📄 unit1.cpp
字号:
WNUMK=0;
//GetSym();
if(SYM!=SQRPAREN)
Error(93); //数组定义不正确
}
else Error(93);
//if(arr)
}
//---------------------------------------------------------------------------
//生成虚拟机代码
void GEN(FCT X, int Y, int Z) {
if (CX>CXMAX) {
Form1->printfs("PROGRAM TOO LONG");
fprintf(FOUT,"PROGRAM TOO LONG\n");
fclose(FOUT);
exit(0);
}
CODE[CX].F=X; CODE[CX].L=Y; CODE[CX].A=Z;
CX++;
} /*GEN*/
//---------------------------------------------------------------------------
//测试当前符号是否合法
void TEST(SYMSET S1, SYMSET S2, int N) {
if (!SymIn(SYM,S1)) {
Error(N);
while (!SymIn(SYM,SymSetUnion(S1,S2))) GetSym();
}
} /*TEST*/
//---------------------------------------------------------------------------
//在名字表中加入一项
void ENTER(OBJECTS K, int LEV, int &TX, int &DX) { /*ENTER OBJECT INTO TABLE*/
TX++;
strcpy(TABLE[TX].NAME,ID); TABLE[TX].KIND=K;
switch (K) {
case CONSTANT:
if (NUM>AMAX) { Error(31); NUM=0; }
TABLE[TX].VAL=NUM;
break;
case VARIABLE:
TABLE[TX].vp.LEVEL=LEV; TABLE[TX].vp.ADR=DX; DX++;
break;
case PROCEDUR:
TABLE[TX].vp.LEVEL=LEV;
break;
}
} /*ENTER*/
//---------------------------------------------------------------------------
//查找名字的位置
int POSITION(ALFA ID, int TX) { /*FIND IDENTIFIER IN TABLE*/
int i=TX;
strcpy(TABLE[0].NAME,ID);
while (strcmp(TABLE[i].NAME,ID)!=0) i--;
return i;
} /*POSITION*/
//---------------------------------------------------------------------------
//常量声明处理
void ConstDeclaration(int LEV,int &TX,int &DX) {
if (SYM==IDENT||SYM==RPAREN) {
GetSym();
if (SYM==EQL||SYM==BECOMES) {
if (SYM==BECOMES) Error(1);
GetSym();
if (SYM==NUMBER) { ENTER(CONSTANT,LEV,TX,DX); GetSym(); }
else Error(2);
}
else Error(3);
}
else Error(4);
} /*ConstDeclaration()*/
//---------------------------------------------------------------------------
//变量声明处理
void VarDeclaration(int LEV,int &TX,int &DX) {
if (SYM==IDENT||SYM==SEMICOLON) { ENTER(VARIABLE,LEV,TX,DX); GetSym(); }
else Error(4);
} /*VarDeclaration()*/
//---------------------------------------------------------------------------
//输出目标代码清单
void ListCode(int CX0) { /*LIST CODE GENERATED FOR THIS Block*/
if (Form1->ListSwitch->ItemIndex==0)
for (int i=CX0; i<CX; i++) {
String s=IntToStr(i);
while(s.Length()<3)s=" "+s;
s=s+" "+MNEMONIC[CODE[i].F]+" "+IntToStr(CODE[i].L)+" "+IntToStr(CODE[i].A);
Form1->printfs(s.c_str());
fprintf(FOUT,"%3d%5s%4d%4d\n",i,MNEMONIC[CODE[i].F],CODE[i].L,CODE[i].A);
}
} /*ListCode()*/;
//---------------------------------------------------------------------------
//因子处理
void FACTOR(SYMSET FSYS, int LEV, int &TX) {
int i;
TEST(FACBEGSYS,FSYS,24);
while (SymIn(SYM,FACBEGSYS)) {
if (SYM==IDENT) {
i=POSITION(ID,TX);
if (i==0) Error(11);
else
switch (TABLE[i].KIND) {
case CONSTANT:
