编译原理实验三 语义分析.doc

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1、精品文档，仅供学习与交流，如有侵权请联系网站删除编译原理实验三 语法分析并进行语义分析输入：经过词法分析后形成的token和tokenstring输出：检查有无语法错误，形成语法树，并检查是否符合语义。样例程序已经能对变量声明填符号表、进行类型检查。文法：stmt_seq -statement ; stmt_seq | statementstatement-decl_stmt | assign_stmtdecl_stmt-type var_listtype-int |floatvar_list-id , var_list | idassign_stmt- id := expexp-exp +

2、term | exp - term |termterm- term * factor | term * factor | factorfactor-id | num | ( exp )要求掌握理解程序设计方法。样例程序#include#include typedef enum MINUS,PLUS,TIMES,OVER,LPAREN,RPAREN,SEMI,ASSIGN,NUM,ID,INT,FLOAT,COMMA,DOLLAR tokentype;/*记号*/typedef enum stmtk,expk nodekind;typedef enum ifk,assignk,declk stm

3、tkind;typedef enum opk,constk,idk expkind;typedef enum integer,real exptype;typedef struct treenode struct treenode * child3; struct treenode * sibling; nodekind nodek; exptype dtype ; union stmtkind stmt; expkind exp; kind; union tokentype op; int val; char * name; attr; treenode;typedef struct buc

4、ket char * name; exptype dtype; struct bucket * next; bucket;bucket * hashtable211; /*tokentype token6=ID,ASSIGN,NUM,PLUS,NUM,INT,FLOAT,COMMA,DOLLAR; char tokenstring630=ab,:=,12,+,5,$;*/tokentype token=INT,ID,COMMA,ID,SEMI, ID,ASSIGN,NUM,PLUS,NUM,TIMES,NUM,SEMI,ID,ASSIGN,NUM,DOLLAR; char tokenstrin

5、g30=int,ab,xy,;,ab,:=,12,+,5,*,3,;,xy,:=,34,$; int wordindex=0; /*以上两个数组的索引*/treenode * decl();treenode * factor();treenode * term();treenode * exp();treenode * assign_stmt();treenode * stmt_seq();pretraverse(treenode *);int hash ( char * );void st_insert( char * ,exptype);int st_lookup ( char * );v

6、oid buildsymtab(treenode * ); void setnodetype(treenode * );main()treenode * t; t=stmt_seq(); /*语法分析建语法树*/buildsymtab(t); /*建符号表*/pretraverse(t); /*遍历语法树*/setnodetype(t); /*类型检查设置*/treenode * stmt_seq()treenode * t; treenode * p; if( tokenwordindex=INT)|(tokenwordindex=FLOAT) t=decl(); if(tokenwordi

7、ndex=ID) t=assign_stmt(); p=t; while( (tokenwordindex=SEMI)& (tokenwordindex!=DOLLAR) treenode * q; wordindex+; q=assign_stmt(); p-sibling=q; p=q; return t;treenode * assign_stmt()treenode * t=(treenode *)malloc(sizeof(treenode); if(tokenwordindex=ID) t-nodek=stmtk; t-kind.stmt=assignk; t-attr.name=

8、tokenstringwordindex; wordindex+; else printf(error); exit(1); if(tokenwordindex=ASSIGN) wordindex+; else printf(error); exit(1); t-child0=exp(); t-child1=NULL; t-child2=NULL; t-sibling=NULL; return t;treenode * exp()treenode * t; t=term(); while(tokenwordindex=PLUS)|(tokenwordindex=MINUS) treenode

9、* p=(treenode *)malloc(sizeof(treenode); p-nodek=expk; p-kind.exp=opk; p-attr.op=tokenwordindex; p-child0=t; t=p; wordindex+; t-child1=term(); t-child2=NULL; t-sibling=NULL;return t;treenode * term()treenode * t=factor(); while(tokenwordindex=TIMES)|(tokenwordindex=OVER) treenode * p=(treenode *)mal

10、loc(sizeof(treenode); p-nodek=expk; p-kind.exp=opk; p-attr.op=tokenwordindex; p-child0=t; t=p; wordindex+; t-child1=factor(); t-child2=NULL; t-sibling=NULL;return t;treenode * factor()treenode * t; switch(tokenwordindex) case LPAREN : wordindex+; t=exp(); if(tokenwordindex=RPAREN) wordindex+; else p

