/*

* This file is part of MiniJVM (https://github.com/muhammad23012009/minijvm)

* Copyright (c) 2025 Muhammad <thevancedgamer@mentallysanemainliners.org>

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, version 3.

*

* This program is distributed in the hope that it will be useful, but

* WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

* General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see <http://www.gnu.org/licenses/>.

*/

#define _GNU_SOURCE

#include <unistd.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <signal.h>

#include <sys/stat.h>

#include <time.h>

#include "minijvm.h"

#include "reader.h"

#include "builtins/builtins.h"

#include "gc.h"

#include "dynarr.h"

#include "thread.h"

static jit_context_t s_jit_context;

static JNI *s_jni;

void destroy_dynamic_methods();

static char *help_text = "miniJVM: a stupidly simple JVM. \n\

Usage: ./miniJVM <class name>\n";

jit_context_t get_jit_context()

{

return s_jit_context;

}

JNI *get_jni()

{

return s_jni;

}

uint64_t get_current_time()

{

struct timespec current_time;

clock_gettime(CLOCK_MONOTONIC, &current_time);

return current_time.tv_sec * 1000 + current_time.tv_nsec / 1000000;

}

void porcodio()

{

// dump the entire stacktrace

printf("Segmentation fault! Stack trace:\n");

Frame *last_frame = get_current_frame();

int i = 0;

while (last_frame) {

printf("\t#%d: %s::%s, (PC %d)\n", i, last_frame->method->class->name, last_frame->method->name, last_frame->pc);

last_frame = last_frame->caller;

i++;

}

exit(1);

}

static void start_main(struct arguments *args)

{

Variant ret = method_execute(args->method, args->arg);

// how do we handle return from main?

free(args);

}

int main(int argc, char *argv[])

{

pthread_t main_thread;

if (argc < 2) {

fprintf(stderr, "miniJVM: invalid arguments!\n");

fprintf(stderr, "%s", help_text);

return 1;

}

// Install a fault handler and print stacktrace

struct sigaction sa;

sa.sa_handler = porcodio;

sa.sa_flags = 0;

sigemptyset(&sa.sa_mask);

sigaction(SIGSEGV, &sa, NULL);

// Setup JIT

s_jit_context = jit_context_create();

s_jni = jni_init();

// Load our own symbols as well.

jni_load(s_jni, NULL);

char filename[2048];

snprintf(filename, 2048, "%s%s", argv[1], ".class");

thread_list_init();

classes_new();

gc_create();

/* Setup built-in classes and methods */

classes_add_class(class_create_builtin("java/lang/Object", &java_lang_Object_builtins));

classes_add_class(class_create_builtin("java/util/Objects", &java_util_Objects_builtins));

//classes_add_class(class_create_builtin("java/io/PrintStream", &java_io_PrintStream_builtins));

//classes_add_class(class_create_builtin("java/lang/System", &java_lang_System_builtins));

classes_add_class(class_create_builtin("java/lang/String", &java_lang_String_builtins));

classes_add_class(class_create_builtin("java/lang/Class", &java_lang_Class_builtins));

classes_add_class(class_create_builtin("java/lang/invoke/CallSite", &java_lang_invoke_CallSite_builtins));

classes_add_class(class_create_builtin("java/lang/invoke/StringConcatFactory", &java_lang_invoke_StringConcatFactory_builtins));

classes_add_class(class_create_builtin("java/lang/invoke/MethodHandles", &java_lang_invoke_MethodHandles_builtins));

classes_add_class(class_create_builtin("java/lang/invoke/MethodHandles$Lookup", &java_lang_invoke_MethodHandles_lookup_builtins));

classes_add_class(class_create_builtin("java/lang/invoke/MethodHandle", &java_lang_invoke_MethodHandle_builtins));

classes_add_class(class_create_builtin("java/lang/invoke/MethodType", &java_lang_invoke_MethodType_builtins));

//classes_add_class(class_create_builtin("java/io/InputStream", &java_io_InputStream_builtins));

//classes_add_class(class_create_builtin("java/io/StdinInputStream", &java_io_StdinInputStream_builtins));

classes_add_class(class_create_builtin("java/lang/reflect/Field", &java_lang_reflect_Field_builtins));

classes_add_class(class_create_builtin("java/lang/Throwable", &java_lang_Throwable_builtins));

classes_add_class(class_create_builtin("java/lang/ArrayIndexOutOfBoundsException", &java_lang_ArrayIndexOutOfBoundsException_builtins));

classes_add_class(class_create_builtin("sun/misc/Unsafe", &sun_misc_Unsafe_builtins));

classes_add_class(class_create_builtin("java/lang/Runtime", &java_lang_Runtime_builtins));

if (!classes_add_class(class_parse_file(filename))) {

classes_free();

return 1;

}

printf("miniJVM: all classes processed!\n");

Method *main_method = classes_get_main_method();

if (!main_method) {

fprintf(stderr, "Failed to find main method. Exiting!\n");

classes_free();

return 1;

}

// Initialize uhhhh

Method *something = class_get_method(classes_get_class("java/lang/System"), "initializeSystemClass", "()V");

method_execute(something);

Object **main_args = arr_init_with_capacity_and_type(sizeof(Object*), argc - 2, ARRAY_TYPE_OBJECT, classes_get_class("java/lang/String"));

for (int i = 2; i < argc; i++) {

Object *str_obj = object_new(classes_get_class("java/lang/String"));

object_set_field(str_obj, "value", variant_make_ref(argv[i]));

arr_push(main_args, str_obj);

}

Variant main_args_variant = variant_make_ref(main_args);

struct arguments *args = malloc(sizeof(struct arguments));

args->method = main_method;

args->arg = main_args_variant;

pthread_create(&main_thread, NULL, (void*(*)(void*))&start_main, args);

pthread_join(main_thread, NULL);

// Wait for all the threads to die

printf("Everything returned from main, now waiting for all threads to die...\n");

thread_list_wait();

classes_free();

destroy_dynamic_methods();

jni_free(s_jni);

gc_free();

jit_context_destroy(s_jit_context);

return 0;

}