Commit Graph
255 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
Nicholas Bishop bd918fb33b Parse vars in classes the same as vars in other locations (#7188)
Class vars are still restricted to simple `name: type` bindings, not
full patterns. This is now handled in the check phase instead of during
parsing.

This is in preparation for supporting `static var`.
2026-05-13 21:22:46 +00:00
Richard Smith dd7cfdb149 Relax alias restrictions. (#7190)
Implement the alias rules from proposal #5389, wherein an alias is
permitted so long as the target has a constant value. While that
proposal is not yet accepted, this seems like a reasonable basis for
further iteration, and will be useful for the examples we're currently
pursuing.
2026-05-12 17:22:44 +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
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
Geoff RomerandChandler Carruth 49c7288619 Restructure return declaration handling (#7076)
- A function with a return declaration always has exactly one
`ReturnSlotPattern`, representing the whole return declaration (whereas
previously that was omitted for value and reference returns).
- The `ReturnSlotPattern` always has a subpattern with the same form.
`OutParamPattern` already plays that role for initializing forms, and
`TuplePattern` will play that role for tuple forms. This change
introduces `ValueReturnPattern` and `RefReturnPattern` to represent
value and reference return forms.
- As before, the `ReturnSlotPattern` has a corresponding `ReturnSlot`
that represents the output that is initialized by a `return` statement.
Its structure parallels the structure of the `ReturnSlotPattern`, so we
need `ValueReturn` and `RefReturn` insts that correspond to
`ValueReturnPattern` and `RefReturnPattern`.

This is a step toward supporting generic return forms, where the
`ReturnSlotPattern`'s subpattern may be an action: this change ensures
that evaluating the action for a specific form produces the same SemIR
as if the form were concrete to begin with. More speculatively, this
should simplify the implementation of `return` statements with compound
return forms.

---------

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2026-04-22 23:38:21 +00:00
Richard Smith 8e0d856725 Improve InPlaceInitializing conversion. (#7021)
Fix some situations where we'd drop the storage argument when building
an in-place initializing expression. We now guarantee that an expression
with the in-place initializing category always has a storage argument.
2026-04-03 21:28:54 +00:00
Nicholas Bishop 396756c151 Handle Temporary values when const-evaling AcquireValue (#6992)
This will be used for const-evaling functions. Splitting into a separate
commit since it touches a lot of test files, and a couple fail_todo
tests are no longer failing.
2026-03-31 15:50:54 +00:00
Nicholas Bishop bf6a14ac39 Support Temporary constants (#6983)
Evaluate `Temporary` constants to a `Temporary` with the `storage` field
set to `None`.
2026-03-30 19:07:46 +00:00
Geoff Romer 18f87e4f79 Include the type in the location of binding insts (#6963) 2026-03-26 18:43:29 +00:00
Richard Smith 37b238fa28 Make C++ types impl Core.Default. (#6962)
C++ classes that are default-constructible now implement `Core.Default`
by calling the default constructor.
2026-03-25 21:07:24 +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
Richard SmithandGeoff Romer ce50f181f1 Add an interface for initialization of vars without an explicit initializer (#6934)
When a `var` is not explicitly given an initializer, initialize it in
one of two ways:

* If its type implements the new interface `Core.Default`, call
`Core.Default.Op` to initialize it.
* Otherwise, if its type implements `UnformedInit`, leave it in an
unformed state. For now, this is always an uninitialized state, but that
will change in the future.
* If neither of those apply, the `var` declaration is ill-formed.

This is a step towards implementing leads decision #6739 and proposals
#257 and #5913.

Assisted-by: Gemini 3.1 Pro via Antigravity

---------

Co-authored-by: Geoff Romer <gromer@google.com>
2026-03-19 23:46:06 +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
Richard Smith 2e5b195813 Make {} as Class an initializing expression. (#6882)
Previously we forced a temporary materialization, resulting in it being
treated as an ephemeral reference expression. This change allows

```carbon
var x: Class = {} as Class;
```

even when `Class` is not copyable.
2026-03-11 20:21:21 +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
Jon Ross-Perkins e2bdbe8507 Make semir scope labels only print when non-empty (#6780)
This shifts logic a little so that empty top-level scopes are printed
less often. This affects imports mainly for now, but should be expected
to affect the soon-to-be-added generated scope more significantly.

