📄 unit1.~cpp
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/*** PL0 COMPILER WITH CODE GENERATION ***/
//---------------------------------------------------------------------------
#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 = 22; /* # 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 */
const SMAX =45; //max of SYMBOL
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,
CONSTSYM, VARSYM, PROCSYM, PROGSYM, ELSESYM,
FORSYM,TOSYM,DOWNTOSYM,RETURNSYM,INC,DEC,
PLUSBK,MINUSBK,REPEATSYM,DOWHILESYM,UNTILSYM
} 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"
"FORSYM","TOSYM","DOWNTOSYM","RETURNSYM","INC","DEC",
"PLUSBK","MINUSBK","REPEATSYM","DOWHILESYM","UNTILSYM"};
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)*SMAX);
for (int i=0; i<SMAX; 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)*SMAX);
for (int i=0; i<SMAX; i++) S1[i]=S[i];
S1[SY]=1;
return S1;
}
//---------------------------------------------------------------------------
SYMSET SymSetNew(SYMBOL a) {
SYMSET S; int i,k;
S=(SYMSET)malloc(sizeof(int)*SMAX);
for (i=0; i<SMAX; 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)*SMAX);
for (i=0; i<SMAX; 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)*SMAX);
for (i=0; i<SMAX; 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)*SMAX);
for (i=0; i<SMAX; 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)*SMAX);
for (i=0; i<SMAX; 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)*SMAX);
for (i=0; i<SMAX; 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)*SMAX);
for (i=0; i<SMAX; i++) S[i]=0;
return S;
}
//---------------------------------------------------------------------------
void Error(int n) {
String s;
switch(n){
case 1: s= "error:常数说明中的=写成：=";
break;
case 2:
s= "error:常数说明中的=后应是数字";
break;
case 3:
s= "error:常数说明中的标识符后应是=。 ";
break;
case 4:s= "error:const，var，procedure后应为标识符。 ";
break;
case 5:
s= "error:漏掉了'，'或'；' ";
break;
case 6:
s= "error:过程说明后的符号不正确(应是语句开始符，或过程定义符)。 ";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d过程说明后的符号不正确(应是语句开始符，或过程定义符)。\n",n);
break;
case 7:
s= "error:应是语句开始符。";
//Form1->printls(s.c_str(),n); fprintf(FOUT," %d应是语句开始符。\n",n);
break;
case 8:
s= "error:程序体内语句部分的后跟符不正确。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d程序体内语句部分的后跟符不正确。\n",n);
break;
case 9:
s= "error:程序结尾丢了句号'．'。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d 程序结尾丢了句号'．'。\n",n);
break;
case 10:
s= "error:语句之间漏了'；'。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d语句之间漏了'；'。\n",n);
break;
case 11:
s= "error:标识符未说明。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d标识符未说明。\n",n);
break;
case 12:
s= "error:赋值语句中，赋值号左部标识符属性应是变量。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d赋值语句中，赋值号左部标识符属性应是变量。\n",n);
break;
case 13:
s= "error:赋值语句左部标识符后应是赋值号'：='。";
//Form1->printls(s.c_str(),n); fprintf(FOUT," %d赋值语句左部标识符后应是赋值号'：='。\n",n);
break;
case 14: s= "error:call后应为标识符。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %dcall后应为标识符。\n",n);
break;
case 15: s= "error:call后标识符属性应为过程。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %dcall后标识符属性应为过程。\n",n);
break;
case 16:s= "error:条件语句中丢了'then'。";
//Form1->printls(s.c_str(),n); fprintf(FOUT," %d条件语句中丢了'then'。\n",n);
break;
case 17:
s= "error:丢了'end'或'；'。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d丢了'end'或'；'。\n",n);
break;
case 18:
s= "error:while型循环语句中丢了'do'。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %dwhile型循环语句中丢了'do'。\n",n);
break;
case 19:s= "error:语句后的符号不正确。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d语句后的符号不正确。\n",n);
break;
case 20:s= "error:应为关系运算符。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d应为关系运算符。\n",n);
break;
case 21:s= "error:表达式内标识符属性不能是过程。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d表达式内标识符属性不能是过程。\n",n);
break;
case 22: s= "error:表达式中漏掉右括号')'。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d表达式中漏掉右括号')'。\n",n);
break;
case 23:
s= "error:因子后的非法符号。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d因子后的非法符号。\n",n);
break;
case 24:s= "error:表达式的开始符不能是此符号。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d表达式的开始符不能是此符号。\n",n);
break;
case 31: s= "error:数越界。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %d数越界。\n",n);
break;
case 32:s= "error:read语句括号中的标识符不是变量。";
// Form1->printls(s.c_str(),n); fprintf(FOUT," %dread语句括号中的标识符不是变量。\n",n);
break;
case 36: s= "error:FOR语句后跟符号错误.";
break;
case 37:s= "error:FOR语句后跟符号错误,或者缺少dowhile 或者until.";
break;
default:s= "error:未定义错误"; break;
}
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 == "+"){
GetCh();
if(CH == '+'){
GetSym();
if(SYM == IDENT){
SYM == INC;
GetCh();
}
}
else Error(8);
}
else if(CH == '-'){
GetCh();
if(CH == '-'){
GetSym();
if(SYM == IDENT){
SYM=DEC;
GetCh();
}
else Error(8);
}
}*/
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);
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