Commit Graph
274 Commits
Author SHA1 Message Date
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 7f7186c227 Extended name lookup replaces inner Self (#6632)
When doing name lookup into an extended scope of an interface or named
constraint, the containing scope has an inner `Self` facet which can
appear in the specific of the extended scope. For instance a constraint
`N` which requires an interface `Z(Self)`:

```js
constraint N {
  extend require impls Z(Self);
}
```

When doing member lookup into a facet constrained by `N`, we need to
find the specific interface `Z(...)` where the `Self` is replaced by the
self-type the member lookup is happening on in order for impl lookup to
find a witness later.

Inside that specific interface we repeat the name lookup to find an
associated entity. Then to produce a witness we perform impl lookup
against the specific interface that name lookup returned with the
self-type of the member access. So if we do member access into `A:! N`
for a member `F`, like `A.F`, we would be doing impl lookup with a query
self of `A` and looking for the interface `Z(...)` returned from name
lookup.

When impl lookup has a facet as the query self, which we do here as `A`,
it takes its type (a facet type) and identifies it to find all the
required interfaces, and it substitutes the query self into those
specific interfaces for `Self`. If the `Z(...)` we acquired from name
lookup is `Z(Self)` it will fail the lookup for `A as Z(Self)`, since in
the facet type of `A` it finds a witness for `Z(A)` instead.

Thus, we replace the inner `Self` in extended scopes, such as `N`, with
the self-type of the member access, which produces the extended scope
`Z(A)` for this example. This allows the impl lookup for `A as Z(A)` to
find a witness from the facet type of `A`.

In order to do this, we include an instruction for the inner self when
registering the extended scope. Then, when we find the extended scope in
name lookup, we can use its CompileTimeBindIndex to replace any instance
of that `Self` facet with a new facet. If the self-type of member access
is a type, we construct a FacetValue with an empty facet type that
refers to the type.
2026-01-21 17:48:18 +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
Dana Jansens c64117d0e0 Make IdTag typesafe (#6574)
The IdTag knows the type of the Id its tagging and the type of the Id
being used as the tag. This prevents mixing up tagged and untagged ids,
and avoids having to work with untyped integers.

Adds an Untagged marker struct that's used as the tag type in IdTag when
no tag is desired.

The complexity of ConstantIds and TypeIds became a bit visible: TypeIds
are concrete ConstantIds. And ConstantIds have two different tagging
schemes, one for concrete and one for symbolic ids. And ConstantIds are
actually re-cast InstIds with the same index. The LoweredTypeStore needs
to work with tagged TypeIds, but the tags actually come from an InstId
store in ConstantValueStore. Now this is expressed in the type system by
getting the tags for TypeIds from the ConstantValueStore.

ValueStores without an TagId type parameter are now visibly untagged.

IdTag is now only default constructible when it does not have a tag,
which means ValueStore is only default constructible when the TagId is
untagged. This forces tagged value stores to be constructed correctly
with a tag at compile time, and untagged ones to be constructed without.

FixedSizeValueStore has overloads for dealing with tagged and untagged
Ids, since it can't default-construct ValueStore for tagged ids, and no
longer requires passing in default-constructed tags when there is no tag
in the ids.
2026-01-13 22:44:38 +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 0e5832d3c2 Model ref tags as insts instead of annotations (#6541)
This continues the implementation of the proposed resolution of #6342.
2026-01-05 22:24:47 +00:00
Geoff Romer 2078721e1c Always build ReturnTypeInfo from a function (#6490)
This is a step toward using it to represent the return form, not just
the return type.
2025-12-31 01:30:09 +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
Richard Smith 6b28213b36 Add interop support for naming and "calling" C++ templates. (#6474)
Expose C++ class templates, variable templates, alias templates, and
concepts as callable values in Carbon, and map calls to them into
template-id formation, mirroring how Carbon generics behave. For now,
only type template parameters are supported; non-type and template
template parameters produce a TODO error.
2025-12-15 17:45:01 +00:00
Dana Jansens 6a60b80508 Remove the FacetTypeId in RequireImpls (#6437)
The FacetTypeId should never be used directly, since the RequireImpls is
a generic and the facet type may be parameterized by generic bindings.
So instead, it should be accessed through GetConstantValueInSpecific,
which works with the facet type InstId that is also already present on
RequireImpls. This change to use GetConstantValueInSpecific was done in
#6435, so the FacetTypeId is now unused except in formatting. So we can
remove it.

