Commit Graph
94 Commits
Author SHA1 Message Date
Richard Smith 05cc09daca Fix cross-package signature mismatches. (#7232)
Fixes link failures when referencing a symbol involving a fingerprint
from a different package.

Previously we included the `Namespace`'s `import_id` as part of its
fingerprint, which caused local and imported namespaces to get different
fingerprints. We now store the `import_id` on the `NameScope` instead of
on the `Namespace` inst to avoid this problem.

Also, when we reach a package-level `NameScopeId`, consistently
fingerprint it as a (package name, library name) pair. Previously the
fingerprinting depended on whether it was imported or not, as an
imported `NameScopeId` had a parent scope (the current package). We need
to include the library name here so that private entities with the same
name in different libraries have different fingerprints.
2026-05-21 00:02:29 +00:00
Richard Smith ce080b3549 Support unqualified lookup into extended interfaces from classes and impls (#7217)
When a class extends an interface, referring to a member name of the
interface as an unqualified name should refer to the class's
corresponding associated entity value, not to the associated entity
itself. Similarly, in an `impl`, unqualified names of associated
entities should refer to the `impl`'s corresponding value for that
entity.

To support this, we treat `impl`s as `extend`ing their implemented facet
type, and we make lookups into an extended facet type use the `Self`
type of the extending `impl` or `class` if lookup finds an associated
entity. We already did the latter if the extending entity was an
interface; this extends the existing support for these other cases.
2026-05-19 18:01:54 +00:00
Dana JansensandRichard Smith 6326bbdbe1 Resolve cycles in .Self replacement in nested designators (#7183)
A nested designator like `.(X.X1).(Y.Y1)` results in nested
ImplWitnessAccess instructions, which can produce cycles in the
toolchain easily when replacing `.Self`.

First, when constructing a facet type like `V:! Z where .Z1 impls (Y
where .Y1 = U)` we substitute replace `.Self` in the nested facet type,
and in this case we replace `.Self` with `.Z1` which contains a `.Self`
of its own. This was coming from us being lazy about replacing `.Self`
in an `impl as` declaration, such as `impl C as Z where .Z1 = .Self`.
The self type is known there, so we can more eagerly replace `.Self` as
we do in a `require impls` declaration. Then the replacement for `.Self`
never comes with a `.Self` that needs to also be replaced. Any resulting
`.Self` would always be the top-level one.

Second, when evaluating ImplWitnessAccess, we were replacing .Self in
the LHS of rewrite constraints, but the `.Self` may itself have a type
that contains rewrite constraints. If one of those rewrite constraints
has nested ImplWitnessAccess instructions, we evaluate the new
ImplWitnessAccess, which again finds rewrite constraints to replace
`.Self` in, and we repeat forever. For this one we just stop replacing
.Self in the LHS of rewrite constraints. Since they are always against
.Self, we can always look in the access facet's type for a value.

While fixing ImplWitness access, also correct the lookup to search
through the types of nested ImplWitnessAccess instructions to find a
rewrite value, since it may find it at any level up to the eventual
`.Self`.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-05-13 16:11:20 +00:00
Dana Jansens f8dd4d85bf Do not treat impls in different scopes as redeclarations (#7161)
An impl in a different scope, with the same parameters, will overlap and
get diagnosed for that later by the [prioritization
rule](https://docs.carbon-lang.dev/docs/design/generics/details.html#prioritization-rule),
if they are not in a match_first block. But they are not considered as
redeclarations.

See [proposal
p5366](https://github.com/carbon-language/carbon-lang/blob/62b94f79322039acc3fc8e175896a64a32df470e/proposals/p5366.md)
for the rule.
2026-05-04 19:11:51 +00:00
Dana Jansens 88931a4196 Give the .Self instruction a location (#7147)
This lets us stop eliding it in textual semir tests with dump ranges.
Previously it would always get elided, even though it was part of the
range being dumped, and was referred to by other instructions in the
dump range.

Since each `.Self` is unique (can change its type if not its value) in a
facet type, having each one distinct by location also aids
understanding.
2026-05-04 14:45:06 +00:00
Dana Jansens 46bb0fecd4 Properly diagnose ambiguous .Self in T impls X where... (#7132)
A `where` expression nested inside a `T impls X` constraint makes
`.Self` ambiguous on the right-hand side of the `where` if `T` is
anything other than `.Self`. After the `where`, the value of a `.Self`
could be `T` or could be the value of `.Self` before the `impls`
constraint: the so-called top-level value of `.Self`.

Implicit use of `.Self` in designators is always allowed, and they are
bound (and replaced by a reference) to the inner-most possible value of
`.Self`. On the right-hand side of the nested `where` above, they have
the value `T as X`.

`.Self impls ...` is also always allowed, since it acts more as a
keyword here, and it always refers to the inner-most possible value of
`.Self`.

