If the deduction fails while forming the parameter type, ensure that we
print an actual diagnostic saying what went wrong.
And always ensure that an invalid array bounds error points at a
location. The `inst_id` given to `EvalConstantInst` always has a
location, but the `bounds_id` instruction inside it may be canonical
when it's coming from inside a larger type. So when it is, fall back to
using the location of the whole array inst.
These files aren't exactly written in Carbon, but rather in some
meta-language with file splits and semantically meaningful comments, and
in any case getting red squiggles for expected errors is distracting and
largely unhelpful.
(We *could* teach the LSP to run the test and produce errors if the test
doesn't match its expectations, but it's not clear that that would be
helpful in practice either.)
This disallows building a facet type that contains another facet type
with non-extend constraints in it. Which in turn prevents the
possibility of introducing a different `.Self` into a facet type.
Eval can still insert a facet type with non-extend constraints, as we
only prevent it for `where` being written into the facet type. There is
a TODO in handle_where.cpp for this and some tests in
toolchain/check/testdata/facet/nested_facet_types_from_eval.carbon
In `PerformActionHelper`, use the unqualified type for lookup.
In `PerformInstanceBinding`, propagate qualifiers to the unbound element
type's class type when doing the `ConvertToValueOrRefOfType` conversion,
and to the element type when forming the `ClassElementAccess` instr
(except for `partial`, which is only used if the member being accessed
is `base`).
In handle_operator.cpp, prevent assignment to a reference to a const
type.
Move the existing derived->base conversion earlier in
`PerformBuiltinConversion`, into the block that handles qualifier
conversions. This allows, for example, converting from `partial Derived`
to `partial Base` -- see the tests in
`toolchain/check/testdata/class/inheritance/derived_to_base.carbon`.
The function to set the visible declarations with a given name
overwrites any existing declarations imported from an AST file, so we
need to avoid calling that for declaration contexts whose names are
managed by Clang to avoid clobbering names imported from modules.
Assisted-by: Gemini via Antigravity
Depending on the order in which type completion identifies things in the
facet type, it may try to replace `.Self` with a facet that fails to
convert to the type of `.Self` due to a monomorphization error. We
should fail gracefully, not crash.
The text SVG would sometimes be processed by vscode before it finished
initializing its font engine and then get aggressively cached, resulting
in the logo sometimes missing one of the characters.
The new SVG logo is a bit more dense than the old text one was, so shows
up as a C++ "banner" a bit better, and should be displayed more
consistently.
Assisted-by: Gemini via Antigravity
Our mirror repositories contain vim scripts and textmate grammars,
neither of which have any need for the LLVM exception, so we can use the
base Apache 2.0 license there with no loss of relevant permissions. This
is a compatible license, so providing these repositories under these
license terms is valid.
Other than removing the LLVM exception, the new license file has one
other change compared to LICENSE: the amount of whitespace on some lines
is reduced from four spaces to three. This makes the new license
*exactly* match the Apache 2.0 license, byte-for-byte.
This is important because the license checking done by GitHub's linguist
project doesn't recognize Apache-2.0-with-LLVM-exception as an
acceptable license, but does allow plain Apache-2.0.
Copy MultiplexExternalSemaSource.h and MultiplexExternalSemaSource.cpp
from https://github.com/llvm/llvm-project/pull/204458 into
third_party/llvm, and apply a few minor changes to allow them to compile
and pass precommit checks.
This allows
`0011-Add-empty-constructor-and-GetSources-method-to-Multi.patch` to be
removed, which brings Carbon closer to being able to compile on an
unmodified LLVM toolchain.
Add support to the dump command to `dump context import_ir_inst123`
Support for dumping the ids was previously added, but missed support for
parsing and creating a C++ id from its printed id.
Formatting an instruction with an initializing expr category will call
`FindStorageArgForInitializer()` to get the target id.
`GetExprCategory()` supports imported instructions by walking to the
imported IR, in order to get the expr category. We do the same in
`FindStorageArgForInitializer()`, instead of hitting a CARBON_CHECK.
The new test crashes without the changes here.
