www.pudn.com > pl0.zip > Grammar.cpp
// Grammar.cpp: implementation of the Grammar class.
//
//////////////////////////////////////////////////////////////////////
#include
#include
#include
#include
#include "Word.h"
#include "Table.h"
#include "pcode.h"
#include "Grammar.h"
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
#define $program 1
#define $const 2
#define $var 3
#define $procedure 4
#define $begin 5
#define $if 6
#define $while 7
#define $call 8
#define $read 9
#define $write 10
#define $end 11
#define $then 12
#define $else 13
#define $do 14
#define $odd 15
#define $lop 16 // → =|<>|<|<=|>|>=
#define $aop 17 // → +|-
#define $mop 18 // → *|/
#define $id 19 // → l{l|d}
#define $integer 20 // → d{d}
#define $ 21 // ;
#define $equal 22 // :=
#define $and 23 // ,
#define $leftbrack 24 //(
#define $rightbrack 25 //)
//using namespace std;
Grammar::Grammar(Simpsc *p)
{
pl=p;
}
bool Grammar::Analysis(Word *Token)
{
lev=-1;
i=0;
if(!ProceProg(Token))
{
cout<<"出现语法错误，分析中断，请检查程序"<Token[i].ReturnCont());
// return name;
return Token[i].ReturnCont();
}
void Grammar::ConstVar(Word *Token)
{
Table *tb=pl->ChaTable;
tb->Enter(constant,Token);
}
void Grammar::ConstDecla(Word *Token)
{
char con[16];
int num;
Table *tb=pl->ChaTable;
strcpy(con,Token[i].ReturnCont());
num=atoi(con);
tb->GetVal(num);
}
void Grammar::VarDecla(Word *Token)
{
Table *tb=pl->ChaTable;
tb->Enter(variable,Token);
dx[lev]++;
}
bool Grammar::ProceFactor(Word *Token) //→||()
{
int p,num;
char con[16];
Table *tb=pl->ChaTable;
pcode *cd=pl->CodeList;
if(Token[i].ReturnWType()==$id)
{
p=tb->Position(Token[i].ReturnCont());
if(p==0)
{
Token[i].ReturnXY(bx,ex,y);
cout<<"未申明的标识符！！第"<table[p].kind)
{
case constant:
cd->Gen(LIT,0,tb->table[p].val);
break;
case variable:
cd->Gen(LOD,lev-tb->table[p].level,tb->table[p].adr);
break;
case procedure:
Token[i].ReturnXY(bx,ex,y);
cout<<"错误的标识符，函数名不可用于表达式:第"<Gen(LIT,0,num);
i++;
}
else if(Token[i].ReturnWType()==$leftbrack)
{
i++;
if(!ProceExp(Token))
return false;
if(Token[i].ReturnWType()==$rightbrack)
i++;
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"左右括号不匹配:第"< → {}
{
char op[2];
pcode *cd=pl->CodeList;
if(!ProceFactor(Token))
return false;
while(Token[i].ReturnWType()==$mop)
{
strcpy(op,Token[i].ReturnCont());
i++;
if(!ProceFactor(Token))
return false;
else
{
if(op[0]=='*')
cd->Gen(OPR,0,4);
else
cd->Gen(OPR,0,5);
}
}
return true;
}
bool Grammar::ProceExp(Word *Token) // → [+|-]{}
{
char op[2];
Table *tb=pl->ChaTable;
pcode *cd=pl->CodeList;
if(!strcmp(Token[i].ReturnCont(),"+") || !strcmp(Token[i].ReturnCont(),"-"))
{
strcpy(op,Token[i].ReturnCont());
i++;
}
if(!ProceTerm(Token))
return false;
else
{
if(op[0]=='-')
cd->Gen(OPR,0,1);
}
while(Token[i].ReturnWType()==$aop)
{
strcpy(op,Token[i].ReturnCont());
i++;
if(!ProceTerm(Token))
return false;
if(op[0]=='+')
cd->Gen(OPR,0,2);
else
cd->Gen(OPR,0,3);
}
return true;
}
bool Grammar::ProceLexp(Word *Token) // → |odd
{
Table *tb=pl->ChaTable;
pcode *cd=pl->CodeList;
char lop[3];
if(Token[i].ReturnWType()==$odd)
{
i++;
if(!ProceExp(Token))
return false;
else
cd->Gen(OPR,0,6);
}
else if(ProceExp(Token))
{
if(Token[i].ReturnWType()==$lop)
{