This depends on #6435.
2025-12-01 20:34:43 +00:00
Richard Smith 6c9a581a83 Switch GetExprCategory to be table-driven. (#6371)
Avoid using a large switch that needs to be manually extended when
adding a new kind of instruction. Instead, the expression category for
an instruction is now specified when defining the `InstKind`.

In passing, add a distinct expression category value for patterns. This
isn't used for much except some error checking at the moment, but it
keeps the number of instructions that we need to manually classify as
`NotExpr` despite having a type very low.
2025-11-20 00:09:10 +00:00
Jon Ross-Perkins fbc7690157 Switch zip to zip_equal where possible (#6389)
There are two uses I'm not converting here, that seem to want the
"shortest" behavior. For everything else, I'm going to `zip_equal` since
it's more restrictive.

I wish `zip` were named `zip_shortest`.
2025-11-18 00:28:06 +00:00
Dana Jansens 0177dc5677 Import contained RequireImpls when importing an Interface or NamedConstraint (#6344)
When importing an Interface or NamedConstraint, walk the block of
`RequireImplsId`s, and for each one:
- Import the RequireImplsDecl from it, which also imports the
`RequireImpls` structure and its id.
- Collect those decls and build a block of `RequireImplsId`s for the
local SemIR to reference from the Interface or NamedConstraint.

The import of RequireImplsDecl is done in a single phase instead of
three, unlike other decls. This is possible since require declarations
have no name, so they can't be referenced by instructions inside them,
thus there's no cycles to concern ourselves with.
2025-11-14 14:31:11 +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
Dana Jansens 81e55bed8a Generate a RequireDecl instruction for require declarations (#6318)
The `RequireDecl` instruction points, via a `RequireImplsId` to a
`RequireImpls` structure in a `ValueStore`. That structure holds the
self-type and facet type, as well as the generic id and parent scope.
`RequireImpls` is always a generic since it only appears in an
`interface` or `constraint`, which both have a generic parameter `Self`
applied to all their members.

The `RequireDecl` instruction evaluates to itself, but drops the
decl_block_id since the instructions within the `require` declaration
are not required in the canonical value which is only used for import.
And import will want to import the `RequireImpls` structure along with
the `Interface` or `NamedConstraint` structure it is in, rather than
recreate it from the decl's instructions. This also avoids repeating all
the instructions within the `require` decl in the textual semir's
constants block.

Adding the `RequireImpls` to the `Interface` or `NamedConstraint`
structure is not yet done, so they are not available for impl lookup or
import yet.
2025-11-11 14:16:09 +00:00
Boaz Brickner b54f2dd592 Support import Cpp; to import Cpp namespace for using C++ builtins (#6320)
This allows writing
```
import Cpp;
```

Instead of writing
```
import Cpp inline "";
```

Part of #6330.
2025-11-06 08:45:28 +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
Dana Jansens ca3f95faa6 Make named constraint eval to a FacetType with itself in it (#6308)
This requires declared FacetTypes to hold NamedConstraintIds (along with
a specific) that are named in an extend or impls requirement. We add
support to stringify and formatter to display the named constraints in
the facet type, and special case when a facet type contains a single
extend named constraint, like we did for a single extend interface.

This means that `RequireIndentifiedFacetType` can now fail, if the facet
type contains a forward-declared named constraint. Add the appropriate
diagnostics for each call to this function, and note the ones that
should change to `RequireCompleteFacetType` in the future with TODOs.

