feat: switch to nlohmann::json

Author: jahan-addison

CMakeLists.txt

@@ -14,7 +14,7 @@ include(GNUInstallDirs)
 if(MSVC)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zc:__cplusplus /utf-8 /D_CRT_SECURE_NO_DEPRECATE /W4 /WX")
 else()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wpedantic -Werror")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wpedantic")
 endif()
 
 include(cmake/CPM.cmake)
@@ -58,14 +58,7 @@ include_directories(${PYTHON_INCLUDE_DIRS})
 
 # CPM Packages
 
-CPMAddPackage(
-  NAME simdjson
-  VERSION 3.11.3
-  GITHUB_REPOSITORY simdjson/simdjson
-  OPTIONS
-    # "SIMDJSON_BUILD_STATIC_LIB ON"
-    # "BUILD_SHARED_LIBS ON"
-)
+CPMAddPackage("gh:nlohmann/[email protected]")
 
 CPMAddPackage(
   NAME cxxopts
@@ -89,4 +82,4 @@ target_include_directories(
 
 target_include_directories(${PROJECT_NAME} PUBLIC ${PYTHON_INCLUDE_DIRS})
 
-target_link_libraries(${PROJECT_NAME} PUBLIC simdjson::simdjson Python3::Python cxxopts::cxxopts)
+target_link_libraries(${PROJECT_NAME} PUBLIC nlohmann_json::nlohmann_json Python3::Python cxxopts::cxxopts)

README.md

@@ -2,7 +2,7 @@
 
 ### B Compiler to z80 in C++
 
-* The frontend (Lexer, Parser) and first-pass is built with an [easy-to-use LALR(1) grammar and parser generator in python](https://github.com/jahan-addison/xion/tree/master), that interfaces with C++ via libpython or json via `simdjson`
+* The frontend (Lexer, Parser) and first-pass is built with an [easy-to-use LALR(1) grammar and parser generator in python](https://github.com/jahan-addison/xion/tree/master), that interfaces with C++ via libpython or json via `nlohmann`
 * The backend will focus on modern work in SSA, Sea of Nodes, and compiler optimizations through IR breakthroughs in LLVM, gcc, V8, and related toolchains
 
 
@@ -41,7 +41,7 @@ make
 
 Note: These are installed automatically via CPM and cmake.
 
-* `simdjson` - Ultra-performant json parser
+* `nlohmann` - JSON for Modern C++
 * `cxxopts` - Lightweight commandline option parser
 
 ### Resources

roxas/main.cc

@@ -17,6 +17,7 @@
 #include <cstdlib>
 #include <cxxopts.hpp>
 #include <iostream>
+#include <nlohmann/json.hpp>
 #include <roxas/python_module.h>
 #include <roxas/util.h>
 
@@ -44,7 +45,7 @@ int main(int argc, char** argv)
         auto result = options.parse(argc, argv);
         auto python_opt = result["python"].as<bool>();
 
-        std::string ast_as_json{};
+        std::string ast_as_json_string{};
 
         if (result.count("help")) {
             std::cout
@@ -57,9 +58,12 @@ int main(int argc, char** argv)
         }
 
         if (result.count("json")) {
-            ast_as_json = roxas::util::read_file_from_path(
+            // If `-j' is passed, load the AST from a pre-compiled JSON on-disk
+            ast_as_json_string = roxas::util::read_file_from_path(
                 result["json"].as<std::string>());
         } else if (python_opt) {
+            // Otherwise, use roxas::PythonModuleLoader to compute an AST from
+            // a source program and a Lexer/Parser in Python (default: Xion)
             auto module_args =
                 result["python-use"].as<std::vector<std::string>>();
 
@@ -72,7 +76,7 @@ int main(int argc, char** argv)
             auto python_module = roxas::PythonModuleLoader(
                 module_args[1], module_args[0], module_args[3]);
 
-            ast_as_json = python_module.call_method_on_module(
+            ast_as_json_string = python_module.call_method_on_module(
                 "get_source_program_ast_as_json", { source, "true", "true" });
         } else {
             std::cerr << "Error :: Invalid arguments try -j <json file> or -p "
@@ -81,10 +85,8 @@ int main(int argc, char** argv)
             return EXIT_FAILURE;
         }
 
-        simdjson::ondemand::parser parser;
-        auto doc = parser.iterate(ast_as_json);
-
-        roxas::util::recursive_print_json(doc);
+        auto json = nlohmann::json::parse(ast_as_json_string);
+        std::cout << "AST: " << json.dump() << std::endl;
 
