C注释风格转化为C++风格注释

来源：互联网发布：阿扎姆号游艇数据编辑：程序博客网时间：2024/05/17 07:47

C转C++可能遇到的问题：

//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*/

我们可以发现注释转换需要考虑的情况是非常多的，这对于我们写程序是非常不利的，为解决这类问题，我们引入有限状态机的概念。

有限状态机简称状态机，是表示有限个状态以及在这些状态之间转移的行为的模型。有限状态机是闭环系统，可以用有限的状态处理无穷的状态。

通常我们使用switch case语句来处理有限状态机，

switch (state )

{

case 1:

// ...

break ;

case 2:

// ...

break ;

case 3:

// ...

break ;

case n :

break ;

default :

}

主要代码设计：

1，我们要声明一个枚举（enum）类型来存放四种状态

typedef enum CONVERT_STATE

{

NULL_STATE,

C_STATE,

CPP_STATE,

END_STATE,

}StateType;

定义全局变量state，初始状态为NULL_STATE.

2，声明一个打开input.c和output.c的函数

void CommentConvert()

{

FILE *pWrite=NULL ;

FILE *pRead = fopen("input.c" , "r");

if (pRead == NULL )

{

perror( "open file for read");

exit( EXIT_FAILURE);

}

pWrite = fopen( "output.c", "w" );

if (pWrite == NULL )

{

fclose(pRead);

perror( "open file for write");

exit( EXIT_FAILURE);

}

ConvertWork(pRead, pWrite);

fclose(pRead);

fclose(pWrite);

}

3，声明一个切换状态的函数

void ConvertWork(FILE *pRead, FILE *pWrite )

{

state = NULL_STATE;

while (state != END_STATE)

{

switch (state)

{

case NULL_STATE:

DoNullState( pRead, pWrite );

break;

case C_STATE:

DoCState( pRead, pWrite );

break;

case CPP_STATE:

DoCppState( pRead, pWrite );

break;

}

4,我们还要声明处理不同状态的函数

处理NULL_STATE的函数：

void DoNullState(FILE *read, FILE *write)

{

int first = fgetc(read );

int second = 0;

switch (first)

{

case '/' :

second = fgetc(read);

if (second == '*' )

{

fputc(first, write);

fputc( '/', write );

state = C_STATE;

}

else if (second == '/')

{

fputc(first, write);

fputc( '/', write );

state = CPP_STATE;

}

else

{

fputc(first, write);

fputc(second, write);

}

break;

case EOF :

fputc(first, write);

state = END_STATE;

break;

default:

fputc(first, write);

break;

}

处理C_STATE的的函数：

void DoCState(FILE *read, FILE *write)

{

int first = fgetc(read );

int second = 0;

switch (first)

{

case '/' :

second = fgetc( read);

if (second == '*' )

{

}

else if (second == '/')

{

}

else

{

fputc(first, write);

fputc(second, write);

}

break;

case '\n' :

fputc( '\n', write );

fputc( '/',write );

fputc( '/', write );

break;

case '*' :

second = fgetc( read);

if (second == '*' )

{

fputc(first, write);

first=fgetc( read);

if (first == '/' )

{

fputc( '\n', write );

state = NULL_STATE;

}

else if (second == '/')

{

fputc( '\n', write );

state = NULL_STATE;

}

else

{

fputc(first, write);

fputc(second, write);

}

break;

case EOF :

fputc(first, write);

state = END_STATE;

break;

default:

fputc(first, write);

break;

}

处理CPP_STATE的函数：

void DoCppState(FILE *read, FILE *write)

{

int first = fgetc(read );

int second = 0;

switch (first)

{

case '/' :

second = fgetc(read);

if (second == '*' )

{

}

else if (second == '/')

{

}

else

{

fputc(first, write);

fputc(second, write);

}

break;

case '\n' :

fputc(first, write);

state = NULL_STATE;

break;

case '*' :

second = fgetc(read);

if (second == '/' )

{

}

else

if (second == '*' )

{

fputc(first, write);

}

break;

case EOF :

fputc(first, write);

state = END_STATE;

break;

default:

fputc(first, write);

break;

}

如图：input.c

运行程序后打开output.c:

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