语法分析器源代码.docx

1、语法分析器源代码#include#include#include#define HIGHER 1#define LOWER -1#define EQUAL 0#define TRUE 1#define FALSE 0 #define OPER_NUM 50 /默认算符数目#define VN_NUM 50 /默认非终结符数目#define MAX_BUFFER 128 /每行输入行最大长度#define MAX_GRA_NUM 20 /最大文法数目#define EMPTY -2 /算符优先表初始值，表示这对算符没有优先关系#define STACK_SIZE 64typedef struct

2、 char c; /非终极符符号 int firstvtOPER_NUM; /firstvt集，保存算符在oper_list中的下标 int fir_n,last_n; int lastvtOPER_NUM;vn_t; int prior_tableOPER_NUMOPER_NUM;char oper_listOPER_NUM;int oper_num = 0;vn_t vn_listVN_NUM;int vn_num = 0; char *grammarMAX_GRA_NUM2;int gra_num = 0;char start_vn;char stackSTACK_SIZE;int to

3、p = 0;void get_input(char *buf);int buf_deal(char* buf); void get_FIRVT_LASTVT(int vn_n); int create_table(); void init_table();int analyze(char *sentence);void display_table();void display_fir_lastvt();int get_oper(char c); /得到算符c的数组下标 没有返回-1 int get_vn(char c); /得到非终结符c的数组下标，没有返回-1 int is_vn(char

4、a) return (A=a&a=Z)?1:0);int get_oper(char c) int i; for(i = 0; i oper_num; +i) if(oper_listi = c) return i; return -1;int get_vn(char c) int i; for(i = 0; i vn_num; +i) if(vn_listi.c = c) return i; return -1; char reduce(int start, int end, int size) /规约 char *tar, *g, t1, t2, left; int i, j =0, gi

5、, ti, cn = 0; int same; tar = (char *)malloc(sizeof(char)*MAX_BUFFER); if(!tar) printf(Allocation fails.n); exit(-1); for(i = start; i = end; +i) /将此最左素短语的终结符存入tar字符串 if(!is_vn(stacki) tarj+ = stacki; tarj+ = 0; for(i = 0; i gra_num; +i) g = grammari1; gi = 0; ti = 0; same = FALSE; t1 = ggi; t2 = ta

6、rti; while (t1 != 0) if(t2 = 0 & !is_vn(t1) same = FALSE; break; if(!is_vn(t1) if(t1 != t2) same = FALSE; break; t2 = tar+ti; same = TRUE; t1= g+gi; if(same & t2 = 0) break; if(i = gra_num) printf(无法找到相应文法！n); return FALSE; left = grammari00; return vn_listget_vn(left).c;int analyze(char *sentence)

7、char r, c,new_vn; int i = 0, k = 0, j, pi, printi = 1, cou = 1; /i是sentence和stack的索引 int r_index, s_index, pre_index; printf(nn规约过程如下表所示：n); printf(-n); stacktop+ = #; printf(序号t符号栈t最左素短语t规约tn); do r = sentencei+; if(r_index = get_oper(r) = -1) printf(Error : 您输入的字符不在文法定义中！n); flushall();c = getchar

8、();flushall(); return FALSE; if(!is_vn(stackk) j = k; s_index = get_oper(stackj); else j = k - 1; s_index = get_oper(stackj); while(prior_tables_indexr_index = HIGHER) do pre_index = s_index; if(!is_vn(stackj-1) j-; s_index = get_oper(stackj); else j -= 2; s_index = get_oper(stackj); while(prior_tab

9、les_indexpre_index != LOWER); printf( %dt, cou+); for(pi = 0; pi top; +pi) printf(%c,stackpi); printf( t); for(pi = j + 1; pi ) return FALSE; pre = buf2; count = 0; while(now = buf+i) != 0) if(now != |) right_gcount = now; count+; if(is_vn(now) & is_vn(pre) return FALSE; if(is_vn(now) if(get_vn(now)

10、 = -1) vn_listvn_num.c = now; vn_listvn_num.fir_n = 0; vn_listvn_num.last_n = 0; vn_num+; else continue; else if(get_oper(now) = -1) oper_listoper_num = now; oper_num+; else continue; pre = now; else right_gcount = 0; grammargra_num0 = left_g; grammargra_num1 = right_g; gra_num+; break; if(bufi = 0)

11、 right_gcount = 0; grammargra_num0 = left_g; grammargra_num1 = right_g; gra_num+; else new_buf = (char *)malloc(sizeof(char)*MAX_BUFFER); new_buf0 = left_g0; new_buf1 = -; new_buf2 = ; strcpy(&new_buf3,&buf+i); return buf_deal(new_buf); return TRUE;int create_table() int gi = 0, ti, ni, fi, li, i; c

