Files
carbon-lang/toolchain/parse/testdata/lambda/lambda.carbon
T
Chandler Carruth 2c9739799b Render diagnostics through the terminal library (#7683)
Diagnostic rendering was part of the data model: `Loc::FormatLocation`
and
`Loc::FormatSnippet` wrote plain text to a stream, so no capability,
color, or
terminal width could reach them.

A diagnostic is now one message with labels, contexts, and location
information
attached, and `Diagnostics::Renderer` draws it into a
`Terminal::Buffer`. The
design is in `toolchain/docs/diagnostics_rendering.md` (#7668),
authoring in
`toolchain/docs/diagnostics.md`.

Before:

```
example.carbon:6:3: error: 1 argument passed to function expecting 0 arguments
  Run0(1);
  ^~~~~~~
example.carbon:3:1: note: calling function declared here
fn Run0() {}
^~~~~~~~~~~
```

After:

```
error: 1 argument passed to function expecting 0 arguments
       ╭─┤ example.carbon:6:3
       ┆
     3 │ fn Run0() {}
       · ─────┬─────
       ·      ╰──┤ calling function declared here
       ┆
->   6 │   Run0(1);
       ·   ───────
       ╰────────────
```

`--no-diagnostic-snippets` gives a compact form, `example.carbon:6:3-9`.
File
tests use it; the rendering tests under `toolchain/diagnostics/testdata`
ask for
snippets.

C++ interop diagnostics are data now rather than text Clang drew:
`SemIR::ClangSourceLocId` names a `clang::SourceRange`, and a Clang
location is
marked as the point it names.

`StreamConsumer` moves to a `:renderer` target that `:emitter` does not
depend
on, keeping `common/terminal` out of `consumer.h`. Capabilities come
from the
file behind the error stream, so tests get plain ASCII.

`renderer_fuzzer` draws diagnostics built from fuzzer bytes with every
capability combination, since a shape the renderer doesn't expect must
never be
why the compiler dies while reporting a problem.

TODOs mark the follow-ups: line weights and crossing lines, wrapping
that keeps
a quoted type whole, and ordering diagnostics that share a byte offset.

Also: `IncorrectExtension`'s hint moves into its message, since its note
had no
location of its own, and `strip_noise` in `check_diagnostics.py` blanks
multi-line `#define`s instead of deleting them.

