Commit Graph

2 Commits

Author SHA1 Message Date
metagn
69ea1336fb sem generic proc param types like generic types + static instantiation fixes (#24005)
fixes #4228, fixes #4990, fixes #7006, fixes #7008, fixes #8406, fixes
#8551, fixes #11112, fixes #20027, fixes #22647, refs #23854 and #23855
(remaining issue fixed), refs #8545 (works properly now with
`cast[static[bool]]` changed to `cast[bool]`), refs #22342 and #22607
(disabled tests added), succeeds #23194

Parameter and return type nodes in generic procs now undergo the same
`inGenericContext` treatment that nodes in generic type bodies do. This
allows many of the fixes in #22029 and followups to also apply to
generic proc signatures. Like #23983 however this needs some more
compiler fixes, but this time mostly in `sigmatch` and type
instantiations.

1. `tryReadingGenericParam` no longer treats `tyCompositeTypeClass` like
a concrete type anymore, so expressions like `Foo.T` where `Foo` is a
generic type don't look for a parameter of `Foo` in non-generic code
anymore. It also doesn't generate `tyFromExpr` in non-generic code for
any generic LHS. This is to handle a very specific case in `asyncmacro`
which used `FutureVar.astToStr` where `FutureVar` is generic.
2. The `tryResolvingStaticExpr` call when matching `tyFromExpr` in
sigmatch now doesn't consider call nodes in general unresolved, only
nodes with `tyFromExpr` type, which is emitted on unresolved expressions
by increasing `c.inGenericContext`. `c.inGenericContext == 0` is also
now required to attempt instantiating `tyFromExpr`. So matching against
`tyFromExpr` in proc signatures works in general now, but I'm
speculating it depends on constant folding in `semExpr` for statics to
match against it properly.
3. `paramTypesMatch` now doesn't try to change nodes with `tyFromExpr`
type into `tyStatic` type when fitting to a static type, because it
doesn't need to, they'll be handled the same way (this was a workaround
in place of the static type instantiation changes, only one of the
fields in the #22647 test doesn't work with it).
4. `tyStatic` matching now uses `inferStaticParam` instead of just range
type matching, so `Foo[N div 2]` can infer `N` in the same way `array[N
div 2, int]` can. `inferStaticParam` also disabled itself if the
inferred static param type already had a node, but `makeStaticExpr`
generates static types with unresolved nodes, so we only disable it if
it also doesn't have a binding. This might not work very well but the
static type instantiation changes should really lower the amount of
cases where it's encountered.
5. Static types now undergo type instantiation. Previously the branch
for `tyStatic` in `semtypinst` was a no-op, now it acts similarly to
instantiating any other type with the following differences:
- Other types only need instantiation if `containsGenericType` is true,
static types also get instantiated if their value node isn't a literal
node. Ideally any value node that is "already evaluated" should be
ignored, but I'm not sure of a better way to check this, maybe if
`evalConstExpr` emitted a flag. This is purely for optimization though.
- After instantiation, `semConstExpr` is called on the value node if
`not cl.allowMetaTypes` and the type isn't literally a `static` type.
Then the type of the node is set to the base type of the static type to
deal with `semConstExpr` stripping abstract types.
We need to do this because calls like `foo(N)` where `N` is `static int`
and `foo`'s first parameter is just `int` do not generate `tyFromExpr`,
they are fully typed and so `makeStaticExpr` is called on them, giving a
static type with an unresolved node.
2024-08-26 06:54:38 +02:00
metagn
ab18962085 sem all call nodes in generic type bodies + many required fixes (#23983)
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.
2024-08-20 21:31:19 +02:00