Files
carbon-lang/toolchain/parse/handle_decl_name_and_params.cpp
T
Richard SmithandJon Ross-Perkins 28170c7867 Parse parameters in name qualifiers. (#3988)
Parse the name of a declaration as a sequence of `NameQualifier`s --
which have a name, possibly parameters, and a trailing period --
followed by a name and possibly parameters. This prepares us for parsing
declarations of members of generic classes and similar cases, but
actually supporting such member redeclarations is left to a future
change.

We previously required functions to have parameters, but no longer do,
following the direction of #3848. Cases like namespaces that can't
actually have parameters are now diagnosed in check instead of in parse.

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
2024-05-29 00:47:29 +00:00

92 lines
3.1 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/parse/context.h"
namespace Carbon::Parse {
auto HandleDeclNameAndParams(Context& context) -> void {
auto state = context.PopState();
auto identifier = context.ConsumeIf(Lex::TokenKind::Identifier);
if (!identifier) {
Lex::TokenIndex token = *context.position();
if (context.tokens().GetKind(token) == Lex::TokenKind::FileEnd) {
// The end of file is an unhelpful diagnostic location. Instead, use the
// introducer token.
token = state.token;
}
if (state.token == *context.position()) {
CARBON_DIAGNOSTIC(ExpectedDeclNameAfterPeriod, Error,
"`.` should be followed by a name.");
context.emitter().Emit(token, ExpectedDeclNameAfterPeriod);
} else {
CARBON_DIAGNOSTIC(ExpectedDeclName, Error,
"`{0}` introducer should be followed by a name.",
Lex::TokenKind);
context.emitter().Emit(token, ExpectedDeclName,
context.tokens().GetKind(state.token));
}
context.ReturnErrorOnState();
context.AddLeafNode(NodeKind::InvalidParse, *context.position(),
/*has_error=*/true);
return;
}
context.AddLeafNode(NodeKind::IdentifierName, *identifier);
switch (context.PositionKind()) {
case Lex::TokenKind::Period:
context.AddNode(NodeKind::NameQualifier,
context.ConsumeChecked(Lex::TokenKind::Period),
state.subtree_start, state.has_error);
context.PushState(State::DeclNameAndParams);
break;
case Lex::TokenKind::OpenSquareBracket:
state.state = State::DeclNameAndParamsAfterImplicit;
context.PushState(state);
context.PushState(State::PatternListAsImplicit);
break;
case Lex::TokenKind::OpenParen:
state.state = State::DeclNameAndParamsAfterParams;
context.PushState(state);
context.PushState(State::PatternListAsTuple);
break;
default:
break;
}
}
auto HandleDeclNameAndParamsAfterImplicit(Context& context) -> void {
auto state = context.PopState();
if (!context.PositionIs(Lex::TokenKind::OpenParen)) {
CARBON_DIAGNOSTIC(
ParamsRequiredAfterImplicit, Error,
"A `(` for parameters is required after implicit parameters.");
context.emitter().Emit(*context.position(), ParamsRequiredAfterImplicit);
context.ReturnErrorOnState();
return;
}
state.state = State::DeclNameAndParamsAfterParams;
context.PushState(state);
context.PushState(State::PatternListAsTuple);
}
auto HandleDeclNameAndParamsAfterParams(Context& context) -> void {
auto state = context.PopState();
if (auto period = context.ConsumeIf(Lex::TokenKind::Period)) {
context.AddNode(NodeKind::NameQualifier, *period, state.subtree_start,
state.has_error);
context.PushState(State::DeclNameAndParams);
}
}
} // namespace Carbon::Parse