c语言语法错误代码 语法分析器错误代码求教！

语法分析器错误代码求教！

编了一个语法分析器，但是运行时说错误了。找不出在哪里，请高手们帮帮忙。

#include

#include

#include

#define NULL 0

FILE *p;

char b=' ';

void zhuprogram();

void son_function();//子函数

//void error();//报错

void function();//函数

int DataType();

void Biaozhifu();//标识符

void xingcan();//形参

void function_body();//函数体

void definate_val();//定义变量

void operate_centence();//执行语句

void centence();//语句

void fuzhi();//赋值语句

void function_diaoyong();

void biaodashi();

void item();//项

void itemrec();

void factrec();

void factor();

void shican();

void condition();

int guanxi();

void condition_centence();

void while_circle();

void function_centence();

void fuhecentence();

void empty();

void read_centence();

void write_centence();

int row=1;

char *sym;

char str1[]={"void"};//字符串

char str2[]={"int"};

void Getsymbol(char s[])

{

int i=0;

char a;

a=b;

if (b!=' '&&b!=9&&b!='\n')

s[i++]=b;

while(!feof(p))

{

a=getc(p);

while(a=' '||a==9)//制表符为9

a=getc(p);

if ((a>='a'&&a<='z')||(a>='A'&&a<='Z'))

{

s[i++]=a;

a=getc(p);

while((a>='a'&&a<='z')||(a>='A'&&a<='Z')||(a>='0'&&a<='9')||a=='-')

{

a=getc(p);

s[i++]=a;

}

s[i]='\0';

b=a;

break;

}

else if (a>='0'&&a<='9')

{

s[i++]=a;

a=getc(p);

while (a>='0'&&a<='9')

{

s[i++]=a;

a=getc(p);

}

s[i]='\0';

b=a;

break;

}

else if(a=='>'||a=='

{

s[i++]=a;

a=getc(p);

while(a=='=')

{

s[i++]=a;

a=getc(p);

}

s[i]='\0';

b=a;

break;

}

else if (a=='+'||a=='-'||a=='*'||a=='/'||a=='('||a==')'||a=='{'||a=='}'||a==';'||a==','||a=='"')

{

s[i++]=a;

a=getc(p);

s[i]='\0';

b=a;

break;

}

else if (a=='%')

{

s[i++]=a;

a=getc(p);

while(a=='d')

{

s[i++]=a;

a=getc(p);

}

s[i]=a;

b=a;

break;

}

else if (a=='\n')

{

row++;

while(a=='\n')

{

row++;

a=getc(p);

}

b=a;

break;

}

else break;

}

}

void main()

{

p=fopen("a.txt","r");

if(p==NULL)

printf("cannot open file\n");

sym=new char[100];

zhuprogram();

Getsymbol(sym);

delete sym;

fclose (p);

}

void zhuprogram()

{

son_function();//可选

zhuprogram();

}

void son_function()//子函数

{

function();

}

void function()//函数

{

DataType();

Biaozhifu();

if(!strcmp(sym,"("))

{

Getsymbol(sym);

xingcan();//可选

if(!strcmp(sym,")"))

{

Getsymbol(sym);

if(!strcmp(sym,"{"))

{

Getsymbol(sym);

function_body();

if(!strcmp(sym,"}"))

{

Getsymbol(sym);

}

else cout<

}

else cout<

}

else cout<

}

else cout<

}

int DataType()

{

if(!strcmp(sym,str1)||strcmp(sym,str2))//字符串表示

return 1;

else

{

cout<

return 0;

}

}

void Biaozhifu()//标识符

{

char zimu[52][2]={"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p",

"q","r","s","r","u","v","w","x","y","z","A","B","C","D","E","F","G","H","I",

"J","K","L","M","N","O","P","Q","R","S","R","U","V","W","X","Y","Z"};

//char shuzi[10]={"0","1","2","3","4","5","6","7","8","9"};

for(int i=0;i<52;i++)

{

if(!strcmp(sym,zimu[i]))

{

Getsymbol(sym);

Biaozhifu();

}

else cout<

}

}

void xingcan()//形参

{

if(!strcmp(sym,str2))

{

Getsymbol(sym);

Biaozhifu();

}

else cout<

}

void function_body()//函数体

{

definate_val();//定义变量

operate_centence();//执行语句

}

void definate_val()//定义变量

{

if(!strcmp(sym,str2))

{

Biaozhifu();

}

else cout<

}

void operate_centence()//执行语句

{

centence();

