LibCpp: Parse If statements

Userland/Libraries/LibCpp/AST.cpp

@@ -379,4 +379,32 @@ NonnullRefPtrVector<Declaration> BlockStatement::declarations() const
     return declarations;
 }
 
+void IfStatement::dump(size_t indent) const
+{
+    ASTNode::dump(indent);
+    if (m_predicate) {
+        print_indent(indent + 1);
+        dbgprintf("Predicate:\n");
+        m_predicate->dump(indent + 1);
+    }
+    if (m_then) {
+        print_indent(indent + 1);
+        dbgprintf("Then:\n");
+        m_then->dump(indent + 1);
+    }
+    if (m_else) {
+        print_indent(indent + 1);
+        dbgprintf("Else:\n");
+        m_else->dump(indent + 1);
+    }
+}
+
+NonnullRefPtrVector<Declaration> IfStatement::declarations() const
+{
+    NonnullRefPtrVector<Declaration> declarations;
+    declarations.append(m_predicate->declarations());
+    declarations.append(m_then->declarations());
+    declarations.append(m_else->declarations());
+    return declarations;
+}
 }

Userland/Libraries/LibCpp/AST.h

@@ -581,4 +581,22 @@ public:
     virtual ~Comment() override = default;
     virtual const char* class_name() const override { return "Comment"; }
 };
+
+class IfStatement : public Statement {
+public:
+    IfStatement(ASTNode* parent, Optional<Position> start, Optional<Position> end)
+        : Statement(parent, start, end)
+    {
+    }
+
+    virtual ~IfStatement() override = default;
+    virtual const char* class_name() const override { return "IfStatement"; }
+    virtual void dump(size_t indent) const override;
+    virtual NonnullRefPtrVector<Declaration> declarations() const override;
+
+    RefPtr<Expression> m_predicate;
+    RefPtr<Statement> m_then;
+    RefPtr<Statement> m_else;
+};
+
 }

Userland/Libraries/LibCpp/Parser.cpp

@@ -186,6 +186,10 @@ NonnullRefPtr<Statement> Parser::parse_statement(ASTNode& parent)
     if (match_keyword("for")) {
         consume_semicolumn.disarm();
         return parse_for_statement(parent);
+    }
+    if (match_keyword("if")) {
+        consume_semicolumn.disarm();
+        return parse_if_statement(parent);
     } else {
         error("unexpected statement type");
         consume_semicolumn.disarm();
@@ -997,4 +1001,23 @@ NonnullRefPtr<ForStatement> Parser::parse_for_statement(ASTNode& parent)
     return for_statement;
 }
 
+NonnullRefPtr<IfStatement> Parser::parse_if_statement(ASTNode& parent)
+{
+    SCOPE_LOGGER();
+    auto if_statement = create_ast_node<IfStatement>(parent, position(), {});
+    consume(Token::Type::Keyword);
+    consume(Token::Type::LeftParen);
+    if_statement->m_predicate = parse_expression(*if_statement);
+    consume(Token::Type::RightParen);
+    if_statement->m_then = parse_statement(*if_statement);
+    if (match_keyword("else")) {
+        consume(Token::Type::Keyword);
+        if_statement->m_else = parse_statement(*if_statement);
+        if_statement->set_end(if_statement->m_else->end());
+    } else {
+        if_statement->set_end(if_statement->m_then->end());
+    }
+    return if_statement;
+}
+
 }

Userland/Libraries/LibCpp/Parser.h

@@ -104,6 +104,7 @@ private:
     NonnullRefPtr<ForStatement> parse_for_statement(ASTNode& parent);
     NonnullRefPtr<BlockStatement> parse_block_statement(ASTNode& parent);
     NonnullRefPtr<Comment> parse_comment(ASTNode& parent);
+    NonnullRefPtr<IfStatement> parse_if_statement(ASTNode& parent);
 
     bool match(Token::Type);
     Token consume(Token::Type);