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.
`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>
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>
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>
These don't fully work in check and beyond yet, because they're not
added into lexical lookup, but already mostly do the right thing.
Per #3407, disallow namespace declarations anywhere other than at file
scope for now.
We don't treat statements starting with a packaging introducer keyword
(`package`, `library`, `import`) as declarations because they're
sufficiently unlikely to occur that the error recovery doesn't seem
important, and this avoids needing to disambiguate `package.` at the
start of an expression.
Also surround it in square brackets rather than parentheses. This
matches the format used by Clang and GCC, and means diagnostics will
still match the `file:line:col: error: ` pattern used by some IDE tools.
Before:
```console
fail_builtins.carbon:11:11: error(AliasRequiresNameRef): alias initializer must be a name reference
```
After:
```console
fail_builtins.carbon:11:11: error: alias initializer must be a name reference [AliasRequiresNameRef]
```
Also tighten up test regex to only match on `STDERR` lines that list a
file name.
This is to help identify which diagnostics we're actually using.
Note that driver/testdata still has tests which don't pass this flag,
and so continue to test the kind-less (default) behavior.
This is a primarily automated change:
- Search & replace for capitalization
-
`(CARBON_DIAGNOSTIC\((?:\n\s+)?\w+,(?:\n\s+)?\s\w+,(?:\n\s+)?\s")([A-Z])`
- `$1\L$2`
- Search & replace for period
-
`(CARBON_DIAGNOSTIC\((?:\n\s+)?\w+,(?:\n\s+)?\s\w+,(?:\n\s+)?\s"(?:[^)]|\n)+)\.("[,)])`
- `$1$2`
- Limited search & replace for `ERROR: ` -> `error: ` in streamed things
- Leaving a TODO for command_line because there's more cleanup that can
be done there
- Modify diagnostic_consumer.cpp
- ERROR -> error
- WARNING -> warning
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This has is a nice-to-have for me. Frequently I want to run a specific
test, and end up digging through output to be able to copy-paste the run
line. This uses TIP lines to inject the command into the file when using
AUTOUPDATE.
Note, one of the reasons I want this is because "bazel test
//toolchain/testing:file_test --test_output=all" has been regularly
exceeding bazel's output limit for me (workaround is either opening the
output file or specifying an obscure output limit flag), making it a
little harder for me to get the commands. However, frequently I'm adding
a file and want to iterate on it, so that's really the use case I have
in mind here.
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>
The purpose of the newline is to make it clearer where a given
diagnostic begins and ends, particularly as the first message of a
diagnostic may not be the error.
This is a trivial code change, but ripples edits through test files.
For now, a builtin function is defined by specifying a string literal
initializer in a function declaration:
```carbon
fn MyBuiltin(a: i32) -> i32 = "builtin.name";
```
End-to-end support is included for a sample `"int.add"` builtin
performing integer addition, covering constant evaluation and code
generation.
The implementation here needs substantial refactoring before we'll be
ready to start adding more builtins. That refactoring work will be
coming next. This change is aiming to checkpoint some incremental
progress.
This doesn't add full support. I'm separating it out to make the effects
of the modifier changes clearer for review. I'm restructuring a little
with the expectation that we'll have some more categories of modifier
keywords in the future (similar to `extern`, these may not be in a "set"
such as access), and thus easily scaling up to a few more would be
useful.
Move handling of mismatched brackets out of the main lexing loop into a
separate pass that is only run if there are mismatched brackets This is
done in preparation for using both lookahead and lookbehind to work out
how to match brackets, and to get this code far away from the hot lexing
loop.
Fix bracket insertion location to be immediately after the token that
we're inserting the bracket after, rather than potentially at the end of
a comment. When there are open brackets at the end of the file, say that
there are open brackets, not that there's a closing bracket without a
matching opening bracket.
This leaves a single state for each in the expr loop. I was trying to
think through ways to have per-token states, but they felt sort of
bulky.
Note this is more verbose: but I think the long-term is going to be that
when we start wanting to add handlers, we're going to need to switch to
different names based on the token found. As a consequence, the parse
state logic will end up diverging a little, and we'll just want to align
towards boilerplate handlers.
Short-term, this opens up a path for saying that each parse node
corresponds to precisely one token in success states, and separates out
what were becoming big handler functions in check.
This is supporting a direction that all parse nodes should correspond to
a single token, allowing for reduced tokenized buffer access during
checking (it's still necessary for diagnostics, and some literals).
One of the justifications for a unified parse node was implementation
LOC: note this is slightly smaller, using macros to reduce some
duplication. While this does add more switching in HandleDeclScopeLoop,
that's offset by less explicit switching in the check handlers. Also, I
think the duplication in HandleDeclScopeLoop can be reduced by shifting
the flow there, which I'll do in a separate PR.
I was suggesting this because `FloatingPoint` is pretty long. `int` and
`float` should be familiar abbreviations. `unsigned` should be familiar
to developers too, but `UnsignedInt` still feels usefully clearer for
the additional chars.
This is an incremental improvement on our diagnostic messages that
simply underlines an entire token if the token is larger than 1 char
(else it points to the single char with a caret like it used to).
Can specify which tokens are allowed generally, and any additional
tokens that only occur when the parse node has an error.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This removes a (very) hot branch in the lexer where we need to special
case when a token is the first token and can't look at its previous
token. It also seems like a generally nice change to the structure of
both the token buffer and parse tree as there are now bracketing
elements for both ends and we should be able to avoid similar branching
in the future.
Mostly mechanical updates to the lexer and parser code to handle this,
but also needed to special case the location information in the
autoupdate code. And then the usual large body of auto-updated tests.
No benchmark data for this change alone as in isolation and in the
current lexer structure it doesn't make a big difference. But this
branch was particularly difficult to handle when trying to update the
whitespace skipping code to be faster, and so I think it is worth
systematically avoiding the special case here.
This makes the difference between errors and lower-level diagnostics
visible to users, and aligns the toolchain's behavior with the
expectations in `driver_fuzzer.cpp`.
Geoff Romer
Richard Smith
Burak Emir
Dana Jansens
Jon Ross-Perkins
Elliott KaltandRichard Smith
David BlaikieandJon Ross-Perkins
Jacob Schneider
Chandler Carruth