Any other explicit use of `.Self` is diagnosed when ambiguous, in any
kind of constraint. This is done in the handling of `WhereExpr` since it
has enough context to allow `.Self impls` (which is an explicit use)
while disallowing other explicit uses. And because it has non-canonical
instructions to work with, so it is able to diagnose errors with precise
locations.

Since `.Self` is no longer going to be marked with depth modifiers, the
eval of `WhereExpr` does not need an input facet value instruction
representing `.Self` to compare with, as they are now going to all be
equivalent. So revert it back to just looking for the `PeriodSelf` name
id, through a shared helper being introduced as `IsPeriodSelf`. And drop
the period self InstId from the `WhereExpr` instruction. This causes
most of the formatted SemIR changes.

Move helpers for working with and replacing `.Self` to their own file,
out of the `facet_type.h` header/cpp files. These are working with
`.Self` facet values more than facet types, though `.Self` is a name
that only exists inside the scope of a facet type.
2026-05-01 21:22:32 +00:00
Geoff Romer 4c9049346d Replace form insts with actions (#7100)
See
[here](https://docs.google.com/document/d/1rWcueFwIfZox6GKVGxiUG4cBzjrZ6djXiIDGyJDtrE4/edit?tab=t.0)
for the design doc.

This also removes the default value of the `result_type_inst_id`
parameter of `HandleAction`, moves it before the action in the parameter
list, and documents it. This solves two problems:
- The default made it easy to forget, leading to unnecessary
`TypeOfInst` instructions.
- When it was present, putting it after the fairly "bulky" action
argument tended to make the callsite harder to read.
2026-04-29 18:13:42 +00:00
Dana Jansens 554b1b8d10 Remove SymbolicBindingType (#7114)
This inst was meant to support tracking the depth of a `.Self` facet,
but we have now implemented substitution of `.Self` in facet type
identification, and in eval of where expressions, without needing to
track the depth.

See history here:
-
[2025-06-30](https://docs.google.com/document/d/1Yt-i5AmF76LSvD4TrWRIAE_92kii6j5yFiW-S7ahzlg/edit?tab=t.0#heading=h.4qd5dkyfn2k3)
-
[2025-07-07](https://docs.google.com/document/d/1Yt-i5AmF76LSvD4TrWRIAE_92kii6j5yFiW-S7ahzlg/edit?tab=t.0#heading=h.7urbxcq23olv)
- #6026
2026-04-27 19:04:59 +00:00
Dana JansensandRichard Smith cc5a42691e Add where T impls X constraints into the FacetTypeInfo (#7038)
This makes them part of the identified facet type, and we can see the
constraints as part of stringify and format output.

But this does not do enough to make them useful yet: Any `T impls X`
constraint must contain a reference to `.Self` somewhere. And `.Self`
references do not get substituted, so neither `T(.Self) impls X` and `T
impls X(.Self)` will match against an incoming facet value derived from
an `impl T(U) as X` or `impl T as X(U)`, since `U` and `.Self` are never
the same thing until `.Self` can be substituted.

Now that impl lookup runs into facet values containing `.Self` (a
symbolic binding), such as in `C(.Self)`, we were crashing assuming the
type of `.Self` is a FacetType, but it can be `type` in the case of
`type where C(.Self) impls...`. Instead, use an empty facet type for the
type of `.Self` so it is always a facet. This assists with substituting
other facets into it, without having to insert an extra FacetAccessType.
`MakePeriodSelfFacetValue()` now enforces this requirement.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-04-10 14:29:36 +00:00
Geoff Romer 18f87e4f79 Include the type in the location of binding insts (#6963) 2026-03-26 18:43:29 +00:00
Geoff Romer e0c6800ab3 Reverse nesting structure of parameter patterns (#6930)
See
[here](https://docs.google.com/document/d/1rWcueFwIfZox6GKVGxiUG4cBzjrZ6djXiIDGyJDtrE4/edit?tab=t.0#heading=h.7mi143mdhr2h)
for an overview of the changes and their rationale.

Assisted-by: Gemini 3.1 Pro via Antigravity
2026-03-23 20:38:20 +00:00
Geoff Romer 08148f3a3a Refactor AddBindingPattern into composable pieces (#6927)
This is part of some bigger changes in pattern matching, factored out
because it causes some test churn.

Assisted-by: Gemini 3.1 Pro via Antigravity
2026-03-19 19:20:03 +00:00
21291b4cc3 Remove InitForm::index (#6817)
This ensures that equal forms always have equal representations (because
the index depends on how the form is used, not on the value of the form
itself).

As a byproduct, also remove `NextCallParamIndex`.