Assisted-by: Claude Code
2026-10-15 06:08:57 +00:00

198 lines
10 KiB
Plaintext

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// AUTOUPDATE
// TIP: To test this file alone, run:
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/parse/testdata/lambda/lambda.carbon
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/lambda/lambda.carbon
// --- basic.carbon
var a: auto = fn [T: type] (x: T) -> T { return x; };
var b: auto = fn (x: i32) => x;
var c: auto = fn { };
var d: auto = fn (ref x: i32) ->? ref i32 { return x; };
// --- fail_unconsumed_lambda_introducer.carbon
// Tests that the compiler does not crash when a LambdaIntroducer (`fn`)
// is left unconsumed inside an invalid binary operator sequence.
// CHECK:STDERR: fail_unconsumed_lambda_introducer.carbon:[[@LINE+6]]:10: error: whitespace missing around binary operator [BinaryOperatorRequiresWhitespace]
// CHECK:STDERR:
// CHECK:STDERR: fail_unconsumed_lambda_introducer.carbon:[[@LINE+4]]:16: error: expected expression [ExpectedExpr]
// CHECK:STDERR:
// CHECK:STDERR: fail_unconsumed_lambda_introducer.carbon:[[@LINE+2]]:16: error: whitespace missing before binary operator [BinaryOperatorRequiresWhitespace]
// CHECK:STDERR:
require j%-fn->>
// CHECK:STDERR: fail_unconsumed_lambda_introducer.carbon:[[@LINE+6]]:1: error: expected expression [ExpectedExpr]
// CHECK:STDERR:
// CHECK:STDERR: fail_unconsumed_lambda_introducer.carbon:[[@LINE+4]]:1: error: expected `=>` or `{` after return type [ExpectedLambdaBodyAfterReturnType]
// CHECK:STDERR:
// CHECK:STDERR: fail_unconsumed_lambda_introducer.carbon:[[@LINE+2]]:1: error: expected `impls` in `require` declaration [RequireExpectedImpls]
// CHECK:STDERR:
// --- fail_expected_body.carbon
fn F() {
// CHECK:STDERR: fail_expected_body.carbon:[[@LINE+2]]:20: error: expected `->`, `=>`, or `{` [ExpectedLambdaBody]
// CHECK:STDERR:
var x: auto = fn ;
}
// --- fail_expected_body_after_return_type.carbon
fn G() {
// CHECK:STDERR: fail_expected_body_after_return_type.carbon:[[@LINE+2]]:27: error: expected `=>` or `{` after return type [ExpectedLambdaBodyAfterReturnType]
// CHECK:STDERR:
var x: auto = fn -> i32 ;
}
// CHECK:STDOUT: - filename: basic.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─VariableIntroducer 'var'
// CHECK:STDOUT: │ │ ╭─IdentifierNameNotBeforeSignature 'a'
// CHECK:STDOUT: │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ ├─AutoTypeLiteral 'auto'
// CHECK:STDOUT: │ │ ╭─VarBindingPattern ':'
// CHECK:STDOUT: │ ├─VariablePattern 'var'
// CHECK:STDOUT: │ ├─VariableInitializer '='
// CHECK:STDOUT: │ │ ╭─LambdaIntroducer 'fn'
// CHECK:STDOUT: │ │ │ ╭─ImplicitParamListStart '['
// CHECK:STDOUT: │ │ │ │ ╭─IdentifierNameNotBeforeSignature 'T'
// CHECK:STDOUT: │ │ │ │ ├─CompileTimeBindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ │ │ ├─TypeTypeLiteral 'type'
// CHECK:STDOUT: │ │ │ ├─CompileTimeBindingPattern ':'
// CHECK:STDOUT: │ │ ├─ImplicitParamList ']'
// CHECK:STDOUT: │ │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ │ │ │ ╭─IdentifierNameNotBeforeSignature 'x'
// CHECK:STDOUT: │ │ │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ │ │ ├─IdentifierNameExpr 'T'
// CHECK:STDOUT: │ │ │ ├─LetBindingPattern ':'
// CHECK:STDOUT: │ │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ │ │ ╭─IdentifierNameExpr 'T'
// CHECK:STDOUT: │ │ ├─ReturnType '->'
// CHECK:STDOUT: │ │ ╭─LambdaDefinitionStart '{'
// CHECK:STDOUT: │ │ │ ╭─ReturnStatementStart 'return'
// CHECK:STDOUT: │ │ │ ├─IdentifierNameExpr 'x'
// CHECK:STDOUT: │ │ ├─ReturnStatement ';'
// CHECK:STDOUT: │ ├─Lambda '}'
// CHECK:STDOUT: ├─VariableDecl ';'
// CHECK:STDOUT: │ ╭─VariableIntroducer 'var'
// CHECK:STDOUT: │ │ ╭─IdentifierNameNotBeforeSignature 'b'
// CHECK:STDOUT: │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ ├─AutoTypeLiteral 'auto'
// CHECK:STDOUT: │ │ ╭─VarBindingPattern ':'
// CHECK:STDOUT: │ ├─VariablePattern 'var'
// CHECK:STDOUT: │ ├─VariableInitializer '='
// CHECK:STDOUT: │ │ ╭─LambdaIntroducer 'fn'
// CHECK:STDOUT: │ │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ │ │ │ ╭─IdentifierNameNotBeforeSignature 'x'
// CHECK:STDOUT: │ │ │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ │ │ ├─IntTypeLiteral 'i32'
// CHECK:STDOUT: │ │ │ ├─LetBindingPattern ':'
// CHECK:STDOUT: │ │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ │ ╭─LambdaDefinitionStart '=>'
// CHECK:STDOUT: │ │ ├─IdentifierNameExpr 'x'
// CHECK:STDOUT: │ ├─Lambda 'fn'
