Use arena in parser

Signed-off-by: CHatingPython <chatingpython@gmail.com>

CMakeLists.txt

@@ -2,6 +2,8 @@ cmake_minimum_required(VERSION 3.14)
 
 project(furlang VERSION 0.0.0 LANGUAGES CXX)
 
+enable_testing()
+
 find_package(GTest REQUIRED)
 
 add_subdirectory(furlang)

furc/include/furc/ast/declaration.hpp

@@ -62,6 +62,23 @@ class function_definition_node : public function_declarartion_node {
 public:
     function_definition_node(front::token name, function_body_handle&& body)
       : function_declarartion_node(name), m_body(std::move(body)) {}
+
+    ~function_definition_node() override = default;
+
+    function_definition_node(function_definition_node&& other) noexcept
+      : function_declarartion_node(std::move(other)), m_name(other.m_name), m_body(std::move(other.m_body)) {}
+
+    function_definition_node(const function_definition_node&) = delete;
+
+    function_definition_node& operator=(function_definition_node&& other) noexcept {
+        if (this == &other) return *this;
+        function_declarartion_node::operator=(std::move(other));
+        m_name = other.m_name;
+        m_body = std::move(other.m_body);
+        return *this;
+    }
+
+    function_definition_node& operator=(const function_definition_node&) = delete;
 public:
     declaration_node_t type() const override { return declaration_node_t::FunctionDefinition; }
 

furc/include/furc/ast/statement.hpp

@@ -35,14 +35,14 @@ public:
 class declaration_node;
 class declaration_statement_node : public statement_node {
 public:
-    declaration_statement_node(declaration_node* declaration)
+    declaration_statement_node(node_handle<declaration_node>&& declaration)
-      : m_declaration(declaration) {}
+      : m_declaration(std::move(declaration)) {}
 public:
     statement_node_t type() const override { return statement_node_t::Declaration; }
 
     std::ostream& print(std::ostream& os) const override { return os; }
 private:
-    declaration_node* m_declaration = nullptr;
+    node_handle<declaration_node> m_declaration;
 };
 
 class return_statement_node : public statement_node {

furc/include/furc/front/parser.hpp

@@ -5,6 +5,7 @@
 #include "furc/ast/node.hpp"
 #include "furc/ast/program.hpp"
 #include "furc/front/lexer.hpp"
+#include "furlang/arena.hpp"
 
 #include <vector>
 
@@ -22,7 +23,8 @@ public:
     parser& operator=(parser&&)      = default;
     parser& operator=(const parser&) = delete;
 public:
-    ast::node_handle<ast::program_node> parse();
+    // parser owns the arena :3c
+    ast::node_handle<ast::program_node> parse() &;
 private:
     ast::node_handle<ast::declaration_node> parse_declaration();
     ast::node_handle<ast::statement_node>   parse_statement();
@@ -36,6 +38,7 @@ private:
     std::string                 m_filename;
     std::string                 m_content;
     lexer                       m_lexer;
+    furlang::arena              m_arena;
     std::vector<token_handle<>> m_peekBuffer;
 };
 

furc/include/furc/handle.hpp

@@ -2,6 +2,7 @@
 #define FURC_HANDLE_HPP
 
 #include "furc/diag.hpp"
+#include "furlang/arena.hpp"
 
 #include <memory>
 #include <optional>
@@ -123,6 +124,10 @@ public:
     handle(location location, Args&&... args)
       : m_location(location), m_value(std::make_shared<value_type>(std::forward<Args>(args)...)) {}
 
+    template <typename... Args, typename = std::enable_if_t<std::is_constructible_v<value_type, Args...>>>
+    handle(location location, furlang::arena& arena, Args&&... args)
+      : m_location(location), m_value(arena.allocate_shared<value_type>(std::forward<Args>(args)...)) {}
+
     handle(location location, Error&& error)
       : m_location(location), m_error(std::move(error)) {}
 

furc/src/front/parser.cpp

@@ -25,8 +25,8 @@ parser::parser(std::string_view filename)
     m_lexer = { filename, m_content };
 }
 
-ast::node_handle<ast::program_node> parser::parse() {
+ast::node_handle<ast::program_node> parser::parse() & {
-    auto program = std::make_shared<ast::program_node>();
+    auto program = m_arena.allocate_shared<ast::program_node>();
 
     while (!m_lexer.empty()) {
         program->push(std::move(parse_declaration()));
@@ -55,11 +55,14 @@ ast::node_handle<ast::declaration_node> parser::parse_declaration() {
             case token_t::Lbrace: {
                 ast::function_body_handle body = parse_body();
                 if (body.error()) return body;
-                return ast::node_handle<ast::function_definition_node>{ first.location(), name, std::move(body) };
+                return ast::node_handle<ast::function_definition_node>{ first.location(),
+                    m_arena,
+                    name,
+                    std::move(body) };
             }
             case token_t::Semicolon: {
                 m_peekBuffer.clear();
-                return ast::node_handle<ast::function_declarartion_node>{ first.location(), name };
+                return ast::node_handle<ast::function_declarartion_node>{ first.location(), m_arena, name };
             }
             case token_t::None:
             case token_t::Identifier:
@@ -106,7 +109,7 @@ ast::node_handle<ast::statement_node> parser::parse_statement() {
         auto err = eat_token(token_t::Semicolon);
         if (err.error()) return err;
 
-        return ast::node_handle<ast::return_statement_node>{ tok.location() };
+        return ast::node_handle<ast::return_statement_node>{ tok.location(), m_arena };
     }
     default: break;
     }
@@ -114,7 +117,7 @@ ast::node_handle<ast::statement_node> parser::parse_statement() {
     auto declaration = parse_declaration();
     if (declaration.error())
         return { declaration.location(), "unexpected token "s + tok->type + ", expected statement" };
-    return ast::node_handle<ast::declaration_statement_node>{ declaration.location(), declaration };
+    return ast::node_handle<ast::declaration_statement_node>{ declaration.location(), m_arena, std::move(declaration) };
 }
 
 ast::function_body_handle parser::parse_body() {

furlang/include/furlang/arena.hpp

@@ -3,6 +3,8 @@
 
 #include <cstddef>
 #include <cstdint>
+#include <memory>
+#include <type_traits>
 
 namespace furlang {
 
@@ -29,9 +31,26 @@ public:
     arena& operator=(arena&& other) noexcept;
     arena& operator=(const arena&) = delete;
 public:
-    template <typename T>
+    template <typename T, typename = std::enable_if_t<std::is_default_constructible_v<T>>>
-    T* allocate(std::size_t count = 1) {
+    T* allocate(std::size_t count) {
-        return reinterpret_cast<T*>(allocate(sizeof(T), count));
+        T* allocated = reinterpret_cast<T*>(allocate(sizeof(T), count));
+        for (std::size_t i = 0; i < count; ++i) {
+            new (&allocated[i]) T();
+        }
+        return allocated;
+    }
+
+    template <typename T, typename... Args, typename = std::enable_if_t<std::is_constructible_v<T, Args...>>>
+    T* allocate(Args&&... args) {
+        T* allocated = reinterpret_cast<T*>(allocate(sizeof(T), 1));
+        new (allocated) T(std::forward<Args>(args)...);
+        return allocated;
+    }
+
+    template <typename T, typename... Args>
+    std::shared_ptr<T> allocate_shared(Args&&... args) {
+        T* allocated = allocate<T>(std::forward<Args>(args)...);
+        return std::shared_ptr<T>(allocated, [](T* object) { object->~T(); });
     }
 
     void reset();