It's actually possible to get into all four combinations of having
parameter lists versus being generic:
- An entity nested within a generic, such as a member class, can be
generic even if it has no parameters.
- As a corner case, an entity with an *empty* parameter list has
parameter lists, but isn't a generic because it doesn't have any generic
parameters.
This prepares us for modeling associated entities of parameterized
interfaces.
We don't use the interface parameters when type-checking `impl`s or uses
of interface members yet, but we do now check interface arguments during
`impl` lookup.
A symbolic constant has an instruction to compute the constant value, as
well as potentially also having a generic ID and an index within that
generic to indicate where corresponding values can be found in a
specific. Import those pieces of information when importing such a
constant.
We try to import the generic before we start the main work of importing
the constant, and retry the import process if importing the generic adds
work to the worklist. This means that the first time we import anything
within a generic, we can now perform three passes calling
`TryResolveInst` instead of two, but the first pass is very lightweight
and only looks up and adds a single instruction, so the added overhead
of the extra pass should be minimal.
To avoid introducing cycles when importing a generic function, make the
import of a function declaration build the new `Function`,
`FunctionDecl`, and `FunctionType` in the first pass, like classes and
interfaces do.
Import generics and specifics when they are referenced by imported
entities.
When importing a generic, we import the symbolic constants required by
its eval block, and then rebuild the eval block itself given the list of
constants it needs to compute. This is likely a bit less efficient than
directly importing the contents of the eval block, but avoids needing to
either extend the importer code to be able to import the instructions
that can appear in the eval block or extend the evaluator to cope with
instructions from a different `SemIR::File`.
Importing a symbolic constant is unaffected, and does not yet preserve
the associated generic and index within that generic, so uses of a
generic from an imported IR still don't pick up values from the
specific, but the improved functionality can be seen in the changes to
the SemIR in the testcases.
Instead of updating the `value_id` on the canonical constant
`BindSymbolicName` to refer to some particular instance of that
constant, create a new instruction, and attach the proper location to
it.
The caching isn't buying us much, and is adding complexity and
divergence between the codepaths for generic and non-generic functions.
This means we no longer suppress diagnostics for the second or
subsequent time we call a function with an incomplete return type. If we
want to add that back, it might be worth considering moving the
suppression to `TryToCompleteType` and only diagnosing that a type is
incomplete once, regardless of why we're requiring it to be complete.
As discussed in toolchain meeting, we want to avoid overloading the
meaning of "instance", and "specific" was the best name we found. It's a
little unorthodox and inventive, but hopefully over time will become as
unsurprising as the term "generic" is.
I'd considered moving DeclParams uses over, but when handling qualified
names, there's a parse node instead of an instruction. I did try to
unify a couple other uses though, including adding MergeDefinition. I
expect `interface` will use a little more once it's more completely
implemented, but maybe I'm wrong about that.
Note this isn't implementing checking through imports. The parse node
there is harder to access through the context, so would require
examining the entity in order to get the import declaration, to get at
the ImportIR. We also don't have a parse tree attached in that case, and
would need to add one to SemIR::File. But I believe we do want to add
that, so it's explicitly a TODO.
Note GetTokenText re-lexes literal values, so there's a bit of potential
overhead there. Not sure if we want a more efficient manner for
comparing in cases like this.
Querying a local constant with an invalid instruction triggers a crash,
this will prevent self_param_id to be used unless it is defined.
Closes#4071 and #4080
This will only fix the crash. The scenario where a declaration-only
interface is imported then defined still gives an error message, but it
won't crash this time.
I'm trying to increase the distinction between BuiltinKind and
BuiltinFunctionKind. BuiltinKind is for instructions,
BuiltinFunctionKind is for function definitions. To get to this point,
I'm doing a few changes:
- BuiltinKind -> BuiltinInstKind
- builtin_kind.* -> builtin_inst_kind.*: filename consistency
- Builtin -> BuiltinInst: mainly for consistency with the above
- Builtin::builtin_kind -> BuiltinInst::builtin_inst_kind: somewhat
repetitive but seems like a consistent edit
- Function::builtin_kind -> Function::builtin_function_kind: seems a
useful distinction
I'm leaving alone things like (and mentioning in case there's a desire
for more renames):
- InstId::BuiltinError, InstId::ForBuiltin: these I think are more
apparent because they're directly associated with Inst.
