Commit Graph
82 Commits
Author SHA1 Message Date
David Blaikie 88b3605eac Fix #7289: Add debug info module flags as-needed and verify if already present (#7336)
This avoids duplicate module flags when compiling C++ interop with debug
info.

Assisted-by: Gemini via Antigravity
2026-06-16 03:18:05 +00:00
Geoff RomerandRichard Smith e023f75254 Implement thunking in terms of constant evaluation (#7332)
The bulk of this change is changing most pattern insts to be `Always`
rather than `AlwaysUnique` constants, so that they can be wrapped in
`SpecificConstant`s to perform substitution. That then lets thunking
rely much more on `SpecificConstant` wrappers instead of deep-copying
the inst tree with modified types.

This approach to thunking should scale better, particularly as things
like form generics make function signatures more complex, because we can
leverage the existing support for constant evaluation and substitution.
Unfortunately, applying this approach to binding patterns will require
more work; see the TODO near the top of `thunk.cpp` for details.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-06-13 00:22:00 +00:00
Richard Smith 25e72882fc Implement Core.CharLiteral operations from #6710 and #7314 (#7316)
Adds support for arithmetic and comparison operators on
`Core.CharLiteral`s, as well as conversions between `CharLiteral` and
integer types.

Make some minor tweaks to fix skill issues encountered while making this
change.

Assisted-by: Gemini via Antigravity
2026-06-11 16:45:39 +00:00
Chandler Carruthandjosh11b 7871237c15 Move self to the explicit () parameter list (proposal #7016) (#7272)
Implements proposal #7016: `self` moves from the deduced implicit list
(`fn F[self: Self]()`) to the front of the explicit list. Its type may
be written explicitly (`fn F(self: Self)`) or omitted, in which case it
defaults to `Self` (`fn F(self)`, `fn F(ref self)`); `self` in the
implicit list is rejected.

Throughout checking, `self` is modeled as the first explicit parameter.
Because a method is just a function whose first parameter is `self`, it
can also be called as an ordinary function with the receiver passed
explicitly (`Type.M(obj, ...)`), not only as `obj.M(...)`. A new
`SemIR::CallArgParamPatterns` helper chooses the parameters matched
against the explicit arguments, excluding a leading `self` only when it
is supplied as a method-call receiver; arity checking, conversion, and
generic deduction use it. The resulting SemIR and lowering are
unchanged: `self` is still `call_param0`, and witnesses, thunks, and
vtables are unaffected.

An omitted `self` type is parsed as a `SelfBindingPattern` node with no
type expression; checking synthesizes the `Self` type so it behaves
exactly like `self: Self`. However, the exact spelling used must match
between a forward declaration and a definition, following #3763's rules
around declaration matching.

Generated functions, thunks, and C++ interop import/export build `self`
as the first explicit parameter, and the `self`-type override (e.g.
Derived->Base for a virtual override) applies to the explicit `self`.
Placement is validated by new diagnostics: `SelfInImplicitParamList`,
`SelfNotFirstParam`, and `SelfOutsideParamList`. The benchmark source
generator and the documentation adopt the `(self)` shorthand; the
prelude, the examples, and the test data are migrated in the following
commits.

Assisted-by: Claude Code with Claude Opus 4.7

---------

Co-authored-by: josh11b <15258583+josh11b@users.noreply.github.com>
2026-06-10 15:30:43 +00:00
Richard Smith cefa0397bb More fixes to package and library fingerprinting. (#7297)
Fix import logic to make all imported packages be children of the
`NameScopeId::Package` scope. Previously, indirectly-imported packages
would end up as children of their importing package's scope, which
resulted in them not being treated as packages at all, and in particular
not being fingerprinted as packages.

Fixing that caused a failure in the fingerprinting logic as we started
to encounter packages with no correspoding import scopes. Instead of
looking for import scopes, use a simpler mechanism to map packages to
their package names, and clean up.

Unfortunately the latter change churns all the fingerprints again :(
Hopefully this is the last time for a while.
2026-06-04 17:41:46 +00:00
Richard Smith 7fe3e35aec Support for float <-> int conversions. (#7275)
Implement support for floating-point <-> integer type conversions as
described in #820 and #845, extended to support `unsafe as` conversions
for the conversions that can't be expressed as either implicit
conversions or `as` conversions.

One tricky part here is conversions from floating-point literals to
integer types. Such literals may have both a very large mantissa and a
corresponding somewhat large negative exponent, and still produce a
result that is in the range of values that a small integer type can
represent. In order to support that while avoiding building very large
2^N or 10^N constants in general, we first compute a conservative
approximation of the number of bits necessary to represent the integer
result, with an early exit if the number is either definitely too large
or definitely zero. The remaining cases have a reasonable bound on the
size of integer necessary to compute the base^exponent multiplicand.

