编译原理实验日志

• 实验原理
• 构造SLR（1）分析表
• 调试过程

首先求得follow集
follow（E）={#，+，-，)}
follow（T）={#，+，-，)，，/}
follow（F）={#，+，-，)，，/}
画出DFA状态转换图

没有判断

因为字符串中没有表示10以上的字符所以只能存之后的符号

最后就能得到正确答案

#include 
#include 

//0 E'->E
//1 E->T
//2 E->E+T
//3 E->E-T
//4 T->F
//5 T->T*F
//6 T->T/F
//7 F->I
//8 F->(E)

//a*(b+c*(a-b))#
//a*b+c/d#


//四元式用到的全局变量
char sem[50]; //语义栈，存放id(指向标识符地址的指针)或四元式编号
int sem1=0;   //语义栈指针
char t='1';      //假设为结果集变量
char id;
char Tri[15][30];  //存放四元式
int tr=0;          //四元式集指针


//状态栈
int s1=0;
int states1[50]={0};
//符号栈
int f1=0;
char fuhao1[50]={'#'};
//输入栈
int in1=0;
char input1[50];

char flag; //定位action表或goto表中的某一个位置


//定义SLR(1)_action表
char action1[16][8]=
//数字：下一个状态集编号(10:':' 11:';' 12:'<' 13:'=' 14:'>' 15:'?') 字母：规约的产生式编号 *：结束规约
{//   +   -   *   /   (   )   i   #
    {' ',' ',' ',' ','5',' ','4',' '}, //0
    {'6','7',' ',' ',' ',' ',' ','*'}, //1
    {'a','a','8','9',' ','a',' ','a'}, //2
    {'d','d','d','d',' ','d',' ','d'}, //3
    {'g','g','g','g',' ','g',' ','g'}, //4
    {' ',' ',' ',' ','5',' ','4',' '}, //5
    {' ',' ',' ',' ','5',' ','4',' '}, //6
    {' ',' ',' ',' ','5',' ','4',' '}, //7
    {' ',' ',' ',' ','5',' ','4',' '}, //8
    {' ',' ',' ',' ','5',' ','4',' '}, //9
    {'6','7',' ',' ',' ','?',' ',' '}, //10
    {'b','b','8','9',' ','b',' ','b'}, //11
    {'c','c','8','9',' ','c',' ','c'}, //12
    {'e','e','e','e',' ','e',' ','e'}, //13
    {'f','f','f','f',' ','f',' ','f'}, //14
    {'h','h','h','h',' ','h',' ','h'}, //15
};

//定义goto表
//数字：产生式编号(10:':' 11:';' 12:'<' 13:'=' 14:'>' 15:'?')
char go[16][3]=
{ //  E   T   F
    {'1','2','3'}, //0
    {' ',' ',' '}, //1
    {' ',' ',' '}, //2
    {' ',' ',' '}, //3
    {' ',' ',' '}, //4
    {':','2','3'}, //5
    {' ',';','3'}, //6
    {' ','<','3'}, //7
    {' ',' ','='}, //8
    {' ',' ','>'}, //9
    {' ',' ',' '}, //10
    {' ',' ',' '}, //11
    {' ',' ',' '}, //12
    {' ',' ',' '}, //13
    {' ',' ',' '}, //14
    {' ',' ',' '}, //15
};

//将文法存入二维数组
char G[9][20]=
{
  {" "},
  {"ET"},
  {"EE+T"},
  {"EE-T"},
  {"TF"},
  {"TT*F"},
  {"TT/F"},
  {"Fi"},
  {"F(E)"},
};

//根据当前输入符号确定action表列号
int number_action(char c)
{
    int n;
    switch(c)
    {
        case '+':n=0;break;
        case '-':n=1;break;
        case '*':n=2;break;
        case '/':n=3;break;
        case '(':n=4;break;
        case ')':n=5;break;
        case 'i':n=6;break;
        case '#':n=7;break;
        default:n=-1;break;
    }
    return n;
}

//根据规约后的栈顶符号确定go表列号
int number_go(char c)
{
    int n;
    switch(c)
    {
        case 'E':n=0;break;
        case 'T':n=1;break;
        case 'F':n=2;break;
        default:n=-1;break;
    }
    return n;
}

//生成四元式的函数
void GenQT(char w)
{
    Tri[tr][0]=w;
    Tri[tr][1]=sem[sem1-2];
    Tri[tr][2]=sem[sem1-1];
    Tri[tr][3]=t;
    //if(tr==0) printf("t(%c,%c,%c,%c)n",Tri[tr][0],Tri[tr][1],Tri[tr][2],Tri[tr][3]);
    //else printf("t(%c,%c,%c,%c)n",Tri[tr][0],Tri[tr][1],Tri[tr][2],Tri[tr][3]);
    tr++;
    sem[sem1-2]=t;
    sem1--;
    t++;
}