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Nicholas Bishop <nicholasbishop@google.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Boaz Brickner <brickner@google.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
Co-authored-by: MK4070 <60286678+MK4070@users.noreply.github.com>
Co-authored-by: Christopher Di Bella <cjdb@google.com>
2026-03-06 17:35:48 +00:00
Geoff RomerandJon Ross-Perkins 6dba8ee111 Remove index fields from ParamPatterns (#6815)
This is a step toward removing the index from `InitForm`, so that equal
form values always have equal representations.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2026-03-03 00:19:47 +00:00
Dana Jansens cea52ad2d8 Format the InterfaceWithSelf and NamedConstraintWithSelf generic name with its ".WithSelf" suffix (#6798)
We used the ".WithSelf" suffix when formatting a parent scope, but
missed the suffix when formatting the scope name on its own.
2026-02-27 13:50:56 +00:00
Richard Smith f9ab963bd6 Add a type_literal instruction to represent syntactic type literals. (#6781)
This allows us to capture the location at which a type literal was used,
even in the cases where we don't otherwise need to create a new
instruction to represent the type such as for `char` or `str`.

The logic used to build the underlying type is now marked as desugaring.
For cases such as `iN`, this causes the call to `Core.Int` to no longer
be added as a dedicated IR instruction, and instead its constant value
is used directly as the value of the `type_literal`. This results in
this being on balance a reduction in the size of the IR.

This also fixes a crash in C++ interop when using a `char` literal as a
template argument. The crash was caused by the template argument not
having an associated location when mapping to a C++ location. See
changes to check/testdata/interop/cpp/template/type_param.carbon for an
example that used to crash before this change.

Update alias handling to allow an alias to point at any type literal,
reinstating support for aliases for type literals such as `bool` and
`i32` that had previously worked but stopped working when we
transitioned those types to being defined in the prelude. See changes to
toolchain/check/testdata/alias/builtins.carbon.

All the test changes other than the two mentioned above are mechanical
autoupdate changes switching to the new instruction.
2026-02-26 20:10:50 +00:00
Dana Jansens fbc8d59d32 Introduce Diagnostics::ContextScope and remove diagnoser callbacks in type completion (#6761)
Introduces `Context` and `SoftContext` messages, which can be introduced
through a `ContextBuilder`:
- The `Context` messages come before the diagnostic in the output.
- The first `Context` message steals the diagnostic level from the main
diagnostic, and turns the main diagnostic into a Note attached to the
context.
- A `SoftContext` message works similarly, but if it's preceeded by a
`Context` or `SoftContext` message, then it is dropped. This can be used
as a default/backup scope when nothing more interesting is provided up
the stack, such as in `TryEvalBlockForSpecific`.

The `ContextBuilder` is provided to a callback through
`Diagnostics::ContextScope`, an RAII type `AnnotationScope` but for
context messages.

This allows a high level operation to provide a context message like
"failed to identify facet type {0}" which will then be used as the error
if a diagnostic is produced during identification, with the latter
diagnostic attached as a note to explain why the contextual operation
failed.

In particular, this allows monomorphization errors (such as an array
bound being negative) to be attached to a higher lever operation instead
of being top-level diagnostics themselves, with the monomorphization
site being a note. This inverts the source code locations that appear in
the diagnostic, so that the top-level diagnostic points to the "user
code" which causes the monomorphization.

This is presented as an alternative strategy to #6753, which plumbed
diagnoser callbacks around to achieve the same goals.

We replace the diagnoser callbacks in type completion and operators with
ContextScope callbacks instead, which now provide better diagnostics for
monomorphization errors. Other callers to MakeSpecific do not yet have
ContextScopes introduced in order to turn monomorphization errors into
more interesting diagnostics.
2026-02-25 15:15:29 +00:00
fdb188ccfd Implement unused pattern bindings, continued (#6518)
Implementation of unused pattern bindings #2022, continued.

Whereas previous PR #6460 took care of parsing, and PR #6479 prepared
the stage by using _ in some test cases, this PR has the the actual
implementation, using a simple dataflow analysis.

---------

Co-authored-by: Burak Emir <bqe@google.com>
Co-authored-by: jonmeow <jperkins@google.com>
2026-02-19 23:33:36 +00:00
Dana Jansens 917a6ea971 Add an interface-with-self generic to each interface and same for constraints (#6667)
Currently each interface has a `Self` facet internally that becomes a
binding to every entity inside the interface: associated constants,
functions, and require decls. Each of these has to be independently
generic as a result. This makes is challenging in extended name lookup
to move into an extended scope of an interface, as we have a specific
for the interface, but the names within require a different specific
that includes a `Self` facet value.

We generalize this relationship by adding a second generic to Interface,
called `generic_with_self`. When we want to work with entities inside
the interface, we move from the interface-without-specific to the
interface-with-self specific by adding a Self to the specific. This is
done independently of any particular entity inside the Interface, as
those entities are now all members of the interface-with-self generic.

Associated constants no longer need a generic of their own, as they do
not have separate generic bindings. Functions retain a generic, but if
the function has no generic arguments, it will have no bindings of its
own now.