Also some Bundle API tweaks:
- Remove support for non-canonical bundle IDs. Bundles don't have a
unique identity, so non-canonical bundle IDs would bloat the SemIR for
no benefit.
- Adjust the conversions between raw and typed bundle IDs to not be
templated. This makes the conversions easier to access in a debugger.
Notably this allows accessing fields in an abstract base class via a
derived class without going through `base`. E.g.
`my_obj.field_in_base_class` rather than
`my_obj.base.field_in_base_class`.
Incorporates changes from these proposals:
- #2022
- #2875
- #3262
- #3763
- #3848
- #5434
A small amount of updating was done to lambdas.md and variadics.md to
harmonize with these changes.
Assisted-by: Gemini via Antigravity
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Geoff Romer <gromer@google.com>
TextMate doesn't support JSON grammars, so convert our JSON grammar to a
plist automatically as a pre-commit check. Fix malformed info.plist
file. Add missing uuid to grammar file.
Assisted-by: Gemini via Antigravity
Switch into C++ syntax highlighting mode inside inline C++ fragments in
Carbon code. Add a background to them to make their boundaries stand out
a bit more.
Assisted-by: Gemini via Antigravity
Refactor the textmate grammar to use a different scope for testdata
files. Move the existing handling for `CHECK:STDOUT:` there, and add
handling for C++ file splits there too.
Assisted-by: Gemini via Antigravity
Bumps the npm_and_yarn group with 2 updates in the /utils/vscode
directory: [form-data](https://github.com/form-data/form-data) and
[js-yaml](https://github.com/nodeca/js-yaml).
Updates `form-data` from 4.0.5 to 4.0.6
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/form-data/form-data/blob/master/CHANGELOG.md">form-data's
changelog</a>.</em></p>
<blockquote>
<h2><a
href="https://github.com/form-data/form-data/compare/v4.0.5...v4.0.6">v4.0.6</a>
- 2026-06-12</h2>
<h3>Commits</h3>
<ul>
<li>[Fix] escape CR, LF, and <code>"</code> in field names and
filenames <a
href="https://github.com/form-data/form-data/commit/8dff42c6da654ed4e7ad4acb7f8ccd3831217c99"><code>8dff42c</code></a></li>
<li>[Dev Deps] update <code>@ljharb/eslint-config</code>,
<code>auto-changelog</code>, <code>tape</code> <a
href="https://github.com/form-data/form-data/commit/f31d21ef10bf46e46344c3ee4f99acbef6be43e1"><code>f31d21e</code></a></li>
<li>[Deps] update <code>hasown</code>, <code>mime-types</code> <a
href="https://github.com/form-data/form-data/commit/92ae0eb5da94d6f01925d5f4fcffb2a1e50ed7cd"><code>92ae0eb</code></a></li>
<li>[Dev Deps] update <code>js-randomness-predictor</code> <a
href="https://github.com/form-data/form-data/commit/67b0f65c2e0b065a511d42227d35e4d367644e97"><code>67b0f65</code></a></li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/form-data/form-data/commit/64190db548c0179e37206858e39f27cf513e9435"><code>64190db</code></a>
v4.0.6</li>
<li><a
href="https://github.com/form-data/form-data/commit/92ae0eb5da94d6f01925d5f4fcffb2a1e50ed7cd"><code>92ae0eb</code></a>
[Deps] update <code>hasown</code>, <code>mime-types</code></li>
<li><a
href="https://github.com/form-data/form-data/commit/f31d21ef10bf46e46344c3ee4f99acbef6be43e1"><code>f31d21e</code></a>
[Dev Deps] update <code>@ljharb/eslint-config</code>,
<code>auto-changelog</code>, <code>tape</code></li>
<li><a
href="https://github.com/form-data/form-data/commit/8dff42c6da654ed4e7ad4acb7f8ccd3831217c99"><code>8dff42c</code></a>
[Fix] escape CR, LF, and <code>"</code> in field names and
filenames</li>
<li><a
href="https://github.com/form-data/form-data/commit/67b0f65c2e0b065a511d42227d35e4d367644e97"><code>67b0f65</code></a>
[Dev Deps] update <code>js-randomness-predictor</code></li>
<li>See full diff in <a
href="https://github.com/form-data/form-data/compare/v4.0.5...v4.0.6">compare