12、har *ng, t,next, next1; int t_index,n_index, n_index1, n_vn, t_vn; vn_t temp; for(gi = 0; gi gra_num; +gi ) ng = grammargi1; t = ng0; ti = 0; t_index = get_oper(t); next = ng1; ni = 1; n_index = get_oper(next); while(next != 0) if(t_index != -1 & n_index != -1) if (prior_tablet_indexn_index = EMPTY)

13、 prior_tablet_indexn_index = EQUAL; else printf(%c与%c有多种优先关系！n,oper_listt_index,oper_listn_index); return FALSE; else if(t_index != -1 & n_index = -1 & ngni+1 != 0) next1 = ngni+1; n_index1 = get_oper(next1); if(prior_tablet_indexn_index1 = EMPTY) prior_tablet_indexn_index1 = EQUAL; else printf(%c与%

14、c有多种优先关系！n,oper_listt_index,oper_listn_index1); return FALSE; prior_tablet_indexoper_num - 1 = -3; prior_tableoper_num - 1n_index1 = -3; if (t_index != -1 & n_index = -1) n_vn = get_vn(next); temp = vn_listn_vn; for(fi = 0; fi temp.fir_n; fi+) if(prior_tablet_indextemp.firstvtfi = EMPTY) prior_table

15、t_indextemp.firstvtfi = LOWER; else printf(%c与%c有多种优先关系！n,oper_listt_index,oper_listtemp.firstvtfi); return FALSE; else if(t_index = -1 & n_index != -1) n_vn = get_vn(t); temp = vn_listn_vn; for(fi = 0; fi temp.last_n; fi+) if(prior_tabletemp.lastvtfin_index = EMPTY) prior_tabletemp.lastvtfin_index

16、= HIGHER; else printf(%c与%c有多种优先关系！n,oper_listfi,oper_listn_index); return FALSE; t = ng+ti; next = ng+ni; t_index = get_oper(t); n_index = get_oper(next); for(i = 0; i oper_num - 1; +i) if(prior_tableoper_num - 1i != -3) prior_tableoper_num - 1i = LOWER; for(i = 0; i oper_num - 1; +i) if(prior_tabl

17、eioper_num - 1 != -3) prior_tableioper_num - 1 = HIGHER; prior_tableoper_num - 1oper_num - 1 = EQUAL; return TRUE;void display_fir_lastvt() int i, j; for (i = 0; i vn_num; +i) printf(FIRSTVT(%c) = , vn_listi.c); for(j = 0; j vn_listi.fir_n; +j) if (j = vn_listi.fir_n - 1) printf( %c ,oper_listvn_lis

18、ti.firstvtj); else printf( %c ,oper_listvn_listi.firstvtj); printf(n); printf(LASTVT(%c) = , vn_listi.c); for(j = 0; j vn_listi.last_n; +j) if (j = vn_listi.last_n - 1) printf( %c ,oper_listvn_listi.lastvtj); else printf( %c ,oper_listvn_listi.lastvtj); printf(nn); void display_table() int i,j; prin

19、tf(nt算 符); for(i = 0; i oper_num; +i) printf(t%c,oper_listi); printf(n); for(i = 0; i oper_num; +i) printf(t%c,oper_listi); for(j = 0; j ); else if(prior_tableij = -1) printf(t); else if(prior_tableij = 0) printf(t=); else printf(tNO); printf(n); void firstvt(int vn) int i, j, t, c_index, v_i, orin,

20、 pre = -1; char *ng, c; for(i = 0; i gra_num; +i) if (grammari00 = vn_listvn.c) ng = grammari1; c = ng0; if(c_index = get_oper(c) != -1) vn_listvn.firstvtvn_listvn.fir_n+ = c_index; continue; else v_i = get_vn(c); if(v_i != vn & v_i != pre) if(vn_listv_i.fir_n = 0 ) firstvt(v_i); orin = vn_listvn.fir_n; vn_listvn.fir_n += vn_listv_i.fir_n; t = 0; for(j = orin; j vn_listvn.fir_n; +j ) vn_listvn.firstvtj = vn_listv_i.firstvtt+; pre = v_i; if(ng1 != 0) vn_listvn.firstvtvn_listvn.fir_n+ = get_oper(ng1); void lastvt(int vn) int i, j, t, c_index, v_i, orin, ni = 0, pre = -1; c