词法分析程序(C语言编写,针对PL_0语言).doc

#include #include #include #define NORW 13 /* of reserved words */#define TXMAX 100 /* length of identifier table */#define NMAX 14 /* max number of digits in numbers */#define AL 10 /* length of identifiers */#define AMAX 2047 /* maxinum address */#define LEVMAX 3 /* max depth of block nesting */#define CXMAX 200 /* size of code array */#define STACKSIZE 500char *symbol32= nul,ident,number,plus,minus,times,slash,oddsym, eql,neq,lss,leq,gtr,geq,lparen,rparen,comma, semicolon,period,becomes,beginsym,endsym,ifsym, thensym,whilesym,writesym,readsym,dosym,callsym, constsym,varsym,procsym; /* type of symbols */char *wordNORW=begin,call,const,do,end,if,odd,procedure, read,then,var,while,write; /* table of reserved words */char *wsymNORW= beginsym,callsym,constsym,dosym,endsym,ifsym, oddsym,procsym,readsym,thensym,varsym,whilesym,writesym; char *mnemonic8= lit,opr,lod,sto,cal,ini,jmp,jpc;char ch; /* last char read */char idAL+1; /*last identifier read */char sym10; /* last symbol read */char line81;char aAL+1,fnameAL+1;enum objectconstant,variable,procedur;enum object kind;enum fctlit,opr,lod,sto,cal,ini,jmp,jpc;enum listswitcherfalse,true; /*true set list object code */enum listswitcher listswitch;FILE *fa;FILE *fa1, *fa2;FILE *fin, *fout;int num; /* last number read */int cc; /* character count */int ll; /* line length */int cx; /* code allocation index */int err;int lev=0,tx=0,dx=3;int linecnt=0;struct instructionenum fct f; /* function code */ int l; /* level */ int a; /* displacement addr */; /* lit 0,a: load constant a opr 0,a: execute opr a lod l,a: load variable 1, a sto l,a: store variable 1, a cal l,a: call procedure a at level 1 int 0,a: increment t-register by a jmp 0,a: jump to a jpc 0,a: jump conditional to a */struct instruction codeCXMAX+1;struct table1char nameAL+1; enum object kind; int val,level,adr,size;struct table1 tableTXMAX+1;struct nodechar *pa32;*declbegsys,*statbegsys,*facbegsys,*tempsetsys;int in(str, set)char *str;struct node *set;int i=0;while(set-pai!=NULL)if(strcmp(str,set-pai)=0)return( 1 );elsei+;return( 0 );struct node *add(set1,set2)struct node *set1,*set2;int i=0,j=0,k=0,cnt;struct node *pt;pt=(struct node *)malloc(sizeof(struct node);for(cnt=0; cnt pacnt=(char*)malloc(10*sizeof(char);while(set1-pai!=NULL)strcpy(pt-paj+,set1-pai+);while(set2-pak!=NULL)if (in(set2-pak,set1)=0)strcpy(pt-paj+,set2-pak+);elsek+;pt-paj=NULL;return( pt );error(int n)int i;printf (*);fputs (*, fa1);for (i=0;icc;i+)printf ( );for (i=0;i=a&ch=z)/* id or reserved word */k=0;do if(k=a&ch=0&ch=9); ak=0;strcpy(id,a);i=0;j=NORW-1;do /* look up reserved words by binary search */k=(i+j)/2;if (strcmp(id,wordk)=0) i=k+1;while (ij) strcpy(sym,wsymk);else strcpy(sym,ident);else if (ch=0&ch=0&chNMAX) error(30);else if (ch=:)get_ch( );if (ch=)strcpy(sym,becomes);get_ch( );else strcpy(sym,nul);else if (ch=)get_ch( );if (ch=)strcpy(sym,geq);get_ch( );else strcpy(sym,gtr);else switch(ch)case +: strcpy(sym,plus);break;case -: strcpy(sym,minus);break;case *: strcpy(sym,times);break;case /: strcpy(sym,slash);break;case (: strcpy(sym,lparen);break;case ): strcpy(sym,rparen);break;case =: strcpy(sym,eql);break;case ,: strcpy(sym,comma);break;case .: strcpy(sym,period);break;case #: strcpy(sym,neq);break;case ;: strcpy(sym,semicolon);break;get_ch( );void gen(x,y,z)enum fct x;int y,z;if (cxCXMAX)printf(program too long);codecx.f=x;codecx.l=y;codecx.a=z;cx+;void test(s1,s2,n)struct node *s1,*s2;int n;if (in(sym,s1)=0)error(n);s1=add(s1,s2);while(in(sym,s1)=0) getsym( );void enter(k) /* enter object into table */enum object k;tx=tx+1;strcpy(,id);tabletx.kind=k;switch(k)case constant:if (numNMAX) error(31);num=0; tabletx.val=num; break;case variable:tabletx.level=lev; tabletx.adr=dx; dx+; break;case procedur:tabletx.level=lev;break;int position(id) /* find identifier in table */char id10;int i;strcpy(,id);i=tx;while (strcmp(,id)!