For #6830, add support for inline C++ fragments as a declaration rather
than as a packaging directive. For now, this uses `inline Cpp
<string-literal>;` as syntax. The prior `import Cpp inline
<string-literal>;` is left alone for the time being. We can decide
separately whether to remove that.
`inline Cpp` requires that there was at least one `import Cpp`. It's not
clear to me if that's the right design long-term, but it seems
reasonable for now.
Assisted-by: Gemini via Google Antigravity
Do not treat it as a 1-tuple pattern as we used to. The design indicates
that `(pattern)` is invalid, but this appears to be an oversight, and
grouping parens appear to be the intended interpretation.
---------
Co-authored-by: Geoff Romer <gromer@google.com>
Use the same node kind for the body of `case` and `default` handlers. We
don't need to distinguish these in check, so don't create extra node
kinds for them.
In order to make the nodes properly delimited, make the label (`case
...` or `default`) nodes be children of the `=>` node rather than
siblings. This allows us to use the node kind of the `=>` as the
bracketing node for the complete handler, rather than having two
different bracketing node kinds, one for each kind of label.
This change ensures that a function signature always starts with an
`IdentifierNameMaybeBeforeSignature` node (renamed from
`IdentifierNameBeforeParams`), even in the case of function declarations
like `fn F -> T` that have no parameter list. As a consequence, this
ensures that we push new entries onto `pattern_block_stack` and
`full_pattern_stack` when we start processing the function signature.
Add support for compile-time functions. `eval fn` is analogous to C++
`constexpr`, and is evaluated at compile time when it has compile-time
arguments. `musteval fn` is analogous to C++ `consteval`, and requires
that its arguments be available at compile time and is always evaluated
at compile time. For now we require the modifier to match across
redeclarations of the function. The specific modifier syntax here is a
placeholder and not yet part of an approved design.
Limitations: Only very basic support for evaluation is provided. So far
there's no support for mutable state or `if` expressions, but otherwise
control flow and passing and returning values should work. Carbon
evaluation recursion is modeled by C++ recursion for now, so you can
overflow the toolchain stack easily. Functions that use in-place
initialization will generally not work yet, as they are modeled as
passing a non-compile-time-constant reference to a temporary to the
call.
Add missing categorization of `name_binding_decl` as `NotExpr` to match
other similar declaration instructions like `FunctionDecl`, so that we
can uniformly skip over them when they occur within function bodies.
Assisted-by: Gemini 3 Pro and Flash via Antigravity
This adds the necessary parser infrastructure to recognize and parse
lambda expressions in Carbon.
Key changes:
- Added and Parse Node Kinds.
- Updated to use to accommodate the growing number of node kinds.
- Implemented parser states and handlers for lambda syntax ( or ).
- Added structure to .
- Added diagnostics for missing lambda bodies.
- Added a stub in phase to defer semantic analysis using .
- Added parser tests for lambdas.
Every test that used `addr` before #6283 should be using `ref` after
this PR. In most cases that was done in #6283, but this PR transitions a
few that I missed in that first pass. In addition, #6283 cloned the old
`addr` tests from `foo.carbon` to `foo_addr.carbon` in order to maintain
test coverage during the transition; this PR removes those cloned tests.
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>
`fn destroy` is being removed per decision on #6124. It seems like the
relevant decision will result in no more keyword-based function names,
so this is removing all related support.
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>
Decouples associated constants from being special cased in let handlers.
Enforces associated constant grammar restrictions in parsing instead of
checking.
Closes#5411
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*`.
We add a virtual node (`CompileTimeBindingPatternStart`) as the first
child of `CompileTimeBindingPattern` which holds the identifier
underneath it, so that it is checked just before the type expression of
the `CompileTimeBindingPattern`. When we reach this virtual node during
check, we add `.Self` as a name in the current scope, and when we reach
`CompileTimeBindingPattern` we remove it from scope, which ensures it's
present during only the checking of the type expression for the compile
time pattern.
At the moment the `.Self` has a different type (it's a `TypeType`) than
other `.Self` in the facet type (which are a single `FacetType`), but
the intention is to immediately substitute it out of the facet type
entirely, replacing it with a reference to the compile time binding (a
`BindSymbolicName`) itself. A TODO has been added for this.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
toolchain/check/testdata/builtins/char/basics.carbon and
toolchain/lower/testdata/builtins/char.carbon are probably the most
interesting tests here. The parse tests is required because this adds a
new node kind, and we need coverage of it; but the attached info is
minor. There's a fair amount of test churn here because I'm adding the
Core.Char and Core.CharLiteral types as new singletons.
My intent here is that `CharId` is always a unicode code point, even
when the type is a `Char` and thus must be a single UTF-8 code unit
(single byte). This mainly means the stored value of a `CharValue` can
be printed internally without knowing the type.
---------
Co-authored-by: josh11b <15258583+josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This adds support for importing C++ code directly from source rather
than via a `#include`.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
In line with the proposal in #4682, this changes the array syntax to be
array(T, N). `array` is a builtin keyword which must be followed by
parens containing two expressions and a separating comma.