Assisted-by: Gemini via Antigravity
2026-06-03 23:41:20 +00:00
Richard Smith f5e9c61f11 Don't include the library name in most fingerprints. (#7292)
When we import from another library in the same package, its entities
end up with our library as their parent scope, resulting in cross-file
fingerprint mismatches. Instead, only include the library ID when
fingerprinting either a package-private entity or an `ImportIRId` that
refers to a particular `SemIR::File`.
2026-06-02 19:31:30 +00:00
Richard Smith b7f11e4c61 Propagate Carbon type alignments into LLVM IR. (#7290)
Use the Carbon-computed alignment for allocas, loads, stores, and
memcpys. Previously we used whatever LLVM felt like giving us, which
would result in ABI mismatches and runtime crashes due to misalignment
when creating objects of imported C++ class types, as well as resulting
in some surprising choices like `(i32, i32)` and `()` having 8-byte
alignment instead of 4 and 1, respectively.
2026-06-02 01:35:03 +00:00
Richard Smith 49e5e15138 Fix mangling collisions for library-private entities. (#7283)
Include the library name in the fingerprint of an entity declared
`private` at namespace scope. Include the entity's fingerprint in the
mangling of a library-private entity.

This fixes miscompiles if two libraries in the same package declare
`private` entites with the same name. We can't fix this with internal
linkage because library-private entities can be reachable through
generics defined in the API file of the library.

Assisted-by: Gemini via Antigravity
2026-06-01 19:19:08 +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
josh11bandJosh L 832d46f01b Update LLVM (#7221)
Assisted-by: Google Antigravity

---------

Co-authored-by: Josh L <josh11b@users.noreply.github.com>
2026-05-18 17:06:58 +00:00
Richard Smith bc06f6c5ec Mangle the signature decl when mangling a thunk. (#7177)
Fixes mangling collisions when two thunks with the same name (eg, `Op`)
are created in the same context, which in turn would lead to LLVM
verifier failures and miscompiles.

To support this, add a new value store to track a little more
information about thunks beyond what's in the `Function`.
2026-05-07 21:58:29 +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
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
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
Richard Smith dfac728571 Fix pointer sizes in debug info. (#7002)
The size is in bits, so 8 is an unlikely value. Also, don't hardcode a
size, ask the data layout for it.
2026-04-01 16:35:12 +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
Richard Smith c297344937 Support conversion between integer types. (#6856)
Add an `IntFitsIn` interface with a custom witness, such that `T impls
IntFitsIn(U)` if `T` is an integer type all of whose values fit
losslessly into the integer type `U`. Use it to constrain implicit
conversions between integer types.

So far, this has not been extended to the
`CppCompat.[U]{Long32,LongLong64}` types, only to `Core.Int(N)` and
`Core.UInt(N)`.

Assisted-by: Gemini 3 Pro via Antigravity
2026-03-10 01:40:16 +00:00
Richard Smith 8353965ca3 Allow conversions between all pointer types with unsafe as. (#6635)
Previously we only allowed conversions from `void*` to `U*` this way,
requiring casting via `void*` to get from `T*` to `U*`. That seems like
an unnecessary circumlocution.
2026-01-21 15:47:51 +00:00
Richard Smith 31919afa24 Allow conversion between T* and Cpp.void*. (#6575)
Support an implicit conversion from `T*` to `Cpp.void*` and to `const
Cpp.void*`, and an `unsafe as` conversion in the opposite direction.

In order to support C++ calls taking and returning `void*` (which get
mapped to Carbon `Optional(Cpp.void*)`, also support conversions from
`Optional(T)` to `Optional(U)` if there's a conversion from `T` to `U`.

Fix a bug in `OptionalStorage` for `T*` where its `HasValue` was exactly
backwards.
2026-01-12 16:32:15 +00:00
Özgür 29018f38a6 Fix name mangling of generic impls (#6533)
### Description
Mangling collisions occur when implementing interfaces with generic
parameters. The mangler does not use the specific id, causing the same
symbol `_C[FunctionName].[PackageName]:[InterfaceName].[PackageName]` to
be generated for all of the implementations below:
```carbon
// Generic interface parameters ignored
impl C as I(A)
impl C as I(B)

// Generic class parameters ignored
impl D(A) as I
impl D(B) as I

// Both ignored
impl D(A) as I(A)
impl D(B) as I(B)
```

### Changes
Updated the mangling logic for `SemIR::ClassDecl` and
`SemIR::InterfaceDecl` to include the specific id. Now the mangling
ensures unique symbols for generic implementations using the format:

`_C[FunctionName].[FunctionSpecificId].[PackageName]:[InterfaceName].[InterfaceSpecificId].[PackageName]`.