=0)i-;return i;void constdeclaration( )if (strcmp(sym,ident)=0)getsym( );if (strcmp(sym,eql)=0|strcmp(sym,becomes)=0)if (strcmp(sym,becomes)=0) error(1);getsym( );if (strcmp(sym,number)=0)enter(constant);getsym( );else error(2);else error(3);else error(4);void vardeclaration( )if (strcmp(sym,ident)=0)enter(variable);getsym( );else error(4);void listcode(int cx0) /* list code generated for this block */int i;if (listswitch=true)for(i=cx0;ipan+=tempsetm+;temp-pan=NULL;test(facbegsys,fsys,24);while(in(sym,facbegsys)=1)if (strcmp(sym,ident)=0)i=position(id);if (i=0) error(11);else switch(tablei.kind)case constant: gen(lit,0,tablei.val); break; /*some thing error here(lev)*/case variable: gen(lod,lev-tablei.level,tablei.adr); /*must use para pass in*/ break;case procedur: error(21); break;getsym( );else if (strcmp(sym,number)=0)if (numAMAX)error(31);num=0;gen(lit,0,num);getsym( );else if (strcmp(sym,lparen)=0)getsym( );expression(add(temp,fsys);if (strcmp(sym,rparen)=0) getsym( );else error(22);test(fsys,facbegsys,23);void term(fsys)struct node *fsys;int i=0,j=0;char mulop10;char *tempset =times,slash,NULL;struct node *temp;temp=(struct node *)malloc(sizeof(struct node);while(tempseti!=NULL)temp-pai+=tempsetj+;temp-pai=NULL;factor(add(temp,fsys);while (in(sym,temp)=1)strcpy(mulop,sym);getsym( );factor(add(temp,fsys);if (strcmp(mulop,times)=0) gen(opr,0,4);else gen(opr,0,5);void expression(fsys)struct node *fsys;int m=0,n=0;char addop10;char *tempset =plus,minus,NULL;struct node *temp;temp=(struct node *)malloc(sizeof(struct node);while(tempsetm!=NULL)temp-pan+=tempsetm+;temp-pan=NULL;if(in(sym,temp)=1)strcpy(addop,sym);getsym( );term(add(fsys,temp);if (strcmp(addop,minus)=0) gen(opr,0,1);else term(add(fsys,temp);while (in(sym,temp)=1)strcpy(addop,sym);getsym( );term(add(fsys,temp);if (strcmp(addop,plus)=0) gen(opr,0,2);else gen(opr,0,3);void condition(fsys)struct node *fsys;int i=0,j=0;char relop10;char *tempset =eql,neq,lss,leq,gtr,geq,NULL;struct node *temp;temp=(struct node *)malloc(sizeof(struct node);while(tempseti!=NULL)temp-paj+=tempseti+;temp-paj=NULL;if (strcmp(sym,oddsym)=0)getsym( );expression(fsys);gen(opr,0,6);else expression(add(temp,fsys);if (in(sym,temp)=0) error(20);else strcpy(relop,sym);getsym( );expression(fsys);if(strcmp(relop,eql)=0) gen(opr,0,8);if(strcmp(relop,neq)=0) gen(opr,0,9);if(strcmp(relop,lss)=0) gen(opr,0,10);if(strcmp(relop,geq)=0) gen(opr,0,11);if(strcmp(relop,gtr)=0) gen(opr,0,12);if(strcmp(relop,leq)=0) gen(opr,0,13);void statement(fsys,plev)struct node *fsys;int plev;int i,cx1,cx2,m=0,n=0;char *tempset1 =rparen,comma,NULL;char *tempset2 =thensym,dosym,NULL;char *tempset3 =semicolon,endsym,NULL;char *tempset4 =semicolon,NULL;char *tempset5 =dosym,NULL;char *tempset6 =NULL;struct node *temp1,*temp2,*temp3,*temp4,*temp5,*temp6;temp1=(struct node *)malloc(sizeof(struct node);temp2=(struct node *)malloc(sizeof(struct node);temp3=(struct node *)malloc(sizeof(struct node);temp4=(struct node *)malloc(sizeof(struct node);temp5=(struct node *)malloc(sizeof(struct node);temp6=(struct node *)malloc(sizeof(struct node);while(tempset1m!=NULL)temp1-pan+=tempset1m+;temp1-pan=NULL;m=0;n=0;while(tempset2m!=NULL)temp2-pan+=tempset2m+;temp2-pan=NULL;m=0;n=0;while(tempset3m!=NULL)temp3-pan+=tempset3m+;temp3-pan=NULL;m=0;n=0;while(tempset4m!=NULL)temp4-pan+=tempset4m+;temp4-pan=NULL;m=0;n=0;while(tempset5m!=NULL)temp5-pan+=tempset5m+;temp5-pan=NULL;m=0;n=0;while(tempset6m!