Require decls retain a generic so that their specific can be
instantiated separately from the interface. Requiring the interface to
be complete does not require the types in a require decl to be complete
unless it is modified by `extend`. So we allow them to be completed
later by keeping them in a separate generic.

Named constraints look like interfaces and gain the additional inner
generic-with-self, with the same relationship to require decls.

This removes the need for name lookup to perform Substitution of a Self
facet into the extended scope instruction. Instead, the
`SpecificConstant` instruction inserted by a `require` decl is part of
the interface-with-self generic. When looking through a FacetType for
extended scopes, for each interface, we push the scope with the specific
for the interface-with-self. Then the constant value of the
`SpecificConstant` is correctly modified by the provided self
automatically through applying that specific.
2026-02-19 16:24:07 +00:00
Geoff Romer 1c885a629e Format FormType as "Core.Form" (#6734) 2026-02-13 19:44:21 +00:00
Özgür bdcac5087d Allow incomplete types in associated constants (#6657)
Reference: #1084, [Example of declaring interfaces with cyclic
references](https://github.com/carbon-language/carbon-lang/blob/trunk/docs/design/generics/details.md#example-of-declaring-interfaces-with-cyclic-references).
Part of #6411: "Associated constants shouldn't have to be complete".
2026-01-28 15:27:14 +00:00
Dana Jansens ee77aa4b67 Member access into a facet is not a "lookup in type of base" (#6631)
This gets us a step closer toward resolving TODOs in member access
around facets, by making the lookup into a facet value a "lookup in
base" operation instead of a "lookup in type of base". However the base
given to find scopes in still remains the facet type of the facet, which
is still a TODO.

Then we can simplify the "lookup in type of base" case a bit, with a
single code path doing the name lookup step. But we keep a TODO where if
the type of base is a facet, we change the lookup target to be the facet
type of the facet instead.

This is toward having name lookup into an interface that is extending a
named constraint work correctly with a `Self` in its specific. To
perform that name lookup, we will need to tell name lookup what is the
base, so that it can replace `Self` with the base. This change gets us
in a position where we can correctly provide the base in the `T.F()`
(lookup in facet) and `t.F()` (lookup in type of facet) correctly and
straightforwardly.

We provide a marginally improved diagnostic when looking into a facet
with an incomplete facet type, which will move into
AppendLookupScopesForConstant once we are looking into the facet
directly instead of its type.
2026-01-20 18:43:16 +00:00
Geoff Romer 4329a83e4c Form-aware textual format for return parameters and arguments (#6588)
The key changes are:
- Function output parameters are now prefixed with `out`, and more
consistently formatted as named parameters.
- Function and inst output arguments are now written as part of the inst
form, rather than as one of the inst arguments.

As a drive-by fix, this also changes `Temporary::storage_id` from
`DestInstId` to `InstId`, because it doesn't represent an output
parameter of the `Temporary` inst itself.

See the review of
[#6532](https://github.com/carbon-language/carbon-lang/pull/6532) and
[this Discord
discussion](https://discord.com/channels/655572317891461132/999638000126394370/1458268977020141589)
for additional background.
2026-01-14 23:27:21 +00:00
Geoff Romer 6985ecb1d4 Replace GetCurrentReturnSlot with GetReturnedVarParam (#6571)
Not all functions have a return slot, and once we have composite forms,
functions will be able to have any number of return slots. Obtaining a
unique return slot for a function only makes sense in `returned var`
handling.
2026-01-10 01:56:32 +00:00
Geoff Romer 505b1c86b9 Initial support for return forms (#6556)
The main changes here are:
- Introducing `InitForm` and `RefForm` to represent initializing and
reference forms (the two return forms currently supported by the
parser).
- Introducing the `FormType` singleton inst to represent their type
(i.e. `Core.Form`).
- Emitting an inst representing a function's declared return form as
part of handling the function signature.

The return form inst is currently ignored. Subsequent PRs will expose it
in `SemIR::Function` and use it to determine the form of call
expressions.
2026-01-07 00:54:18 +00:00
Jon Ross-Perkins c5eba90317 Change Destroy to use a CustomWitness instead of a blanket impl (#6512)
Pursuant to recent decisions on #6124, switch `Destroy` to use a
`CustomWitness` for its implementation. Right now this is manufacturing
no-op implementation functions on each lookup, which obviously isn't
ideal but is intended as a first pass. I'm mostly trying to find the
right balance between updating the approach to reflect new decisions,
while still breaking apart work in a way.

The `CoreInterface` logic is intended to build on `CoreIdentifier`
support. We have a number of additional interfaces that require
specialized logic, and that'll extend pretty far with C++ interop, so it
seemed easiest to have a generic function for it. That's what's
replacing the logic inside C++ interop that was doing string comparisons
(which could have already been moved to `CoreIdentifier`, I just missed
it in my first pass).