We also add tests for using facet types that can or can't be identified,
or completed, with named constraints in them.
2025-10-31 22:10:35 +00:00
Boaz Brickner d3762f9723 Remove unused ImportCppId and list of Cpp imports in File (#6290)
See discussion:
https://discord.com/channels/655572317891461132/655578254970716160/1432518191350808659

Part of #5245.
2025-10-30 18:03:34 +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
Dana Jansens 22580a47d3 Initial support for empty named constraints (#6245)
Type check named constraint decls and definitions. We don't correctly
error if you put a `fn` inside them. There is no support for `require`
or `alias` yet, so there's nothing useful you can do with them yet.

We have attempted to share code between `interface` and `constraint` as
they are quite similar. First by splitting out some of
handle_interface.cpp to a separate file. Second by sharing some code
paths when you want a facet type from either one, as they both turn into
a facet type.
2025-10-22 18:26:32 +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
David BlaikieandRichard Smith 12fa65e53c Check for use of InstIds from the wrong SemIR::File (#5997)
Use the `CheckIRId` as a unique identifier for the scope of an `InstId`
- if an `InstId` is created within the scope of one `CheckIRId` it must
not be used in the scope of a different `CheckIRId`.

This is achieved without extra storage, but with false negatives for
large inputs.

When an `InstId` is created, the original index of the `Inst` is XORed
with a tag derived from the `CheckIRId` to produce the final `InstId`.
When the `InstId` is used, the expected tag is XORed with the `InstId`
to get back to the original index - if the tags don't match, the
resulting index will be corrupted, likely too large - resulting in an
out of bounds index CHECK-failure.

(the tag value is derived as such:
* take the CheckIRId
* left shift one bit (padding zero)
* left shift another bit (padding 1 - used to signify that the resulting
`InstId` has a tag combined into it)
* reverse the bits

In this way, the tag is unlikely to overlap with the index for small
test cases - making it possible to separate out the `CheckIRId` from the
index in these cases to provide more meaningful debugging/CHECK
messages, and more informative `SemIR` textual dumping that can now
include the `CheckIRId` along with the `Inst`'s index in the name of an
`inst`)

The test churn here is improved printing as tagged `InstId`s can now,
with best effort (more likely for small test cases where the `CheckIRId`
and the `Inst` index aren't at risk of overlapping from the high and low
bits), render the `CheckIRId` as part of the inst's name. Going from
`instNN` to `irMM.instNN`.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-10-02 23:07:36 +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 ef1e47cd07 Remove redundant SemIR:: uses in SemIR (#6106)
Also cleaned up some in #6105, which is what got me looking for more.
2025-09-22 15:55:46 +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
Elliott KaltandRichard Smith f4bd6e42f9 Replace impl fn with override fn (#6008)
This proposal renames the syntax used to mark an overriding definition
of a virtual method from `impl fn` to `override fn` to avoid ambiguity:
besides indicating an overriding virtual function, it can be parsed as
an "impl" declaration when the construct following "impl" begins with a
lambda introduced by "fn".

Closes #5711

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-09-12 23:27:02 +00:00
Jon Ross-Perkins b0d93c2393 Use enumerated values in formatter (#6042)
Noticed this was essentially just fetching then discarding the values,
which felt odd to me. I was considering adding an `ids()` function, but
this would leave only 3 spots that'd use it, and the absence seems like
it'll nudge code towards using the value of `enumerate()` when
reasonable.
2025-09-10 18:40:48 +00:00
Dana Jansens 64139e5d65 Stop using Map for the cache in InstFingerprinter (#6019)
This takes the debug runtime of
`toolchain/check/testdata/interop/cpp/function/arithmetic_types_bridged.carbon`
from 4.7s down to about 4s (so 15% faster overall).

There's still lots of room to improve this test which seems to be
hitting lots of pathological behaviour, but InstNamer is 30% of the
runtime, with fingerprinting's `InstFingerprinter::GetOrCompute`
consuming 10% of cycles. We reduce its impact by using a vector of
vectors instead of a Map for the cache of fingerprints. After this
change InstNamer drops below 24% of the runtime.

