PL/0修改 C语言版本

/*** PL0 COMPILER WITH CODE GENERATION ***/ //--------------------------------------------------------------------------- #define RESERVENUM 40 #include <vcl.h> #pragma hdrstop #include "Unit1.h" //--------------------------------------------------------------------------- #pragma package(smart_init) #pragma resource "*.dfm" TForm1 *Form1; //--------------------------------------------------------------------------- const AL = 10; /* LENGTH OF IDENTIFIERS */ const NORW = 18; /* # OF RESERVED WORDS */ const TXMAX = 100; /* LENGTH OF IDENTIFIER TABLE */ const NMAX = 14; /* MAX NUMBER OF DEGITS IN NUMBERS */ const AMAX =2047; /* MAXIMUM ADDRESS */ const LEVMAX= 3; /* MAX DEPTH OF BLOCK NESTING */ const CXMAX = 200; /* SIZE OF CODE ARRAY */ typedef enum { 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,RETURNSYM, CONSTSYM, VARSYM, PROCSYM, PROGSYM,ELSESYM,REPEATSYM, DOWHILESYM,PLUSEQL,PLUSPLUS,MINUSEQL,MINUSMINUS } SYMBOL; char *SYMOUT[] = {"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", "PROGSYM","ELSESYM" "REPEATSYM","DOWHILESYM","PLUSEQL","PLUSPLUS","MINUSEQL","RETURN", "MINUSMINUS"}; typedef int *SYMSET; // SET OF SYMBOL; typedef char ALFA[11]; typedef enum { CONSTANT, VARIABLE, PROCEDUR } OBJECTS ; typedef enum { LIT, OPR, LOD, STO, CAL, INI, JMP, JPC } FCT; typedef struct { FCT F; /*FUNCTION CODE*/ int L; /*0..LEVMAX LEVEL*/ int A; /*0..AMAX DISPLACEMENT ADDR*/ } INSTRUCTION; /* LIT O A -- LOAD CONSTANT A */ /* OPR 0 A -- EXECUTE OPR A */ /* LOD L A -- LOAD VARIABLE L,A */ /* STO L A -- STORE VARIABLE L,A */ /* CAL L A -- CALL PROCEDURE A AT LEVEL L */ /* INI 0 A -- INCREMET T-REGISTER BY A */ /* JMP 0 A -- JUMP TO A */ /* JPC 0 A -- JUMP CONDITIONAL TO A */ char CH; /*LAST CHAR READ*/ SYMBOL SYM; /*LAST SYMBOL READ*/ ALFA ID; /*LAST IDENTIFIER READ*/ int NUM; /*LAST NUMBER READ*/ int CC; /*CHARACTER COUNT*/ int LL; /*LINE LENGTH*/ int CX; /*CODE ALLOCATION INDEX*/ char LINE[81]; INSTRUCTION CODE[CXMAX]; ALFA KWORD[NORW+1]; SYMBOL WSYM[NORW+1]; SYMBOL SSYM['^'+1]; ALFA MNEMONIC[9]; SYMSET DECLBEGSYS, STATBEGSYS, FACBEGSYS; struct { ALFA NAME; OBJECTS KIND; union { int VAL; /*CONSTANT*/ struct { int LEVEL,ADR,SIZE; } vp; /*VARIABLE,PROCEDUR:*/ }; } TABLE[TXMAX]; FILE *FIN,*FOUT; int ERR; void EXPRESSION(SYMSET FSYS, int LEV, int &TX); void TERM(SYMSET FSYS, int LEV, int &TX); //--------------------------------------------------------------------------- int SymIn(SYMBOL SYM, SYMSET S1) { return S1[SYM]; } //--------------------------------------------------------------------------- SYMSET SymSetUnion(SYMSET S1, SYMSET S2) { SYMSET S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (int i=0; i<RESERVENUM; i++) if (S1[i] || S2[i]) S[i]=1; else S[i]=0; return S; } //--------------------------------------------------------------------------- SYMSET SymSetAdd(SYMBOL SY, SYMSET S) { SYMSET S1; S1=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (int i=0; i<RESERVENUM; i++) S1[i]=S[i]; S1[SY]=1; return S1; } //--------------------------------------------------------------------------- SYMSET SymSetNew(SYMBOL a) { SYMSET S; int i,k; S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (i=0; i<RESERVENUM; i++) S[i]=0; S[a]=1; return S; } //--------------------------------------------------------------------------- SYMSET SymSetNew(SYMBOL a, SYMBOL b) { SYMSET