11、rintf(error); exit(1); break; case NUM : t=(treenode *)malloc(sizeof(treenode); t-nodek=expk; t-kind.exp=constk; t-attr.val=atoi(tokenstringwordindex); t-child0=NULL; t-child1=NULL; t-child2=NULL; t-sibling=NULL; wordindex+; break; case ID : t=(treenode *)malloc(sizeof(treenode); t-nodek=expk; t-kin

12、d.exp=idk; t-attr.name=tokenstringwordindex; wordindex+; break; default: printf(error);return t;pretraverse(treenode * t)if (t!=NULL) if (t-nodek=stmtk) printf(stmt-id:%sn,t-attr.name); if (t-nodek=expk & t-kind.exp=idk) printf(exp-id:%sn,t-attr.name); if (t-nodek=expk & t-kind.exp=opk) printf(exp-o

13、p:%dn,t-attr.op); if (t-nodek=expk & t-kind.exp=constk) printf(exp-val:%dn,t-attr.val); if(t-child0!=NULL) pretraverse(t-child0); if(t-child1!=NULL) pretraverse(t-child1); if(t-child2!=NULL) pretraverse(t-child2); if(t-sibling!=NULL) pretraverse(t-sibling);treenode * decl()treenode * p,* q,* t1; tre

14、enode * t=(treenode *)malloc(sizeof(treenode); t-nodek=stmtk; t-kind.stmt=declk; t-attr.name=tokenstringwordindex; t-child1=NULL; t-child2=NULL; wordindex+; if(tokenwordindex=ID) t1=(treenode *)malloc(sizeof(treenode); t-child0=t1; t1-nodek= expk; t1-kind.exp=idk; t1-attr.name=tokenstringwordindex;

15、t1-child0=NULL; t1-child1=NULL; t1-child2=NULL; t1-sibling=NULL; wordindex+; p=t1; while( tokenwordindex=COMMA) wordindex+; q=(treenode *)malloc(sizeof(treenode); q-nodek= expk; q-kind.exp=idk; q-attr.name=tokenstringwordindex; q-child0=NULL; q-child1=NULL; q-child2=NULL; q-sibling=NULL; p-sibling=q

16、; wordindex+; p=q; return t;int hash ( char * key ) int temp = 0; int i = 0; while (keyi != 0) temp = (temp name) != 0) l = l-next; if (l = NULL) /* variable not yet in table */ l = (bucket *) malloc(sizeof(bucket); l-name = name; l-dtype=datatype; l-next = NULL; l-next = hashtableh; hashtableh = l;

17、 int st_lookup ( char * name ) int h = hash(name); bucket * l = hashtableh; while (l != NULL) & (strcmp(name,l-name) != 0) l = l-next; if (l = NULL) return -1; else return 1;void buildsymtab(treenode * t)exptype datatype; treenode * q; if (t!=NULL) if (t-nodek=stmtk & t-kind.stmt=declk) if (strcmp(t

18、-attr.name,int)=0) datatype=integer; if(t-attr.name=float) datatype=real; q=t-child0; while(q!=NULL) st_insert(q-attr.name,datatype); q=q-sibling; if(t-nodek!=stmtk & t-kind.stmt!=declk & t-child0!=NULL) buildsymtab(t-child0); if(t-child1!=NULL) buildsymtab(t-child1); if(t-child2!=NULL) buildsymtab(

19、t-child2); if(t-sibling!=NULL) buildsymtab(t-sibling); void setnodetype(treenode * t)if(t!=NULL) if(t-child0!=NULL) setnodetype (t-child0); if(t-child1!=NULL) setnodetype (t-child1); if (t-nodek=expk & t-kind.exp=idk) int h = hash(t-attr.name); bucket * l = hashtableh; while (l != NULL) & (strcmp(t-

20、attr.name,l-name) != 0) l = l-next; if (l=NULL) printf(no declare);exit(1); else t-dtype=l-dtype; if (t-nodek=expk & t-kind.exp=constk) t-dtype=integer; if (t-nodek=expk & t-kind.exp=opk) if(t-child1=NULL) t-dtype=t-child0-dtype; else if(t-child0-dtype=t-child1-dtype ) t-dtype=t-child0-dtype; else p

21、rintf(type no match);exit(1); if (t-nodek=stmtk) t-dtype=t-child0-dtype; if(t-sibling!=NULL) setnodetype (t-sibling);查看主要内存变量：t-attr.name t-attr.valt-child0-attr.name t-child0-attr.valt-child1-attr.name t-child1-attr.valt-sibling-attr.name t-sibling-attr.val语法树样例：constk(34)assignk(ab)constk(3)constk(5)opk(*)constk(12)opk(+)assignk(xy)idk(ab)idk(ab)declk(int)【精品文档】第 7 页