This adds `CustomWitness` support because the `Destroy` witnesses can be
imported cross-file. `CustomWitness` was previously only used for C++
types, which don't yet support import, which is why that wasn't
previously an issue. The addition of `query_specific_interface_id` is
similarly needed in order to get correct sorting of witness blocks when
imported.

This PR also removes builtin constraint logic (note this is in a
separate commit to help review; it's not a separate PR because it's
difficult to split apart without tests breaking). This had been made
generic with the expectation that destroy, copy, move, and conversions
would all need related support. Under the new decision, we are not going
to do blanket impls and will instead just manufacture a `CustomWitness`
for everything.

A lot of SemIR fingerprints change, but that's probably because the
addition of `Destroy` on core classes is yielding structural changes.
2025-12-19 18:36:06 +00:00
Dana Jansens 7c1798d96d Format impl witness instructions as part of the impl (#6485)
The impl's body block has to end before we make its ImplDecl
instruction, and the witness instructions come later, so they don't end
up in the body block. Currently they just end up in the enclosing (file,
typically, or class) scope block.

Add a new InstBlockId to Impl for holding witness instructions, and
explicitly insert them into that block. Then include those instructions
into the scope of the Impl for naming, and format them into the Impl
right after the body block.

This is based on #6484
2025-12-17 15:46:30 +00:00
Jon Ross-Perkins 47e551141f Change the package namespace to use the package name (#6495)
Instead of naming the root namespace `package` (because it's accessed by
the `package` keyword), change it to use the current package name. Note,
buried in the checksum changes,
`toolchain/check/testdata/package_expr/fail_not_found.carbon`:

```
-  // CHECK:STDERR: fail_not_found.carbon:[[@LINE+4]]:16: error: member name `x` not found in `package` [MemberNameNotFoundInInstScope]
+  // CHECK:STDERR: fail_not_found.carbon:[[@LINE+4]]:16: error: member name `x` not found in `Main` [MemberNameNotFoundInInstScope]
```

for:

```
  // CHECK:STDERR:   var y: i32 = package.x;
  // CHECK:STDERR:                ^~~~~~~~~
```

I'll leave it to you if you prefer this; the alternative I see is to
just rename `IsCorePackage` to `IsImportedCorePackage`, and/or change it
to a helper that takes a `Context` and does the right thing with
`parse_tree` (which, I need for `Destroy`-related reasons and was my
default approach).
2025-12-16 01:33:53 +00:00
Dana Jansens fbcaf34494 Defer RequireCompleteType to impl definition (Refactor Impl construction 7/7) (#6470)
Explicitly run `RequireCompleteType` for an impl's facet type constraint
in two places:
- For a new `Impl` declaration that is `extend`
- At the start of the `Impl` definition

Stop trying to RequireCompleteType in the definition when constructing
the witness. If we have a rewrite of a name in `.Self`, then we can
construct a full witness, otherwise we defer to the definition.

Now GetOrAddImpl does not need to track `is_definition` anymore, so we
remove a lot of plumbing.

We inline the `AllocateFacetTypeImplWitness` since it has a single
caller and it is just 2 lines, to help improve understanding of the
steps and comments in setting up the impl definition.

Note that this puts the `RequreCompleteType` instruction into the
definition's generic eval block always, avoiding the issue of ensuring
that each generic redecl has the exact same instructions, and forcing
coordination to have `RequireCompleteType` inserted into every
declaration's eval block or none. The result also more closely matches
the design, with the complete type not being required until inside the
definition.

This is part of #6420 which is being split up into a chain of smaller
PRs. It is based on #6469.
2025-12-11 23:50:10 +00:00
Richard Smith 154e4012c4 Include the parent scope when fingerprinting an entity name. (#6473)
This is a prerequisite for support for interop with C++ template names.
No behavior change here, except that it sadly changes the fingerprinting
for a lot of tests.
2025-12-08 15:31:13 +00:00
Dana Jansens 5ae5170421 Allow deduction of tuple and struct literals as symbolic generic facet types (#6365)
Give TupleLiteral and StructLiteral a constant value, if their contents
have constant values. Their constant values are TupleValue and
StructValue respectively. This supports their ability to convert to a
constant type (or facet type).

This way when deduce finds a TupleLiteral as the argument to a
_symbolic_ facet type, it can also find a constant value to use for that
argument. This allows deduction to move onto step two, where it can
substitute into the symbolic parameter from previous deduced arguments,
and then perform the conversion from the TupleValue to the desired facet
type.

Allow `PerformBuiltinConversion()` to convert from a canonical
TupleValue or StructValue to `type` instead of only from literals. Then,
also support conversion from a symbolic binding of type TupleType or
StructType to `type`.
2025-11-13 20:17:44 +00:00
Dana JansensandJon Ross-Perkins ff0cea55f6 Add require decls to Interface and NamedConstraint (#6321)
They are not used for impl lookup or verifying anything yet, but now
they appear in the textual semir.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-11-11 16:36:15 +00:00
Jon Ross-PerkinsandDana Jansens 42e2280150 Clean up singleton TypeId use (#6300)
#6289 absentmindedly added fields in more places, and this is undoing
that plus further fixes.