}

void centence()//语句

{

if ((!strcmp(sym,str1))&&(!strcmp(sym,str2)))

fuzhi();

else if (!(!strcmp(sym,"if")))

condition_centence();

else if(!(!strcmp(sym,"while")))

while_circle();

else if (!(!strcmp(sym,"{")))

{

Getsymbol(sym);

if (!(!strcmp(sym,"}")))

empty();

else fuhecentence();

}

else if (!(!strcmp(sym,"scanf")))

read_centence();

else if(!(!strcmp(sym,"printf")));

else

function_diaoyong();

Getsymbol(sym);

}

void fuzhi()//赋值语句

{

//Biaozhifu()=biaodashi;

}

void biaodashi()

{

item();

itemrec();

}

void item()//项

{

factor();

factrec();

}

void itemrec()

{

if(!strcmp(sym,"+")||strcmp(sym,"-"))

Getsymbol(sym);

item();

itemrec();

}

void factrec()

{

if(!strcmp(sym,"*")||strcmp(sym,"/"))

Getsymbol(sym);

factor();

factrec();

}

void factor()

{

if(!(*sym>='A'&&*sym<='Z') && !(*sym>='a'&&*sym<='z')

&& !(*sym>='0'&&*sym<='9') && strcmp(sym,"("))

cout<

else

if(!strcmp(sym,"("))

{

Getsymbol(sym);

biaodashi();

if(!strcmp(sym,")"))

cout<

}

Getsymbol(sym);

}

void condition_centence()//条件语句

{

if(!strcmp(sym,"if"))

{

Getsymbol(sym);

if(!strcmp(sym,"("))

{

Getsymbol(sym);

condition();

if(!strcmp(sym,")"))

{

Getsymbol(sym);

centence();

if(!strcmp(sym,";"))

{

Getsymbol(sym);

if(!strcmp(sym,"else"))

{

Getsymbol(sym);

centence();

}

}

else cout<

}

else cout<

}

else cout<

}

}

void condition()//条件

{

biaodashi();

guanxi();

biaodashi();

}

int guanxi()

{

if(sym==">")

return 1;

else if(sym=="

return 1;

else if(sym==">=")

return 1;

else if(sym=="<=")

return 1;

else if(sym=="==")

return 1;

else if(sym=="!=")

return 1;

else

return 0;

}

void while_circle()//当循环语句

{

if(sym=="while")

{

Getsymbol(sym);

if(sym=="(")

{

Getsymbol(sym);

condition();

if(sym==")")

{

Getsymbol(sym);

centence();

}

else cout<

}

else cout<

}

}

void function_diaoyong()//函数调用语句

{

Biaozhifu();

if(sym=="(")

{

Getsymbol(sym);

shican();

if(sym==")")

Getsymbol(sym);

else cout<

}

else cout<

}

void shican() //实参

{

biaodashi();

}

void fuhecentence() //复合语句，没有最外边的else表示可选

{

if(sym=="{")

{

Getsymbol(sym);

centence();

if(sym=="}")

Getsymbol(sym);

else cout<

}

}

void empty()//空语句

{

}

void read_centence()//读语句

{

if(strcmp(sym,"scanf")==0)

{

Getsymbol(sym);

if(strcmp(sym,"(")==0)

{

Getsymbol(sym);

if(strcmp(sym,"\" ")==0)

{

Getsymbol(sym);

if(strcmp(sym,"%d")==0)

{

Getsymbol(sym);

if(strcmp(sym," \" ")==0)

{

Getsymbol(sym);

if(strcmp(sym,",")==0)

{

Getsymbol(sym);

if(strcmp(sym,"&")==0)

{

Getsymbol(sym);

Biaozhifu();

if(strcmp(sym,")")==0)

Getsymbol(sym);

else cout<

}

else cout<

}

else cout<

}

else cout<

}

else cout<

}

else cout<

}

else cout<

}

}

void write_centence()//写语句

{

if(strcmp(sym,"printf")==0)

{

Getsymbol(sym);

if(strcmp(sym,"(")==0)

{

Getsymbol(sym);

if(strcmp(sym,"\" ")==0)

{

Getsymbol(sym);

if(strcmp(sym,"%d")==0)

{

Getsymbol(sym);

if(strcmp(sym," \" ")==0)

{

Getsymbol(sym);

if(strcmp(sym,",")==0)

{

Getsymbol(sym);

biaodashi();

if(strcmp(sym,")")==0)

Getsymbol(sym);

else cout<

}

else cout<

}

else cout<

}

else cout<

}

else cout<

}

else cout<

}

}

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