim
type
Type = ref object
context: ref object
```
Ref alias won't trigger mata fields checking so there won't have
cascaded errors on `TypeBase`.
```nim
type
TypeBase = object
context: ref object
Type = ref TypeBase
context: ref object
```
fixes#23730
Since #23188 the compiler errors when matching a type variable to an
uninstantiated static value. However sometimes an uninstantiated static
value is given even when only a type match is being performed to the
base type of the static type, in the given issue this case is:
```nim
proc foo[T: SomeInteger](x: T): int = int(x)
proc bar(x: static int): array[foo(x), int] = discard
discard bar(123)
```
To deal with this issue we only error when matching against a type
variable constrained to `static`.
Not sure if the `q.typ.kind == tyGenericParam and
q.typ.genericConstraint == tyStatic` check is necessary, the code above
for deciding whether the variable becomes `skConst` doesn't use it.
fixes#23568, fixes#23310
In #23091 `semFinishOperands` was changed to not be called for `mArrGet`
and `mArrPut`, presumably in preparation for #23188 (not sure why it was
needed in #23091, maybe they got mixed together), since the compiler
handles these later and needs the first argument to not be completely
"typed" since brackets can serve as explicit generic instantiations in
which case the first argument would have to be an unresolved generic
proc (not accepted by `finishOperand`).
In this PR we just make it so `mArrGet` and `mArrPut` specifically skip
calling `finishOperand` on the first argument. This way the generic
arguments in the explicit instantiation get typed, but not the
unresolved generic proc.
fixes#23186
As explained in #23186, generics can transform `genericProc[int]` into a
call `` `[]`(genericProc, int) `` which causes a problem when
`genericProc` is resemmed, since it is not a resolved generic proc. `[]`
needs unresolved generic procs since `mArrGet` also handles explicit
generic instantiations, so delay the resolved generic proc check to
`semFinishOperands` which is intentionally not called for `mArrGet`.
The root issue for
[t6137](https://github.com/nim-lang/Nim/blob/devel/tests/generics/t6137.nim)
is also fixed (because this change breaks it otherwise), the compiler
doesn't consider the possibility that an assigned generic param can be
an unresolved static value (note the line `if t.kind == tyStatic: s.ast
= t.n` below the change in sigmatch), now it properly errors that it
couldn't instantiate it as it would for a type param. ~~The change in
semtypinst is just for symmetry with the code above it which also gives
a `cannot instantiate` error, it may or may not be necessary/correct.~~
Now removed, I don't think it was correct.
Still possible that this has unintended consequences.
refs #23091, especially post merge comments
Unsure if `experimental` and `bind` are the perfect constructs to use
but they seem to get the job done here. Symbol nodes do not get marked
`nfOpenSym` if the `bind` statement is used for their symbol, and
`nfOpenSym` nodes do not get replaced by new local symbols if the
experimental switch is not enabled in the local context (meaning it also
works with `push experimental`). However this incurs a warning as the
fact that the node is marked `nfOpenSym` means we did not `bind` it, so
we might want to do that or turn on the experimental switch if we didn't
intend to bind it.
The experimental switch name is arbitrary and could be changed.
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
fixes#22605, separated from #22744
This marks symbol captures in macro calls in generic contexts as
`nfOpenSym`, which means if there is a new symbol in the local
instantiatied body during instantiation time, this symbol replaces the
captured symbol. We have to be careful not to consider symbols outside
of the instantiation body during instantiation, because this will leak
symbols from the instantiation context scope rather than the original
declaration scope. This is done by checking if the local context owner
(maybe should be the symbol of the proc currently getting instantiated
instead? not sure how to get this) is the same as or a parent owner of
the owner of the replacement candidate symbol.
This solution is distinct from the symchoice mechanisms which we
originally assumed had to be related, if this assumption was wrong it
would explain why this solution took so long to arrive at.
**TODO**
- [x] fixes changelog
With the new option `nimPreviewVtables`, `methods` are confined in the
same module where the type of the first parameter is defined
- [x] make it opt in after CI checks its feasibility
## In the following-up PRs
- [ ] in the following PRs, refactor code into a more efficient one
- [ ] cpp needs special treatments since it cannot embed array in light
of the preceding limits: ref
https://github.com/nim-lang/Nim/pull/20977#discussion_r1035528927; we
can support cpp backends with vtable implementations later on the
comprise that uses indirect vtable access
---------
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
Close#22826
I am not sure why this code skips generic insts, so letting CI tell me.
Update: It has told me nothing. Maybe someone knows during review.
Issue itself seems to be that the generic instance is skipped thus it
ends up being just `float` which makes it use the wrong generic instance
of the proc because it matches the one in cache
---------
Co-authored-by: SirOlaf <>
fixes#22753
## Future work
We should turn all the error nodes into nodes of a nkError kind, which
could be a industrious task. But perhaps we can add a special treatment
for error nodes to make the transition smooth.
Close#21742
Checking if there's any side-effects and if just changing typeRel is
adequate for this issue before trying to look into related ones.
`skipBoth` is also not that great, it can lead to code that works
sometimes but fails when the proc is instantiated with branching
aliases. This is mostly an issue with error clarity though.
