Files
carbon-lang/toolchain/parse/handle_period.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

85 lines
3.3 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/parse/context.h"
namespace Carbon::Parse {
// Handles PeriodAs variants and ArrowExpr.
// TODO: This currently only supports identifiers on the rhs, but will in the
// future need to handle things like `object.(Interface.member)` for qualifiers.
static auto HandlePeriodOrArrow(Context& context, NodeKind node_kind,
State paren_state, bool is_arrow) -> void {
auto state = context.PopState();
// We're handling `.something` or `->something`.
auto dot = context.ConsumeChecked(is_arrow ? Lex::TokenKind::MinusGreater
: Lex::TokenKind::Period);
if (context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Identifier,
NodeKind::IdentifierName)) {
// OK, `.` identifier.
} else if (context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Base,
NodeKind::BaseName)) {
// OK, `.base`.
} else if (paren_state != State::Invalid &&
context.PositionIs(Lex::TokenKind::OpenParen)) {
state.state = paren_state;
context.PushState(state);
context.PushState(State::OnlyParenExpr);
return;
} else {
CARBON_DIAGNOSTIC(ExpectedIdentifierAfterDotOrArrow, Error,
"Expected identifier after `{0}`.", llvm::StringLiteral);
context.emitter().Emit(
*context.position(), ExpectedIdentifierAfterDotOrArrow,
is_arrow ? llvm::StringLiteral("->") : llvm::StringLiteral("."));
// If we see a keyword, assume it was intended to be a name.
// TODO: Should keywords be valid here?
if (context.PositionKind().is_keyword()) {
context.AddLeafNode(NodeKind::IdentifierName, context.Consume(),
/*has_error=*/true);
} else {
context.AddLeafNode(NodeKind::IdentifierName, *context.position(),
/*has_error=*/true);
// Indicate the error to the parent state so that it can avoid producing
// more errors.
context.ReturnErrorOnState();
}
}
context.AddNode(node_kind, dot, state.subtree_start, state.has_error);
}
auto HandlePeriodAsExpr(Context& context) -> void {
HandlePeriodOrArrow(context, NodeKind::MemberAccessExpr,
State::CompoundMemberAccess,
/*is_arrow=*/false);
}
auto HandlePeriodAsStruct(Context& context) -> void {
HandlePeriodOrArrow(context, NodeKind::StructFieldDesignator, State::Invalid,
/*is_arrow=*/false);
}
auto HandleArrowExpr(Context& context) -> void {
HandlePeriodOrArrow(context, NodeKind::PointerMemberAccessExpr,
State::CompoundPointerMemberAccess,
/*is_arrow=*/true);
}
auto HandleCompoundMemberAccess(Context& context) -> void {
auto state = context.PopState();
context.AddNode(NodeKind::MemberAccessExpr, state.token, state.subtree_start,
state.has_error);
}
auto HandleCompoundPointerMemberAccess(Context& context) -> void {
auto state = context.PopState();
context.AddNode(NodeKind::PointerMemberAccessExpr, state.token,
state.subtree_start, state.has_error);
}
} // namespace Carbon::Parse