Files
carbon-lang/toolchain/check/handle_export.cpp
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

109 lines
4.3 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/check/context.h"
#include "toolchain/check/decl_name_stack.h"
#include "toolchain/check/generic.h"
#include "toolchain/check/handle.h"
#include "toolchain/check/inst.h"
#include "toolchain/check/modifiers.h"
#include "toolchain/check/name_component.h"
#include "toolchain/check/name_lookup.h"
#include "toolchain/parse/typed_nodes.h"
#include "toolchain/sem_ir/ids.h"
#include "toolchain/sem_ir/typed_insts.h"
namespace Carbon::Check {
auto HandleParseNode(Context& context, Parse::ExportIntroducerId /*node_id*/)
-> bool {
// Export declarations can't be generic, but we might have parsed a generic
// parameter in their name, so enter a generic scope just in case.
StartGenericDecl(context);
context.decl_introducer_state_stack().Push<Lex::TokenKind::Export>();
// TODO: Probably need to update DeclNameStack to restrict to only namespaces.
context.decl_name_stack().PushScopeAndStartName();
return true;
}
auto HandleParseNode(Context& context, Parse::ExportDeclId node_id) -> bool {
auto name_context = context.decl_name_stack().FinishName(
PopNameComponentWithoutParams(context, Lex::TokenKind::Export));
DiscardGenericDecl(context);
context.decl_name_stack().PopScope();
auto introducer =
context.decl_introducer_state_stack().Pop<Lex::TokenKind::Export>();
LimitModifiersOnDecl(context, introducer, KeywordModifierSet::None);
if (name_context.state == DeclNameStack::NameContext::State::Error) {
// Should already be diagnosed.
return true;
}
// Exporting uses the decl name primarily for lookup, so treat poisoning the
// same as "not found".
auto inst_id =
name_context.state == DeclNameStack::NameContext::State::Poisoned
? SemIR::InstId::None
: name_context.prev_inst_id();
if (!inst_id.has_value()) {
DiagnoseNameNotFound(context, node_id, name_context.name_id_for_new_inst());
return true;
}
auto inst = context.insts().Get(inst_id);
if (inst.Is<SemIR::ExportDecl>()) {
CARBON_DIAGNOSTIC(ExportRedundant, Warning,
"`export` matches previous `export`");
CARBON_DIAGNOSTIC_LABEL(ExportPrevious, Info, "previous `export` here");
context.emitter()
.Build(node_id, ExportRedundant)
// Use the location of the export itself, not the exported instruction.
//
// TODO: This construction of a LocId that does not just contain the
// InstId prevents GetAbsoluteNodeIdImpl() from seeing the `ExportDecl`
// instruction, which prevents it from chasing through it to the entity
// being exported. It might be nice to make this more explicit.
.Attach(context.insts().GetCanonicalLocId(inst_id), ExportPrevious)
.Emit();
return true;
}
auto import_ref = context.insts().TryGetAs<SemIR::ImportRefLoaded>(inst_id);
if (!import_ref) {
CARBON_DIAGNOSTIC(ExportNotImportedEntity, Error,
"only imported entities are valid for `export`");
CARBON_DIAGNOSTIC_LABEL(ExportNotImportedEntitySource, Info,
"name is declared here");
context.emitter()
.Build(node_id, ExportNotImportedEntity)
.Attach(inst_id, ExportNotImportedEntitySource)
.Emit();
return true;
}
auto export_id =
AddInst<SemIR::ExportDecl>(context, node_id,
{.type_id = import_ref->type_id,
.entity_name_id = import_ref->entity_name_id,
.value_id = inst_id});
context.exports().push_back(export_id);
// Replace the ImportRef in name lookup, both for the above duplicate
// diagnostic and so that cross-package imports can find it easily.
auto entity_name = context.entity_names().Get(import_ref->entity_name_id);
auto& parent_scope = context.name_scopes().Get(entity_name.parent_scope_id);
auto& scope_result =
parent_scope.GetEntry(*parent_scope.Lookup(entity_name.name_id)).result;
CARBON_CHECK(scope_result.target_inst_id() == inst_id);
scope_result = SemIR::ScopeLookupResult::MakeFound(
export_id, scope_result.access_kind());
return true;
}
} // namespace Carbon::Check