This does some cleanup of types with relation to singletons. For
`TypeType` and `ErrorInst`, they're always complete due to a
`SetComplete` call in `file.cpp`. For `CppVoidType`, it's intended to be
incomplete by construction, and so a `TypeId` should be okay. The intent
though on not generally providing these had been that `GetSingletonType`
needs to be called to get a type to be marked as complete.

In the case of `AutoType`, removing `TypeId`does change a small printing
detail. I think that's old legacy that's just been carried forward.

Otherwise, for both `InstType` and `AutoType`, I've added
`GetSingletonType` calls where they were used in order to ensure
completeness is applied correctly. These calls cause small SemIR
permutations.

This causes `AutoType` to be seen by lowering, so I'm adding a
placeholder for it. Also merging two functions that look like they're
identical in intent -- not sure why they're separate.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-10-30 22:50:59 +00:00
Dana Jansens f272198ce5 Don't elide Self when dumping the interface/constraint (#6297)
We give `Self` in an interface/constraint a location so it's not elided
when trying to dump the interface/constraint. We use the location of the
start of the definition, which is the scope for which the `Self` is
constructed and is available in.
2025-10-30 20:47:16 +00:00
Geoff Romer 0811d996e1 Finish renaming BindName and related insts. (#6281)
Resolves the TODO from #6235
2025-10-28 17:17:38 +00:00
Geoff Romer 09710d102f Separate binding insts for refs and values (#6235)
This resolves a TODO in `expr_info.cpp` by using the inst kind rather
than the bound value to track the binding's category.

Since we're churning all the `bind_name` insts in testdata anyway, I'm
also taking this opportunity to align the inst naming with the design's
terminology, by calling these insts "bindings" (this aspect of the PR is
dependent on #6231 resolving an ambiguity in that terminology). For
consistency we'll need to rename several other insts as well (see the
TODO on `RefBinding`); I'm deferring that to a separate PR to minimize
the review load, but I think those name changes are in-scope for this
review.
2025-10-23 01:46:24 +00:00
Dana Jansens fe020ee08b Make FacetAccessType evaluate to SymbolicBindingType for type-of a BindSymbolicName (#6115)
The SymbolicBindingType refers to the type value that will be
substituted in for the BindSymbolicName, but holds onto the EntityNameId
from the BindSymbolicName instead of (or in addition to, for now) the
instruction.

The EntityNameId will be used to look in the ScopeStack to find the
witnesses either from the BindSymbolicName instruction, or other
instructions that specify `impls` constraints against the EntityName.

This will allow us to have the `T` in `I(T)` resolve to a `.Self`
reference in the type so that we get type equality with the binding's
type: `T:! I(.Self)`.
2025-10-06 18:56:43 +00:00
Jon Ross-Perkins 47081be67a Reduce test sensitivity to small import loc changes (#6145)
Locations are similarly fragile, because adding a comment changes them.
This has made me pause when making prelude changes in #6144, so dropping
them for those cases.

Instruction ids aren't actually that interesting outside debugging, and
can be churny when doing other structural changes. I've seen this in
particular when doing singleton changes, which bump every instruction
id.

Note there are still other ways fragility from locations can crop up.
This shouldn't be considered a complete fix, but hopefully a small
improvement.
2025-09-30 17:20:14 +00:00
Jon Ross-Perkins 49ba8cf3e1 Switch class to use a blanket impl for Destroy (#6125)
Right now, the class destroy impl is incorrectly generated (first
discussed [in
Discord](https://discord.com/channels/655572317891461132/941071822756143115/1418614787449032826)).
If we want it to be correct, deferred definition logic would need to be
added, and the declaration would need to be moved inside the `class`
scope (along with whatever generic logic that needs).

This instead switches to a blanket impl, to avoid creating latent bugs
with generating the `impl` and function body in the wrong scope. This
approach uses the same blanket impl as aggregate destruction that was
added by #6098.

The intent here is to allow progress on other parts of `Destroy`. For
example, under this model the implementation of the function body could
be done as part of lowering the specific.
2025-09-29 16:05:06 +00:00
Dana JansensandRichard Smith 82679e6689 Make BindSymbolicName the canonical form of a FacetValue wrapping the BindSymbolicName (#6107)
If a `BindSymbolicName` is converted to `type` and then to its exact
`FacetType`, we get a `FacetValue` wrapping the `BindSymbolicName` but
providing no different information: it has the same witnesses and
`FacetType` as the original `BindSymbolicName`. Yet it is a different
constant value, creating multiple canonical forms with the same meaning.
Now we make that `FacetValue` with the same `FacetType` as the
`BindSymbolicName` it wraps evaluate back to the `BindSymbolicName`,
making it the unique canonical form.

