Files
swift-mirror/lib/Syntax/ExprSyntax.cpp
David Farler c343298b8f [Syntax] Implement return-statement and integer-literal-expr
A return statement needs something to return, so implement
integer-literal-expression too. This necessarily also forced
UnknownExprSyntax, UnknownStmtSyntax, and UnknownDeclSyntax,
which are stand-in token buckets for when we don't know
how to transform/migrate an AST.

This commit also contains the core function for caching
SyntaxData children. This is highly tricky code, with some
detailed comments in SyntaxData.{h,cpp}. The gist is that
we have to atomically swap in a SyntaxData pointer into the
child field, so we can maintain pointer identity of SyntaxData
nodes, while still being able to cache them internally.

To prove that this works, there is a multithreaded test that
checks that two threads can ask for a child that hasn't been
cached yet without crashing or violating pointer identity.

https://bugs.swift.org/browse/SR-4010
2017-02-22 18:45:29 -08:00

114 lines
3.8 KiB
C++

//===--- ExprSyntax.cpp - Swift Expression Syntax Impl. ---------*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "swift/Syntax/ExprSyntax.h"
using namespace swift;
using namespace swift::syntax;
#pragma mark - expression Data
RC<ExprSyntaxData> ExprSyntaxData::make(RC<RawSyntax> Raw,
const SyntaxData *Parent,
CursorIndex IndexInParent) {
return RC<ExprSyntaxData> {
new ExprSyntaxData {
Raw, Parent, IndexInParent
}
};
}
RC<ExprSyntaxData> ExprSyntaxData::makeBlank() {
return make(RawSyntax::missing(SyntaxKind::MissingExpr));
}
#pragma mark - expression API
ExprSyntax::ExprSyntax(const RC<SyntaxData> Root, const ExprSyntaxData *Data)
: Syntax(Root, Data) {}
#pragma mark - unknown-expression Data
UnknownExprSyntaxData::UnknownExprSyntaxData(RC<RawSyntax> Raw,
const SyntaxData *Parent,
CursorIndex IndexInParent)
: ExprSyntaxData(Raw, Parent, IndexInParent) {
assert(Raw->Kind == SyntaxKind::UnknownExpr);
}
RC<UnknownExprSyntaxData>
UnknownExprSyntaxData::make(RC<RawSyntax> Raw,
const SyntaxData *Parent,
CursorIndex IndexInParent) {
return RC<UnknownExprSyntaxData> {
new UnknownExprSyntaxData {
Raw, Parent, IndexInParent
}
};
}
#pragma mark - unknown-expression API
UnknownExprSyntax::UnknownExprSyntax(const RC<SyntaxData> Root,
const UnknownExprSyntaxData *Data)
: ExprSyntax(Root, Data) {}
#pragma mark - integer-literal-expression Data
IntegerLiteralExprSyntaxData::
IntegerLiteralExprSyntaxData(RC<RawSyntax> Raw,
const SyntaxData *Parent,
CursorIndex IndexInParent)
: ExprSyntaxData(Raw, Parent, IndexInParent) {
assert(Raw->Kind == SyntaxKind::IntegerLiteralExpr);
assert(Raw->Layout.size() == 2);
syntax_assert_child_token(Raw, IntegerLiteralExprSyntax::Cursor::Sign,
tok::oper_prefix);
syntax_assert_child_token(Raw, IntegerLiteralExprSyntax::Cursor::Digits,
tok::integer_literal);
}
RC<IntegerLiteralExprSyntaxData>
IntegerLiteralExprSyntaxData::make(RC<RawSyntax> Raw,
const SyntaxData *Parent,
CursorIndex IndexInParent) {
return RC<IntegerLiteralExprSyntaxData> {
new IntegerLiteralExprSyntaxData {
Raw, Parent, IndexInParent
}
};
}
RC<IntegerLiteralExprSyntaxData> IntegerLiteralExprSyntaxData::makeBlank() {
auto Raw = RawSyntax::make(SyntaxKind::IntegerLiteralExpr,
{
TokenSyntax::missingToken(tok::oper_prefix, ""),
TokenSyntax::missingToken(tok::integer_literal, "")
},
SourcePresence::Present);
return make(Raw);
}
#pragma mark - integer-literal-expression API
IntegerLiteralExprSyntax::
IntegerLiteralExprSyntax(const RC<SyntaxData> Root,
const IntegerLiteralExprSyntaxData *Data)
: ExprSyntax(Root, Data) {}
IntegerLiteralExprSyntax
IntegerLiteralExprSyntax::withDigits(RC<TokenSyntax> NewDigits) const {
assert(NewDigits->getTokenKind() == tok::integer_literal);
return Data->replaceChild<IntegerLiteralExprSyntax>(NewDigits,
Cursor::Digits);
}