ladybird/Userland/Libraries/LibSQL/Parser.cpp
Brian Gianforcaro 1682f0b760 Everything: Move to SPDX license identifiers in all files.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.

See: https://spdx.dev/resources/use/#identifiers

This was done with the `ambr` search and replace tool.

 ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
2021-04-22 11:22:27 +02:00

768 lines
24 KiB
C++

/*
* Copyright (c) 2021, Tim Flynn <trflynn89@pm.me>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "Parser.h"
#include <AK/TypeCasts.h>
namespace SQL {
Parser::Parser(Lexer lexer)
: m_parser_state(move(lexer))
{
}
NonnullRefPtr<Statement> Parser::next_statement()
{
switch (m_parser_state.m_token.type()) {
case TokenType::Create:
return parse_create_table_statement();
case TokenType::Drop:
return parse_drop_table_statement();
case TokenType::Delete:
case TokenType::With:
return parse_delete_statement();
default:
expected("CREATE, DROP, or DELETE");
return create_ast_node<ErrorStatement>();
}
}
NonnullRefPtr<CreateTable> Parser::parse_create_table_statement()
{
// https://sqlite.org/lang_createtable.html
consume(TokenType::Create);
bool is_temporary = false;
if (consume_if(TokenType::Temp) || consume_if(TokenType::Temporary))
is_temporary = true;
consume(TokenType::Table);
bool is_error_if_table_exists = true;
if (consume_if(TokenType::If)) {
consume(TokenType::Not);
consume(TokenType::Exists);
is_error_if_table_exists = false;
}
String schema_or_table_name = consume(TokenType::Identifier).value();
String schema_name;
String table_name;
if (consume_if(TokenType::Period)) {
schema_name = move(schema_or_table_name);
table_name = consume(TokenType::Identifier).value();
} else {
table_name = move(schema_or_table_name);
}
// FIXME: Parse "AS select-stmt".
NonnullRefPtrVector<ColumnDefinition> column_definitions;
consume(TokenType::ParenOpen);
do {
column_definitions.append(parse_column_definition());
if (match(TokenType::ParenClose))
break;
consume(TokenType::Comma);
} while (!match(TokenType::Eof));
// FIXME: Parse "table-constraint".
consume(TokenType::ParenClose);
consume(TokenType::SemiColon);
return create_ast_node<CreateTable>(move(schema_name), move(table_name), move(column_definitions), is_temporary, is_error_if_table_exists);
}
NonnullRefPtr<DropTable> Parser::parse_drop_table_statement()
{
// https://sqlite.org/lang_droptable.html
consume(TokenType::Drop);
consume(TokenType::Table);
bool is_error_if_table_does_not_exist = true;
if (consume_if(TokenType::If)) {
consume(TokenType::Exists);
is_error_if_table_does_not_exist = false;
}
String schema_or_table_name = consume(TokenType::Identifier).value();
String schema_name;
String table_name;
if (consume_if(TokenType::Period)) {
schema_name = move(schema_or_table_name);
table_name = consume(TokenType::Identifier).value();
} else {
table_name = move(schema_or_table_name);
}
consume(TokenType::SemiColon);
return create_ast_node<DropTable>(move(schema_name), move(table_name), is_error_if_table_does_not_exist);
}
NonnullRefPtr<Delete> Parser::parse_delete_statement()
{
// https://sqlite.org/lang_delete.html
bool recursive = false;
RefPtr<CommonTableExpression> common_table_expression;
if (consume_if(TokenType::With)) {
recursive = consume_if(TokenType::Recursive);
common_table_expression = parse_common_table_expression();
}
consume(TokenType::Delete);
consume(TokenType::From);
auto qualified_table_name = parse_qualified_table_name();
RefPtr<Expression> where_clause;
if (consume_if(TokenType::Where))
where_clause = parse_expression();
RefPtr<ReturningClause> returning_clause;
if (match(TokenType::Returning))
returning_clause = parse_returning_clause();
consume(TokenType::SemiColon);
return create_ast_node<Delete>(recursive, move(common_table_expression), move(qualified_table_name), move(where_clause), move(returning_clause));
}
NonnullRefPtr<Expression> Parser::parse_expression()
{
// https://sqlite.org/lang_expr.html
auto expression = parse_primary_expression();
if (match_secondary_expression())
expression = parse_secondary_expression(move(expression));
// FIXME: Parse 'bind-parameter'.
// FIXME: Parse 'function-name'.
// FIXME: Parse 'exists'.