- GetBuiltinICmpPredicate in lowering: maybe builtin function handling
should be in its own file, but these local names don't feel problematic
to me.
- GetBuiltinType, BuildBuiltinValueRepr, PerformBuiltinIntComparison:
similar to the above, names don't feel too problematic
This executes on a TODO in AddImportRef to add instructions to their own
block instead of the File block. This has an important consequence of
removing a pattern from InstBlockStack that added to blocks not
currently at the top, cleaning up an issue for ArrayStack. The delta
here is then mostly in different formatting of the import refs, a
consequence of the separation.
By adding an `ImportDecl` instruction, this creates something that can
be referenced through `ImportIRInst`.
packages/no_prelude/implicit_imports_entities.carbon is getting a test
of this (import_conflict and import_conflict_reverse).
Also re-packs ImportIR from 24 bytes to 16 on 64-bit, since I'm touching
everywhere that makes one anyways.
When checking a declaration or definition of a generic, track a list of
created instructions that depend on the generic's parameters in some
way, along with information on how they depend on the parameters. This
will eventually be used to determine what information we need to compute
when creating instances of the generic, but for now we're just building
the list.
Information is tracked separately for the declaration region and the
definition region of the generic, because in general these may be first
provided in separate declarations, and they should be substituted into
at different times.
This refactors how the implicit import is handled in order to retain
more name scope information. As a consequence, private access control
works better between api files and implementation files. Note though
that this will also be essential for name poisoning between the API and
implementation, as discussed in #3763.
In implementing this, I ran into a couple issues with namespaces that I
think point to flaws in their handling. I've fixed some and added a TODO
for the biggest issue (in check.cpp line 281-288), which relates to the
handling of namespaces of direct imports which are first evaluated
indirectly.
In `ClassType`s and `InterfaceType`s, track a `GenericInstanceId` for
the instance rather than just the argument list.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Build a `Generic` object for generic functions. This object tracks the
generic parameters that are in scope for the generic entity. Eventually
it will track other information about the generic too.
Add basic SemIR formatting support for generic functions.
Name scopes store the names in their scope in a `DenseMap`. Several
places reasonably avoid depending on the iteration order by sorting the
names -- they're in the formatting code path where that's a solid
approach.
Unfortunately, when we're importing one scope into another, we also need
to walk the entire scope and do something for each name. =[ This doesn't
seem like a great place to sort things to stabilize them.
I've switched to a fairly simplistic solution of having a vector of name
entries that can be iterated stably, and a separate map for lookups. I
didn't use the set-of-indices trick here because it's not clear that's
the right trade-off for a scope: likely a lot of small scopes here with
relatively hot name lookups. And the key here isn't a large or
dynamically sized thing that we're canonicalizing, it's a `NameId`. That
made me lean towards duplicating the name in the hashtable for lookup
and the vector for iteration.
I thought about a fancy approach of sorting the hashtable keys by their
values (the indices), but that would still require a bit of copying and
more code.
I also thought a bit about other optimizations, but decided to leave a
comment for now -- it's not obvious to me exactly how hot this is and
whether it's better served by faster lookups, being more memory dense,
etc. And that might involve more of an SOA layout change or some other
approach. Rather than do that here, and especially before switching
hashtables, I stuck with a simple approach to address the ordering.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Require mapping from a `ConstantId` to an `InstId` to go through the
`ConstantValueStore`.
This is a preparatory step for an upcoming generics change where
symbolic `ConstantId`s are no longer just a thin wrapper around an
`InstId` but instead are indexes into a table with additional
information about the symbolic constant beyond its `InstId`.