Also move the instruction name when giving it to `AllocateName` since it
receives std::string by value, though this doesn't show up in the
profile for the test.
2025-09-08 16:15:10 +00:00
Boaz Brickner b5d86fdb6f Properly dump SemIR for inline C++ imports (#6001)
Dumping SemIR crashed on inline C++ imports and this outputs `import Cpp
inline` instead.
Followup of #5904.
2025-08-29 21:36:10 +00:00
Richard Smith 816d4589cd Make use of new ArrayRef::consume_* functions. (#5975)
Minor code simplifications.
2025-08-21 21:41:53 +00:00
David BlaikieandRichard Smith 3f9fc633fe Add a vtableDecl inst and use that in classes instead of VtablePtr (#5945)
This addresses/avoids the duplicate import of vtables.

I went through a few iterations/etc along the way and left them in the
commit
history for the PR in case any of them are useful to illustrate how I
got here,
or worth revisiting.

Essentially I ended up with a circularity in importing - importing the
class
imported the vtable_decl which imported the virtual functions - and then
pending
specifics of the virtual functions needed the self specific of the
enclosing
class which wasn't ready yet.

Adding ImportRef to the vtable_decl to break the cycle caused me trouble
when
naming the vtable_decl instructions - so I tried making the functions in
the
vtable unloaded ImportRefs instead. That worked, but meant that
importing a
class still was doing O(number of vtable entries) even if the vtable
wasn't
used.

So I revisited the lazy vtable_decl - figured out how to make the naming
work
(when building the vtable_ptr, even though the vtable_decl doesn't have
to be
loaded for the vtable_ptr, I force it to be loaded anyway, to load the
vtable so
it's usable by lowering, etc). And then I could go back to the old
non-lazy
loaded vtable entries (using some loaded ImportRefs in the cases where
we needed
them/had already adopted them).

Then thinking about the VtablePtr instruction, went back/forth on
exactly what
it needed - went from VtablePtr's member being a VtableDecl InstId, to a
ClassId, then back to a VtableId as it was before this patch.

Naming the instructions has one oddity, that the VtableDecl and
VtablePtr
instructions seem to need to add the pending name for the VtableId -
despite not
using the VtableId in their own name - should the inst namer be doing
this work
for parameters of instructions rather than requiring the inst to do it
deliberately? (or am I holding it wrong in some way?)

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2025-08-15 18:36:54 +00:00
Richard Smithandgoogle-labs-jules[bot] 4685890d63 Rename FloatLiteral to FloatValue. (#5911)
In preparation for `FloatValue` being used more generally, and not only
for literals.

---------

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
2025-08-05 22:34:34 +00:00
Richard Smith 36f0a73092 Initial support for interop with class/struct/union fields. (#5849)
Add a new type, `custom_layout_type`, representing a struct type whose
size, alignment, and field offsets can be manually controlled. Use this
as the object representation type for imported C++ class types (which
also includes struct and union types), allowing us to model C++ class
type layouts. In passing, also add support for incomplete C++ class
types, mapping them into incomplete Carbon class types.

Map C++ fields into Carbon field declarations, allowing direct access to
C++ fields from Carbon. So far, no support is added for base classes nor
anonymous struct or union declarations; those will be added in
subsequent PRs. Also, we don't map C++ access control into Carbon yet,
so all C++ fields are accessible regardless of their access control.

For now we still use a `struct_type` as the object representation for
empty C++ classes, in order to continue to support our existing tests
that convert `{}` to empty C++ class types. This is temporary and should
be removed once we support interop with C++ class initialization.
2025-07-25 21:09:24 +00:00
Jon Ross-Perkins fce98b7331 Allow formatting instructions with a missing name (#5839)
This is to make it easier to debug formatter issues. It means printing
can now result in things like:

```
<unexpected>.inst57.loc4_24: type = bind_symbolic_name ...
```

Where the "unexpected" reflects incorrect construction.
2025-07-22 22:46:58 +00:00
Jon Ross-Perkins bd4fbb4393 Expand use of CheckIRId stores (#5820)
This is trying to make it clearer when vectors are being indexed with
`CheckIRId`.

The only one that I still kind of want to change is the
`SmallVector<std::unique_ptr<CompilationUnit>>`, but because it's a
`unique_ptr` that's a little more complex. I may not bother.