// FIXME: Parse 'raise-function'.
return expression;
}
NonnullRefPtr<Expression> Parser::parse_primary_expression()
{
if (auto expression = parse_literal_value_expression(); expression.has_value())
return move(expression.value());
if (auto expression = parse_column_name_expression(); expression.has_value())
return move(expression.value());
if (auto expression = parse_unary_operator_expression(); expression.has_value())
return move(expression.value());
if (auto expression = parse_chained_expression(); expression.has_value())
return move(expression.value());
if (auto expression = parse_cast_expression(); expression.has_value())
return move(expression.value());
if (auto expression = parse_case_expression(); expression.has_value())
return move(expression.value());
expected("Primary Expression");
consume();
return create_ast_node<ErrorExpression>();
}
NonnullRefPtr<Expression> Parser::parse_secondary_expression(NonnullRefPtr<Expression> primary)
{
if (auto expression = parse_binary_operator_expression(primary); expression.has_value())
return move(expression.value());
if (auto expression = parse_collate_expression(primary); expression.has_value())
return move(expression.value());
if (auto expression = parse_is_expression(primary); expression.has_value())
return move(expression.value());
bool invert_expression = false;
if (consume_if(TokenType::Not))
invert_expression = true;
if (auto expression = parse_match_expression(primary, invert_expression); expression.has_value())
return move(expression.value());
if (auto expression = parse_null_expression(primary, invert_expression); expression.has_value())
return move(expression.value());
if (auto expression = parse_between_expression(primary, invert_expression); expression.has_value())
return move(expression.value());
if (auto expression = parse_in_expression(primary, invert_expression); expression.has_value())
return move(expression.value());
expected("Secondary Expression");
consume();
return create_ast_node<ErrorExpression>();
}
bool Parser::match_secondary_expression() const
{
return match(TokenType::Not)
|| match(TokenType::DoublePipe)
|| match(TokenType::Asterisk)
|| match(TokenType::Divide)
|| match(TokenType::Modulus)
|| match(TokenType::Plus)
|| match(TokenType::Minus)
|| match(TokenType::ShiftLeft)
|| match(TokenType::ShiftRight)
|| match(TokenType::Ampersand)
|| match(TokenType::Pipe)
|| match(TokenType::LessThan)
|| match(TokenType::LessThanEquals)
|| match(TokenType::GreaterThan)
|| match(TokenType::GreaterThanEquals)
|| match(TokenType::Equals)
|| match(TokenType::EqualsEquals)
|| match(TokenType::NotEquals1)
|| match(TokenType::NotEquals2)
|| match(TokenType::And)
|| match(TokenType::Or)
|| match(TokenType::Collate)
|| match(TokenType::Is)
|| match(TokenType::Like)
|| match(TokenType::Glob)
|| match(TokenType::Match)
|| match(TokenType::Regexp)
|| match(TokenType::Isnull)
|| match(TokenType::Notnull)
|| match(TokenType::Between)
|| match(TokenType::In);
}
Optional<NonnullRefPtr<Expression>> Parser::parse_literal_value_expression()
{
if (match(TokenType::NumericLiteral)) {
auto value = consume().double_value();
return create_ast_node<NumericLiteral>(value);
}
if (match(TokenType::StringLiteral)) {
// TODO: Should the surrounding ' ' be removed here?
auto value = consume().value();
return create_ast_node<StringLiteral>(value);
}
if (match(TokenType::BlobLiteral)) {
// TODO: Should the surrounding x' ' be removed here?