---------
Co-authored-by: SirOlaf <unknown>
Co-authored-by: SirOlaf <>
Close#17509
Current knowledge:
- delaying cache fixes the issue
- changing return of `if inst.len < key.len:` in `searchInstTypes` to
`continue` fixes the issue. With return the broken types are also cached
over and over
Related issues are completely unaffected as of now, so there must be
something deeper.
I am also still trying to find the true cause, so feel free to ignore
for now
---------
Co-authored-by: SirOlaf <>
fixes#22639 for the third time
Nodes generated by `getType` for `tyGenericInst` types, instead of
having the original `tyGenericInst` type, will have the type of the last
child (due to the `mapTypeToAst` calls which set the type to the given
argument). This will cause subsequent `getType` calls to lose
information and think it's OK to use the sym of the instantiated type
rather than fully expand the generic instantiation.
To prevent this, update the type of the node from the `mapTypeToAst`
calls to the full generic instantiation type.
fixes#22639
A `tyGenericInst` has its last son as the instantiated body of the
original generic type. However this type keeps its original `sym` field
from the original generic types, which means the sym's type is
uninstantiated. This causes problems in the implementation of `getType`,
where it uses the `sym` fields of types to represent them in AST, the
relevant example for the issue being
[here](d13aab50cf/compiler/vmdeps.nim (L191))
called from
[here](d13aab50cf/compiler/vmdeps.nim (L143)).
To fix this, create a new symbol from the original symbol for the
instantiated body during the creation of `tyGenericInst`s with the
appropriate type. Normally `replaceTypeVarsS` would be used for this,
but here it seems to cause some recursion issue (immediately gives an
error like "cannot instantiate HSlice[T, U]"), so we directly set the
symbol's type to the instantiated type.
Avoiding recursion means we also cannot use `replaceTypeVarsN` for the
symbol AST, and the symbol not having any AST crashes the implementation
of `getType` again
[here](d13aab50cf/compiler/vmdeps.nim (L167)),
so the symbol AST is set to the original generic type AST for now which
is what it was before anyway.
Not sure about this because not sure why the recursion issue is
happening, putting it at the end of the proc doesn't help either. Also
not sure if the `cl.owner != nil and s.owner != cl.owner` condition from
`replaceTypeVarsS` is relevant here. This might also break some code if
it depended on the original generic type symbol being given.
* test case haul for old generic/template/macro issues
closes#12582, closes#19552, closes#2465, closes#4596, closes#15246,
closes#12683, closes#7889, closes#4547, closes#12415, closes#2002,
closes#1771, closes#5121
The test for #5648 is also moved into its own test
from `types/tissues_types` due to not being joinable.
* fix template gensym test
* fix#12938 nim compiler assertion fail when literal integer is passed as template argument for array size
* use new flag tfImplicitStatic
* fix
* fix#14193
* correct tfUnresolved add condition
* clean test
* Play with typeRel
* Temp solution: Fixup call's param types
* Test result type with two generic params
* Asserts
* Tiny cleanup
* Skip sink
* Ignore proc
* Use changeType
* Remove conversion
* Remove last bits of conversion
* Flag
---------
Co-authored-by: SirOlaf <>
* Add test case
* Add in a bounds check when accessing generic types
Removes idnex out of bounds exception when comparing a generic that isn't fully instantiated
* Infer generic bindings
* Simple test
* Add t
* Allow it to work for templates too
* Fix some builds by putting bindings in a template
* Fix builtins
* Slightly more exotic seq test
* Test value-based generics using array
* Pass expectedType into buildBindings
* Put buildBindings into a proc
* Manual entry
* Remove leftover `
* Improve language used in the manual
* Experimental flag and fix basic constructors
* Tiny commend cleanup
* Move to experimental manual
* Use 'kind' so tuples continue to fail like before
* Explicitly disallow tuples
* Table test and document tuples
* Test type reduction
* Disable inferGenericTypes check for CI tests
* Remove tuple info in manual
* Always reduce types. Testing CI
* Fixes
* Ignore tyGenericInst
* Prevent binding already bound generic params
* tyUncheckedArray
* Few more types
* Update manual and check for flag again
* Update tests/generics/treturn_inference.nim
* var candidate, remove flag check again for CI
* Enable check once more
---------
Co-authored-by: SirOlaf <>
Co-authored-by: Andreas Rumpf <rumpf_a@web.de>
* sacrifice "tgenericshardcases" for working statics
* legacy switch for CI, maybe experimental later
* convert to experimental
* apparently untyped needs the experimental switch
* try special case call semcheck
* try fix
* fix compilation
* final cleanup, not experimental, make `when` work
* remove last needed use of untyped
* fix unused warning in test
* remove untyped feature
* clean up some test categories
* mention exact slice issue
* magics into system
* move trangechecks into overflow
* move tmemory to system
* try fix CI
* try fix CI
* final CI fix
* always force open generic dot field symbols?
fixes#21724 but might break code
* alternative, should fix CI
* other alternative, add test for previous CI failure
* not needed
* make sure call doesn't compile too
* ok actual second test
* ok final actual correct test
* apply performance idea
* don't make fromDotExpr static
