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Chandler Carruth
2c9739799b
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
55 lines
1.9 KiB
C++
55 lines
1.9 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#include "toolchain/check/unused.h"
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#include "toolchain/base/kind_switch.h"
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#include "toolchain/check/context.h"
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#include "toolchain/check/diagnostic_helpers.h"
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namespace Carbon::Check {
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auto CheckUnusedBinding(Context& context, SemIR::NameId name_id,
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const LexicalLookup::Result& result) -> void {
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// Don't warn about the special name `_`. Other special names, such as `self`,
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// are warned if unused. `.Self` is also excluded as it is often implicit.
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if (name_id == SemIR::NameId::Underscore ||
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name_id == SemIR::NameId::PeriodSelf) {
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return;
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}
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// Don't warn about names that aren't in the current file.
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auto decl_loc = context.insts().GetCanonicalLocId(result.inst_id);
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if (decl_loc.kind() == SemIR::LocId::Kind::ImportIRInstId) {
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return;
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}
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auto binding = context.insts().TryGetAs<SemIR::AnyBinding>(result.inst_id);
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if (!binding) {
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return;
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}
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const auto& entity_name = context.entity_names().Get(binding->entity_name_id);
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if (entity_name.is_unused) {
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if (result.use_loc_id.has_value()) {
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CARBON_DIAGNOSTIC_ON_SCOPE(UnusedButUsed, Error,
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"variable `{0}` marked `unused` but used",
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SemIR::NameId);
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CARBON_DIAGNOSTIC_LABEL(UnusedButUsedHere, Info, "usage here");
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context.emitter()
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.Build(decl_loc, UnusedButUsed, name_id)
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.Attach(result.use_loc_id, UnusedButUsedHere)
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.Emit();
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}
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} else {
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if (!result.use_loc_id.has_value() && result.is_decl_reachable) {
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CARBON_DIAGNOSTIC_ON_SCOPE(UnusedBinding, Warning, "binding `{0}` unused",
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SemIR::NameId);
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context.emitter().Emit(decl_loc, UnusedBinding, name_id);
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}
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}
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}
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} // namespace Carbon::Check
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