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-rw-r--r--Libraries/LibJS/Parser.cpp199
1 files changed, 164 insertions, 35 deletions
diff --git a/Libraries/LibJS/Parser.cpp b/Libraries/LibJS/Parser.cpp
index ebbae3c475..64a9763d38 100644
--- a/Libraries/LibJS/Parser.cpp
+++ b/Libraries/LibJS/Parser.cpp
@@ -25,14 +25,142 @@
*/
#include "Parser.h"
+#include <AK/HashMap.h>
#include <AK/StdLibExtras.h>
#include <stdio.h>
namespace JS {
+
+static HashMap<TokenType, int> g_operator_precedence;
+
Parser::Parser(Lexer lexer)
: m_lexer(move(lexer))
, m_current_token(m_lexer.next())
{
+ if (g_operator_precedence.is_empty()) {
+ // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence
+ g_operator_precedence.set(TokenType::Period, 20);
+ g_operator_precedence.set(TokenType::BracketOpen, 20);
+ g_operator_precedence.set(TokenType::ParenOpen, 20);
+ g_operator_precedence.set(TokenType::QuestionMarkPeriod, 20);
+
+ g_operator_precedence.set(TokenType::New, 19);
+
+ g_operator_precedence.set(TokenType::PlusPlus, 18);
+ g_operator_precedence.set(TokenType::MinusMinus, 18);
+
+ g_operator_precedence.set(TokenType::ExclamationMark, 17);
+ g_operator_precedence.set(TokenType::Tilde, 17);
+ g_operator_precedence.set(TokenType::Typeof, 17);
+ g_operator_precedence.set(TokenType::Void, 17);
+ g_operator_precedence.set(TokenType::Delete, 17);
+ g_operator_precedence.set(TokenType::Await, 17);
+
+ g_operator_precedence.set(TokenType::DoubleAsterisk, 16);
+
+ g_operator_precedence.set(TokenType::Asterisk, 15);
+ g_operator_precedence.set(TokenType::Slash, 15);
+ g_operator_precedence.set(TokenType::Percent, 15);
+
+ g_operator_precedence.set(TokenType::Plus, 14);
+ g_operator_precedence.set(TokenType::Minus, 14);
+
+ g_operator_precedence.set(TokenType::ShiftLeft, 13);
+ g_operator_precedence.set(TokenType::ShiftRight, 13);
+ g_operator_precedence.set(TokenType::UnsignedShiftRight, 13);
+
+ g_operator_precedence.set(TokenType::LessThan, 12);
+ g_operator_precedence.set(TokenType::LessThanEquals, 12);
+ g_operator_precedence.set(TokenType::GreaterThan, 12);
+ g_operator_precedence.set(TokenType::GreaterThanEquals, 12);
+ g_operator_precedence.set(TokenType::In, 12);
+ g_operator_precedence.set(TokenType::Instanceof, 12);
+
+ g_operator_precedence.set(TokenType::EqualsEquals, 11);
+ g_operator_precedence.set(TokenType::ExclamationMarkEquals, 11);
+ g_operator_precedence.set(TokenType::EqualsEqualsEquals, 11);
+ g_operator_precedence.set(TokenType::ExclamationMarkEqualsEquals, 11);
+
+ g_operator_precedence.set(TokenType::Ampersand, 10);
+
+ g_operator_precedence.set(TokenType::Caret, 9);
+
+ g_operator_precedence.set(TokenType::Pipe, 8);
+
+ g_operator_precedence.set(TokenType::DoubleQuestionMark, 7);
+
+ g_operator_precedence.set(TokenType::DoubleAmpersand, 6);
+
+ g_operator_precedence.set(TokenType::DoublePipe, 5);
+
+ g_operator_precedence.set(TokenType::QuestionMark, 4);
+
+ g_operator_precedence.set(TokenType::Equals, 3);
+ g_operator_precedence.set(TokenType::PlusEquals, 3);
+ g_operator_precedence.set(TokenType::MinusEquals, 3);
+ g_operator_precedence.set(TokenType::AsteriskAsteriskEquals, 3);
+ g_operator_precedence.set(TokenType::AsteriskEquals, 3);
+ g_operator_precedence.set(TokenType::SlashEquals, 3);
+ g_operator_precedence.set(TokenType::PercentEquals, 3);
+ g_operator_precedence.set(TokenType::ShiftLeftEquals, 3);
+ g_operator_precedence.set(TokenType::ShiftRightEquals, 3);
+ g_operator_precedence.set(TokenType::UnsignedShiftRightEquals, 3);
+ g_operator_precedence.set(TokenType::PipeEquals, 3);
+
+ g_operator_precedence.set(TokenType::Yield, 2);
+
+ g_operator_precedence.set(TokenType::Comma, 1);
+ }
+}
+
+int Parser::operator_precedence(TokenType type) const
+{
+ auto it = g_operator_precedence.find(type);
+ if (it == g_operator_precedence.end()) {
+ fprintf(stderr, "No precedence for operator %s\n", Token::name(type));
+ ASSERT_NOT_REACHED();
+ return -1;
+ }
+
+ return it->value;
+}
+
+Associativity Parser::operator_associativity(TokenType type) const
+{
+ switch (type) {
+ case TokenType::Period:
+ case TokenType::BracketOpen:
+ case TokenType::ParenOpen:
+ case TokenType::QuestionMarkPeriod:
