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.
Fixes a compiler crash that occurs when a malformed lambda is provided
as an operand to an operator that strictly expects an expression
Changes:
- Emits an `InvalidParse` dummy node at the current position to act as a
placeholder for the missing body
- Changed state transitions so that `LambdaIntroducer` gets properly
wrapped into a `Lambda` node
Closes#6823
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
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.
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>
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>
They don't get stored anywhere yet, but this type checks the
declarations and diagnoses errors in their form, such as not placing a
facet type after `impls` or a type before it.
Type check named constraint decls and definitions. We don't correctly
error if you put a `fn` inside them. There is no support for `require`
or `alias` yet, so there's nothing useful you can do with them yet.
We have attempted to share code between `interface` and `constraint` as
they are quite similar. First by splitting out some of
handle_interface.cpp to a separate file. Second by sharing some code
paths when you want a facet type from either one, as they both turn into
a facet type.
`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*`.
Add a `Core.String` class to the prelude representing a string view, and
rename the `String` keyword to `str` and make it evaluate to
`Core.String`.
`Core.String` is represented as a pair of a pointer to a character
(actually, to the first character of a string, but we don't have a way
of modeling that yet) and a size (which should be pointer-width, but is
currently always a `u64` as we don't have a `usize` equivalent yet).
`Core.String` values are generated directly by the toolchain for string
literal expressions.
This follows the direction established at the recent summit, but the
design implemented here has not been through the proposal process yet.
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>
Adds minimal defaults for codegen so that those tests don't need to
specify the full command line.
Moves driver/testdata/compile to check/testdata/basics/raw_sem_ir, which
seems like it better reflects the focus. Removes the textual IR test
because we have plenty of those now.
Moves a multiline token diagnostic test to parse because (a) diagnostics
doesn't have other tests and (b) this is really testing the way that
parse structures the location.
Drops `--include-diagnostic-kind` from some driver tests that aren't
testing a diagnostic, so the flag felt a bit like noise (even before
this change, there are a few tests that don't specify it because they're
not intended to test an emitted diagnostic, just high-level diagnostic
behaviors).
Adds some comments to reflect my understanding of why a test exists,
when I was pausing to think about it.
Modifies the stdin test to do more dumps; which happens to expose we
currently misbehave.
According to approved syntax at
https://github.com/carbon-language/carbon-lang/blob/trunk/proposals/p3848.md#syntax-defined,
`fn F[]` without explicit parameters should be valid. This makes it
work, then adds some validation to prevent `class C[]` in check.
Note that for `fn`, positional parameters are a TODO -- but this allows
me to test validation in `fn destroy[]` which is rejected, not just a
TODO.
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>
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>
Based on [the lastest thinking on
#4672](https://github.com/carbon-language/carbon-lang/issues/4672#issuecomment-2606209281)
, require a full syntactic match for impl redeclaration, instead of
excluding the `where` restriction. This means no updates to the impl
witness on redeclaration, and no diagnostics that those updates are
consistent.
Not included in this PR, but will need to be done in the future:
* Support for assigning values to associated constants in the body of
the impl definition. This will require moving the checking that
non-function associated constants are set from the definition start to
definition end.
* Identify semantic redeclarations that are not syntactic matches to
give a failed redeclaration diagnostic. This should be done once we are
already identifying impl declarations with the same type structure in
order to require they be identified in an impl_priority/match_first
block.
* Merging of the functions in `check/impl.cpp` that are now always
called together.
Also add some test coverage of `where` parsing I developed in PR I've
now abandoned because of this new simplification of the impl
redeclaration semantics.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This removes some churn when adding new diagnostic cases to test files
(where previous to this change the newly added newline would cause the
previous diagnostic CHECKs to be updated including changes to the line
number because the CHECK for the blank line meant an extra line between
CHECK and source line).
A few alternatives discussed here:
https://discord.com/channels/655572317891461132/655578254970716160/1329573358475673723
---------
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>
Richard Smith
Geoff RomerandDavid Blaikie
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Elliott KaltandRichard Smith
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