     } catch (std::runtime_error& e) {
         std::cerr << "Runtime Exception :: " << e.what() << std::endl;

roxas/symbol.h

@@ -16,6 +16,62 @@
 
 #pragma once
 
+#include <array>
+#include <roxas/util.h>
+#include <string>
+#include <unordered_map>
+#include <variant>
+
 namespace roxas {
+/**
+ * @brief Symbol table object
+ *
+ * Constructs a symbol table via pass on an AST in simdjson::ondemand::value
+ * format.
+ *
+ * Structure:
+ *
+ * Name (LValue)
+ *        \
+ *         \
+ *   ------------------------------------------------------
+ *   | Type | Size | Line Declare | Line Usage |  Address |
+ *   ------------------------------------------------------
+ */
+class Symbol_Table
+{
+  public:
+  public:
+    Symbol_Table& operator=(Symbol_Table const&) = delete;
+    Symbol_Table(Symbol_Table const&) = delete;
+
+    using symbol_data = std::array<std::string, 5>;
+
+    /**
+     * @brief Construct a new Symbol_Table object
+     *
+     * @param ast simdjson::ondemand::value
+     */
+    explicit Symbol_Table(std::string_view ast);
+
+  public:
+    /**
+     * @brief Get a symbol by name in the symbol table
+     *
+     * @param name
+     * @return symbol_data
+     */
+    symbol_data get_symbol_by_name(std::string_view name);
+    /**
+     * @brief Get a symbol by address in the symbol table
+     *
+     * @param name
+     * @return symbol_data
+     */
+    symbol_data get_symbol_by_address(unsigned int address);
+
+  private:
+    std::unordered_map<std::string, symbol_data> table_;
+};
 
 } // namespace roxas

roxas/util.cc

@@ -21,70 +21,6 @@ namespace roxas {
 
 namespace util {
 
-/**
- * @brief Recursively print a simdjson::ondemand json element
- *
- * @param element
- */
-void recursive_print_json(simdjson::ondemand::value element)
-{
-    bool add_comma;
-    switch (element.type()) {
-        case simdjson::ondemand::json_type::array:
-            std::cout << "[";
-            add_comma = false;
-            for (auto child : element.get_array()) {
-                if (add_comma) {
-                    std::cout << ",";
-                }
-                // We need the call to value() to get
-                // an simdjson::ondemand::value type.
-                recursive_print_json(child.value());
-                add_comma = true;
-            }
-            std::cout << "]";
-            break;
-        case simdjson::ondemand::json_type::object:
-            std::cout << "{";
-            add_comma = false;
-            for (auto field : element.get_object()) {
-                if (add_comma) {
-                    std::cout << ",";
-                }
-                // key() returns the key as it appears in the raw
-                // JSON document, if we want the unescaped key,
-                // we should do field.unescaped_key().
-                // We could also use field.escaped_key() if we want
-                // a std::string_view instance, but we do not need
-                // escaping.
-                std::cout << "\"" << field.key() << "\": ";
-                recursive_print_json(field.value());
-                add_comma = true;
-            }
-            std::cout << "}\n";
-            break;
-        case simdjson::ondemand::json_type::number:
-            // assume it fits in a double
-            std::cout << element.get_double();
-            break;
-        case simdjson::ondemand::json_type::string:
-            // get_string() would return escaped string, but
-            // we are happy with unescaped string.
-            std::cout << "\"" << element.get_raw_json_string() << "\"";
-            break;
-        case simdjson::ondemand::json_type::boolean:
-            std::cout << element.get_bool();
-            break;
-        case simdjson::ondemand::json_type::null:
-            // We check that the value is indeed null
-            // otherwise: an error is thrown.
-            if (element.is_null()) {
-                std::cout << "null";
-            }
-            break;
-    }
-}
-
 /**
  * @brief read source file
  *

roxas/util.h

@@ -15,21 +15,23 @@
  */
 
 #pragma once
+
 #include <filesystem>
-#include <simdjson.h>
 
 namespace roxas {
 
 namespace util {
 
-namespace fs = std::filesystem;
+// The overload pattern
+template<class... Ts>
+struct overload : Ts...
+{
+    using Ts::operator()...;
+};
+template<class... Ts>
+overload(Ts...) -> overload<Ts...>;
 
-/**
- * @brief Recursively print a simdjson::ondemand json element
- *
- * @param element
- */
-void recursive_print_json(simdjson::ondemand::value element);
+namespace fs = std::filesystem;
 
 /**
  * @brief read a file from a fs::path