Files
carbon-lang/toolchain/parse/testdata/let/expression_pattern_precedence.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

132 lines
5.7 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/let/expression_pattern_precedence.carbon
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/let/expression_pattern_precedence.carbon
// --- parens.carbon
fn F() {
let (a == b) = c;
let (a and b) = c;
let (if true then 1 else 2) = 3;
}
// --- fail_relational.carbon
fn G() {
// CHECK:STDERR: fail_relational.carbon:[[@LINE+2]]:9-10: error: `let` declarations must end with a `;` [ExpectedDeclSemi]
// CHECK:STDERR:
let a == b = c;
}
// --- fail_logical.carbon
fn H() {
// CHECK:STDERR: fail_logical.carbon:[[@LINE+2]]:9-11: error: `let` declarations must end with a `;` [ExpectedDeclSemi]
// CHECK:STDERR:
let a and b = c;
}
// --- fail_if.carbon
fn I() {
// CHECK:STDERR: fail_if.carbon:[[@LINE+2]]:7-8: error: parentheses are required around this unary `if` operator [UnaryOperatorRequiresParentheses]
// CHECK:STDERR:
let if true then 1 else 2 = 3;
}
// CHECK:STDOUT: - filename: parens.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─FunctionIntroducer 'fn'
// CHECK:STDOUT: │ ├─IdentifierNameMaybeBeforeSignature 'F'
// CHECK:STDOUT: │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ ╭─FunctionDefinitionStart '{'
// CHECK:STDOUT: │ │ ╭─LetIntroducer 'let'
// CHECK:STDOUT: │ │ │ ╭─TuplePatternStart '('
// CHECK:STDOUT: │ │ │ │ ╭─IdentifierNameExpr 'a'
// CHECK:STDOUT: │ │ │ │ ├─IdentifierNameExpr 'b'
// CHECK:STDOUT: │ │ │ ├─InfixOperatorEqualEqual '=='
// CHECK:STDOUT: │ │ ├─ParenPattern ')'
// CHECK:STDOUT: │ │ ├─LetInitializer '='
// CHECK:STDOUT: │ │ ├─IdentifierNameExpr 'c'
// CHECK:STDOUT: │ ├─LetDecl ';'
// CHECK:STDOUT: │ │ ╭─LetIntroducer 'let'
// CHECK:STDOUT: │ │ │ ╭─TuplePatternStart '('
// CHECK:STDOUT: │ │ │ │ ╭─IdentifierNameExpr 'a'
// CHECK:STDOUT: │ │ │ │ ╭─ShortCircuitOperandAnd 'and'
// CHECK:STDOUT: │ │ │ │ ├─IdentifierNameExpr 'b'
// CHECK:STDOUT: │ │ │ ├─ShortCircuitOperatorAnd 'and'
// CHECK:STDOUT: │ │ ├─ParenPattern ')'
// CHECK:STDOUT: │ │ ├─LetInitializer '='
// CHECK:STDOUT: │ │ ├─IdentifierNameExpr 'c'
// CHECK:STDOUT: │ ├─LetDecl ';'
// CHECK:STDOUT: │ │ ╭─LetIntroducer 'let'
// CHECK:STDOUT: │ │ │ ╭─TuplePatternStart '('
// CHECK:STDOUT: │ │ │ │ ╭─BoolLiteralTrue 'true'
// CHECK:STDOUT: │ │ │ │ ╭─IfExprIf 'if'
// CHECK:STDOUT: │ │ │ │ │ ╭─IntLiteral '1'
// CHECK:STDOUT: │ │ │ │ ├─IfExprThen 'then'
// CHECK:STDOUT: │ │ │ │ ├─IntLiteral '2'
// CHECK:STDOUT: │ │ │ ├─IfExprElse 'else'
// CHECK:STDOUT: │ │ ├─ParenPattern ')'
// CHECK:STDOUT: │ │ ├─LetInitializer '='
// CHECK:STDOUT: │ │ ├─IntLiteral '3'
// CHECK:STDOUT: │ ├─LetDecl ';'
// CHECK:STDOUT: ├─FunctionDefinition '}'
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)
// CHECK:STDOUT: - filename: fail_relational.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─FunctionIntroducer 'fn'
// CHECK:STDOUT: │ ├─IdentifierNameMaybeBeforeSignature 'G'
// CHECK:STDOUT: │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ ╭─FunctionDefinitionStart '{'
// CHECK:STDOUT: │ │ ╭─LetIntroducer 'let'
// CHECK:STDOUT: │ │ ├─IdentifierNameExpr 'a'
// CHECK:STDOUT: │ ├─LetDecl ';' has_error
// CHECK:STDOUT: ├─FunctionDefinition '}'
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)
// CHECK:STDOUT: - filename: fail_logical.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─FunctionIntroducer 'fn'
// CHECK:STDOUT: │ ├─IdentifierNameMaybeBeforeSignature 'H'
// CHECK:STDOUT: │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ ╭─FunctionDefinitionStart '{'
// CHECK:STDOUT: │ │ ╭─LetIntroducer 'let'
// CHECK:STDOUT: │ │ ├─IdentifierNameExpr 'a'
// CHECK:STDOUT: │ ├─LetDecl ';' has_error
// CHECK:STDOUT: ├─FunctionDefinition '}'
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)
// CHECK:STDOUT: - filename: fail_if.carbon
// CHECK:STDOUT: ╭─FileStart ''
// CHECK:STDOUT: │ ╭─FunctionIntroducer 'fn'
// CHECK:STDOUT: │ ├─IdentifierNameMaybeBeforeSignature 'I'
// CHECK:STDOUT: │ │ ╭─ExplicitParamListStart '('
// CHECK:STDOUT: │ ├─ExplicitParamList ')'
// CHECK:STDOUT: │ ╭─FunctionDefinitionStart '{'
// CHECK:STDOUT: │ │ ╭─LetIntroducer 'let'
// CHECK:STDOUT: │ │ │ ╭─BoolLiteralTrue 'true'
// CHECK:STDOUT: │ │ │ ╭─IfExprIf 'if'
// CHECK:STDOUT: │ │ │ │ ╭─IntLiteral '1'
// CHECK:STDOUT: │ │ │ ├─IfExprThen 'then'
// CHECK:STDOUT: │ │ │ ├─IntLiteral '2'
// CHECK:STDOUT: │ │ ├─IfExprElse 'else'
// CHECK:STDOUT: │ │ ├─LetInitializer '='
// CHECK:STDOUT: │ │ ├─IntLiteral '3'
// CHECK:STDOUT: │ ├─LetDecl ';'
// CHECK:STDOUT: ├─FunctionDefinition '}'
// CHECK:STDOUT: ├─FileEnd ''
// CHECK:STDOUT: (root)