C语言：C语言注释转换C++，注释转化项目C-->C++注释

在较早的C、C++版本中，注释并不是通用的，如果注释统一在编译后会便于查看，//注释可以叠加，/* 与 * /之前不允许出现* /，在注释是容易带来歧义，故引入本项目。
CommentConvert.h

#ifndef __COMMENTCONVERT_H__
#define __COMMENTCONVERT_H__

#define _CRT_SECURE_NO_WARNINGS 10
#include<stdio.h>
#include<stdlib.h>
#include<assert.h>

#define INPUTFILENAME "input.c"  
#define OUTPUTFILENAME "output.c"  

typedef enum COMMENT_START//枚举表示操作选项；  
{
    NULL_START,//0
    C_START,//1
    CPP_START,//2
    END_START//3
}StateType;

void CommentsInto();
void ConvertWork(FILE *read, FILE *write);//注释转换操作选项函数；  
void DoCState(FILE *read, FILE *write);//C 转换为 C++；  
void DoNullState(FILE *read, FILE *write);//普通语句空转换函数；  
void DoCppState(FILE *read, FILE *write);//C++转换 C ；  

#endif//__COMMENTCONVERT_H__

CommentConvert.c

#include"CommentConvert.h"
StateType state;

void DoNullState(FILE *read, FILE *write)//普通语句空转换函数；  
{
    int first = fgetc(read);
    int second;

    switch (first)
    {
    case'/':
        second = fgetc(read);
        if (second == '*')
        {
            fputc(first, write);
            fputc('/', write);
            state = C_START;//如果是C注释我们将状态改为C++状态，并且将注释开头改为C++注释；  
        }
        else if (second == '/')
        {
            fputc(first, write);
            fputc(second, write);
            state = CPP_START; //如果是C++注释我们将状态改为C++状态,keep;  
        }

        else //普通语句就直接写入；  
        {
            fputc(first, write);
            fputc(second, write);
        }
        break;
    case EOF:
        fputc(first, write);
        state = END_START;//注释结束，状态调整；  
        break;
    default://开始就为普通内容，直接写入；  
        fputc(first, write);
        break;
    }
}

void DoCState(FILE *read, FILE *write)//C 转换为 C++；  
{
    int first = fgetc(read);
    int second;
    int third;

    switch (first)
    {
        case '*':
            second = fgetc(read);
            if (second == '/')
            {
                third = fgetc(read);
                if (third == '\n')
                {
                    fputc(third, write);
                    state = NULL_START; 
                }
                if (third != '\n')
                {
                    fputc('\n',write);
                    ungetc(third, read);//ungetc函数的功能是将已读数据还回缓冲区；  
                    state = NULL_START;
                }
            }
            else
            {
                fputc(first, write);
                ungetc(second, read);//将*之后的内容还回缓冲区；  
            }
            break;
        case '\n'://如果是换行，那就是连续注释，就将下一行开头加入Cpp注释；  
            fputc(first, write);
            fputc('/', write);
            fputc('/', write);
            break;
        case EOF://文件最后一个非显示字符
            fputc(first, write);
            state = END_START;
            break;
        default:
            fputc(first, write);
            break;
    }
}

void DoCppState(FILE *read, FILE *write)//C++转换 C ；  
{
    int first = fgetc(read);
    switch (first)
    {
    case '\n':
        fputc(first, write);
        state = NULL_START;
        break;
    case EOF:
        fputc(first, write);
        state = END_START;
    default:
        fputc(first, write);
        break;
    }
}

void ConvertWork(FILE *read, FILE *write)//注释转换操作选项函数；  
{
    state = NULL_START;//一开始我们选择无状态,保证能够进入读取字符循环

    while (state != END_START)
    {
        switch (state)
        {
        case NULL_START://正常，AND FIRST START
            DoNullState(read, write);
            break;
        case C_START://C注释
            DoCState(read, write);
            break;
        case CPP_START://C++注释
            DoCppState(read, write);
            break;
        default:
            break;
        }
    }
}

void CommentsInto()
{
    FILE *pWrite = NULL;
    //打开提前编辑好的"input.c"文件;  

    FILE *pRead = fopen(INPUTFILENAME, "r");//read
    if (pRead == NULL)
    {
        perror("open file for read");
        exit(EXIT_FAILURE);
    }

    //写入新创建的"output.c"文件;  

    pWrite = fopen(OUTPUTFILENAME, "w");//write
    if (pWrite == NULL)
    {
        fclose(pRead);
        perror(" open file for write ");
        exit(EXIT_FAILURE);
    }

    //调用操作选项函数;  
    //关闭已经打开的文件;  

    ConvertWork(pRead, pWrite);
    fclose(pRead);
    fclose(pWrite);
}

main.c

这里写代码片#include"CommentConvert.h"

void Test()
{
    CommentsInto();
}

int main()
{
    Test();

    //system("pause");
    return 0;
}

input.c

// 1.一般情况  
/* int i = 0; */

// 2.换行问题  
/* int i = 0; */int j = 0;
/* int i = 0; */
int j = 0;

// 3.匹配问题  
/*int i = 0;/*xxxxx*/

// 4.多行注释问题  
/*
int i=0;
int j = 0;
int k = 0;
*/int k = 0;

// 5.连续注释问题  
/**//**/

// 6.连续的**/问题  
/***/

// 7.C++注释问题  
// /*xxxxxxxxxxxx*/  

output.c

// 1.一般情况  
// int i = 0; 

// 2.换行问题  
// int i = 0; 
int j = 0;
// int i = 0; 
int j = 0;

// 3.匹配问题  
//int i = 0;/*xxxxx

// 4.多行注释问题  
//
//int i=0;
//int j = 0;
//int k = 0;
//
int k = 0;

// 5.连续注释问题  
//
//

// 6.连续的**/问题  
//*

// 7.C++注释问题  
// /*xxxxxxxxxxxx*/