编译原算符优先分析实验报告(共12页)

1、精选优质文档-倾情为你奉上学号 E 专业 计算机科学与技术 姓名 万学进实验日期2010-5-25 教师签字 成绩实 验 报 告【实验名称】 算符优先文法分析【实验目的】掌握算符优先分析法的原理，利用算符优先分析法将赋值语句进行语法分析，翻译成等价的四元式表示。【实验内容】1.算术表达式的文法可以是： 专心-专注-专业（1）S->#E#（2）E->E+T（3）E->T（4）T->T*F（5）T->F（6）F->PF（7）F->P（8）P->(E)（9）P->i2.根据算符优先分析法，将表达式进行语法分析，判断一个表达式是否正确。 【设计思想

2、】（1）定义部分：定义常量、变量、数据结构。（2）初始化：设立算符优先关系表、初始化变量空间（包括堆栈、结构体、数组、临时变量等）；（3）控制部分：从键盘输入一个表达式符号串；（4）利用算符优先文法分析算法进行表达式处理：根据优先关系表对表达式符号串进行堆栈（或其他）操作，输出分析结果，如果遇到错误则显示错误信息。【流程图】【源代码】#include<stdio.h>#include<stdlib.h>#include<string.h>char Grammar2010;char VN10,VT10;char BoolArray1010;char First

3、BoolArray1010;char LastBoolArray1010;char RelationShip1010;#define StackSize 100;int vtNum,vnNum;int grammarNum;int scount=0;int VNum20;int GF210;typedef struct char vt;char vn;array;typedef struct array *base;array *top;int stacksize;SqStack;typedef structchar s20;int step;char curInVt;CharType;typ

4、edef structCharType *base;CharType *top;Stack;typedef structint x;int y;Position;SqStack S;Stack CS;SqStack InitStack()int i,j;S.base=(array *)malloc(100*sizeof(array);if(!S.base)exit(1);S.top=S.base;S.stacksize=StackSize;array temp;printf("初始化栈：n");for(i=1;i<=vnNum;i+)for(j=1;j<=vtN

5、um;j+)if(BoolArrayij='1')temp.vt=BoolArray0j;temp.vn=BoolArrayi0;*S.top=temp;S.top+;printf("%c,%cn",temp.vn,temp.vt);return S;int vNumCount()for(int i=0;i<=grammarNum;i+)int j=1;while(Grammarij!='0')j+;VNumi=j;printf("%d ",VNumi);printf("n");return 0;

6、int ScanGrammar()FILE *fp=fopen("算符优先文法.txt","r"); FILE *tp;char singleChar,nextChar;int i=0,j=0,k,count;while(!feof(fp)fscanf(fp,"%c",&singleChar);if(singleChar='?')Grammarij='0'break;if(singleChar='n')Grammarij='0'i+;j=0;continue;if

7、(singleChar='-')tp=fp;fscanf(tp,"%c",&nextChar);if(nextChar='>')fp=tp;continue;if(singleChar='|')Grammari+10=Grammari0;Grammarij='0' i+;j=1;continue;Grammarij=singleChar;if(singleChar>='A'&&singleChar<='Z')count=0;while(V

8、Ncount!=singleChar&&VNcount!='0')count+;if(VNcount='0')VNcount=singleChar;vnNum=count+1;else count=0;while(VTcount!=singleChar&&VTcount!='0')count+;if(VTcount='0')VTcount=singleChar;vtNum=count+1;j+;printf("输入的文法：n");for(k=0;k<=i;k+)j=0;wh

9、ile(Grammarkj!='0')if(j=1)printf("->");printf("%c",Grammarkj);j+; printf("n");printf("vnNum:%dn",vnNum);printf("vtNum:%dn",vtNum);printf("%dnVN:",i);count=0;while(VNcount!='0')BoolArraycount+10=VNcount;LastBoolArraycount+

10、10=VNcount;printf("%d%c ",count+1,BoolArraycount+10);count+; printf("nVT:");count=0;while(VTcount!='0')BoolArray0count+1=VTcount;LastBoolArray0count+1=VTcount;printf("%d%c ",count+1,BoolArray0count+1);count+;printf("n");fclose(fp); return i;int print()