Closes #6498
2025-12-23 00:36:03 +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
Burak Emir 992d435023 Replace unused bindings with anonymous binding in lower/testdata. (#6479)
This updates lower/testdata to use _ instead of proper names, in order
to avoid the "unused binding" warnings from #2022 which are being
implemented. These changes do not depend on the implementation which
should make everything easier to review.

See #6460 with part 1 of the implementation. It was split upon request
in order to make reviewing easier, the original state of the PR was
updating hundreds of test cases.
The PR has thus been split, part 2 including test cases changes can be
viewed at
https://github.com/burakemir/carbon-lang/tree/unused_pattern_bindings_p2022_impl_part2
... many tests need to be updated, so it seems best to get those tests
out of the way that are not interesting.

These are not all tests in lower/testdata - a few of them are
interesting in the sense that they cannot use '_' because it leads to
failed redeclaration check. This is exactly the scenario described in
#3763 which requires the 'unused' marker. Those are left untouched here
but are updated in
https://github.com/burakemir/carbon-lang/tree/unused_pattern_bindings_p2022_impl_part2
2025-12-17 15:43:04 +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
Ammar AlassalandDana Jansens a848ae11e4 Added string indexing (#6329)
Implemented string indexing for Core.string
Handles references or struct values. No runtime checks as per
https://discord.com/channels/655572317891461132/655578254970716160/1431015866270748682
Part of #6270

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-12-11 21:31:31 +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
David BlaikieandDana Jansens a179bd461b Start plumbing through debug info type information with function parameters/return value (#6410)
This adds just enough debug info for i32/int parameters and return
values, with a path forward for adding DWARF type metadata for other
types.

As it happens, return type information is carried separately from
parameter information:
* Return type information is carried in the `type` of the `DISubprogram`
  (as a `DISubroutineType` - which does carry parameter type information
  as well, but that's unused when the DWARF is emitted by LLVM)
* Parameter information is carried by `DILocalVariable`s with a non-zero
  `arg` value (representing the order of function parameters)

In the absence of locations for the parameters (future work), nothing
would usually keep the `DILocalVariable` live/reachable when emitting
DWARF - so for cases where this can happen (for clang, this happens in
optimized builds where all references to the parameter variable might be
optimized away) the variables can be "retained" in a list on the
`DISubprogram` - achieved by passing `AlwaysPreserve` parameter to
`createParameterVariable` (adds them to a list, then that list gets
attached to the `DISubprogram` when it's finalized later)

For now, any unsupported types are emitted as `void*` (except void
return, which is implemented as void) as a placeholder.

Given this example:
```
import Core library "io";
class MyClass {
}
fn Unsupported(v: MyClass) {
}
fn Ret() -> i32 {
  return 42;
}
fn Arg(x: i32) {
  Core.Print(x);
}
fn Run() {
}
```
this is the resulting DWARF:
```
DW_TAG_compile_unit
  DW_AT_name    ("test.carbon")
  DW_TAG_subprogram
    DW_AT_name  ("Unsupported")
    DW_TAG_formal_parameter
      DW_AT_type        (0x00000066 "void *")
  DW_TAG_subprogram
    DW_AT_name  ("Ret")
    DW_AT_type  (0x00000062 "int")
  DW_TAG_subprogram
    DW_AT_name  ("Arg")
    DW_TAG_formal_parameter
      DW_AT_type        (0x00000062 "int")
  DW_TAG_subprogram
    DW_AT_name  ("Run")
  DW_TAG_base_type
    DW_AT_name  ("int")
  DW_TAG_pointer_type
```
And the debugger:
```
(gdb) p Ret()
$1 = 42
(gdb) p Arg(4)
4
$2 = void
```

I'm not sure if there's a way this logic should be merged with the logic
for making the `llvm::Function` type (which the `DISubroutineType`
building code was inspired by/copied from) - since they're done at
different times/places, I don't think there's an easy way to do it in
one pass, but maybe the code can be shared (even if it's run twice) in
some generic `SemIR::Function` type walker.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-11-25 23:25:09 +00:00
David Blaikie bb9942823f DebugInfo: Emit as "C++" rather than "C" (#6361)
This helps at least lldb handle calling functions (currently the debug
info describes every function as `void()`, so no parameters or return
values are supported) - seems gdb and lldb both depend on demangling to
varying degrees in C code (marking a function as "prototyped" in C in
DWARF does seem to also address this problem).