The array type expression is still fully builtin, it does not forward to
a Core.Array library type yet. It merely adds the `ArrayType`
instruction, as was done with the previous syntax.
Followup work will change the instruction to reference to Core.Array,
once the library type exists and can be used directly.
---------
Co-authored-by: zygoloid <richard@metafoo.co.uk>
Parameter lists need substantially different treatment than tuple
patterns in other contexts, so this change splits them into separate
parse node kinds.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
When I open a .def file, there are often 4 errors:
- The #error
- The #define is not defined
- Missing `;`
- Identifier naming
This PR is meant to disable all of these, since they can be distracting
from fixable diagnostics.
Change parse tree from `template (T:! type)` to `(template T):! type`,
so that we have information about whether a binding is a template
binding available when forming the representation of the binding
pattern. This incidentally fixes a bug that we would accept `template
addr A:! B` instead of the intended `addr template A:! B`.
Track whether a symbolic binding is a template binding on the
`EntityName` object. I'm borrowing a bit from the `CompileTimeBindIndex`
for this in order to avoid making `EntityName`s larger. Longer-term, we
should think about using a different representation for symbolic
bindings, to avoid including these fields in all `EntityName`s, but
that's out of scope for this change.
So far, template bindings are treated as having the same phase as
checked bindings, but that will change in a future PR.
To do this, we restructure the parse tree to make `forall` a leaf node
that comes before the parameter list.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Change representation of package names from `IdentifierId` to
`PackageNameId`, and add a special value `PackageNameId::Core` for the
Core package. Add a `Core` expression to name the Core package, and
support for parsing the `Core` keyword in `package` and `import`
declarations.
For now, I've made no changes to instruction fingerprinting or name
mangling. This means that fingerprints and mangled names will collide
between names in the `Core` package and names in a `r#Core` package. See
#4908.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This change splits `NodeKind::IdentifierName` into separate node kinds
depending on whether the identifier is followed by parameters, and
similarly splits `NameQualifier` based on whether the qualifier has
parameters. This enables us to only push a pattern block when it's
actually needed, rather than "defensively" pushing one when it might be
needed.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Split StructComma into StructLiteralComma and StructTypeLiteralComma in
order to easily differentiate handling (remains the same in this PR).
Add "Literal" to StructField and StructTypeField because it feels
inconsistent versus the other non-shared things. StructFieldDesignator
remains shared between value literals and type literals.
Note I probably would've made StructFieldDesignator non-shared too, but
that'd require either a lookahead of 2 (to see the separator`) or a
writeback after parsing the separator, neither of which felt especially
crucial for this, when what I'm really trying to do is split type
literal handling a little further.
Includes support for the `impls`, `=`, and `==` requirement operators to
the right of a `where`, but `and` to allow multiple requirements is
still a TODO.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
These appear in `where` clauses, as in:
```
U:! InterfaceB where .C = Vector(.D)
V:! type where Vector(.Self) impls Sortable
```
`.Self` can additionally appear in type expressions in a binding pattern
such as `T:! InterfaceA(.Self)`.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Instead of tracking the token associated with a parse node in the `.def`
file macro, track it on the typed node instead. List the token as a
field inside the node structure to show the order of the token relative
to the other components of the grammar production, and to allow the
token index to be accessed when the node is extracted.
Remove the corresponding information from the `.def` file, leaving
behind just a list of parse node kinds in the majority of cases.
This also removes the checking of the token kind associated with a parse
node in the case where the parse node has errors. Previously we had a
flag on the node kind to indicate whether we should check this, but per
[discord
discussion](https://discord.com/channels/655572317891461132/655578254970716160/1246214418979881052),
we have decided to remove this.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Instead of tracking the bracketing and child count information in the
kind macro in `node_kind.def`, provide it to `NodeKind::Define` in
`typed_nodes.h`. If a node is both bracketed and has a fixed child
count, track both facts and check them both in tree verification, since
it's easy to do so now.
The overall goal here is to reduce `node_kind.def` down to a simple list
of names. I have a slightly different approach in mind for the token
kinds.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
Parse the name of a declaration as a sequence of `NameQualifier`s --
which have a name, possibly parameters, and a trailing period --
followed by a name and possibly parameters. This prepares us for parsing
declarations of members of generic classes and similar cases, but
actually supporting such member redeclarations is left to a future
change.
We previously required functions to have parameters, but no longer do,
following the direction of #3848. Cases like namespaces that can't
actually have parameters are now diagnosed in check instead of in parse.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Change syntax for package declaration to put the `impl` keyword at the
start and remove the `api` keyword.
To support this, rearrange processing of package, library, and import
declarations to use the general modifier handling support in declaration
parsing rather than special-case logic.
There is an ambiguity in `impl package.Foo as Bar`, which we resolve by
treating `package` as an introducer after a modifier only if it's not
followed by `.`.
Richard Smith
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Burak Emir
Jon Ross-PerkinsandDana Jansens
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