This makes the "shortcut" in convert for avoiding impl lookup when
converting from `FacetAccessType` to `FacetType` in this exact scenario
work the same as doing the full impl lookup.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-09-23 22:11:11 +00:00
Jon Ross-PerkinsandDana Jansens 5e3bb523f8 Add builtin functions for destroy, with special requirements in facet types (#6035)
This is in support of a goal of changing the blanket `destroy` impl to
use (roughly):

```
private fn CanAggregateDestroy() -> type = "type.can_aggregate_destroy";

// Handles aggregate type destruction.
impl forall [AggregateDestroyT:! CanAggregateDestroy()] AggregateDestroyT as Destroy {
  fn Op[addr self: Self*]() = "type.aggregate_destroy";
}
```

That isn't done here because there's still other issues that migrating
raises. What this *does* do is add the builtin functions, and in
particular, support to `FacetTypeInfo` to make `CanAggregateDestroy`
work.

The "special requirement" approach in `FacetTypeInfo` allows us to
support restricting a blanket impl under the current approach of impls.
Maybe we'll find a cleaner approach that can work in the future, but
this fits into the current model by propagating similar to other
requirements. I'm using an enum mask because we have a number of similar
things to add (e.g. copy, move) but I'm not sure we need a full vector.

A few alternatives considered were:

- Supporting syntax more like `where .Self impls
TypeCanAggregateDestroy(.Self, SupportedInterface,
UnsupportedInterface)`. I think it'd be a little cleaner, but requires
better compile-time evaluation in order to assess the type of the call.
Right now it's expected to be a `FacetType` too early to make this work,
and I was concerned about pouring too much more time down this route.
- Providing an actual interface, in particular doing name lookup back
into `Core.` for an interface. This would've added name lookup overhead,
and the question of whether an `impl` exists.
- Generating an interface. This avoids the name lookup, but would still
raise the question of whether an `impl` should also be generated. Work
I've previously done generating interfaces for class destruction also
feels complex to both write and understand (an unfortunate issue).
- Still modeling as an `ImplsConstraint`, for example by defining a
special `InterfaceId::CanAggregateDestroy = -2` similar to what we do on
other ids. I was hesitant because of how this expands the number of
modes of `InterfaceId`, and things for consuming code to watch out for,
for what feels like a relatively niche set of use-cases that are only
interface-like.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-09-15 17:03:43 +00:00
Richard SmithandGeoff Romer 1ec8ac7ef9 Add Copy interface and use it for making copies. (#6034)
Instead of hardcoding which types are copyable, add a `Core.Copy`
interface to perform copying. Move almost all the current copy support
to that interface. Some remaining pieces are still using builtin logic
after this PR:

* For tuples and structs, builtin logic is used to perform elementwise
copies. This also supports copying *adapters of* tuples and structs,
which seems like it may not be desirable, especially for non-extending
adapters. A `Copy` impl is provided for tuples of at most 2 elements, so
that `Core.Copy` constraints are satisfied, but we can't implement this
generally until we have variadics support, and don't yet have a
mechanism to generalize this to structs.
* For `enum` types imported from C++, builtin logic is used to perform a
copy. This is temporary until we have a mechanism to identify these
types from an impl in the prelude.

One lowering test in `toolchain/lower/testdata/class/generic.carbon` is
disabled for now, as it causes a crash in the lowering code due to an
ABI mismatch between the call signature in the lowered declaration of a
specific function and the call that is generated in the specific callee.
Fixing this is a little involved, and will be done in a separate PR.

---------

Co-authored-by: Geoff Romer <gromer@google.com>
2025-09-10 23:55:55 +00:00
Richard Smith e8cd229e74 When performing an impl lookup, only import impls for related interfaces. (#6040)
This avoids impl lookups involving, say, `Core.Int` pulling in all ~65
impls in "prelude/types/int", which resulted in a lot of unnecessary
importing work, followed by a lot of unnecessary inst namer and inst
formatter work.

Before:
```
Ran 1335 tests in 6186 ms wall time, 146818 ms across threads
  Slowest tests:
  - toolchain/check/testdata/interop/cpp/function/arithmetic_types_bridged.carbon: 5611 ms, 5532 ms in Run
  - toolchain/check/testdata/interop/cpp/function/operators.carbon: 2034 ms, 1981 ms in Run
  - toolchain/check/testdata/primitives/import_symbolic.carbon: 1796 ms, 1786 ms in Run
  - toolchain/lower/testdata/operators/arithmetic.carbon: 1729 ms, 1728 ms in Run
  - toolchain/lower/testdata/function/generic/call_recursive_sccs_deep.carbon: 1700 ms, 1697 ms in Run
[==========] 1335 tests from 1 test suite ran. (682 ms total)
```