=NULL)temp6-pan+=tempset6m+;temp6-pan=NULL;m=0;n=0;if (strcmp(sym,ident)=0)i=position(id);if (i=0)error(11);else if (tablei.kind!=variable)error(12);i=0;getsym( );if (strcmp(sym,becomes)=0) getsym( );else error(13);expression(fsys);if (i!=0)gen(sto,plev-tablei.level,tablei.adr);else if (strcmp(sym,readsym)=0)getsym( );if (strcmp(sym,lparen)!=0) error(24);else dogetsym( );if (strcmp(sym,ident)=0) i=position(id);else i=0;if (i=0) error(35);else gen(opr,0,16);gen(sto,plev-tablei.level,tablei.adr);getsym( );while(strcmp(sym,comma)=0);if (strcmp(sym,rparen)!=0) error(22);while(in(sym,fsys)=0) getsym( );else getsym( );else if (strcmp(sym,writesym)=0)getsym( );if (strcmp(sym,lparen)=0)dogetsym( );expression(add(temp1,fsys);gen(opr,0,14);while(strcmp(sym,comma)=0);if (strcmp(sym,rparen)!=0) error(33);else getsym( );gen(opr,0,15);else if (strcmp(sym,callsym)=0)getsym( );if (strcmp(sym,ident)!=0) error(14);else i=position(id);if (i=0) error(11);else if (tablei.kind=procedur)gen(cal,plev-tablei.level,tablei.adr);else error(15);getsym( );else if (strcmp(sym,ifsym)=0)getsym( );condition(add(temp2,fsys);if (strcmp(sym,thensym)=0) getsym( );else error(16);cx1=cx;gen(jpc,0,0);statement(fsys,plev);codecx1.a=cx;else if (strcmp(sym,beginsym)=0)getsym( );statement(add(temp3,fsys),plev);while(in(sym,add(temp4,statbegsys)=1)if (strcmp(sym,semicolon)=0) getsym( );else error(10);statement(add(temp3,fsys),plev);if (strcmp(sym,endsym)=0) getsym( );else error(17);else if (strcmp(sym,whilesym)=0)cx1=cx;getsym( );condition(add(temp5,fsys);cx2=cx;gen(jpc,0,0);if (strcmp(sym,dosym)=0) getsym( );else error(18);statement(fsys,plev);gen(jmp,0,cx1);codecx2.a=cx;test(fsys,temp6,19);void block(plev,fsys)int plev;struct node *fsys;int m=0,n=0; int dx0=3; /* data allocation index */int tx0; /* initial table index */int cx0; /* initial code index */char *tempset1 =semicolon,endsym,NULL;char *tempset2 =ident,procsym,NULL;char *tempset3 =semicolon,NULL;char *tempset4 =ident,NULL;char *tempset5 =NULL;struct node *temp1,*temp2,*temp3,*temp4,*temp5;temp1=(struct node *)malloc(sizeof(struct node);temp2=(struct node *)malloc(sizeof(struct node);temp3=(struct node *)malloc(sizeof(struct node);temp4=(struct node *)malloc(sizeof(struct node);temp5=(struct node *)malloc(sizeof(struct node);while(tempset1m!=NULL)temp1-pan+=tempset1m+;temp1-pan=NULL;m=0;n=0;while(tempset2m!=NULL)temp2-pan+=tempset2m+;temp2-pan=NULL;m=0;n=0;while(tempset3m!=NULL)temp3-pan+=tempset3m+;temp3-pan=NULL;m=0;n=0;while(tempset4m!=NULL)temp4-pan+=tempset4m+;temp4-pan=NULL;m=0;n=0;while(tempset5m!=NULL)temp5-pan+=tempset5m+;temp5-pan=NULL;m=0;n=0;lev=plev;tx0=tx;tabletx.adr=cx;gen(jmp,0,1);if (plevLEVMAX) error(32);doif (strcmp(sym,constsym)=0)getsym( );doconstdeclaration( );while(strcmp(sym,comma)=0)getsym( );constdeclaration( );if (strcmp(sym,semicolon)=0) getsym( );else error(5);while(strcmp(sym,ident)=0);if (strcmp(sym,varsym)=0)getsym( );do dx0+;vardeclaration( );while (strcmp(sym,comma)=0)getsym( ); dx0+;vardeclaration( );if (strcmp(sym,semicolon)=0) getsym( );else error(5);while(strcmp(sym,ident)=0);while (strcmp(sym,procsym)=0)getsym( );if (strcmp(sym,ident)=0)enter(procedur);getsym( );else error(4);if (strcmp(sym,semicolon)=0) getsym( );else error(5);block(plev+1,add(temp3,fsys);lev=lev-1;if (strcmp(sym,semicolon)=0)getsym( );test(add(statbegsys,temp2),fsys,6);else error(5);test(add(statbegsys,temp4),declbegsys,7);while(in(sym,declbegsys)=1);codetabletx0.adr.a=cx;tabletx0.adr=cx;tabletx0.size=dx0;cx0=cx; gen(ini,0,dx0);statement(add(temp1,fsys),plev);gen(opr,0,0);test(fsys,temp5,8);listcode(cx0); int base(l,b,s) int l; int *b; int sSTACKSIZE; int b1; b1=*b; /*find base l level down */ w