From fc503b13688dd7d6078caa7692640302e861df61 Mon Sep 17 00:00:00 2001
From: Itamar <itamar8910@gmail.com>
Date: Fri, 2 Apr 2021 10:49:12 +0300
Subject: [PATCH] LibCpp: Parse sizeof() expression

---
 Userland/Libraries/LibCpp/AST.cpp    |  7 +++++++
 Userland/Libraries/LibCpp/AST.h      | 14 ++++++++++++++
 Userland/Libraries/LibCpp/Parser.cpp | 22 +++++++++++++++++++++-
 Userland/Libraries/LibCpp/Parser.h   |  2 ++
 4 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/Userland/Libraries/LibCpp/AST.cpp b/Userland/Libraries/LibCpp/AST.cpp
index f5088dbf5d..5ae64b30a4 100644
--- a/Userland/Libraries/LibCpp/AST.cpp
+++ b/Userland/Libraries/LibCpp/AST.cpp
@@ -530,4 +530,11 @@ void CppCastExpression::dump(size_t indent) const
         m_expression->dump(indent + 1);
 }
 
+void SizeofExpression::dump(size_t indent) const
+{
+    ASTNode::dump(indent);
+    if(m_type)
+        m_type->dump(indent+1);
+}
+
 }
diff --git a/Userland/Libraries/LibCpp/AST.h b/Userland/Libraries/LibCpp/AST.h
index 04c1247340..257ff23938 100644
--- a/Userland/Libraries/LibCpp/AST.h
+++ b/Userland/Libraries/LibCpp/AST.h
@@ -715,4 +715,18 @@ public:
     RefPtr<Expression> m_expression;
 };
 
+class SizeofExpression : public Expression {
+public:
+    SizeofExpression(ASTNode* parent, Optional<Position> start, Optional<Position> end, const String& filename)
+        : Expression(parent, start, end, filename)
+    {
+    }
+
+    virtual ~SizeofExpression() override = default;
+    virtual const char* class_name() const override { return "SizeofExpression"; }
+    virtual void dump(size_t indent) const override;
+
+    RefPtr<Type> m_type;
+};
+
 }
diff --git a/Userland/Libraries/LibCpp/Parser.cpp b/Userland/Libraries/LibCpp/Parser.cpp
index baef20b692..6c77bcf956 100644
--- a/Userland/Libraries/LibCpp/Parser.cpp
+++ b/Userland/Libraries/LibCpp/Parser.cpp
@@ -447,6 +447,9 @@ NonnullRefPtr<Expression> Parser::parse_primary_expression(ASTNode& parent)
     if (match_cpp_cast_expression())
         return parse_cpp_cast_expression(parent);
 
+    if(match_sizeof_expression())
+        return parse_sizeof_expression(parent);
+
     if (match_name()) {
         if (match_function_call() != TemplatizedMatchResult::NoMatch)
             return parse_function_call(parent);
@@ -847,7 +850,8 @@ bool Parser::match_expression()
     return match_literal()
         || token_type == Token::Type::Identifier
         || match_unary_expression()
-        || match_cpp_cast_expression();
+        || match_cpp_cast_expression()
+        || match_sizeof_expression();
 }
 
 bool Parser::eof() const
@@ -1399,4 +1403,20 @@ NonnullRefPtr<CppCastExpression> Parser::parse_cpp_cast_expression(ASTNode& pare
     return cast_expression;
 }
 
+bool Parser::match_sizeof_expression()
+{
+    return match_keyword("sizeof");
+}
+
+NonnullRefPtr<SizeofExpression> Parser::parse_sizeof_expression(ASTNode& parent)
+{
+    auto exp = create_ast_node<SizeofExpression>(parent, position(), {});
+    consume(Token::Type::Keyword);
+    consume(Token::Type::LeftParen);
+    exp->m_type = parse_type(parent);
+    consume(Token::Type::RightParen);
+    exp->set_end(position());
+    return exp;
+}
+
 }
diff --git a/Userland/Libraries/LibCpp/Parser.h b/Userland/Libraries/LibCpp/Parser.h
index de6a614028..0c308a90ff 100644
--- a/Userland/Libraries/LibCpp/Parser.h
+++ b/Userland/Libraries/LibCpp/Parser.h
@@ -90,6 +90,7 @@ private:
     bool match_template_arguments();
     bool match_name();
     bool match_cpp_cast_expression();
+    bool match_sizeof_expression();
 
     enum class TemplatizedMatchResult {
         NoMatch,
@@ -133,6 +134,7 @@ private:
     NonnullRefPtrVector<Type> parse_template_arguments(ASTNode& parent);
     NonnullRefPtr<Name> parse_name(ASTNode& parent);
     NonnullRefPtr<CppCastExpression> parse_cpp_cast_expression(ASTNode& parent);
+    NonnullRefPtr<SizeofExpression> parse_sizeof_expression(ASTNode& parent);
 
     bool match(Token::Type);
     Token consume(Token::Type);