GEN(LIT,0,TABLE[i].VAL); break;
case VARIABLE: //添加
GEN(LOD,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
// GetSym();
if(SYM==INC||SYM==DEC)
{
if(SYM==INC) GEN(OPR,0,17);
else
GEN(OPR,0,18);
GEN(STO,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
GEN(LOD,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
GetSym();
}
break;
case PROCEDUR:
Error(21); break;
}
GetSym();
}
else
if (SYM==NUMBER) {
if (NUM>AMAX) { Error(31); NUM=0; }
GEN(LIT,0,NUM); GetSym();
}
else
if (SYM==LPAREN) {
GetSym(); EXPRESSION(SymSetAdd(RPAREN,FSYS),LEV,TX);
if (SYM==RPAREN) GetSym();
else Error(22);
}
TEST(FSYS,FACBEGSYS,23);
}
}/*FACTOR*/
//---------------------------------------------------------------------------
//项处理
void TERM(SYMSET FSYS, int LEV, int &TX) { /*TERM*/
SYMBOL MULOP;
FACTOR(SymSetUnion(FSYS,SymSetNew(TIMES,SLASH)), LEV,TX);
while (SYM==TIMES || SYM==SLASH) {
MULOP=SYM; GetSym();
FACTOR(SymSetUnion(FSYS,SymSetNew(TIMES,SLASH)),LEV,TX);
if (MULOP==TIMES) GEN(OPR,0,4);
else GEN(OPR,0,5);
}
} /*TERM*/;
//---------------------------------------------------------------------------
//表达式处理
void EXPRESSION(SYMSET FSYS, int LEV, int &TX) {
SYMBOL ADDOP;
if (SYM==PLUS || SYM==MINUS) {
ADDOP=SYM; GetSym();
TERM(SymSetUnion(FSYS,SymSetNew(PLUS,MINUS)),LEV,TX);
if (ADDOP==MINUS) GEN(OPR,0,1);
}
else TERM(SymSetUnion(FSYS,SymSetNew(PLUS,MINUS)),LEV,TX);
while (SYM==PLUS || SYM==MINUS) {
ADDOP=SYM; GetSym();
TERM(SymSetUnion(FSYS,SymSetNew(PLUS,MINUS)),LEV,TX);
if (ADDOP==PLUS) GEN(OPR,0,2);
else GEN(OPR,0,3);
}
} /*EXPRESSION*/
//---------------------------------------------------------------------------
//条件处理
void CONDITION(SYMSET FSYS,int LEV,int &TX) {
SYMBOL RELOP;
if (SYM==ODDSYM)
{
GetSym();
EXPRESSION(FSYS,LEV,TX);
GEN(OPR,0,6);
}
else {
EXPRESSION(SymSetUnion(SymSetNew(EQL,NEQ,LSS,LEQ,GTR,GEQ,PLUSBK,MINUSBK),FSYS),LEV,TX);
if (!SymIn(SYM,SymSetNew(EQL,NEQ,LSS,LEQ,GTR,GEQ,PLUSBK,MINUSBK))) Error(20);
else {
RELOP=SYM; GetSym(); //5
EXPRESSION(FSYS,LEV,TX);
switch (RELOP) {
case EQL: GEN(OPR,0,8); break;
case NEQ: GEN(OPR,0,9); break;
case LSS: GEN(OPR,0,10); break;
case GEQ: GEN(OPR,0,11); break;
case GTR: GEN(OPR,0,12); break;
case LEQ: GEN(OPR,0,13); break;
case PLUSBK: GEN(OPR,0,14); break;
case MINUSBK: GEN(OPR,0,15); break;
}
}
}
} /*CONDITION*/
//---------------------------------------------------------------------------
//语句处理
void STATEMENT(SYMSET FSYS,int LEV,int &TX) { /*STATEMENT*/
int i,CX1,CX2,CX3,tm=0,jk=0;
FCT STOMode[3]={STO,STOARR,STOVAR};
FCT LODMode[3]={LOD,LODARR,LODVAR};
SYMBOL Temp;
switch (SYM) {
case IDENT:
i=POSITION(ID,TX);
if (i==0) Error(11);
else
if (TABLE[i].KIND!=VARIABLE) { /*ASSIGNMENT TO NON-VARIABLE*/