Instead of redundantly storing both the `return_type_id` and
`return_storage_id`, where the declared return type is just the type of
the return storage, store only the `return_storage_id`.
Add a convenience property to get the declared return type of the
function.
In addition to avoiding storing redundant information, this is a
preparatory step for an upcoming change for generics support that will
make it more expensive and awkward to store `TypeId`s in places other
than the type of an instruction.
In some cases this is just a refactoring; in others, we no longer import
both an instruction in no block plus a constant instruction, resulting
in creating fewer instructions. The non-constant version of the
instruction always ended up unreferenced in the affected cases.
Following up on a comment in #4042.
This is mostly mechanically duplicating work done for generic classes to
also support generic interfaces.
Also fix both generic interfaces and generic classes to support
importing class and interface types with arguments from another file.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
Adds access to the name lookup table in name scopes. This is so that we
can quickly check access during name lookup without resolving the entity
itself. Does this for names in general, but does not implement handling
for entity-scoped names, only namespace-scoped names (where they're
essentially just not exported).
Excludes `private` names from exports. Although names should be
accessible to `impl` files, that's not implemented here because we'll
probably want to do it by directly copying name lookup tables.
Check the parameters specified in a name qualifier against the
parameters of the entity that the qualifier refers to.
For interfaces, this required adding minimal support for parameterized
interface names.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Following up on discussion from #3948, doing a general rename of
"enclosing scope" to "parent scope" (and "enclosing scopes" to "ancestor
scopes"). The intent is to improve understandability and collide less
with C++ terminology for "enclosing scope". Note this changes most uses
of "enclosing", but leaves behind a few like "enclosing function" and
"enclosing block".
Note this does create some "parent class" mentions for "adapt" and "var"
(the class they're within), which is maybe unfortunate, but we'd
probably say "base class" if we meant inheritance so perhaps that's
okay. Along the same lines, these are the only `parent_class` uses I see
now, and we do have a few `base_class`.
Trying to conform with #4009. Changes SemIR::LocIdAndInst construction
to root out struct init cases with AddInst and related functions. I'm
using templating of AddInst functions in order to avoid `AddInst(loc_id,
InstName{...})` and instead have `AddInst<InstName>(loc_id, {...})` with
I think similar readability results. There are a couple cases where inst
construction is templated and so designated initializers couldn't be
used, so this may be better for those in particular due to the extra
type enforcement.
This probably doesn't clean up every last case, but I was trying to get
the bulk at once without bleeding over into less related changes.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Right now, each sequential modifier verification tends to re-fetch the
enclosing scope, doing equivalent verification. Change code to more
explicitly do the fetch once, sharing the result, also making the
enclosing scope available to the caller for other work.
Note, the type store similarly carries an inst store pointer; that's
what I'm basing having the name scope store's inst store pointer on.
This adds a `BindExport` instruction in order to better track the
location of the `export` itself, but a `bind_name_id` is also added to
`ImportRef` so that we know quickly where to put it in name lookup.
Merging identical names is a TODO. I haven't quite decided how best to
achieve that, because I do think the BindExport should be what's
actually added to name lookup.
Also, I will probably add a mode to DeclNameStack that blocks
non-namespace scopes. This seems to already be an error, but the wrong
one (maybe due to lack of support for cross-file decl/def support).
This provides `export import` logic in lex, parse, and check; `export
name` logic is only in lex and parse, not check.
I think with `export name` I'm going to need to modify import_ref and
some consolidation logic, whereas `export import` seems feasible to keep
as primarily import logic. Given the implementations were looking like
they'd diverge more substantially, I thought it'd be helpful to cut the
PR here.
This is modeled analogously to FunctionType. So far, GenericClassType
has no operations, but eventually values of that type will be callable
like values of FunctionType.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This was to track use of a declaration after import, prior to a
redeclaration. Per [discussion on
Discord](https://discord.com/channels/655572317891461132/1217182321933815820/1236016521059237962),
we likely don't need this check due to the change in behavior of
`extern`.