Given:
```
fn PrintThree() {
  Core.Print(3);
}
```
Before:
```
  (lldb) p PrintThree()
  error: Couldn't look up symbols:
    PrintThree
  Hint: The expression tried to call a function that is not present in
    the target, perhaps because it was optimized out by the compiler.
```
After:
```
  (lldb) p PrintThree()
  3
  (lldb)
```
2025-11-18 18:28:56 +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
aa69a484eb Add support for running LLVM optimizer. (#6225)
Adds a flag `--optimize=<mode>` that specifies what to optimize for:

* `--optimize=none` turns off the optimizer as much as possible, but
still respects always_inline.
* `--optimize=debug` aims to be the equivalent of `-Og` / `-O1`, and
provides optimizations that don't affect the ability to debug the
program. This is the default.
* `--optimize=size` optimizes for the size of the produced program, and
aims to be the equivalent of `-Oz`.
* `--optimize=speed` optimizes for the execution time of the produced
program, and aims to be the equivalent of `-O3`.

Following the approach taken by Clang, the optimization level feeds into
both the configuration of the LLVM pass pipeline and the attributes
added to function definitions generated by the frontend.

Optimization is performed in a new phase, `optimize`, which runs between
`lower` and `codegen`.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2025-11-05 00:15:14 +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 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-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
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 50e5476ee3 Add support for unsafe as operator to the toolchain. (#5993)
Following the direction of #5913, add support for parsing an `unsafe as`
operator. For now, we allow one additional conversion using `unsafe as`
beyond the conversions supported by `as`: we permit pointer conversions
that remove qualifiers, such as `const T*` -> `T*`.
2025-08-28 23:00:53 +00:00
Richard Smith 742017c475 Widen integer loads and stores to a multiple of 8 bits. (#5986)
This makes Carbon's loads and stores ABI-compatible with Clang's for
`bool` and `_BitInt(N)`.
2025-08-26 21:49:24 +00:00
Chandler Carruth 0a679504a5 Update LLVM again to 2025-08-09 (#5958)
This lets us pick up another API update to creating lifetimes, as well
as the consequent test updates.
2025-08-14 19:19:27 +00:00
Richard Smith e3a366f1c3 Add prelude impl of Iterate for array types. (#5895)
Iterate over arrays by producing their elements in the obvious way. We
use `i32` as the cursor type because that's the type that check converts
array indexes to. This may need revisiting if we support arrays with
more than 2Bi elements.

Also includes a fix for an import crash bug that's triggered by this
change, borrowed from #5873.
2025-08-01 16:13:22 +00:00
Jon Ross-Perkins 8ea92b728c Update prelude files to increase destroy dependencies (#5848)
This is in anticipation of having `class` depending on the `Destroy`
interface, in order to automatically generate implementations of it.

I'm doing some sorting of imports in the prelude too, which I hope will
be uncontroversial; clang-format would do similar in C++...
2025-07-24 23:57:25 +00:00
Jon Ross-Perkins 7ccc1e0144 Expand naming for impls and functions (#5808)
Change impls from `<interface>.impl` to `<self>.as.<interface>.impl`,
and *member* functions to `<parent scope>.<fn>` (non-member functions
exclude their parent scope). Stop special-casing builtin functions,
given the new naming scheme.

The purpose of this is to make it clearer when a member function is
being accessed and, if so, which member function. In particular, we
often access interface `Op` functions. The builtin function
special-casing was intended to help with that, but we still have lots of
`Op` functions. This particular approach should make the interactions
clearer.

This changes up queueing of block IDs a little because, in particular,
we need to process bodies of entities only after constants finish
processing. But, it should also result in less memory usage during
processing because it means we have less on the insts stack at any given
time, since we track a block rather than all instructions contained by
the block.
2025-07-21 18:45:07 +00:00
Dana Jansens bcba76aca7 Require file tests to specify a min-prelude (#5818)
Use `full.carbon` min-prelude for any tests using the full prelude. A
few tests were using it unnecessarily and are changed to a more minimal
one in the process.

Any test which does not include some min-prelude will now fail with an
error.
2025-07-18 16:26:12 +00:00
Jon Ross-Perkins 4aa62bf5cd Switch Destroy to addr self (#5748)
Pointed out by zygoloid on #toolchain, just taking care of this now.
2025-06-28 00:50:47 +00:00
Jon Ross-Perkins 0722dab0ef Reimplement destroy as an interface (#5678)
This changes `Destroy` to use an interface for its implementation.

