import java.io.*;

/**
 * @Author Cherry
 * @Date 2021年1月26日
 * @Time 16:32
 * @Brief 处理 ASM 汇编文件,删除全局变量声明 (global)
 * 外部变量声明 (extern) 和 SECTION 段定义
 */

public class ProcessASMFile {
 private String fileName = null;
 private static String bakFileName = null;
 private FileWriter fileWriter = null;
 static boolean isRename = false;
 static File bakFile = null;

 /**
 * 将原 ASM 文件拷贝一份,加上 .bak 后缀,再将拷贝的文件进行处理写入原文件
 * @param fileName 最终保存的文件名,也是一开始需要处理的文件
 * @throws IOException IOException
 */
 public ProcessASMFile(String fileName) throws IOException {
 this.fileName = fileName;
 File file = new File(fileName);
 if (file.exists()) {
 bakFileName = fileName + ".bak";
 bakFile = new File(bakFileName);
 isRename = file.renameTo(bakFile);
 fileWriter = new FileWriter(fileName, true);
 } else {
 System.out.println("Do not exist this file!");
 }

 }

 /**
 * 删除全局变量声明 (global) 外部变量声明 (extern) 和 SECTION 段定义
 * @throws IOException IOException
 */
 public void processASM() throws IOException {
 File file = new File(bakFileName);
 FileInputStream fis = new FileInputStream(file);
 BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
 if (file.getName().endsWith(".asm.bak") && file.exists() && file.isFile()) {
 String lineText;
 while ((lineText = reader.readLine()) != null) {
 while (lineText.toLowerCase().contains("global") |
 lineText.toLowerCase().contains("extern") |
 lineText.toLowerCase().contains("section")) {
 lineText = reader.readLine();
 }
 //System.out.println(lineText);
 fileWriter.write(lineText + "\n");
 }
 }
 fileWriter.flush();
 fileWriter.close();
 fis.close(); //必须关闭流才能删除文件
 }

 /**
 * 运行 NASM 命令
 * nasm kernel.asm -o kernel
 */
 public void runNASM() throws IOException {
 Process process;
 //process = Runtime.getRuntime().exec("cd ..");
 process = Runtime.getRuntime().exec("nasm boot.asm -o boot");
 read(process.getInputStream(), System.out);
 read(process.getErrorStream(), System.err);
 process = Runtime.getRuntime().exec("nasm kernel.asm -o kernel");
 read(process.getInputStream(), System.out);
 read(process.getErrorStream(), System.err);
 //System.out.println("NSAM excuting done!");
 }

 /**
 * 读出控制台输出内容
 */
 public void read(InputStream inputStream, PrintStream out) throws IOException {
 BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
 String line;
 while ((line = reader.readLine()) != null) {
 out.println(line);
 }
 inputStream.close();
 }

 public static void main(String[] args) throws IOException {
 ProcessASMFile processASMFile = new ProcessASMFile(args[0]); //用于命令行输入参数执行
 if (isRename) {
 processASMFile.processASM();
 System.out.println("ASM file modified done!");
 System.out.println(bakFile.getName() + " delete " + bakFile.delete());
 } else {
 System.out.println("ASM file modified failed!");
 }
 }
}