+ case TokenType::Asterisk:
+ case TokenType::Slash:
+ case TokenType::Percent:
+ case TokenType::Plus:
+ case TokenType::Minus:
+ case TokenType::ShiftLeft:
+ case TokenType::ShiftRight:
+ case TokenType::UnsignedShiftRight:
+ case TokenType::LessThan:
+ case TokenType::LessThanEquals:
+ case TokenType::GreaterThan:
+ case TokenType::GreaterThanEquals:
+ case TokenType::In:
+ case TokenType::Instanceof:
+ case TokenType::EqualsEquals:
+ case TokenType::ExclamationMarkEquals:
+ case TokenType::EqualsEqualsEquals:
+ case TokenType::ExclamationMarkEqualsEquals:
+ case TokenType::Ampersand:
+ case TokenType::Caret:
+ case TokenType::Pipe:
+ case TokenType::DoubleQuestionMark:
+ case TokenType::DoubleAmpersand:
+ case TokenType::DoublePipe:
+ case TokenType::Comma:
+ return Associativity::Left;
+ default:
+ return Associativity::Right;
+ }
}
NonnullOwnPtr<Program> Parser::parse_program()
@@ -54,7 +182,7 @@ NonnullOwnPtr<Program> Parser::parse_program()
NonnullOwnPtr<Statement> Parser::parse_statement()
{
if (match_expression()) {
- return make<JS::ExpressionStatement>(parse_expression());
+ return make<JS::ExpressionStatement>(parse_expression(0));
}
switch (m_current_token.type()) {
@@ -83,7 +211,7 @@ NonnullOwnPtr<Expression> Parser::parse_primary_expression()
switch (m_current_token.type()) {
case TokenType::ParenOpen: {
consume(TokenType::ParenOpen);
- auto expression = parse_expression();
+ auto expression = parse_expression(0);
consume(TokenType::ParenClose);
return expression;
}
@@ -113,68 +241,75 @@ NonnullOwnPtr<ObjectExpression> Parser::parse_object_expression()
return make<ObjectExpression>();
}
-NonnullOwnPtr<Expression> Parser::parse_expression()
+NonnullOwnPtr<Expression> Parser::parse_expression(int min_precedence, Associativity associativity)
{
auto expression = parse_primary_expression();
while (match_secondary_expression()) {
- expression = parse_secondary_expression(move(expression));
+ int new_precedence = operator_precedence(m_current_token.type());
+ if (new_precedence < min_precedence)
+ break;
+ if (new_precedence == min_precedence && associativity == Associativity::Left)
+ break;
+
+ Associativity new_associativity = operator_associativity(m_current_token.type());
+ expression = parse_secondary_expression(move(expression), new_precedence, new_associativity);
}
return expression;
}
-NonnullOwnPtr<Expression> Parser::parse_secondary_expression(NonnullOwnPtr<Expression> lhs)
+NonnullOwnPtr<Expression> Parser::parse_secondary_expression(NonnullOwnPtr<Expression> lhs, int min_precedence, Associativity associativity)
{
switch (m_current_token.type()) {
case TokenType::Plus:
consume();
- return make<BinaryExpression>(BinaryOp::Plus, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::Plus, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::PlusEquals:
consume();
- return make<AssignmentExpression>(AssignmentOp::AdditionAssignment, move(lhs), parse_expression());
+ return make<AssignmentExpression>(AssignmentOp::AdditionAssignment, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::Minus:
consume();
- return make<BinaryExpression>(BinaryOp::Minus, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::Minus, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::MinusEquals:
consume();
- return make<AssignmentExpression>(AssignmentOp::SubtractionAssignment, move(lhs), parse_expression());
+ return make<AssignmentExpression>(AssignmentOp::SubtractionAssignment, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::Asterisk:
consume();
- return make<BinaryExpression>(BinaryOp::Asterisk, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::Asterisk, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::AsteriskEquals:
consume();
- return make<AssignmentExpression>(AssignmentOp::MultiplicationAssignment, move(lhs), parse_expression());
+ return make<AssignmentExpression>(AssignmentOp::MultiplicationAssignment, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::Slash:
consume();
- return make<BinaryExpression>(BinaryOp::Slash, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::Slash, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::SlashEquals:
