mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 22:02:23 +01:00
simontran7
64ce58dd64
Fixes the malformed parse tree produced for an invalid let struct
pattern containing a single identifier (e.g., `let {s};`).
As pointed out by @DavidLoftus, the parser should produce a parse tree
similar to that of `let {ref s};`, since both are missing a binding
power operator `:`, and both do not have a `.` preceding the identifier
(i.e., `state.in_field_shorthand_pattern == true`).
This means that the parser can produce an the `InvalidParse` node just
as it does for `let {ref s};`.
Closes #7674
97 lines
3.8 KiB
C++
97 lines
3.8 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"
|
|
#include "toolchain/parse/handle.h"
|
|
|
|
namespace Carbon::Parse {
|
|
|
|
auto HandlePattern(Context& context) -> void {
|
|
auto state = context.PopState();
|
|
switch (context.PositionKind()) {
|
|
case Lex::TokenKind::OpenParen:
|
|
context.PushStateForPattern(
|
|
StateKind::PatternListAsTuple, state.in_var_pattern,
|
|
state.in_unused_pattern, state.in_field_shorthand_pattern,
|
|
state.binding_context, state.ambient_precedence);
|
|
break;
|
|
case Lex::TokenKind::OpenCurlyBrace:
|
|
context.PushStateForPattern(
|
|
StateKind::PatternListAsStruct, state.in_var_pattern,
|
|
state.in_unused_pattern, state.in_field_shorthand_pattern,
|
|
state.binding_context, state.ambient_precedence);
|
|
break;
|
|
case Lex::TokenKind::Var:
|
|
context.PushStateForPattern(
|
|
StateKind::VariablePattern, state.in_var_pattern,
|
|
state.in_unused_pattern, state.in_field_shorthand_pattern,
|
|
state.binding_context, state.ambient_precedence);
|
|
break;
|
|
case Lex::TokenKind::Unused:
|
|
context.PushStateForPattern(
|
|
StateKind::UnusedPattern, state.in_var_pattern,
|
|
state.in_unused_pattern, state.in_field_shorthand_pattern,
|
|
state.binding_context, state.ambient_precedence);
|
|
break;
|
|
case Lex::TokenKind::Template:
|
|
case Lex::TokenKind::Generic:
|
|
case Lex::TokenKind::Runtime:
|
|
case Lex::TokenKind::Ref:
|
|
// `self` is always a binding, even when its type is omitted (and so is not
|
|
// followed by a `:`).
|
|
case Lex::TokenKind::SelfValueIdentifier:
|
|
context.PushStateForPattern(
|
|
StateKind::BindingPattern, state.in_var_pattern,
|
|
state.in_unused_pattern, state.in_field_shorthand_pattern,
|
|
state.binding_context, state.ambient_precedence);
|
|
break;
|
|
default:
|
|
if ((context.PositionKind().is_word() &&
|
|
context.PositionKind(Lookahead::NextToken)
|
|
.is_binding_pattern_operator()) ||
|
|
state.in_field_shorthand_pattern) {
|
|
context.PushStateForPattern(
|
|
StateKind::BindingPattern, state.in_var_pattern,
|
|
state.in_unused_pattern, state.in_field_shorthand_pattern,
|
|
state.binding_context, state.ambient_precedence);
|
|
break;
|
|
}
|
|
context.PushStateForPattern(
|
|
StateKind::ExprPattern, state.in_var_pattern, state.in_unused_pattern,
|
|
state.in_field_shorthand_pattern, state.binding_context,
|
|
state.ambient_precedence);
|
|
context.PushStateForExpr(state.ambient_precedence);
|
|
break;
|
|
}
|
|
}
|
|
|
|
auto HandleExprPattern(Context& context) -> void {
|
|
auto state = context.PopState();
|
|
|
|
// If we parsed an expression followed by a binding operator, we most likely
|
|
// have a malformed attempt to introduce a binding pattern that we interpreted
|
|
// as an expression pattern, so diagnose that here rather than diagnosing a
|
|
// missing `;` at an outer level.
|
|
if (context.PositionKind().is_binding_pattern_operator()) {
|
|
if (!state.has_error) {
|
|
CARBON_DIAGNOSTIC(ExpectedBindingName, Error,
|
|
"unexpected expression before {0} in binding pattern",
|
|
Lex::TokenKind);
|
|
// TODO: Underline the parsed expression.
|
|
context.emitter().Emit(*context.position(), ExpectedBindingName,
|
|
context.PositionKind());
|
|
state.has_error = true;
|
|
}
|
|
context.Consume();
|
|
// It'd be nice to skip the type expression here too, but we can't determine
|
|
// the end of it.
|
|
}
|
|
|
|
if (state.has_error) {
|
|
context.ReturnErrorOnState();
|
|
}
|
|
}
|
|
|
|
} // namespace Carbon::Parse
|