Commit Graph
223 Commits
Author SHA1 Message Date
Geoff Romer d21cc3197f Fix the textual IR name of WrapperBindingPattern (#7650)
`at_binding_pattern` is a relic from an earlier revision of #6930.
2026-08-18 22:31:27 +00:00
DavidLoftus 70b6abd6f1 Implement FloatLiteral addition and subtraction (#7621)
Addresses part of issue raised in
https://github.com/carbon-language/carbon-lang/issues/7159 by
implementing float.add & float.sub builtin for FloatLiteralValues

The following code now compiles:

```
let a: f64 = 1.0 + 1.0;
```

Code handles case where operands are both decadic (base 10) and dyadic
(base 2) real literals, with the result being whichever format results
in smaller mantisssa.

File tests assert equality by converting to f128, this can possibly be
improved once CompareWith is implemented for FloatLiteral too.

Assisted-By: Gemini
2026-08-18 17:47:58 +00:00
DavidLoftus 54b7f1345a Implement Core.Negate for float literals (#7616)
Addresses part of issue raised in #7159 by implementing float.negate
builtin for FloatLiteralValues

The following code now compiles:

```
let a: f64 = -1.0;
```

To achieve this I switch the mantissa from being unsigned to signed.
Lexed literals within source file will still always be unsigned, however
it is now possible to create negative FloatLiteralValue constants. Main
non-local changes this causes is:

- All llvm::APInt parsing / printing calls flipped isSigned param
- Zero extension replaced with sign extension
- getActiveBits() replaced with getSignificantBits() for min bit width
calculation
2026-08-13 20:28:42 +00:00
Christopher Di BellaandRichard Smith 4ea5ef45dd Skip ImplWitnessTable::elements_id when generating fingerprints (#7629)
Implementing interface modifiers causes an infinite loop when generating
fingerprints because the witness value generates a fingerprint that's
dependent on something dependent on the witness value. We've debugged
this to the witness table's `elements_id` field.

This hack is a workaround for creating a new block type whose value is
not codependent with its identity.

Co-authored-by: Richard Smith <richard@metafoo.co.uk>

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-08-11 22:39:30 +00:00
Dana Jansens f51c075f8b Avoid symbolic witnesses for .Self in an impl decl (#7564)
Point symbolic witnesses into `.Self` written inside an impl decl at the
impl that is being declared. This is tricky because the impl does not
yet exist. So we use a new instruction `ImplSelfWitness` which _will_ be
replaced by the `ImplWitness` once it becomes available. The
`ImplSelfWitness` acts like a symbolic witness, except it does not
perform lookup, since we know which impl we will get a witness from.

This prevents us from finding other impls when performing lookups into
`.Self` in an impl decl, which produces incorrect/incoherent results.
2026-07-29 16:25:23 +00:00
Lucile Rose Nihlen 625f2ca629 precompile and cache Carbon prelude (#7432)
Refactors the link driver to automatically compile and cache the carbon
prelude for use in linking.

Implements a `carbon_library` rule for compiling the Core library
dependencies in the examples.
2026-07-16 18:02:14 +00:00
Richard Smith a8afc45ed5 Omit empty observe: blocks from formatted SemIR. (#7487)
Also add SemIR ranges to observe test, removing 5K lines of
uninteresting SemIR output.
2026-07-13 20:38:19 +00:00
Chandler Carruth 8be274cf60 Replace :! binding syntax with phase keywords and contextual defaults (#7479)
Implement the toolchain side of proposal #7254, removing the `:!`
binding
syntax for generic and template parameters in favor of the keywords
`generic`,
`template`, and `runtime` plus contextual defaults for phase.

For valid programs this is semantics-preserving: each binding resolves
to the
same phase, and produces the same SemIR, as it did under `:!`/`:`. The
parser
derives a binding's phase from its syntactic context plus any explicit
phase
keyword; new diagnostics and error recovery for misused keywords are
described
below.

Implementation details for each component:

- Lexer: remove the `:!` (`ColonExclaim`) token, move its virtual
parse-node
  budget onto `:`, and add the `generic` and `runtime` keywords.
- Parser: thread a `BindingContext` (`ExplicitParam`, `DeducedParam`, or
`CompileTimeEntityParam`) from declaration introducers down through
parameter
lists to each binding pattern, using a one-token lookahead to
distinguish a
name-qualifier parameter list from a declaration's own final list.
Parameters
of a compile-time entity (`class`, `interface`, `constraint`, `choice`,
`alias`, `export`, `namespace`) and deduced `[]` parameters default to
checked
generic; explicit function parameters and local bindings default to
runtime.
`HandleBindingPattern` resolves the phase from that context plus the
keyword: a
`generic` keyword needs no node of its own (the phase is carried by the
  binding's node kind), while a `runtime` keyword is preserved as a
`RuntimeBindingName` node so `check` can name it in a diagnostic. A
phase
keyword that is merely redundant with the contextual default is
diagnosed
  here, without invalidating the parse tree.
- Check: a phase keyword that is invalid for its context (for example
`runtime`
on a checked-generic parameter) is diagnosed here, and recovers by
building an
error binding that still introduces the name so that later uses of it do
not
  produce cascading errors.

