Commit Graph
275 Commits
Author SHA1 Message Date
Richard Smith 49024c8d83 Improve diagnostics and error recovery for invalid identifiers. (#7249)
If a keyword or a sized type literal (eg, `f2`) is used in a context
where we are confident that we are expecting an identifier -- either
before a `:` in a binding pattern or after a `.` in a member access or
designator -- then recover as if a raw identifier was used.

This appears to be a particular stumbling block for coding agents, so
seems worth paying special attention to.

Add a mechanism to the tokenized buffer to track additional tokens
synthesized for error recovery so that we can keep the lexed token
sequence immutable and still satisfy the invariants throughout the rest
of the toolchain for recovery tokens. Thanks to chandlerc for suggesting
this approach!
2026-05-22 23:53:19 +00:00
Nicholas Bishop e6b1679552 Add support for field initializers (#7238)
In handle_let_and_var.cpp, field initializers are now handled like
regular `var` initializers, by calling `LocalPatternMatch`.

In pattern_match.cpp, `FieldDecl`s with initializers are handled by
storing a value in `SemIR::File::field_initializers()`. This is a new
map where the keys are `FieldDecl` `InstId`s and the map values are
`InstId`s representing the initializer value.

In convert.cpp, `ConvertStructToStructOrClass` now has a `get_default`
function parameter that callers can use to provide a field default.
`ConvertStructToClass` uses this to provide a default from field
initializers.
2026-05-22 02:48:07 +00:00
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
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
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
Jon Ross-Perkinsandjonmeow 9266ced4e3 Improve CanDestroyType to handle remaining cases (#6943)
This is only fixing the decision about *whether* to produce a witness.
Implementation of the witness is still a TODO, though where a body is
generated, it should also precisely reflect where one _needs_ to be
generated.

Note the tests:

- toolchain/lower/testdata/function/generic/import_core_witness.carbon
- toolchain/lower/testdata/function/generic/import_unused_def.carbon

These tests can probably be produced _without_ Core.Destroy, but I found
the essence of them while trying to build //examples with Core.Destroy
and a simpler minimization wasn't striking me.

Assisted-by: Google Antigravity with Gemini

---------

Co-authored-by: jonmeow <jperkins@google.com>
2026-04-02 22:54:58 +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
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
Jon Ross-Perkins c5761d2d16 Improve parsing large integers (#6908)
Though I started this thinking about performance of parse of large
decimal integers, I extended it to generally improve performance of
integer values (TBH I hadn't expected such a difference for binary/hex,
but I'll take it).

Note I think tests change because I'm making subtle changes to bit
widths. The changes themselves appear harmless to me, but happy to make
changes if it'd help.

Bumping up the number of digits by 10x because it's not really a
performance issue anymore (eh, maybe somebody will want to specify a
256-byte value in binary). But, at a certain point it still seems like a
mistake if somebody has that many digits in a row.

Fixes #980

Highlighting benchmark differences:
```diff
- BM_ComputeValue_IntDecimalN/1           37.1 ns         37.1 ns     18887116
+ BM_ComputeValue_IntDecimalN/1           21.9 ns         21.9 ns     31902433
- BM_ComputeValue_IntDecimalN/10000 1251228680 ns   1250457559 ns            1
+ BM_ComputeValue_IntDecimalN/10000     458818 ns       458626 ns         1523
- BM_ComputeValue_IntBinaryN/1            29.0 ns         29.0 ns     24058533
+ BM_ComputeValue_IntBinaryN/1            22.2 ns         22.1 ns     31566949
- BM_ComputeValue_IntBinaryN/10000     1390557 ns      1389782 ns          506
+ BM_ComputeValue_IntBinaryN/10000       16402 ns        16396 ns        42744
- BM_ComputeValue_IntHexN/1               34.0 ns         34.0 ns     20562432
+ BM_ComputeValue_IntHexN/1               22.4 ns         22.4 ns     31238055
- BM_ComputeValue_IntHexN/10000        5387942 ns      5385262 ns          130
+ BM_ComputeValue_IntHexN/10000          39249 ns        39233 ns        17859
```