Assisted-by: Google Antigravity with Gemini 3 Flash
2026-02-25 00:28:59 +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
Geoff RomerandRichard Smith e5b05a1fac ExprCategory for guaranteed-in-place initializing expressions (#6623)
The primary change in this PR is to split the `Initializing` expression
category into separate `ReprInitializing` and `InPlaceInitializing`
categories, depending on whether initialization uses the types
initializing representation, or is guaranteed to be in place. It also
rationalizes and documents the SemIR-level semantics of those categories
(including where #5545's "ephemeral entire reference" category will
fit), and introduces two new inst kinds to close gaps exposed in the
process.

Some additional secondary changes:
- Consistently format the storage arguments of initializers with `to`,
regardless of whether initialization is in-place, and document the `to`
notation.
- Rename some inst kinds and functions, and restructure some of the
code, for clarity and consistency with the new documentation.
- Resolve a TODO to handle more category conversions in
`CategoryConverter`, in order to make it easier to reason about category
conversions.

See #6588 and the review history of this PR for background.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-02-04 02:27:12 +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 e1ec8d42d1 Give ReturnExpr a target only when initialization is in-place (#6570)
Also clarify and enforce that `ConversionTarget::init_id` is used only
as storage for in-place initialization, and correspondingly rename it to
`storage_id`.
2026-01-13 01:20:15 +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
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
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
Jon Ross-Perkins 6b1ef75ac5 Make generic decl resolution happen during non-pending import flow (#6394)
This is just an incremental step towards removing pending logic. The
rest seems like it'll be more complex due to interdependencies (I've
been poking at behavior).
2025-11-19 21:54:25 +00:00
Jon Ross-Perkins 4a8efd81e3 Rewrite generic binding imports to use AddLoadedImportRef (#6388)
This is part of trying to rewrite pending specific/generic code to make
use of the standard constant resolution flow. The LoadImportRef code was
a particular sticking point due to the recursion it does, which makes it
difficult to adapt over.
2025-11-19 00:56:17 +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
Jon Ross-PerkinsandDana Jansens 8166f9a7cf Formalize Cpp as a PackageNameId (#6306)
This turns `Cpp` into a keyword, and makes it map to `NameId::Cpp` and
`PackageNameId::Cpp`.

Per discussion with zygoloid, the keyword versus identifier question is
deliberately kept open by #4846. This PR switches to a keyword because
mapping to a specific `PackageNameId` works best with a special `NameId`
not backed by an `IdentifierId`. We could in theory make it work using
`IdentifierId` or a runtime-tracked `PackageNameId` for `Cpp` (e.g.
stored on `SemIR::File`), but this approach is consistent with `Core`
and so seemed like a good starting point.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-11-05 17:21:41 +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
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 93b79f159e Change InstId dumping to hex numbers that include the tag (#6175)
This change makes dumping and debugging work again with InstIds that are
now tagged with the CheckIRId. The textual representation of an InstId
is changed from `irN.instM` back to `instM` but the `M` is now a hex
value with the tag as part of it, which is the same number that is
physically in the `InstId::index` field. This prevents any cases where
we would potentially print incorrect values for large InstIds.

We teach the `dump` command in lldb to parse hex values for InstId so
that we can paste these numbers back into the debugger.
2025-10-08 18:45:35 +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 Smith d60900cbeb Remove special case for returning value expressions by copy (#6052)
When returning a value from a function whose return type has a by-copy
initializing representation, perform initialization like we do when the
return type has an in-place initializing representation. This makes our
SemIR representation more uniform, as the return expression will now
always be an initializing expression rather than a value expression, but
more importantly it means that attempts to return a non-copyable type by
value now fail, even if the type has a by-copy initializing
representation.

This catches a bunch of places where we were returning a value of an
unconstrained template parameter `T:! type`, which we were incorrectly
allowing because we didn't notice it was not copyable. Unfortunately
this then requires quite a few test updates.

Like #6034, this exposes a lowering issue where lowering crashes when
attempting to lower a specific copy operation for certain types; a
couple more tests are temporarily disabled here. An upcoming PR
dependent on this one will fix the issue and re-enable those tests.
2025-09-12 00:13:33 +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