11、for(int i=1;i<=vnNum;i+)for(int j=1;j<=vtNum;j+)if(BoolArrayij='1')printf("%c %cn",BoolArrayi0,BoolArray0j);return 0;int printlast()for(int i=1;i<=vnNum;i+)for(int j=1;j<=vtNum;j+)if(LastBoolArrayij='1')printf("%c %cn",LastBoolArrayi0,LastBoolArray0j);

12、return 0;int BoolArrayInitial(char vn,char vt)int row=1,column=1;while(BoolArrayrow0!=vn)row+;while(BoolArray0column!=vt)column+;if(BoolArrayrowcolumn='1')return 0;BoolArrayrowcolumn='1'printf("%d %dn",row,column);return 0;int LastBoolArrayInitial(char vn,char vt)int row=1,

13、column=1;while(LastBoolArrayrow0!=vn)row+;while(LastBoolArray0column!=vt)column+;if(LastBoolArrayrowcolumn='1')return 0;LastBoolArrayrowcolumn='1'printf("%d %dn",row,column);return 0;int FirstInitial(int grammarNum)int i;for(i=0;i<=grammarNum;i+)if(Grammari1<'A

14、9;|Grammari1>'Z')BoolArrayInitial(Grammari0,Grammari1);continue;if(Grammari1>='A'&&Grammari1<='Z'&&Grammari2!='0')if(Grammari2<'A'|Grammari2>'Z')BoolArrayInitial(Grammari0,Grammari2);printf("文法表中各行文法字符数：");vNumC

15、ount();return 0;int LastInitial(int grammarNum)int i,count;for(i=0;i<=grammarNum;i+)count=VNumi-1;if(Grammaricount<'A'|Grammaricount>'Z')LastBoolArrayInitial(Grammari0,Grammaricount);continue;if(count<=1)continue;if(Grammaricount>='A'&&Grammaricount<

16、='Z'&&Grammaricount-1!='0')if(Grammaricount-1<'A'|Grammaricount-1>'Z')LastBoolArrayInitial(Grammari0,Grammaricount-1);printlast();return 0;Position GetPos(array temp)for(int i=1;i<=vnNum;i+)if(BoolArrayi0=temp.vn)break;for(int j=1;j<=vtNum;j+)if(Bo

17、olArray0j=temp.vt)break;Position pos;pos.x=i;pos.y=j;return pos;int PrintStack()array *p=S.top,scan;scount+;printf("scount %d:n",scount);while(p!=S.base)scan=*p;printf("%c %cn",scan.vn,scan.vt);p-;return 0;int Insert(array pushTemp)Position pos;array scan;pos=GetPos(pushTemp);if(

18、BoolArraypos.xpos.y='0')BoolArraypos.xpos.y='1'array *p=S.base;while(p!=S.top)scan=*p;if(scan.vn=pushTemp.vn && scan.vt=pushTemp.vt)break;p+;if(p=S.top)S.top+;*S.top=pushTemp;PrintStack();return 1;int PushPop()int i;array temp,pushTemp;while(S.top!=S.base)temp=*S.top;S.top-;f

19、or(i=0;i<=grammarNum;i+)if(Grammari1=temp.vn)pushTemp.vn=Grammari0;pushTemp.vt=temp.vt;Insert(pushTemp);print();return 0;int LastPushPop()int i,count;array temp,pushTemp;while(S.top!=S.base)temp=*S.top;S.top-;for(i=0;i<=grammarNum;i+)count=VNumi-1;if(Grammaricount=temp.vn)pushTemp.vn=Grammari0

20、;pushTemp.vt=temp.vt;Insert(pushTemp);print();return 0;int ResetStack()int i,j;array temp;while(S.top!=S.base)S.top-;printf("n");for(i=1;i<=vnNum;i+)for(j=1;j<=vtNum;j+)if(BoolArrayij='1')temp.vt=BoolArray0j;temp.vn=BoolArrayi0;*S.top=temp;S.top+;printf("%c,%cn",tem