consume();
- return make<AssignmentExpression>(AssignmentOp::DivisionAssignment, move(lhs), parse_expression());
+ return make<AssignmentExpression>(AssignmentOp::DivisionAssignment, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::GreaterThan:
consume();
- return make<BinaryExpression>(BinaryOp::GreaterThan, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::GreaterThan, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::GreaterThanEquals:
consume();
- return make<BinaryExpression>(BinaryOp::GreaterThanEquals, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::GreaterThanEquals, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::LessThan:
consume();
- return make<BinaryExpression>(BinaryOp::LessThan, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::LessThan, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::LessThanEquals:
consume();
- return make<BinaryExpression>(BinaryOp::LessThanEquals, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::LessThanEquals, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::EqualsEqualsEquals:
consume();
- return make<BinaryExpression>(BinaryOp::TypedEquals, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::TypedEquals, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::ExclamationMarkEqualsEquals:
consume();
- return make<BinaryExpression>(BinaryOp::TypedInequals, move(lhs), parse_expression());
+ return make<BinaryExpression>(BinaryOp::TypedInequals, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::ParenOpen:
return parse_call_expression(move(lhs));
case TokenType::Equals:
consume();
- return make<AssignmentExpression>(AssignmentOp::Assignment, move(lhs), parse_expression());
+ return make<AssignmentExpression>(AssignmentOp::Assignment, move(lhs), parse_expression(min_precedence, associativity));
case TokenType::Period:
consume();
- return make<MemberExpression>(move(lhs), parse_expression());
+ return make<MemberExpression>(move(lhs), parse_expression(min_precedence, associativity));
case TokenType::PlusPlus:
consume();
return make<UpdateExpression>(UpdateOp::Increment, move(lhs));
@@ -196,7 +331,7 @@ NonnullOwnPtr<CallExpression> Parser::parse_call_expression(NonnullOwnPtr<Expres
NonnullOwnPtrVector<Expression> arguments;
while (match_expression()) {
- arguments.append(parse_expression());
+ arguments.append(parse_expression(0));
if (!match(TokenType::Comma))
break;
consume();
@@ -204,20 +339,14 @@ NonnullOwnPtr<CallExpression> Parser::parse_call_expression(NonnullOwnPtr<Expres
consume(TokenType::ParenClose);
- // FIXME: Allow lhs expression instead of just a string
- if (lhs->is_identifier()) {
- return make<CallExpression>(static_cast<Identifier*>(lhs.ptr())->string(), move(arguments));
- }
-
- m_has_errors = true;
- return make<CallExpression>("***ERROR***");
+ return make<CallExpression>(move(lhs), move(arguments));
}
NonnullOwnPtr<ReturnStatement> Parser::parse_return_statement()
{
consume(TokenType::Return);
if (match_expression()) {
- return make<ReturnStatement>(parse_expression());
+ return make<ReturnStatement>(parse_expression(0));
}
return make<ReturnStatement>(nullptr);
}
@@ -283,7 +412,7 @@ NonnullOwnPtr<VariableDeclaration> Parser::parse_variable_declaration()
OwnPtr<Expression> initializer;
if (match(TokenType::Equals)) {
consume();
- initializer = parse_expression();
+ initializer = parse_expression(0);
}
return make<VariableDeclaration>(make<Identifier>(name), move(initializer), declaration_type);
}
@@ -313,7 +442,7 @@ NonnullOwnPtr<ForStatement> Parser::parse_for_statement()
case TokenType::Semicolon:
break;
default:
- test = parse_expression();
+ test = parse_expression(0);
break;
}
@@ -324,7 +453,7 @@ NonnullOwnPtr<ForStatement> Parser::parse_for_statement()
case TokenType::Semicolon:
break;
default:
- update = parse_expression();
+ update = parse_expression(0);
break;
}
@@ -405,9 +534,9 @@ bool Parser::done() const
Token Parser::consume()
{
- auto oldToken = m_current_token;
+ auto old_token = m_current_token;
m_current_token = m_lexer.next();
- return oldToken;
+ return old_token;
}
Token Parser::consume(TokenType type)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 14:39:59 +0000