C语言注释转化为C++注释（C语言实现）

/* int a=0;*/是C语言注释风格，而我们都知道C语言这样的注释是有缺陷的（不能嵌套注释），为了弥补这一缺陷，可将C语言注释风格改为C++注释风格（//int a=0;）.本文就来讲一下怎么运用C语言实现C注释转化为C++注释。

在一段代码中，往往会出现很多种情况，先来讨论一下可能存在的情况。

看图：（NUL代表正常情况，END代表结束）



请看具体代码：

头文件及函数声明（ComentConvert.h）部分

#define _CRT_SECURE_NO_WARNINGS
#ifndef __COMMENT_CONVER_H__
#define __COMMENT_CONVER_H__

#include <stdio.h>
#include <stdlib.h>

enum STATE
{
END_STATE,
NUL_STATE,
C_STATE,
CPP_STATE
};

void DoNulState(FILE* pfIn, FILE* pfOut, enum STATE *s);//处理正常情况
void DoCState(FILE* pfIn, FILE* pfOut, enum STATE *s);//处理C语言注释部分
void DoCPPState(FILE* pfIn, FILE* pfOut, enum STATE *s);//处理C++注释部分

#endif//__COMMENT_CONVER_H__

具体函数实现ConmentConvert.c部分

#define _CRT_SECURE_NO_WARNINGS
#include "ComentConvert.h"

void DoNulState(FILE* pfIn, FILE* pfOut, enum STATE *s)
{
int first = 0;
first = fgetc(pfIn);
switch (first)
{
case '/':
{
int second = 0;
second = fgetc(pfIn);
switch (second)
{
case '/':
fputc(first, pfOut);
fputc(second, pfOut);
*s = CPP_STATE;
break;
case '*':
fputc(first, pfOut);
fputc(first, pfOut);
*s = C_STATE;
break;
default:
fputc(first, pfOut);
fputc(second, pfOut);
break;
}
}
break;
case EOF:
*s = END_STATE;
break;
default:
fputc(first,pfOut);
break;
}
}
void DoCState(FILE* pfIn, FILE* pfOut, enum STATE *s)
{
int first = 0;
first = fgetc(pfIn);
switch (first)
{
case '*':
{
int second = 0;
second = fgetc(pfIn);
switch (second)
{
case '*':
ungetc(second, pfIn);
fputc(second, pfOut);
break;
case '/':
fputc('\n', pfOut);
*s = NUL_STATE;
break;
default:
fputc(first, pfOut);
fputc(second, pfOut);
break;
}
}
break;
case '\n':
fputc(first, pfOut);
fputc('/', pfOut);
fputc('/', pfOut);
break;
default:
fputc(first, pfOut);
break;
}
}
void DoCPPState(FILE* pfIn, FILE* pfOut, enum STATE *s)
{
int first = 0;
first = fgetc(pfIn);
switch (first)
{
case EOF:
*s = END_STATE;
break;
default:
fputc(first, pfOut);
*s = NUL_STATE;
break;
}
}

#include "ComentConvert.h"

void test()
{
FILE* pfIn = NULL;
FILE* pfOut = NULL;
pfIn = fopen("input.c", "r");
if (pfIn == NULL)
{
perror("open a file for read");
exit(EXIT_FAILURE);
}
pfOut = fopen("output.c", "w");
if (pfOut == NULL)
{
perror("open a file for write");
fclose("input.c");
exit(EXIT_FAILURE);
}
enum STATE state=NUL_STATE;
while (state!=END_STATE)
{
switch (state)
{
case NUL_STATE:
DoNulState(pfIn, pfOut, &state);
break;
case C_STATE:
DoCState(pfIn, pfOut, &state);
break;
case CPP_STATE:
DoCPPState(pfIn, pfOut, &state);
break;
}
}
}

int main()
{
test();
return 0;
}

注释转换前后的对比：



PS：欢迎大家提出宝贵意见