view</a></li>
</ul>
</details>
<br />
Updates `js-yaml` from 4.1.1 to 4.2.0
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/nodeca/js-yaml/blob/master/CHANGELOG.md">js-yaml's
changelog</a>.</em></p>
<blockquote>
<h2>[4.2.0] - 2026-06-01</h2>
<h3>Added</h3>
<ul>
<li>Added <code>docs/safety.md</code> with notes about processing
untrusted YAML.</li>
<li>Added <code>maxDepth</code> (100) loader option. Not a problem, but
gives a better
exception instead of RangeError on stack overflow.</li>
<li>Added <code>maxMergeSeqLength</code> (20) loader option. Not a
problem after <code>merge</code> fix,
but an additional restriction for safety.</li>
<li>Added sourcemaps to <code>dist/</code> builds.</li>
</ul>
<h3>Changed</h3>
<ul>
<li>Stop resolving numbers with underscores as numeric scalars, <a
href="https://redirect.github.com/nodeca/js-yaml/issues/627">#627</a>.</li>
<li>Switched dev toolchains to Vite / neostandard.</li>
<li>Updated demo.</li>
<li>Reorganized tests.</li>
<li><code>dist/</code> files are no longer kept in the repository.</li>
</ul>
<h3>Fixed</h3>
<ul>
<li>Fix parsing of properties on the first implicit block mapping key,
<a
href="https://redirect.github.com/nodeca/js-yaml/issues/62">#62</a>.</li>
<li>Fix trailing whitespace handling when folding flow scalar lines, <a
href="https://redirect.github.com/nodeca/js-yaml/issues/307">#307</a>.</li>
<li>Reject top-level block scalars without content indentation, <a
href="https://redirect.github.com/nodeca/js-yaml/issues/280">#280</a>.</li>
<li>Ensure numbers survive round-trip, <a
href="https://redirect.github.com/nodeca/js-yaml/issues/737">#737</a>.</li>
<li>Fix test coverage for issue <a
href="https://redirect.github.com/nodeca/js-yaml/issues/221">#221</a>.</li>
<li>Fix flow scalar trailing whitespace folding, <a
href="https://redirect.github.com/nodeca/js-yaml/issues/307">#307</a>.</li>
<li>Fix digits in YAML named tag handles.</li>
</ul>
<h3>Security</h3>
<ul>
<li>Fix potential DoS via quadratic complexity in merge - deduplicate
repeated
elements (makes sense for malformed files > 10K).</li>
</ul>
<h2>[3.14.2] - 2025-11-15</h2>
<h3>Security</h3>
<ul>
<li>Backported v4.1.1 fix to v3</li>
</ul>
</blockquote>
</details>
<details>
<summary>Commits</summary>
<ul>
<li>See full diff in <a
href="https://github.com/nodeca/js-yaml/commits">compare view</a></li>
</ul>
</details>
<br />
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In `Convert`, allow forming a value or reference of abstract class type,
but not an initializer.
For now, limit the scope to just `ClassElementAccess` to avoid affecting
tests where I'm unclear if allowing abstract types is correct.
This test was assuming that we'd allow qualified lookup in rewrite
constraints, but that is not in agreement with the design. The design
says that the LHS of a rewrite must be a member access designator like
`.Member`.
Provide a cut-down repository containing just our textmate bundle, both
for easy installation in general and so that github's linguist in
particular can pick it up and use it for highlighting Carbon files.
The sync_repos script is automatically run by our github workflow
whenever utils/ changes.
If C++ overload resolution selects a builtin operator candidate for an
enum comparison or bitwise operator, provide support for that operator
by generating a corresponding Carbon builtin function. This is
structured to be easily extensible to other C++ builtin overload
candidates if we so choose, but for now the operators defined in the
prelude are doing what we want in most cases.
Bitwise operators on enums produce the same enum type as a result. This
intentionally deviates from C++, where they produce a promoted integral
type.
Assisted-by: Gemini via Antigravity
The conversion will just produce an ErrorInst output.