21、p.vn,temp.vt);return 0;int Judge(int i,int j)if(Grammarij+1='0')return -1;if(Grammarij>='A'&&Grammarij<='Z'&&(Grammarij+1<'A'|Grammarij+1>'Z')return 0;else return 1;Position GetOpPos(char vni,char vnj)for(int i=1;i<=vtNum;i+)if(R

22、elationShipi0=vni)break;for(int j=1;j<=vtNum;j+)if(RelationShip0j=vnj)break;Position pos;pos.x=i;pos.y=j;return pos;int GetVtPos(char vt)for(int i=1;i<=vtNum;i+)if(LastBoolArrayi0=vt)break;return i;int RelEqual() Position pos;int j;for(int i=0;i<=grammarNum;i+)j=1;while(Grammarij!='0

23、9;)if(Grammarij+2='0')break;if(Grammarij<'A'|Grammarij>'Z')&&(Grammarij+2<'A'|Grammarij+2>'Z')pos=GetOpPos(Grammarij,Grammarij+2);RelationShippos.xpos.y='='/2表示=j+;return 0;int RelShBlanket()int row;Position pos;int i,j;for(i=1;i<

24、;=vtNum;i+)RelationShipi0=BoolArray0i;RelationShip0i=BoolArray0i;for(i=0;i<=grammarNum;i+)j=1;while(Grammarij!='0')if(Judge(i,j)=-1)break;if(Judge(i,j)=0)row=GetVtPos(Grammarij);for(int ii=1;ii<=9;ii+)if(LastBoolArrayrowii='1')pos=GetOpPos(LastBoolArray0ii,Grammarij+1);Relation

25、Shippos.xpos.y='>'/3表示大于if(Judge(i,j)=1)row=GetVtPos(Grammarij+1);for(int ii=1;ii<=9;ii+)if(FirstBoolArrayrowii='1')pos=GetOpPos(Grammarij,FirstBoolArray0ii);RelationShippos.xpos.y='<'/1表示小于j+; RelEqual();printf("表达式文法算符优先关系表：n");RelationShip00=' 'f

26、or(i=0;i<=vtNum;i+)for(int j=0;j<=vtNum;j+)if(RelationShipij='0')RelationShipij='0'printf("%4c ",RelationShipij);printf("n");return 0;int ChangeValue()int change=0;int i,j;for(i=1;i<=vtNum;i+)for(j=1;j<=vtNum;j+)if(RelationShipij='>')if(GF0i

27、<=GF1j)GF0i=GF1j+1;change=1;if(RelationShipij='<')if(GF0i>=GF1j)GF1j=GF0i+1;change=1;if(RelationShipij='=')if(GF0i!=GF1j)if(GF0i>GF1j)GF1j=GF0i;change=1;if(GF0i<GF1j)GF0i=GF1j;change=1;if(change=1)ChangeValue();return 0;int PreFunction()int change=0,j;for(int i=1;i<

28、=vtNum;i+)GF0i=1;GF1i=1;ChangeValue();printf("优先函数:n");for(i=0;i<=1;i+)for(j=1;j<=vtNum;j+) printf("%3d",GFij);printf("n");return 0;int PrintCStack()CharType *p=CS.top,scan;while(p!=CS.base)scan=*p;printf("%d %c %sn",scan.step,scan.curInVt,scan.s);p-;ret

29、urn 0;int JudgeVt(char a)for(int j=1;j<=vtNum;j+)if(a=BoolArray0j)return 1;return 0;int JudgeRela(char a,char b)/判断优先关系int apos,bpos;for(int i=1;i<=vtNum;i+)if(a=BoolArray0i)apos=i;if(b=BoolArray0i)bpos=i;if(GF0apos>GF1bpos)return 1;if(GF0apos<GF1bpos)return -1;else return 0;int Reduction()int count=1,i=0,k=1,j,p,sign;char prerela;char operate5;char q;char S100='0',Input20;S0=' 'scanf("%s",Input);Sk='#'printf("步骤 栈 优先关系 当前符号 剩余输入串 移进或规约n");while(Inputi!='0')if(JudgeVt(Sk)j=k;else j=