auto value = consume().value();
return create_ast_node<BlobLiteral>(value);
}
if (consume_if(TokenType::Null))
return create_ast_node<NullLiteral>();
return {};
}
Optional<NonnullRefPtr<Expression>> Parser::parse_column_name_expression()
{
if (!match(TokenType::Identifier))
return {};
String first_identifier = consume(TokenType::Identifier).value();
String schema_name;
String table_name;
String column_name;
if (consume_if(TokenType::Period)) {
String second_identifier = consume(TokenType::Identifier).value();
if (consume_if(TokenType::Period)) {
schema_name = move(first_identifier);
table_name = move(second_identifier);
column_name = consume(TokenType::Identifier).value();
} else {
table_name = move(first_identifier);
column_name = move(second_identifier);
}
} else {
column_name = move(first_identifier);
}
return create_ast_node<ColumnNameExpression>(move(schema_name), move(table_name), move(column_name));
}
Optional<NonnullRefPtr<Expression>> Parser::parse_unary_operator_expression()
{
if (consume_if(TokenType::Minus))
return create_ast_node<UnaryOperatorExpression>(UnaryOperator::Minus, parse_expression());
if (consume_if(TokenType::Plus))
return create_ast_node<UnaryOperatorExpression>(UnaryOperator::Plus, parse_expression());
if (consume_if(TokenType::Tilde))
return create_ast_node<UnaryOperatorExpression>(UnaryOperator::BitwiseNot, parse_expression());
if (consume_if(TokenType::Not))
return create_ast_node<UnaryOperatorExpression>(UnaryOperator::Not, parse_expression());
return {};
}
Optional<NonnullRefPtr<Expression>> Parser::parse_binary_operator_expression(NonnullRefPtr<Expression> lhs)
{
if (consume_if(TokenType::DoublePipe))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Concatenate, move(lhs), parse_expression());
if (consume_if(TokenType::Asterisk))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Multiplication, move(lhs), parse_expression());
if (consume_if(TokenType::Divide))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Division, move(lhs), parse_expression());
if (consume_if(TokenType::Modulus))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Modulo, move(lhs), parse_expression());
if (consume_if(TokenType::Plus))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Plus, move(lhs), parse_expression());
if (consume_if(TokenType::Minus))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Minus, move(lhs), parse_expression());
if (consume_if(TokenType::ShiftLeft))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::ShiftLeft, move(lhs), parse_expression());
if (consume_if(TokenType::ShiftRight))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::ShiftRight, move(lhs), parse_expression());
if (consume_if(TokenType::Ampersand))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::BitwiseAnd, move(lhs), parse_expression());
if (consume_if(TokenType::Pipe))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::BitwiseOr, move(lhs), parse_expression());
if (consume_if(TokenType::LessThan))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::LessThan, move(lhs), parse_expression());
if (consume_if(TokenType::LessThanEquals))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::LessThanEquals, move(lhs), parse_expression());
if (consume_if(TokenType::GreaterThan))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::GreaterThan, move(lhs), parse_expression());
if (consume_if(TokenType::GreaterThanEquals))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::GreaterThanEquals, move(lhs), parse_expression());
if (consume_if(TokenType::Equals) || consume_if(TokenType::EqualsEquals))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Equals, move(lhs), parse_expression());
if (consume_if(TokenType::NotEquals1) || consume_if(TokenType::NotEquals2))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::NotEquals, move(lhs), parse_expression());
if (consume_if(TokenType::And))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::And, move(lhs), parse_expression());
if (consume_if(TokenType::Or))
return create_ast_node<BinaryOperatorExpression>(BinaryOperator::Or, move(lhs), parse_expression());
return {};
}
Optional<NonnullRefPtr<Expression>> Parser::parse_chained_expression()
{
if (!match(TokenType::ParenOpen))
return {};
NonnullRefPtrVector<Expression> expressions;
consume(TokenType::ParenOpen);
do {
expressions.append(parse_expression());
if (match(TokenType::ParenClose))
break;
consume(TokenType::Comma);
} while (!match(TokenType::Eof));
consume(TokenType::ParenClose);
return create_ast_node<ChainedExpression>(move(expressions));
}
Optional<NonnullRefPtr<Expression>> Parser::parse_cast_expression()
{
if (!match(TokenType::Cast))
return {};
consume(TokenType::Cast);
consume(TokenType::ParenOpen);
auto expression = parse_expression();
consume(TokenType::As);
auto type_name = parse_type_name();
consume(TokenType::ParenClose);
return create_ast_node<CastExpression>(move(expression), move(type_name));
}
Optional<NonnullRefPtr<Expression>> Parser::parse_case_expression()
{
if (!match(TokenType::Case))
return {};
consume();
RefPtr<Expression> case_expression;
