📄 plxanalyzer.cs
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if(sym == symbol.semicolon)
{
GetSym();
level++;
patch = DS(dsfollsys);
if (sym == symbol.beginsym)
{
DoPatch(patch);
GetSym();
SS(ssfollsys);
Gen(fct.opr, 0, 0);
level--;
}
if (sym == symbol.endsym)
GetSym();
else
Error(ER_WAIT_END);
}
else
Error(ER_MISS_COMMA_OR_SEMICOLON);
}
else
Error(ER_ONLY_IDIENT); //这里必须是标识符
}
}while(AssistOpr.IsContain<symbol>(dsbegsys,sym));
}
protected void S(symbol[] fsys)
{
int cx1, cx2;
if (sym == symbol.ident)
{
int i = Position(strID);
GetSym();
if (i == -1)
Error(ER_ID_NOTFOUND);
else
{
switch (FindIDKind(i))
{
case objekt.integer:
CheckAssignment();
AE(aefollsys);
Gen(fct.sto, level - wordtab[i].level, wordtab[i].addr);
break;
case objekt.logical:
CheckAssignment();
BE(befollsys);
Gen(fct.sto, level - wordtab[i].level, wordtab[i].addr);
break;
case objekt.array:
ArrayItemStatement();
CheckAssignment();
AE(aefollsys);
Gen(fct.sta, level - wordtab[i].level, wordtab[i].addr);
break;
default:
break;
}
}
}
if(sym == symbol.callsym)
{
GetSym();
if (sym == symbol.ident)
{
int i = Position(strID);
if (i == -1)
Error(ER_ID_NOTFOUND);
else
{
if (wordtab[i].kind == objekt.procedure)
Gen(fct.cal, level - wordtab[i].level, wordtab[i].addr);
else
Error(ER_ILLEGAL_CALL);
}
}
else
Error(ER_ONLY_IDIENT);
GetSym();
}
else if(sym == symbol.ifsym)
{
GetSym();
BE(befollsys);
if (sym == symbol.thensym)
{
GetSym();
cx1 = codeIndex;
Gen(fct.jpc, 0, 0);
SS(fsys);
cx2 = codeIndex;
if (sym == symbol.elsesym)
{
Gen(fct.jmp, 0, 0);
GetSym();
code[cx1].address = codeIndex;
SS(fsys);
code[cx2].address = codeIndex;
}
//if there is no else,then modify jpc address
if(code[cx1].address == 0)
code[cx1].address = codeIndex;
if (sym == symbol.endsym)
{
GetSym();
}
else
{
Error(ER_WAIT_END);
}
}
else
{
Error(ER_WAIT_THEN);
}
}
else if(sym == symbol.whilesym)
{
cx1 = codeIndex;
GetSym();
BE(befollsys);
cx2 = codeIndex;
Gen(fct.jpc, 0, 0);
if (sym == symbol.dosym)
{
GetSym();
SS(fsys);
Gen(fct.jmp, 0, cx1);
code[cx2].address = codeIndex;
if (sym == symbol.endsym)
{
GetSym();
}
else
{
Error(ER_WAIT_END);
}
}
else
{
Error(ER_WAIT_DO);
}
}
else if(sym == symbol.repeatsym)
{
cx1 = codeIndex;
GetSym();
SS( fsys);
if (sym == symbol.untilsym)
{
GetSym();
BE( befollsys);
Gen(fct.jpc, 0, cx1);
}
else
{
Error(ER_WAIT_UNTIL);
}
}
else if (sym == symbol.writesym)
{
GetSym();
AE( aefollsys);
Gen(fct.opr, 0, 14);
}
}
protected void AE(symbol[] fsys)
{
symbol oprsym = sym;
if (sym == symbol.minus)
{
GetSym();
}
AT(atfollsys);
if (oprsym == symbol.minus)
Gen(fct.opr, 0, 1);
while (sym == symbol.minus || sym == symbol.plus)
{
oprsym = sym;
GetSym();
AT( atfollsys);
if (oprsym == symbol.plus)
Gen(fct.opr, 0, 2);
else
Gen(fct.opr, 0, 3);
}
}
protected void AT(symbol[] fsys)
{
symbol oprsym;
AF(afbegsys);
while (sym == symbol.times || sym == symbol.slash || sym == symbol.mod)
{
oprsym = sym;