Benchmark before:
```
----------------------------------------------------------------------------
Benchmark                                  Time             CPU   Iterations
----------------------------------------------------------------------------
BM_Lex_Float                            10.6 ns         10.6 ns     66138191
BM_Lex_Int                              15.5 ns         15.4 ns     45149703
BM_Lex_IntDecimalN/1                    3.11 ns         3.11 ns    225524908
BM_Lex_IntDecimalN/10                   11.8 ns         11.8 ns     56719805
BM_Lex_IntDecimalN/100                   102 ns          102 ns      6867468
BM_Lex_IntDecimalN/1000                  943 ns          942 ns       745313
BM_Lex_IntDecimalN/10000                9465 ns         9461 ns        73970
BM_ComputeValue_Float                   61.6 ns         61.6 ns     11377463
BM_ComputeValue_Int                      106 ns          106 ns      6587381
BM_ComputeValue_IntDecimalN/1           37.1 ns         37.1 ns     18887116
BM_ComputeValue_IntDecimalN/10          87.7 ns         87.7 ns      7960837
BM_ComputeValue_IntDecimalN/100         7963 ns         7956 ns        88858
BM_ComputeValue_IntDecimalN/1000     1212577 ns      1211906 ns          578
BM_ComputeValue_IntDecimalN/10000 1251228680 ns   1250457559 ns            1
BM_ComputeValue_IntBinaryN/1            29.0 ns         29.0 ns     24058533
BM_ComputeValue_IntBinaryN/10           69.4 ns         69.4 ns     10108642
BM_ComputeValue_IntBinaryN/100           963 ns          962 ns       726982
BM_ComputeValue_IntBinaryN/1000        21562 ns        21551 ns        32506
BM_ComputeValue_IntBinaryN/10000     1390557 ns      1389782 ns          506
BM_ComputeValue_IntHexN/1               34.0 ns         34.0 ns     20562432
BM_ComputeValue_IntHexN/10              70.4 ns         70.4 ns      9953165
BM_ComputeValue_IntHexN/100             1474 ns         1473 ns       472776
BM_ComputeValue_IntHexN/1000           61818 ns        61762 ns        11363
BM_ComputeValue_IntHexN/10000        5387942 ns      5385262 ns          130
```

Benchmark after:
```
----------------------------------------------------------------------------
Benchmark                                  Time             CPU   Iterations
----------------------------------------------------------------------------
BM_Lex_Float                            10.9 ns         10.9 ns     63993114
BM_Lex_Int                              15.1 ns         15.1 ns     46869766
BM_Lex_IntDecimalN/1                    3.16 ns         3.16 ns    220923300
BM_Lex_IntDecimalN/10                   12.2 ns         12.2 ns     57731654
BM_Lex_IntDecimalN/100                   102 ns          102 ns      6875516
BM_Lex_IntDecimalN/1000                  942 ns          942 ns       742359
BM_Lex_IntDecimalN/10000                9353 ns         9350 ns        75096
BM_ComputeValue_Float                   44.9 ns         44.9 ns     15619691
BM_ComputeValue_Int                     48.9 ns         48.9 ns     14361507
BM_ComputeValue_IntDecimalN/1           21.9 ns         21.9 ns     31902433
BM_ComputeValue_IntDecimalN/10          30.3 ns         30.3 ns     23134117
BM_ComputeValue_IntDecimalN/100          224 ns          223 ns      3092567
BM_ComputeValue_IntDecimalN/1000        5834 ns         5830 ns       117469
BM_ComputeValue_IntDecimalN/10000     458818 ns       458626 ns         1523
BM_ComputeValue_IntBinaryN/1            22.2 ns         22.1 ns     31566949
BM_ComputeValue_IntBinaryN/10           32.9 ns         32.9 ns     21306927
BM_ComputeValue_IntBinaryN/100           198 ns          198 ns      3545277
BM_ComputeValue_IntBinaryN/1000         1671 ns         1669 ns       419656
BM_ComputeValue_IntBinaryN/10000       16402 ns        16396 ns        42744
BM_ComputeValue_IntHexN/1               22.4 ns         22.4 ns     31238055
BM_ComputeValue_IntHexN/10              47.8 ns         47.7 ns     14694407
BM_ComputeValue_IntHexN/100              436 ns          436 ns      1609794
BM_ComputeValue_IntHexN/1000            3966 ns         3962 ns       177109
BM_ComputeValue_IntHexN/10000          39249 ns        39233 ns        17859
```

Assisted-by: Google Antigravity with Gemini
2026-03-16 20:00:51 +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
Jon Ross-Perkins b14015602b Make Destroy.Op functions able to have a body (#6729)
This is iterating on how `Destroy.Op` generates, to start adding body
capabilities. This changes the way the signature is created, and adds a
`CoreWitness` function kind so that mangling can prevent name
collisions. The result is that what _was_ `DestroyOp` is now
`Core.Destroy.Op` or, as can be seen in
toolchain/lower/testdata/interop/cpp/nullptr.carbon,
`_COp.<hash>:core.Destroy.Core` where `:core` is indicating that it's a
core witness (taking a note from `:thunk`).

Assisted-by: Google Antigravity with Gemini 3 Flash
2026-03-02 17:57:31 +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 3c324e4877 Add category to parameter format, and share some code. (#6730) 2026-02-13 22:20:05 +00:00
Geoff Romer 1c885a629e Format FormType as "Core.Form" (#6734) 2026-02-13 19:44:21 +00:00
Geoff Romer 7938d9a8d0 Lex/parse support for ->?, :?, and form literals (#6695)
See #5389 (pending) for the language design.
2026-02-07 02:41:22 +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
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 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
Geoff Romer 2b8fdf3417 Switch the prelude to use ref instead of addr (#6359) 2025-11-14 00:40:26 +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
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 e682a6660d Avoid adding extraneous local instructions while importing witness table entries (#6180)
When deducing arguments for generic parameters of an `impl`, the
deduction calls `Convert` on the input arguments. Often, the input
argument is a facet, and needs to be converted to a type via
FacetAccessType in order to produce a different facet. These
instructions end up being added to the semir, but only their constant
values are needed for the resulting specific returned from Deduce.