if (!match(TokenType::When)) {
case_expression = parse_expression();
}
Vector<CaseExpression::WhenThenClause> when_then_clauses;
do {
consume(TokenType::When);
auto when = parse_expression();
consume(TokenType::Then);
auto then = parse_expression();
when_then_clauses.append({ move(when), move(then) });
if (!match(TokenType::When))
break;
} while (!match(TokenType::Eof));
RefPtr<Expression> else_expression;
if (consume_if(TokenType::Else))
else_expression = parse_expression();
consume(TokenType::End);
return create_ast_node<CaseExpression>(move(case_expression), move(when_then_clauses), move(else_expression));
}
Optional<NonnullRefPtr<Expression>> Parser::parse_collate_expression(NonnullRefPtr<Expression> expression)
{
if (!match(TokenType::Collate))
return {};
consume();
String collation_name = consume(TokenType::Identifier).value();
return create_ast_node<CollateExpression>(move(expression), move(collation_name));
}
Optional<NonnullRefPtr<Expression>> Parser::parse_is_expression(NonnullRefPtr<Expression> expression)
{
if (!match(TokenType::Is))
return {};
consume();
bool invert_expression = false;
if (match(TokenType::Not)) {
consume();
invert_expression = true;
}
auto rhs = parse_expression();
return create_ast_node<IsExpression>(move(expression), move(rhs), invert_expression);
}
Optional<NonnullRefPtr<Expression>> Parser::parse_match_expression(NonnullRefPtr<Expression> lhs, bool invert_expression)
{
auto parse_escape = [this]() {
RefPtr<Expression> escape;
if (consume_if(TokenType::Escape))
escape = parse_expression();
return escape;
};
if (consume_if(TokenType::Like))
return create_ast_node<MatchExpression>(MatchOperator::Like, move(lhs), parse_expression(), parse_escape(), invert_expression);
if (consume_if(TokenType::Glob))
return create_ast_node<MatchExpression>(MatchOperator::Glob, move(lhs), parse_expression(), parse_escape(), invert_expression);
if (consume_if(TokenType::Match))
return create_ast_node<MatchExpression>(MatchOperator::Match, move(lhs), parse_expression(), parse_escape(), invert_expression);
if (consume_if(TokenType::Regexp))
return create_ast_node<MatchExpression>(MatchOperator::Regexp, move(lhs), parse_expression(), parse_escape(), invert_expression);
return {};
}
Optional<NonnullRefPtr<Expression>> Parser::parse_null_expression(NonnullRefPtr<Expression> expression, bool invert_expression)
{
if (!match(TokenType::Isnull) && !match(TokenType::Notnull) && !(invert_expression && match(TokenType::Null)))
return {};
auto type = consume().type();
invert_expression |= (type == TokenType::Notnull);
return create_ast_node<NullExpression>(move(expression), invert_expression);
}
Optional<NonnullRefPtr<Expression>> Parser::parse_between_expression(NonnullRefPtr<Expression> expression, bool invert_expression)
{
if (!match(TokenType::Between))
return {};
consume();
auto nested = parse_expression();
if (!is<BinaryOperatorExpression>(*nested)) {
expected("Binary Expression");
return create_ast_node<ErrorExpression>();
}
const auto& binary_expression = static_cast<const BinaryOperatorExpression&>(*nested);
if (binary_expression.type() != BinaryOperator::And) {
expected("AND Expression");
return create_ast_node<ErrorExpression>();
}
return create_ast_node<BetweenExpression>(move(expression), binary_expression.lhs(), binary_expression.rhs(), invert_expression);
}
Optional<NonnullRefPtr<Expression>> Parser::parse_in_expression(NonnullRefPtr<Expression> expression, bool invert_expression)
{
if (!match(TokenType::In))
return {};
consume();
if (consume_if(TokenType::ParenOpen)) {
if (match(TokenType::Select)) {
// FIXME: Parse "select-stmt".
return {};
}
// FIXME: Consolidate this with parse_chained_expression(). That method consumes the opening paren as
// well, and also requires at least one expression (whereas this allows for an empty chain).
NonnullRefPtrVector<Expression> expressions;
if (!match(TokenType::ParenClose)) {
do {
expressions.append(parse_expression());
if (match(TokenType::ParenClose))
break;
consume(TokenType::Comma);
} while (!match(TokenType::Eof));
}
consume(TokenType::ParenClose);
auto chain = create_ast_node<ChainedExpression>(move(expressions));
return create_ast_node<InChainedExpression>(move(expression), move(chain), invert_expression);
}
String schema_or_table_name = consume(TokenType::Identifier).value();
String schema_name;
String table_name;
if (consume_if(TokenType::Period)) {
schema_name = move(schema_or_table_name);
table_name = consume(TokenType::Identifier).value();
} else {
table_name = move(schema_or_table_name);
}
if (match(TokenType::ParenOpen)) {
// FIXME: Parse "table-function".
return {};
}
return create_ast_node<InTableExpression>(move(expression), move(schema_name), move(table_name), invert_expression);
}
NonnullRefPtr<ColumnDefinition> Parser::parse_column_definition()
{
// https://sqlite.org/syntax/column-def.html
auto name = consume(TokenType::Identifier).value();
auto type_name = match(TokenType::Identifier)
? parse_type_name()
// https://www.sqlite.org/datatype3.html: If no type is specified then the column has affinity BLOB.