After:
```
Ran 1335 tests in 2419 ms wall time, 109587 ms across threads
  Slowest tests:
  - toolchain/check/testdata/interop/cpp/function/arithmetic_types_bridged.carbon: 1748 ms, 1665 ms in Run
  - toolchain/check/testdata/interop/cpp/function/operators.carbon: 1106 ms, 1057 ms in Run
  - toolchain/lower/testdata/function/generic/call_recursive_diamond.carbon: 1044 ms, 1041 ms in Run
  - toolchain/lower/testdata/function/generic/call_recursive_sccs_deep.carbon: 1015 ms, 1012 ms in Run
  - toolchain/lower/testdata/operators/arithmetic.carbon: 998 ms, 997 ms in Run
[==========] 1335 tests from 1 test suite ran. (652 ms total)
```

That's still slower than it should be, but a large improvement
nonetheless.

Fixes #6029
2025-09-10 21:40:27 +00:00
Dana Jansens ed43fd2c1c Give the BindSymbolicName for .Self in a binding pattern a FacetType type (#6036)
If it's just `TypeType` then the `BindSymbolicName` appears directly in
type positions, but if it is replaced with another facet value, then we
would need to insert a `FacetAccessType` around it. By giving it a
`FacetType` type, like other `BindSymbolicName`s we make it consistent
and avoid having to introduce extra instructions.
2025-09-10 17:57:08 +00:00
Jon Ross-Perkins 0518fdebbc Fix potential fingerprint conflict in constraints (#6033)
This uses each vector's size as a barrier between lists, to eliminate
the possibility of incidental collisions between entries of different
lists. This is the same as is done inside `AddBlock`.
2025-09-09 21:44:03 +00:00
Elliott Kalt 58de34e534 Decouple associated constants from let (#5973)
Decouples associated constants from being special cased in let handlers.
Enforces associated constant grammar restrictions in parsing instead of
checking.

Closes #5411
2025-09-02 23:15:26 +00:00
Dana JansensandJon Ross-Perkins 4b0e2b03b6 Add the .Self name for the type expression of a compile time binding (#5937)
We add a virtual node (`CompileTimeBindingPatternStart`) as the first
child of `CompileTimeBindingPattern` which holds the identifier
underneath it, so that it is checked just before the type expression of
the `CompileTimeBindingPattern`. When we reach this virtual node during
check, we add `.Self` as a name in the current scope, and when we reach
`CompileTimeBindingPattern` we remove it from scope, which ensures it's
present during only the checking of the type expression for the compile
time pattern.

At the moment the `.Self` has a different type (it's a `TypeType`) than
other `.Self` in the facet type (which are a single `FacetType`), but
the intention is to immediately substitute it out of the facet type
entirely, replacing it with a reference to the compile time binding (a
`BindSymbolicName`) itself. A TODO has been added for this.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2025-08-12 16:27:07 +00:00
Jon Ross-Perkins b410ebd088 Fix destruction of generic types (#5943)
The self access is important; for the test `generic_class.carbon` being
added to `toolchain/check/testdata/class/destroy_calls.carbon`, it was
using `%T.as.Destroy` instead of `%D.as.Destroy`, indicating the default
blank impl was being used instead of the type-specific version. That
test is trying to focus on the issue, but the delta is visible in a
couple other files in this PR, for example
`toolchain/check/testdata/class/generic/init.carbon`.

I'm separately working on getting rid of the default impl, which is how
I noticed this.
2025-08-12 00:10:43 +00:00
Dana Jansens 3d77c4441b Compare ImplWitnessAccess into Self as canonical constants (#5883)
This makes all `.Self` references in a facet type canonically the same
(which will remain true iff they refer to the same `Self` type in the
future), removing the need to do more complex comparisons between them
using the EntityName, interface, and index. This allows the comparison
of types containing `.Self` references to be done correctly regardless
of where the `.Self` appears, as such type expressions will all be
canonically equal if they otherwise equal now, regardless of whether
they are written in the context where `.Self` could have seen different
`Self` facet types.

In order to retain access to constraints on a base `.Self` facet type,
in the case of applying `where` to an existing facet type, we:
- Give the base facet type as a `RequirementBaseFacetType` constraint so
that eval of `WhereExpr` can find and copy all the constraints off of
it.
- Introduce eager/early rewrite constraint resolution, which allows a
constraint to eagerly resolve access to earlier rewrite constraints
(`where .A = () and .B = .A` is eagerly transformed into `where .A = ()
and .B = ()`) before the full constraint resolution step. This allows
use of rewrite constraints in larger type expressions, such as `where .A
= () and .B = C(.A)` and `C` will know that the argument is `()`.
2025-08-08 18:36:39 +00:00
Jon Ross-Perkins 55085de6aa Use GetStructType when building object repr structs (#5923)
I was thinking about this for destruction, which I may not be able to
use it for, but still think this may be a good change to keep features
consistent.
2025-08-06 23:55:05 +00:00