Note, some of the changes around nuanced `SmallVector` interactions were
based on trying to copy the way `SmallVector` itself takes arguments,
like with range passing.
2025-07-21 20:02:27 +00:00
124313269a Represent vtables as a top level SemIR construct (#5472)
The goal was/is to reduce the overhead for vtables in generics - the
previous representation/prior to this patch caused a new vtable to be
created in every specific which isn't generally what we want for Carbon
generics (the whole specific/generic thing is meant to avoid creating
specific versions for things that can be a generic form parameterized by
a specific instead of manifest as a unique entity per specific)

So this moves vtables to a top level object (like functions, classes,
etc). Each dynamic class will have a vtable in this list.

Classes have a `vtable_ptr` instruction in them that points to the
vtable.

The actual generic support hasn't been implemented in this patch, as
I've been struggling with just getting this part of the migration going
& wanted to get it flushed out before adding the additional
complications.

It's possible more laziness when doing cross-file importing would be
suitable - for instance if we only need to reference the vtable from
another file, but don't need to know its individual contents, it may be
beneficial for the functions in the vtable to be import_refs (or to add
another layer of indirection - so it can be a single import_ref
all-or-nothing for the functions in the vtable).

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
2025-06-27 18:45:26 +00:00
Richard Smith 4e5dccdbf7 When making a direct call to a thunk, inline the call in SemIR. (#5642)
This preserves the constant values of the arguments to the thunk, which
is important if the thunk requires conversion of an `IntLiteral` to some
other type. This should become unnecessary once we have form support,
but avoiding the indirection through a thunk function seems valuable
even once that support is in place.

To support this, track whether a function is a thunk on the Function
object, and if so, what the callee of the thunk is. This information is
also included in formatted SemIR when dumping the thunk.
2025-06-11 21:34:01 +00:00
Jon Ross-Perkins 81ca949ab8 Replacing lowering vectors with FixedSizeValueStore (#5636)
Changes the vectors on `Lower::FileContext` to be `FixedSizeValueStore`
where possible, which we have several at this point.

This changes `FixedSizeValueStore` to prefer inferring the size from a
`ValueStore<IdT>`, which should make adding incorrect sizes harder. Note
I wasn't sure that adding a `size()` to `TypeStore` that returned
`insts().size()` would be good because it doesn't directly work that
way; `ConstantValueStore` would've also required more work since it
doesn't have access to that right now.
2025-06-10 20:15:19 +00:00
Jon Ross-Perkins 2e297b5258 Add a fixed-size ValueStore (#5628)
Trying to build a type around the common idiom we have for types based
on an Id range. The primary advantage of this is it makes clear the `Id`
association, and drops the `.index` use.

Lowering was motivating me because it has a few of these, and check
probably has more (e.g. `tree_and_subtrees_getters`), but I'm just
changing a handful of examples to show the concept and see if there's
agreement.

I wanted to inherit from ValueStoreTypes, but name lookup didn't seem to
find the types without `using` statements, at which point there didn't
seem to be much reason to use inheritance.
2025-06-06 22:10:12 +00:00
Jon Ross-Perkins 1e9e148c3b Rename the ImportRefs block to Imports (#5618)
I've been mulling the name of this, changing it and updating comments to
try and better reflect the current semantic. "Imports" reflects how
we're currently printing this in SemIR.
2025-06-05 21:24:58 +00:00
Dana Jansens 02fc484f23 Make pointers in ValueStore stable across insertions (#5576)
This avoids reallocating the backing buffer in ValueStore so that
references into the ValueStore are never invalidated when adding new
values. This works especially well since we never delete values from a
ValueStore.

The strategy used is to allocate chunks of a fixed size, and inserting
into each chunk until it is full before allocating the next. The
ValueStore starts with an initial allocated chunk in all cases, so that
there is only a single indirection for adding and accessing values from
this chunk. After it's full, additional chunks are allocated in a
vector, so two indirections are required to add or access values in
these chunks.