GetSym();
AF( afbegsys);
if (oprsym == symbol.times)
Gen(fct.opr, 0, 4);
else if (oprsym == symbol.slash)
Gen(fct.opr, 0, 5);
else
Gen(fct.opr, 0, 6);
}
}
protected void AF(symbol[] fsys)
{
Test(afbegsys, fsys, ER_WRONG_BEGINID_INTFACTOR);
while (AssistOpr.IsContain<symbol>(afbegsys, sym))
{
if (sym == symbol.ident)
{
int i = Position(strID);
if (i == -1)
Error(ER_ID_NOTFOUND);
else
{
switch (FindIDKind(i))
{
case objekt.integer:
Gen(fct.lod, level - wordtab[i].level, wordtab[i].addr);
GetSym();
break;
case objekt.array:
GetSym();
ArrayItemStatement();
Gen(fct.loa, level - wordtab[i].level, wordtab[i].addr);
break;
case objekt.constant:
Gen(fct.lit,0,wordtab[i].value);
GetSym();
break;
default:
break;
}
}
}
else if (sym == symbol.number)
{
Gen(fct.lit, 0, num);
GetSym();
}
else if (sym == symbol.lparen)
{
GetSym();
AE( aefollsys);
if (sym == symbol.rparen)
{
GetSym();
}
else
{
Error(ER_MISS_RPAREN);
}
}
else
{
Error(ER_MISS_LPAREN);
}
}
}
protected void BE(symbol[] fsys)
{
BT( btfollsys);
while (sym == symbol.orsym)
{
GetSym();
BT( btfollsys);
Gen(fct.opr, 0, 2);
}
}
protected void BT(symbol[] fsys)
{
BF( bffollsys);
while (sym == symbol.andsym)
{
GetSym();
BF( bffollsys);
Gen(fct.opr, 0, 4);
}
}
protected void BF(symbol[] fsys)
{
Test(bfbegsys, fsys, ER_WRONG_BEGINID_LOGICALFACTOR);
while (AssistOpr.IsContain<symbol>(bfbegsys, sym))
{
if (sym == symbol.ident)
{
int i = Position(strID);
if (i == -1)
Error(ER_ID_NOTFOUND);
else
{
if (wordtab[i].kind == objekt.logical)
{
Gen(fct.lod, level - wordtab[i].level, wordtab[i].addr);
GetSym();
}
else
{
switch(FindIDKind(i))
{
case objekt.integer:
Gen(fct.lod, level - wordtab[i].level, wordtab[i].addr);
GetSym();
RE();
break;
case objekt.constant:
Gen(fct.lit, 0, wordtab[i].value);
GetSym();
RE();
break;
case objekt.array:
GetSym();
ArrayItemStatement();
Gen(fct.loa, level - wordtab[i].level, wordtab[i].addr);
RE();
break;
default:
break;
}
}
}
}
else if (sym == symbol.number)
{
Gen(fct.lit, 0, num);
GetSym();
RE();
}
else if (sym == symbol.truesym)
{
Gen(fct.lit, 0, 1);
GetSym();
}
else if (sym == symbol.falsesym)
{
Gen(fct.lit, 0, 0);
GetSym();
}
else if (sym == symbol.notsym)
{
GetSym();
BF( null);
Gen(fct.opr, 0, 13);
}
else if (sym == symbol.lparen)
{
GetSym();
BE( befollsys);
if (sym == symbol.rparen)
GetSym();
else
Error(ER_MISS_RPAREN);
}
}
}
protected void RE()
{
if (sym == symbol.eql || sym == symbol.gtr || sym == symbol.geq || sym == symbol.lss || sym == symbol.leq || sym == symbol.neq)
{
symbol relsym = sym;
GetSym();
AE(aefollsys);
switch (relsym)
{
case symbol.eql:
Gen(fct.opr, 0, 7);
break;
case symbol.neq:
Gen(fct.opr, 0, 8);
break;
case symbol.gtr:
Gen(fct.opr, 0, 9);
break;
case symbol.geq:
Gen(fct.opr, 0, 10);
break;
case symbol.lss:
Gen(fct.opr, 0, 11);
break;
case symbol.leq:
Gen(fct.opr, 0, 12);
break;
}
}
}
}
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