In the best case, these extra instructions are just noise in the semir,
or they just cause instruction names to get differentiated with larger
suffixes.

In the worst case, these extra instructions contain references to
instructions from a generic context, and leak them out of that generic
context and into another. In particular, when importing a
LookupImplWitness instruction, the re-evaluation of it can do deduce
(when the lookup is against a generic `impl`). The instructions created
in Deduce are not part of the import, and end up referring to imported
instructions from the local context, which leads to confusion in the
toolchain, and can crash.

The `import_self_specific.carbon` test demonstrates this. It causes the
`I.F` function to be imported from the `I` interface when building the
witness table for the `impl`. Doing so imports the specific of `C` which
includes a LookupImplWitness for `Self.Accoc` in `I`. The `Self` is a
BindSymbolicName with generic binding index 0, in `I`. When Convert
creates instructions in the generic `impl forall D`, however, they end
up referencing and including this BindSymbolicName into its eval block.
But the generic binding 0 in the `impl` is a very different thing (a
value of type `E`). This confusion leads to crashes.
2025-10-09 16:07:30 +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
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 4a6376cf59 Rename/restructure Destroy logic to better reflect #6124 (#6144)
This also does a little restructuring in the same direction, following
#6124.

Leads want `Destroy` to work similarly now for all types. As a
consequence, there doesn't seem to be as much benefit to splitting off
aggregate destruction. In this PR, the `type.destroy` function can now
be expected to destroy anything that's destructible; that means it'll be
usable for the `final fn` once that support is available.

Similarly, this gets rid of the impls other than the single blanket
impl, now using `type.can_destroy`. Since they all need to use the same
function, there's no benefit to splitting approaches. Also, now it can
just be a `final impl` since there should be no need for people to
create specializations -- if this blanket impl applies, it means the
`final fn` is the same.

This also slips in `partial` support since there's no reason to have it
diverge anymore. Also `abstract`, which I'm not sure is broadly testable
since most cases it'd come up, the `abstract` keyword is explicitly
detected/rejected.

Note though that this doesn't make any really big changes. It's just
realigning on the leads decision. I'm going this way to try to reduce
name-related churn for other changes.
2025-09-30 20:43:36 +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
Dana Jansens a6bb11f1cf Rearrange convert: construct FacetAccessType from a facet value before impl lookup instead of after (#6113)
This makes convert more consistent, it always makes a FacetAccessType
for a facet value, rather than only doing so after lookup returns. The
intention for this is that FacetAccessType will evaluate to
SymbolicBindingType in the future, so this will expose that constant
value to impl lookup instead of the original facet value, which will
avoid impl lookup having to deal with `.Self` or `BindSymbolicName`
specifically.
2025-09-29 22:49:06 +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-Perkins 9704dc670e Change the Destroy blanket impls to be more specific (#6098)
The main direction of this change is the edits to `destroy.carbon`
(matching in both prelude and min_prelude).

Previously there was a no-op blanket impl for `Destroy`, which hid all
missing implementations of `Destroy`. This does a few things:

- Sets up builtin aggregate destruction for struct and tuple types as
before, but also adds C++ class types and array types to the same
handling. (all as a TODO for actual implementation)
- Also maybe-unformed destruction, for now at least. (there's a chance I
may try a different approach on this, but the impl lookup wasn't working
as I'd hope in order to write it in code)
- Adds handlers for simple things that are easy to do in code: `type`,
`bool`, pointers. (because these are no-op destruction)
- Redirect `const T` destruction to `T` destruction.

This leaves as future issues:

- `partial T` destruction. (this can't be done similar to `const`
because it only works for non-`final` class types; I think `class`
definitions should just generate what's needed)
- Destruction of other prelude-provided types. (will probably come up as
we implement class destruction, that the adapted builtin type doesn't
implement `Destroy` -- but may end up special-casing that in a way that
moots it)

This moves the `&` operator from `facet_types.carbon` to
`convert.carbon` because more things need to handle type and now that
we're getting separate copy and destroy interfaces. It should be
low-cost (an interface and builtin) so hopefully this is the right
balance for complexity and re-use.

A few tests are also edited in order to focus them more on what they
intend to test, and avoid a `Destroy` dependency.
2025-09-18 22:10:50 +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
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
Richard Smith db0a00d713 Fix double-destruction of temporaries. (#6010)
Attach the cleanup to the `Temporary` instruction instead of to the
`TemporaryStorage` instruction. We create `TemporaryStorage`
instructions speculatively when creating an initializing expression, and
may overwrite those instructions with other instructions if it turns out
that a temporary is not required. Instead, wait until we finalize the
temporary and create a `Temporary` instruction to register the cleanup.
2025-09-04 19:19:59 +00:00
Richard Smith 1331ade57f Attempt to complete the source type in a conversion. (#5984)
This is necessary if the source type is an adapter, as we would not
otherwise be able to determine what type it adapts and hence could be
converted to.
2025-08-26 00:33:12 +00:00