This obviates the need for
https://github.com/carbon-language/carbon-lang/pull/5529 as we no longer
need to worry about holding pointers into a ValueStore.

We introduce a Flatten operation for ranges. It flattens a "range over
ranges over Ts" down to a "range over Ts". This allows us to make an
range over the values in the ValueStore from a range over the chunks in
the ValueStore. See
https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.flatten
for inspiration for this name choice. Flatten is used in one other case
where we were writing two levels of for loops to do the same thing.

The `array_ref()` accessor is changed to `values()` and its now a range
(typed as a `ValueStoreRange`) over all values as references (like
ArrayRef was, but without random access).

As pointers to a ValueStore can no longer be invalidated, we remove the
ASAN poisoning feature and support from ValueStore.

This may cause a regression in our compile benchmark of up to 5%, though
that is close to or within the noise of the benchmark. We can look at
ways to optimize things further in the future. Perhaps by tuning the
chunk size further, or by making later chunks larger than earlier
chunks, or other strategies.
2025-06-02 19:16:31 +00:00
Jon Ross-Perkins e3738eb196 Try out a different IdKind table approach (#5528)
I was thinking about these after #5526, was wondering how others will
feel about this kind of approach:

- Adding a helper to `TypeEnum` to get the table construction.
- In what were previously `Make` functions, return the element instead
of returning the table.
- By returning the element, no more need to pass in a nullptr (now have
a concrete instance).

I think this is a mild simplification, but maybe worth it.

Note, would appreciate it if there are thoughts on how to provide a
boilerplate `Invalid` implementation (maybe it'd be fine to just return
`nullptr` and cause a crash that way, but I was hesitant to do that).
2025-05-31 02:15:45 +00:00
Jon Ross-Perkins a01648cd44 Use concat in formatter (#5577)
Because this is coming up on #5576
2025-05-30 14:36:19 +00:00
Jon Ross-Perkins 34b892b774 Fix formatting of forward declared generics (#5530)
Noticed this while working on class tests (crash bug). Forward declared
generics have a decl_id of the forward declaration, not the definition.
I'm giving up trying to have the caller know if it's a start node, and
instead just choosing based on the node kind.
2025-05-29 20:20:06 +00:00
Jon Ross-Perkins c0d31d428b Change range formatting to be more conservative about specifics (#5516) 2025-05-22 16:31:27 +00:00
Jon Ross-Perkins 0091c699a9 Unwrap FormatInst templating (#5505)
Now that `FormatInstLhs` and `FormatInstRhs` are no longer templated,
remove `FormatInst` templating.
2025-05-21 16:21:13 +00:00
Jon Ross-Perkins 7c2a6ef0e9 Restructure FormatInstRhs to allow for better logic sharing (#5494)
Taking a stab at restructuring towards allowing better reuse. Some of
that is with `AnyAggregateInit` and `AnyImportRef`. Some with
`FormatDeclRhs`.

This adds a `FormatArg` dispatch table so that `FormatInstRhs` doesn't
rely as heavily on templating. I'm mixed on the intermediate result -- a
step further might be to change `FormatArg` to dispatch to a
`FormatArgAndKind` that could use a switch. But, figured I'd check in on
the general direction.

Note this kind of direction opens up changing `FormatInst` to not be
templated, too, removing the `#define CARBON_SEM_IR_INST_KIND(InstT)`
variant of `FormatInst`.
2025-05-20 23:05:23 +00:00
Jon Ross-Perkins 27d0d26739 Replace value_kind with has_type, make FormatInstLhs name-dependent (#5501)
InstValueKind is really just wrapping HasTypeIdMember. Rather than
exposing this as an enum, expose it as a bool since it better reflects
what's going on.

In eval.cpp, AddImportedConstant should never be called on an untyped
instruction.

In FormatInstLhs, we can also depend on whether InstNamer has assigned a
name in order to decide whether to print an instruction. This should
avoid some divergence with CollectNamesInBlock.

We also discussed restoring InstValueKind::Untyped, but that's mainly
motivated by the formatter, and the InstNamer approach gives a more
localized implementation.
2025-05-19 23:26:32 +00:00