Note that this change includes a lot of test updates. Even when
`Destroy` is a no-op, it still causes code generation as part of
determining that.

Originally I was trying to use ranges to cut down the scope of this, and
to a degree I think they have. But a flipside here is that cases where
no destructors should be generated -- particularly globals -- would be
needed to completely remove destructor calls. Even for ranges, the range
can often include the destructor placement. So I've shifted
frame-of-thought a little: accept a bunch of destructor churn, because
destructors are needed and will be prevalent. The verbosity is a feature
of the design to make desugaring apparent in IR, not a bug.
2025-06-27 21:57:14 +00:00
Jon Ross-PerkinsandDana Jansens c3b0c2e425 Use LLVM verifier in lowering (#5733)
Suggested by zygoloid while looking at #5678 

```
CHECK failure at toolchain/lower/context.cpp:62: !llvm::verifyModule(*llvm_module_, &errs): Verifier errors: Instruction does not dominate all uses!
  %.loc17_46.1.temp = alloca { i1, i32, i32 }, align 8, !dbg !13
  %tuple.elem0.loc17_46.2.tuple.elem = getelementptr inbounds nuw { i1, i32, i32 }, ptr %.loc17_46.1.temp, i32 0, i32 0, !dbg !13
Instruction does not dominate all uses!
  %.loc17_46.1.temp = alloca { i1, i32, i32 }, align 8, !dbg !13
  %tuple.elem1.loc17_46.2.tuple.elem = getelementptr inbounds nuw { i1, i32, i32 }, ptr %.loc17_46.1.temp, i32 0, i32 1, !dbg !13
Instruction does not dominate all uses!
  %.loc17_46.1.temp = alloca { i1, i32, i32 }, align 8, !dbg !13
  %tuple.elem2.loc17_46.2.tuple.elem = getelementptr inbounds nuw { i1, i32, i32 }, ptr %.loc17_46.1.temp, i32 0, i32 2, !dbg !13
```

Adds a `--llvm-verifier` flag to be able to turn this off easily,
particularly for debugging the LLVM IR.

The call workaround is due to a verifier requirement `inlinable function
call in a function with debug info must have a !dbg location`. It
specifically comes up for the `++x` case, with `%1 = call i32
@"_CConvert.8b3d5d6a6c17be04:ImplicitAs.Core.b88d1103f417c6d4"(i32
%other)`. I think #5397 is in the direction of a fix for that, but #5397
was set aside because it puts the debug info in too many places.
Instead, address this by adding a stub location for calls that don't
have a good location. I'm deliberately putting this next to the TODO so
that it's easier to understand the association.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2025-06-26 21:34:09 +00:00
Richard Smith a556cf41fc Use static allocas for temporaries. (#5734)
Previously we created allocas for temporaries at whatever point in the
output LLVM function we'd reached. This would result in these being
dynamic allocas (performing a dynamic stack allocation), which is
inefficent and can lead to a stack overflow if it happens in a loop.

Switch to putting the allocas in the entry block instead, and instead
generate a lifetime start marker when we reach the point where the
temporary is introduced. We already did this for local variables; this
is just factoring out and reusing that code.
2025-06-25 21:53:39 +00:00
Dana Jansens badd544798 Add a full.carbon min-prelude that pulls in the full production prelude (#5703)
The `full.carbon` prelude just sets a flag indicating an explicit intent
to include the full prelude. Once all tests include some prelude file,
an error can be enabled (currently it's commented out) that requires an
`INCLUDE-FILE` of some min-prelude to be present in all `check/` and
`lower/` file tests.
2025-06-24 18:10:55 +00:00
Dana Jansens 28fea821b7 Add min-preludes to more slow tests (part 4) (#5682)
Adds min-preludes more tests which were seen as slow and their
surrounding neighbours. This drops the file_test runtime on my machine
from about 6s to about 4.5s.

For a few files that are clearly only testing diagnostics, we drop the
if-present semir ranges and the associated TODO.
2025-06-17 21:10:04 +00:00
Richard Smith 344f0b7550 Support for heterogeneous operators. (#5653)
Replace the binary `Operation` interfaces with the `OperationWith(T:!
type)` interfaces described in the design, and add a `Result` associated
type for both unary and binary operations. Update the `impl`s in the
prelude for integer types to use the new form, including supporting
implicit conversion of either operand.

I've tried to split this PR up into commits focused on distinct changes
for review convenience. It may be simplest to review it one commit at a
time.
2025-06-13 01:55:24 +00:00