S; int i,k; S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (i=0; i<RESERVENUM; i++) S[i]=0; S[a]=1; S[b]=1; return S; } //--------------------------------------------------------------------------- SYMSET SymSetNew(SYMBOL a, SYMBOL b, SYMBOL c) { SYMSET S; int i,k; S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (i=0; i<RESERVENUM; i++) S[i]=0; S[a]=1; S[b]=1; S[c]=1; return S; } //--------------------------------------------------------------------------- SYMSET SymSetNew(SYMBOL a, SYMBOL b, SYMBOL c, SYMBOL d) { SYMSET S; int i,k; S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (i=0; i<RESERVENUM; i++) S[i]=0; S[a]=1; S[b]=1; S[c]=1; S[d]=1; return S; } //--------------------------------------------------------------------------- SYMSET SymSetNew(SYMBOL a, SYMBOL b, SYMBOL c, SYMBOL d,SYMBOL e) { SYMSET S; int i,k; S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (i=0; i<RESERVENUM; i++) S[i]=0; S[a]=1; S[b]=1; S[c]=1; S[d]=1; S[e]=1; return S; } //--------------------------------------------------------------------------- SYMSET SymSetNew(SYMBOL a, SYMBOL b, SYMBOL c, SYMBOL d,SYMBOL e, SYMBOL f) { SYMSET S; int i,k; S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (i=0; i<RESERVENUM; i++) S[i]=0; S[a]=1; S[b]=1; S[c]=1; S[d]=1; S[e]=1; S[f]=1; return S; } //--------------------------------------------------------------------------- SYMSET SymSetNULL() { SYMSET S; int i,n,k; S=(SYMSET)malloc(sizeof(int)*RESERVENUM); for (i=0; i<RESERVENUM; i++) S[i]=0; return S; } //--------------------------------------------------------------------------- void Error(int n) { String s = "***"+AnsiString::StringOfChar(' ', CC-1)+"^"; Form1->printls(s.c_str(),n); fprintf(FOUT,"%s%d\n", s.c_str(), n); ERR++; } /*Error*/ //--------------------------------------------------------------------------- void GetCh() { if (CC==LL) { if (feof(FIN)) { Form1->printfs("PROGRAM INCOMPLETE"); fprintf(FOUT,"PROGRAM INCOMPLETE\n"); fclose(FOUT); exit(0); } LL=0; CC=0; CH=' '; while (!feof(FIN) && CH!=10) { CH=fgetc(FIN); LINE[LL++]=CH; } LINE[LL-1]=' '; LINE[LL]=0; String s=IntToStr(CX); while(s.Length()<3) s=" "+s; s=s+" "+LINE; Form1->printfs(s.c_str()); fprintf(FOUT,"%s\n",s); } CH=LINE[CC++]; } /*GetCh()*/ //--------------------------------------------------------------------------- void GetSym() { int i,J,K; ALFA A; while (CH<=' ') GetCh(); if (CH>='A' && CH<='Z') { /*ID OR RESERVED WORD*/ K=0; do { if (K<AL) A[K++]=CH; GetCh(); }while((CH>='A' && CH<='Z')||(CH>='0' && CH<='9')); A[K]='\0'; strcpy(ID,A); i=1; J=NORW; do { K=(i+J) / 2; if (strcmp(ID,KWORD[K])<=0) J=K-1; if (strcmp(ID,KWORD[K])>=0) i=K+1; }while(i<=J); if (i-1 > J) SYM=WSYM[K]; else SYM=IDENT; } else if (CH>='0' && CH<='9') { /*NUMBER*/ K=0; NUM=0; SYM=NUMBER; do { NUM=10*NUM+(CH-'0'); K++; GetCh(); }while(CH>='0' && CH<='9'); if (K>NMAX) Error(30); } else if (CH==':') { GetCh(); if (CH=='=') { SYM=BECOMES; GetCh(); } else SYM=NUL; } else /* THE FOLLOWING TWO CHECK WERE ADDED BECAUSE ASCII DOES NOT HAVE A SINGLE CHARACTER FOR <= OR >= */ if (CH=='<') { GetCh(); if (CH=='=') { SYM=LEQ; GetCh(); }/*小于或等于*/ else if(CH=='>') { SYM=NEQ; GetCh(); } else SYM=GTR; } else if (CH=='>') { GetCh(); if (CH=='=') { SYM=GEQ; GetCh(); } /*大于或等于*/ else SYM=LSS; } else if(CH=='+') /*++和+＝运算*/ { GetCh(); if(CH=='=') { SYM=PLUSEQL; GetCh(); }