Error(12); i=0;
}
GetSym();
switch(SYM)
{ //添加INC,DEC,PLUSBK,MINUSBK
case BECOMES:
GetSym();
EXPRESSION(FSYS,LEV,TX);
if(i!=0) GEN(STO,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
break;
case INC: //++运算
GetSym();
GEN(LODMode[jk],LEV-TABLE[i].vp.LEVEL+tm,TABLE[i].vp.ADR);
GEN(LIT,0,1);
GEN(OPR,0,2);
GEN(STOMode[jk],LEV-TABLE[i].vp.LEVEL+tm,TABLE[i].vp.ADR);
break;
case DEC: //--运算
GetSym();
GEN(LODMode[jk],LEV-TABLE[i].vp.LEVEL+tm,TABLE[i].vp.ADR);
GEN(LIT,0,1);
GEN(OPR,0,3);
GEN(STOMode[jk],LEV-TABLE[i].vp.LEVEL+tm,TABLE[i].vp.ADR);
break;
case PLUSBK:
case MINUSBK:
int flag=SYM; //flag是一个局部整型变量
GetSym();
GEN(LOD,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
EXPRESSION(FSYS,LEV,TX);
if(flag==PLUSBK) GEN(OPR,0,2);
else GEN(OPR,0,3);
GEN(STO,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
break;
// default: Error(13); GetSym();
}
break;
case READSYM:
GetSym();
if (SYM!=LPAREN) Error(34);
else
do {
GetSym();
if (SYM==IDENT) i=POSITION(ID,TX);
else i=0;
if (i==0) Error(35);
else {
GEN(OPR,0,16);
GEN(STO,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
}
GetSym();
}while(SYM==COMMA);
if (SYM!=RPAREN) {
Error(33);
while (!SymIn(SYM,FSYS)) GetSym();
}
else GetSym();
break; /* READSYM */
case WRITESYM:
GetSym();
if (SYM==LPAREN) {
do {
GetSym();
EXPRESSION(SymSetUnion(SymSetNew(RPAREN,COMMA),FSYS),LEV,TX);
GEN(OPR,0,14);
}while(SYM==COMMA);
if (SYM!=RPAREN) Error(33);
else GetSym();
}
GEN(OPR,0,15);
break; /*WRITESYM*/
case CALLSYM:
GetSym();
if (SYM!=IDENT) Error(14);
else {
i=POSITION(ID,TX); if (i==0) Error(11);
GetSym();
if(SYM==LPAREN)
{
GetSym();
int k=0;
EXPRESSION(SymSetUnion(SymSetNew(RPAREN,COMMA),FSYS),LEV,TX);
GEN(PUSH,0,k);
k++;
while(SYM==COMMA)
{
GetSym();
EXPRESSION(SymSetUnion(SymSetNew(RPAREN,COMMA),FSYS),LEV,TX);
GEN(PUSH,0,k);
k++;
}
if(SYM==RPAREN) GetSym();
else Form1->printls("错误CALL",400);
//String s=IntToStr(i);
//Form1->printls(s.c_str(),700);
GEN(CAL,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
}
else
{
if (TABLE[i].KIND==PROCEDUR)
GEN(CAL,LEV-TABLE[i].vp.LEVEL,TABLE[i].vp.ADR);
else Error(15);
}
}
break;
case IFSYM:
GetSym();
CONDITION(SymSetUnion(SymSetNew(THENSYM,DOSYM,ELSESYM),FSYS),LEV,TX);
if (SYM==THENSYM) GetSym();
else Error(16);
CX1=CX;
GEN(JPC,0,0);
STATEMENT(SymSetUnion(SymSetNew(IDENT,ELSESYM,SEMICOLON),FSYS),LEV,TX);
if(SYM!=SEMICOLON) Form1->printls("错误IF",300);
else GetSym();
if(SYM!=ELSESYM)
{
b=1;
CODE[CX1].A=CX;
return;
}
else //6 添加else
{
GetSym();
CX2=CX;
GEN(JMP,0,0);
STATEMENT(FSYS,LEV,TX);
CODE[CX1].A=CX2+1;
CODE[CX2].A=CX;
}
break;
case BEGINSYM:
GetSym();
STATEMENT(SymSetUnion(SymSetNew(SEMICOLON,ENDSYM),FSYS),LEV,TX);
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