The removed `:!` syntax is now rejected as an ordinary parse error.

The `form`/`:?`/`->?` ("extended types") portion of proposal #7254 is
left for a
separate change.

Assisted-by: Claude Code
2026-07-11 01:22:44 +00:00
Dana Jansens 4261bb2dd2 Track and don't replace active .Self (#7443)
In #7436 we stopped substituting `.Self` when collecting witnesses out
of a facet type. While this was correct, it did not capture all the
cases that need to avoid substituting `.Self`. And it poisoned the
`IdentifiedFacetType` cache by not replacing `.Self` but storing the
result in the cache. This led to incoherent behaviour, where the result
of an impl lookup would change depending on which ones had been done
previously.

Now we use a flag to track for each `.Self` if we're currently
type-checking inside the scope where it was introduced in a facet type.
While inside that scope, identify should not replace the `.Self`. Any
use of it should remain as-is since we don't yet know what value will
replace it. We call this state "frozen" since it should not be modified
by identify. This requires a substitution step when we leave the scope
that introduced the `.Self`, to remove the flag. The flag is set in the
`EntityName` of the `SymbolicBinding`, and is part of the canonical
value, since `.Self` can become part of types, which are constants, and
the flag needs to follow it for correct behaviour.

We also have to ensure the flag is the same when doing comparison with
constants from inside a facet type and constants from outside. For
instance in `(Z where .Z1 = ()) where .Z2 = .Z1`, when we arrive at the
second `.Z1` its `.Self` will be frozen, while the `.Z1 = ()` contains a
non-frozen `.Self`. So we add the frozen flag to the first when storing
it in `where_stack` in order to compare the constant values of the two
`.Z1`.

The `WhereExpr` requirement inst kinds now have an `InstConstantKind` of
`AlwaysUnique` instead of `Never`. This allows us to add them to the
usual InstBlocks, and in an `eval fn` body they have a constant value,
so eval does not fail when trying to call that function. We have to be
careful to not consider `AlwaysUnique` as being actually concrete
though, since their constant value erases `.Self`-dependence. This
allows us to stop special casing them when thawing the requirements
block in a `WhereExpr`, and we can just thaw each `InstId` in the block
in a straightforward manner.

We add the new flag to the instruction's fingerprint and name in
formatted semir.
2026-07-08 18:04:56 +00:00
Özgür T. ÖnsoyandDana Jansens 08385adeb5 Implement checking observe declarations (#6709)
This adds SemIR structs and implements building `observe` lists, as well
as naming, formatting, and importing `observe` declarations.

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
2026-07-08 17:07:10 +00:00
Geoff Romer 8945305dfc Emit NameBindingDecl after the initializer (if any) (#7467)
In some cases the pattern block can depend on the initializer, so it
must be sequenced after it. See #7469 for a more detailed explanation of
why this is necessary.
2026-07-07 19:18:33 +00:00
Geoff Romer 0460f6b7ba Label VarStorage as var_storage instead of var (#7447)
This makes the textual format clearer and more self-explanatory, and
avoids ambiguity about whether this inst refers to the storage or the
pattern.
2026-07-02 01:02:19 +00:00
Geoff Romer e4b0903d2e Remove ValueBinding and RefBinding (#7427)
These inst kinds are now redundant with `WrapperBinding`.
2026-06-29 17:41:23 +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
mstr-six 250da35c3b Recover when converting to an invalid integer type (#7342)
Converting an integer value to a destination type that is not a valid
integer type -- such as `i8388609` or `i16777216`, whose bit widths are
diagnosed as invalid -- hit a CHECK failure in
`TypeStore::GetIntTypeInfo` during constant evaluation of `int.convert`
/ `int.convert_checked`:

```
CHECK failure at toolchain/sem_ir/type.cpp:189: int_info: Type type(...) is not an integer type
```

The width error is already diagnosed when forming the type
(`IntWidthNotMultipleOf8` / `IntWidthTooLarge`), so `PerformIntConvert`
and `PerformCheckedIntConvert` now use `TryGetIntTypeInfo` and produce
an error value instead of crashing, following the existing
`SemIR::ErrorInst::ConstantId` convention in `eval.cpp`.

Added a file test covering all three reproducers from the issue
(`i8388609`, `i16777216`, `Core.Int(8388609)`); it crashes without this
change. The full `//toolchain/testing:file_test` suite (1578 tests)
passes.

Fixes #7278.

I have reviewed this change and take responsibility for it.

Assisted-by: Claude
2026-06-12 21:19:57 +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
Richard Smith ae6846197a Remove trailing () from Core.*Literal and Core.Bool. (#7313)
We exposed `Core.IntLiteral()`, `Core.FloatLiteral()`,
`Core.CharLiteral()`, and `Core.Bool()` as functions as a workaround,
because we had no way to provide the type names without parentheses that
the design requests. But now we can do so, by using an alias. Switch all
of these over from being functions to simply being names of the
corresponding types.