// CHECK:STDOUT: ├─VariableDecl ';'
// CHECK:STDOUT: │ ╭─VariableIntroducer 'var'
// CHECK:STDOUT: │ │ ╭─IdentifierNameNotBeforeSignature 'c'
// CHECK:STDOUT: │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ ├─AutoTypeLiteral 'auto'
// CHECK:STDOUT: │ │ ╭─VarBindingPattern ':'
// CHECK:STDOUT: │ ├─VariablePattern 'var'
// CHECK:STDOUT: │ ├─VariableInitializer '='
// CHECK:STDOUT: │ │ ╭─LambdaIntroducer 'fn'
// CHECK:STDOUT: │ │ ╭─LambdaDefinitionStart '{'
// CHECK:STDOUT: │ ├─Lambda '}'
// CHECK:STDOUT: ├─VariableDecl ';'
// CHECK:STDOUT: │ ╭─VariableIntroducer 'var'
// CHECK:STDOUT: │ │ ╭─IdentifierNameNotBeforeSignature 'd'
// CHECK:STDOUT: │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ ├─AutoTypeLiteral 'auto'
// CHECK:STDOUT: │ │ ╭─VarBindingPattern ':'
// CHECK:STDOUT: │ ├─VariablePattern 'var'
// CHECK:STDOUT: │ ├─VariableInitializer '='
// CHECK:STDOUT: │ │ ╭─LambdaIntroducer 'fn'
// CHECK:STDOUT: │ │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ │ │ │ ╭─IdentifierNameNotBeforeSignature 'x'
// CHECK:STDOUT: │ │ │ │ ╭─RefBindingName 'ref'
// CHECK:STDOUT: │ │ │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ │ │ ├─IntTypeLiteral 'i32'
// CHECK:STDOUT: │ │ │ ├─LetBindingPattern ':'
// CHECK:STDOUT: │ │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ │ │ ╭─IntTypeLiteral 'i32'
// CHECK:STDOUT: │ │ │ ╭─PrefixOperatorRef 'ref'
// CHECK:STDOUT: │ │ ├─ReturnForm '->?'
// CHECK:STDOUT: │ │ ╭─LambdaDefinitionStart '{'
// CHECK:STDOUT: │ │ │ ╭─ReturnStatementStart 'return'
// CHECK:STDOUT: │ │ │ ├─IdentifierNameExpr 'x'
// CHECK:STDOUT: │ │ ├─ReturnStatement ';'
// CHECK:STDOUT: │ ├─Lambda '}'
// CHECK:STDOUT: ├─VariableDecl ';'
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)
// CHECK:STDOUT: - filename: fail_unconsumed_lambda_introducer.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─RequireIntroducer 'require'
// CHECK:STDOUT: │ │ ╭─IdentifierNameExpr 'j'
// CHECK:STDOUT: │ │ │ ╭─LambdaIntroducer 'fn'
// CHECK:STDOUT: │ │ │ │ ╭─InvalidParse '>' has_error
// CHECK:STDOUT: │ │ │ │ ├─InvalidParse '' has_error
// CHECK:STDOUT: │ │ │ │ ╭─InfixOperatorGreater '>' has_error
// CHECK:STDOUT: │ │ │ ├─ReturnType '->'
// CHECK:STDOUT: │ │ │ ╭─LambdaDefinitionStart '' has_error
// CHECK:STDOUT: │ │ │ ╭─Lambda 'fn' has_error
// CHECK:STDOUT: │ │ ├─PrefixOperatorMinus '-'
// CHECK:STDOUT: │ ├─InfixOperatorPercent '%'
// CHECK:STDOUT: ├─RequireDecl '>' has_error
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)
// CHECK:STDOUT: - filename: fail_expected_body.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─FunctionIntroducer 'fn'
// CHECK:STDOUT: │ ├─IdentifierNameMaybeBeforeSignature 'F'
// CHECK:STDOUT: │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ ╭─FunctionDefinitionStart '{'
// CHECK:STDOUT: │ │ ╭─VariableIntroducer 'var'
// CHECK:STDOUT: │ │ │ ╭─IdentifierNameNotBeforeSignature 'x'
// CHECK:STDOUT: │ │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ │ ├─AutoTypeLiteral 'auto'
// CHECK:STDOUT: │ │ │ ╭─VarBindingPattern ':'
// CHECK:STDOUT: │ │ ├─VariablePattern 'var'
// CHECK:STDOUT: │ │ ├─VariableInitializer '='
// CHECK:STDOUT: │ │ │ ╭─LambdaIntroducer 'fn'
// CHECK:STDOUT: │ │ │ ╭─LambdaDefinitionStart ';' has_error
// CHECK:STDOUT: │ │ ├─Lambda 'fn' has_error
// CHECK:STDOUT: │ ├─VariableDecl ';'
// CHECK:STDOUT: ├─FunctionDefinition '}'
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)
// CHECK:STDOUT: - filename: fail_expected_body_after_return_type.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─FunctionIntroducer 'fn'
// CHECK:STDOUT: │ ├─IdentifierNameMaybeBeforeSignature 'G'
// CHECK:STDOUT: │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ ╭─FunctionDefinitionStart '{'
// CHECK:STDOUT: │ │ ╭─VariableIntroducer 'var'
// CHECK:STDOUT: │ │ │ ╭─IdentifierNameNotBeforeSignature 'x'
// CHECK:STDOUT: │ │ │ ├─BindingPatternTypeStart ':'
// CHECK:STDOUT: │ │ │ ├─AutoTypeLiteral 'auto'
// CHECK:STDOUT: │ │ │ ╭─VarBindingPattern ':'
// CHECK:STDOUT: │ │ ├─VariablePattern 'var'
// CHECK:STDOUT: │ │ ├─VariableInitializer '='
// CHECK:STDOUT: │ │ │ ╭─LambdaIntroducer 'fn'
// CHECK:STDOUT: │ │ │ │ ╭─IntTypeLiteral 'i32'
// CHECK:STDOUT: │ │ │ ├─ReturnType '->'
// CHECK:STDOUT: │ │ │ ╭─LambdaDefinitionStart ';' has_error
// CHECK:STDOUT: │ │ ├─Lambda 'fn' has_error
// CHECK:STDOUT: │ ├─VariableDecl ';'
// CHECK:STDOUT: ├─FunctionDefinition '}'
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)