Files
carbon-lang/toolchain/diagnostics/mocks.cpp
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

54 lines
1.5 KiB
C++

// 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
#include "toolchain/diagnostics/mocks.h"
#include <ostream>
namespace Carbon::Diagnostics {
auto PrintTo(const Diagnostic& diagnostic, std::ostream* os) -> void {
*os << "Diagnostic{";
PrintTo(diagnostic.level, os);
const Loc& loc = diagnostic.message.loc;
*os << ", {" << loc.filename << ":" << loc.line_number << ":"
<< loc.column_number << ", \"" << diagnostic.message.Format() << "\"}";
for (const auto& context : diagnostic.contexts) {
*os << ", {Context " << context.loc.filename << ":"
<< context.loc.line_number << ":" << context.loc.column_number << ", \""
<< context.Format() << "\"}";
}
for (const auto& label : diagnostic.labels) {
*os << ", {";
PrintTo(label.category, os);
*os << " " << label.loc.filename << ":" << label.loc.line_number << ":"
<< label.loc.column_number << ", \"" << label.Format() << "\"}";
}
*os << "}";
}
auto PrintTo(Level level, std::ostream* os) -> void {
switch (level) {
case Level::Warning:
*os << "Warning";
break;
case Level::Error:
*os << "Error";
break;
}
}
auto PrintTo(LabelCategory category, std::ostream* os) -> void {
switch (category) {
case LabelCategory::Info:
*os << "Info";
break;
case LabelCategory::Primary:
*os << "Primary";
break;
}
}
} // namespace Carbon::Diagnostics