Rather than potentially getting one of many `extern` decls and depending
on it by accident, it is now planned to be _required_ to be imported,
and the library doing a non-`extern` decl must _know_ it's importing the
`extern` decl. The stricter requirement on the library means it now
seems more reasonable to use the `extern` decl.
So kind of rolling back #3831, though keeping `ImportIRInstId` (at least
for now) and keeping `Loaded`/`Unloaded` terminology (seems a nicer
fit).
This removes the builtin FunctionType, replacing it with a FunctionType
instruction. The constant for a FunctionDecl is now a StructValue with
type of FunctionType.
Note this means a function declaration produces _both_ a type, and a
value of the type. This has some consequences in terms of circularity,
and makes the importing of function declarations a little more complex.
It'll get particularly peculiar for imports because of the behavior of
the reference, but that's a known issue due to other things such as
`alias`. The impact will hopefully be contained to
ResolvePrevInstForMerge (and ImportRefs).
To note a small formatting change in diagnostics:
```
- // CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated <function> in Interface>` is not callable.
+ // CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated F in Interface>` is not callable.
- // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated <function> in Interface>` is not callable.
+ // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated F in Interface>` is not callable.
```
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
As we talk about how imports should work, we want to start having
indirectly imported IRs in `import_irs`, where it's currently only
directly imported IRs. The tracking of `CheckIRId` is set up to be able
to determine whether an IR being indirectly imported is actually already
tracked (and may be a direct import). Changes here to how ApiForImpl is
handled start using the logic.
Note that indirect imports may be added while processing even the first
import from the current library. As a consequence, it's necessary to
prepare this map before starting imports, in particular, setting
ApiForImpl before any indirect imports may encounter the same import.
Also, prior validation that `num_irs` matches the final size are no
longer relevant.
check_ir_id is tracked on SemIR because I want to be able to figure it
out given an ImportIR, but the mapping is ephemeral after checking and
so I store that in Context.
I'm putting relevant logic into import_ref.cpp because the primary
alternative is import.cpp, and as more logic is added, ImportRefResolver
will be adding import IRs.
This allows ImportRefs to point at a potentially distant instruction,
while still providing a LocId that can be used for diagnostics. I think
this'll be used if we're trying to point ImportRefs at canonical
instructions in distant IRs. It conveniently eliminates a special-case
in check.cpp.
Restructures LocIdAndInst::Untyped because I think it's not really
needed after this change (the key non-import use was GetWithLocId, which
I just give friend access for). Adding NoLoc for things that don't
provide _any_ location because it turns out Inst can easily be passed in
this way which was not what I had intended, but is used.
Use a level comparison during substitution to determine whether we're
substituting a particular binding. Evaluate symbolic bindings with the
same name and the same level to the same symbolic constant, for example
across redeclarations of a generic function.
In handle_class and handle_interface we assign TypeType, so is more
consistent. I think this had been missed because we haven't really been
using these declarations (historically, declarations didn't have a
type). It seems not to significantly affect output at present, although
I found this while trying to change merge behavior.
This doesn't actually track whether a declaration is `extern`. It does,
however:
- Factor out and expand merge support for classes, sharing handling with
functions.
- This makes the ClassRedefinition diagnostic redundant, as the
redeclaration checking overlaps.
- Add partial `extern` handling to class handling; just some
verifications of correct use.
- Factor out `extern` on member handling for sharing with `fn`.
- Fixes a bug in import_ref where a class's definition_id wasn't
assigned when defining.
This changes how a redefinition is handled (replaced, rather than
merged). I don't know whether that's ideal, but I think it results in
easy-to-understand consequences, and it's more consistent with how `fn`
works.
There's enough work here that this felt like a decent cut point,
particularly as the amount of work to actually add `extern` tracking
will be significant.
Richard Smith
Jon Ross-Perkins
Geoff Romer
Gıyaseddin Tanrıkulu
Chandler CarruthandRichard Smith