Right now I am not sure how to get an ErrorInst into that position, but
with https://github.com/carbon-language/carbon-lang/pull/7364 rejecting
`.Self` we end up with this, and it crashes otherwise.
In generate_ast.cpp, an `CarbonExternalASTSource` is installed that has
a `Check::Context` pointer. During lowering, this `ExternalASTSource` is
still installed, and using it can cause a crash if the now-invalid
pointer is dereferenced.
Fix by adding a new `ReadOnlyASTSource` in sem_ir, and using that during
lowering.
`CarbonExternalASTSource` now inherits from `ReadOnlyASTSource` to avoid
some code duplication.
In generate_ast.cpp, we now always install a multiplex source, even if
there's only one child source. Clang internally keeps pointers to the
top-level `ExternalASTSource` installed via `setExternalSource`, and
those pointers aren't updated if `setExternalSource` is called again. By
using `MultiplexExternalSemaSource`, we can keep the top-level
`ExternalASTSource` pointer the same, and only update its children.
Using `MultiplexExternalSemaSource` this way requires a new constructor
and a method to modify its child sources; added a new LLVM patch adding
those.
Originally landed in #7335, reverted in #7353 due to ASAN errors.
Changes since original:
* Use LLVM RTTI to make `Lower::Context::Finalize` less brittle.
Add LLVM RTTI to `ReadOnlyASTSource` (and `CarbonExternalASTSource`).
Change Finalize so that instead of just deleting the last multiplex
child source, it erases any multiplex child sources that match
`ReadOnlyASTSource`; this includes `CarbonExternalASTSource` since it's
a subclass.
* Fix ASAN error by updating the `MultiplexExternalSemaSource` earlier
in lowering. It is sometimes accessed during PrepareToLower, so update
it in `Context::GetFileContext` rather than `Context::Finalize`.
Fixes https://github.com/carbon-language/carbon-lang/issues/7142
When a facet type contains a rewrite constraint like `.(J.J1).(I.I1)`
the ImplWitnessAccess should only use its RHS value if it's trying to
find `.(J.J1).(I.I1)`. It can't just look at the `.(I.I1)` part or it
may grab the RHS for a similar `.(K.K2).(I.I1)` rewrite.
While it's not possible to write a nested access on the LHS of a rewrite
constraint like `.(J.J1).(I.I1)`, it is possible to construct a facet
type that ends up with that as its rewrite using nested facet types:
```carbon
T:! J where .J1 impls (I where .I1 = ())
```
The access `T.(J.J1).(I.I1)` should evaluate to `()`. The
ImplWitnessAccess evaluation starts by looking for a rewrite of
`.(I.I1)` in the type of the access self, which is `T.(J.J1)`. Then it
looks for `.(I.I1)` in the type of that access self, which is `T`. At
that point it finds the rewrite of `.(J.J1).(I.I1) = ()` and can use the
`()`. However it can also find other rewrites that end in `.(I.I1)`.
To do this correctly, when moving through an ImplWitnessAccess to the
next nested access self, we record the access (interface, element) pair
that we are looking through. And then we require the rewrite constraint
to be prefixed by all of the (interface, element) pairs that we have
recorded.
Also:
- Introduce `buf` so that existing examples using arrays can be updated
to use it.
- Update the examples linked to on the Carbon front page to something
closer to what we expect, moving away from old array syntax. Uses
`slice` though that name hasn't been settled. Updating the SVGs actually
referenced will need to be done as a separate step.
- Update links to the expression operators while I'm touching that
section.
Assisted-by: Gemini via Antigravity
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Nicholas Bishop <nbishop@nbishop.net>
- A test showing we need to search facets in the specific interface of
an access to find a witness
- A test using a `<type> impls ...` constraint from earlier in the same
facet type
- Some tests to show a rewrite constraint from earlier in the same facet
type is not incorrectly used when it's applied to a different facet
- A test of a facet type with a rewrite as the RHS of another rewrite,
and the rewrite there should not leak or access things from the outer
facet type
Dana Jansens
Richard Smith
Nicholas Bishop
dependabot[bot]
Geoff Romer
Christopher Di Bella
David Blaikie