//四元式语义子程序
void four(int f)
{
    switch(f)
    {
        case 0: break;              //E'->E
        case 1: break;              //E->T
        case 2: GenQT('+'); break;  //E->E+T
        case 3: GenQT('-'); break;  //E->E-T
        case 4: break;              //T->F
        case 5: GenQT('*'); break;  //T->T*F
        case 6: GenQT('/'); break;  //T->T/F
        case 7: sem[sem1++]=id; break; //F->i
        case 8: break;              //F->(E)
    }
}


//输出分析过程
void print(int step,int state[],int s,char fuhao[],int f,char input[],int in)
{
    int i=0;
    printf("%3dt",step); //步骤号
    while(i<=s) //状态栈
    {
        if(state[i]>9) printf(" ");
        printf("%d",state[i++]);
    }
    printf("tt");
    i=0;
    while(i<=f) //符号栈
    {
        printf("%c",fuhao[i++]);
    }
    printf("tt");
    i=in;
    while(input[i]!='')
    {
        printf("%c",input[i++]);
    }
    printf("t");
}

void SLR1()
{
    int m,n; //m->action、goto表行号 n->action、goto表列号
    int step=1;
    printf("nntttSLR(1)分析");
    printf("n步骤  状态栈          符号栈          剩余串         action     goton");
    while(1)
    {

        m=states1[s1]; 
        //n=number_action(input1[in1]);
        //将输入中除'终结符'及'非终结符'以外的符号换位'i'
        if(input1[in1]!='+' && input1[in1]!='-' && input1[in1]!='*' &&
           input1[in1]!='/' && input1[in1]!='(' && input1[in1]!=')' &&
           input1[in1]!='i' && input1[in1]!='#' && input1[in1]!='E' &&
           input1[in1]!='T' && input1[in1]!='F')  { n=number_action('i'); }
        else n=number_action(input1[in1]);

        flag=action1[m][n];

        
        if(n==6) id=input1[in1];  //6为'i'的列号，说明当前输入符号为操作数

        if(('0'<=flag && flag<='9') || flag==':' || flag==';' || flag=='<'
           || flag=='=' || flag=='>' || flag=='?') //移进
        {
            print(step,states1,s1,fuhao1,f1,input1,in1);

             //
            if('0'<=flag && flag<='9') printf("tS%cn",flag);
            if(flag==':') printf("tS10n");
            if(flag==';') printf("tS11n");
            if(flag=='<') printf("tS12n");
            if(flag=='=') printf("tS13n");
            if(flag=='>') printf("tS14n");
            if(flag=='?') printf("tS15n");

            states1[++s1]=flag-'0'; 
            fuhao1[++f1]=input1[in1++];
            step++;
        }
        else if('a'<=flag && flag<='z') //规约
        {
            print(step,states1,s1,fuhao1,f1,input1,in1);
            int f=flag-'a'+1;  //产生式编号
            printf("tr%d",f);

            //从状态栈和符号栈中弹出产生式右部
            int len=strlen(G[f])-1; //-1是因为G[][0]记录产生式左部
            f1=f1-len;
            s1=s1-len;
            fuhao1[++f1]=G[f][0];
            m=states1[s1];  //goto表的行号
            n=number_go(fuhao1[f1]); //goto表的列号
            flag=go[m][n];

            //
            if('0'<=flag && flag<='9') printf("t%cn",flag);
            if(flag==':') printf("t10n");
            if(flag==';') printf("t11n");
            if(flag=='<') printf("t12n");
            if(flag=='=') printf("t13n");
            if(flag=='>') printf("t14n");
            if(flag=='?') printf("t15n");

            
            four(f);

            states1[++s1]=flag-'0';
            step++;
        }
        else if(flag=='*') //规约成功，接受
        {
            print(step,states1,s1,fuhao1,f1,input1,in1);
            printf("t接受！n");

            return;
        }
        else    //查action表为空
        {
            print(step,states1,s1,fuhao1,f1,input1,in1);
            printf("t出错");
            return;
        }
    }
}



int main()
{
    printf("请输入：n");
    gets(input1);
    SLR1();
    printf("四元式序列：n");
    for(int i=0;i<(t-'0'-1);i++)  //t是从'1'开始
    {

        if(i==0) printf("t%d.(%c,%c,%c,%c)n",i+1,Tri[i][0],Tri[i][1],Tri[i][2],Tri[i][3]);
        else printf("t%d.(%c,%c,%c,%c)n",i+1,Tri[i][0],Tri[i][1],Tri[i][2],Tri[i][3]);

    }
}
//a+b-c/d#
//A*(B+C*(A-B))#
//A*(B+C)#