: create_ast_node<TypeName>("BLOB", NonnullRefPtrVector<SignedNumber> {});
// FIXME: Parse "column-constraint".
return create_ast_node<ColumnDefinition>(move(name), move(type_name));
}
NonnullRefPtr<TypeName> Parser::parse_type_name()
{
// https: //sqlite.org/syntax/type-name.html
auto name = consume(TokenType::Identifier).value();
NonnullRefPtrVector<SignedNumber> signed_numbers;
if (consume_if(TokenType::ParenOpen)) {
signed_numbers.append(parse_signed_number());
if (consume_if(TokenType::Comma))
signed_numbers.append(parse_signed_number());
consume(TokenType::ParenClose);
}
return create_ast_node<TypeName>(move(name), move(signed_numbers));
}
NonnullRefPtr<SignedNumber> Parser::parse_signed_number()
{
// https://sqlite.org/syntax/signed-number.html
bool is_positive = true;
if (consume_if(TokenType::Plus))
is_positive = true;
else if (consume_if(TokenType::Minus))
is_positive = false;
if (match(TokenType::NumericLiteral)) {
auto number = consume(TokenType::NumericLiteral).double_value();
return create_ast_node<SignedNumber>(is_positive ? number : (number * -1));
}
expected("NumericLiteral");
return create_ast_node<SignedNumber>(0);
}
NonnullRefPtr<CommonTableExpression> Parser::parse_common_table_expression()
{
// https://sqlite.org/syntax/common-table-expression.html
auto table_name = consume(TokenType::Identifier).value();
Vector<String> column_names;
if (consume_if(TokenType::ParenOpen)) {
do {
column_names.append(consume(TokenType::Identifier).value());
if (match(TokenType::ParenClose))
break;
consume(TokenType::Comma);
} while (!match(TokenType::Eof));
consume(TokenType::ParenClose);
}
consume(TokenType::As);
consume(TokenType::ParenOpen);
// FIXME: Parse "select-stmt".
consume(TokenType::ParenClose);
return create_ast_node<CommonTableExpression>(move(table_name), move(column_names));
}
NonnullRefPtr<QualifiedTableName> Parser::parse_qualified_table_name()
{
// https://sqlite.org/syntax/qualified-table-name.html
String schema_or_table_name = consume(TokenType::Identifier).value();
String schema_name;
String table_name;
if (consume_if(TokenType::Period)) {
schema_name = move(schema_or_table_name);
table_name = consume(TokenType::Identifier).value();
} else {
table_name = move(schema_or_table_name);
}
String alias;
if (consume_if(TokenType::As))
alias = consume(TokenType::Identifier).value();
// Note: The qualified-table-name spec may include an "INDEXED BY index-name" or "NOT INDEXED" clause. This is a SQLite extension
// "designed to help detect undesirable query plan changes during regression testing", and "application developers are admonished
// to omit all use of INDEXED BY during application design, implementation, testing, and tuning". Our implementation purposefully
// omits parsing INDEXED BY for now until there is good reason to add support.
return create_ast_node<QualifiedTableName>(move(schema_name), move(table_name), move(alias));
}
NonnullRefPtr<ReturningClause> Parser::parse_returning_clause()
{
// https://sqlite.org/syntax/returning-clause.html
consume(TokenType::Returning);
if (consume_if(TokenType::Asterisk))
return create_ast_node<ReturningClause>();
Vector<ReturningClause::ColumnClause> columns;
do {
auto expression = parse_expression();
consume_if(TokenType::As); // 'AS' is optional.
String column_alias;
if (match(TokenType::Identifier))
column_alias = consume().value();
columns.append({ move(expression), move(column_alias) });
if (!match(TokenType::Comma))
break;
consume(TokenType::Comma);
} while (!match(TokenType::Eof));
return create_ast_node<ReturningClause>(move(columns));
}
Token Parser::consume()
{
auto old_token = m_parser_state.m_token;
m_parser_state.m_token = m_parser_state.m_lexer.next();
return old_token;
}
Token Parser::consume(TokenType expected_type)
{
if (!match(expected_type)) {
expected(Token::name(expected_type));
}
return consume();
}
bool Parser::consume_if(TokenType expected_type)
{
if (!match(expected_type))
return false;
consume();
return true;
}
bool Parser::match(TokenType type) const
{
return m_parser_state.m_token.type() == type;
}
void Parser::expected(StringView what)
{
syntax_error(String::formatted("Unexpected token {}, expected {}", m_parser_state.m_token.name(), what));
}
void Parser::syntax_error(String message)
{
m_parser_state.m_errors.append({ move(message), position() });
}
Parser::Position Parser::position() const
{
return {
m_parser_state.m_token.line_number(),
m_parser_state.m_token.line_column()
};
}
Parser::ParserState::ParserState(Lexer lexer)
: m_lexer(move(lexer))
, m_token(m_lexer.next())
{
}
}