Assisted-by: Gemini via Antigravity
2026-06-05 22:33:30 +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 88c191146d Support for float <-> float conversions. (#7279)
Implement support for floating-point <-> floating-point type conversions
as described in https://github.com/carbon-language/carbon-lang/pull/820
and https://github.com/carbon-language/carbon-lang/pull/845.
Value-preserving conversions are implicit; narrowing conversions require
explicit `as`.

Assisted-by: Gemini via Antigravity
2026-06-04 00:33:33 +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 e45045d63b Implement char operations from #6710 (#7266)
This only covers `char`, and does not include the `CharLiteral`
operations.

Assisted-by: Gemini via Antigravity
2026-05-27 23:18:27 +00:00
Richard Smith a779cc37a0 Support converted ref arguments. (#7258)
Allow a `ref`-tagged expression to be converted to match a reference
parameter. Move the `ref` checks to the start of `Convert`. Remove the
diagnostic for applying `ref` to a non-reference expression so that
non-reference expressions that convert to a reference would be accepted
(although we don't currently have any such conversions).

Assisted-by: Gemini via Antigravity
2026-05-26 20:38:49 +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 Romer 4c9049346d Replace form insts with actions (#7100)
See
[here](https://docs.google.com/document/d/1rWcueFwIfZox6GKVGxiUG4cBzjrZ6djXiIDGyJDtrE4/edit?tab=t.0)
for the design doc.

This also removes the default value of the `result_type_inst_id`
parameter of `HandleAction`, moves it before the action in the parameter
list, and documents it. This solves two problems:
- The default made it easy to forget, leading to unnecessary
`TypeOfInst` instructions.
- When it was present, putting it after the fairly "bulky" action
argument tended to make the callsite harder to read.
2026-04-29 18:13:42 +00:00
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
Geoff Romer 34764d0d0e Fix issues from #6745 (#6811)
- Typo in the definition of `Core.Form`
- Resolved TODO to add test coverage
- Restored lexicographic order in a switch
2026-02-27 22:47:00 +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
Jon Ross-Perkins e2bdbe8507 Make semir scope labels only print when non-empty (#6780)
This shifts logic a little so that empty top-level scopes are printed
less often. This affects imports mainly for now, but should be expected
to affect the soon-to-be-added generated scope more significantly.

Assisted-by: Google Antigravity with Gemini 3 Flash
2026-02-25 00:28:59 +00:00
fdb188ccfd Implement unused pattern bindings, continued (#6518)
Implementation of unused pattern bindings #2022, continued.

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

---------

Co-authored-by: Burak Emir <bqe@google.com>
Co-authored-by: jonmeow <jperkins@google.com>
2026-02-19 23:33:36 +00:00
Geoff Romer 6a3529f4b5 Add Core.Form to prelude (#6745)
Unfortunately, currently it has to be a function rather than a constant.
2026-02-19 19:26:56 +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
Jon Ross-Perkins 917ce5bd6b Fix a duplicate diagnostic on incomplete return types. (#6684)
For example, see toolchain/check/testdata/class/fail_incomplete.carbon
for the diagnostic changes. `IncompleteTypeInFunctionReturnType` should
remain, while the redundant `IncompleteTypeInFunctionParam` is removed.

Note I'm deliberately trying to validate the return type after other
parameters, because I think that's the better user experience. This does
also incrementally change IR.
2026-02-03 17:57:51 +00:00
Richard Smith c0b24047dd Interop support for initialization via std::initializer_list. (#6672)
Add a new builtin function `cpp.std.initializer_list.make` that takes an
array and returns a `std::initializer_list`, initialized to refer to
that array. When C++ initialization wants to perform a
`std::initializer_list`-from-array construction, synthesize a
declaration of a matching builtin function and use that to perform the
initialization.

Ideally we would specify this conversion as an impl of `ImplicitAs` in
the prelude instead of hardcoding it in the interop layer, but
unfortunately that's not currently possible, for various reasons -- we
can't make the conversion form-generic, we can't deduce the array length
from the initializer, and we can't deduce against the arguments of
imported C++ class templates yet -- so for now synthesizing a builtin
function on demand is the best we can do.

Assisted-by: Gemini 3 Pro via Antigravity
2026-01-30 22:24:18 +00:00
f42352759f Adding support for UInt-to-char conversion (#6425)
This pull request adds support for integer-to-char conversion, allowing
the compiler to correctly handle character casting, implementing part of
the issue #5922.

```carbon
import Core library "io";

fn Run() -> i32 {
	var i : i32 = 65;
	var ch: char = (i as char); // Support implemented!
	Core.PrintChar(ch); // Print 'A'
	return 0;
}
```

---------

Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
2026-01-21 21:48:49 +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
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