strcpy(lop,Token[i].ReturnCont());
i++;
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"缺少关系运算符:第"<"))
cd->Gen(OPR,0,9);
else if(!strcmp(lop,"<"))
cd->Gen(OPR,0,10);
else if(!strcmp(lop,">="))
cd->Gen(OPR,0,11);
else if(!strcmp(lop,">"))
cd->Gen(OPR,0,12);
else if(!strcmp(lop,"<="))
cd->Gen(OPR,0,13);
}
}
else
return false;
return true;
}
bool Grammar::ProceState(Word *Token) // →
{
int cx1,cx2,p;
Table *tb=pl->ChaTable;
pcode *cd=pl->CodeList;
if(Token[i].ReturnWType()==$id) // :=
{
p=tb->Position(Token[i].ReturnCont());
if(p==0)
{
Token[i].ReturnXY(bx,ex,y);
cout<<"未申明的标识符！！第"<table[p].kind!=variable)
{
Token[i].ReturnXY(bx,ex,y);
cout<<"赋值号左部标识符属性应是变量!!第"<0)
cd->Gen(STO,lev-tb->table[p].level,tb->table[p].adr);
}
else if(Token[i].ReturnWType()==$if) //if then [else ]
{
i++;
if(!ProceLexp(Token))
return false;
if(Token[i].ReturnWType()==$then)
{
i++;
cx1=cd->cx;
cd->Gen(JPC,0,0);
}
else
return false;
if(!ProceState(Token))
return false;
if(Token[i].ReturnWType()==$else)
{
i++;
cx2=cd->cx;
cd->Gen(JMP,0,0);
if(!ProceState(Token))
return false;
else
{
cd->code[cx1].a=cx2+1;
cd->code[cx2].a=cd->cx;
}
}
else
cd->code[cx1].a=cd->cx;
}
else if(Token[i].ReturnWType()==$while) //while do
{
cx1=cd->cx;
i++;
if(!ProceLexp(Token))
return false;
else
{
cx2=cd->cx;
cd->Gen(JPC,0,0);
}
if(Token[i].ReturnWType()==$do)
i++;
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"缺少\"do\":第"<Gen(JMP,0,cx1);
cd->code[cx2].a=cd->cx;
}
}
else if(Token[i].ReturnWType()==$call) //call [（{,}）]
{
i++;
if(Token[i].ReturnWType()==$id)
{
p=tb->Position(Token[i].ReturnCont());
if(p==0)
{
Token[i].ReturnXY(bx,ex,y);
cout<<"未定义的函数!!第"<table[p].kind!=procedure)
{
Token[i].ReturnXY(bx,ex,y);
cout<<"错误的函数名!!第"<Gen(CAL,lev-tb->table[p].level,tb->table[p].adr);
i++;
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"缺少标识符:第"<
else if(Token[i].ReturnWType()==$read) //read ({，})
{
i++;
if(Token[i].ReturnWType()==$leftbrack)
i++;
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"缺少\"(\":第"<Position(Token[i].ReturnCont());
i++;
if(p==0)
{
Token[i].ReturnXY(bx,ex,y);
cout<<"未申明的标识符！！第"<Gen(RED,lev-tb->table[p].level,tb->table[p].adr);
}
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"此处输入的应是变量!!第"<Position(Token[i].ReturnCont());
i++;
if(p==0)
{
Token[i].ReturnXY(bx,ex,y);
cout<<"未申明的标识符！！第"<Gen(RED,lev-tb->table[p].level,tb->table[p].adr);
}
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"此处输入的应是变量!!第"<{,})
{
i++;
if(Token[i].ReturnWType()==$leftbrack)
i++;
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"缺少\"(\":第"<Gen(WRT,0,0);
while(Token[i].ReturnWType()==$and)
{
i++;
if(!ProceExp(Token))
return false;
else
cd->Gen(WRT,0,0);
}
if(Token[i].ReturnWType()==$rightbrack)
i++;
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"左右括号不匹配:第"<Gen(OPR,0,15);
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"错误的语句:第"< → begin {;}end
{
if(Token[i].ReturnWType()==$begin)
{
i++;
if(!ProceState(Token))
return false;
while(Token[i].ReturnWType()==$)
{
i++;
if(!ProceState(Token))
return false;
}
}
else
return false;
if(Token[i].ReturnWType()==$end)
i++;
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"此处应输入\"end\":第"< → :=
{
if(Token[i].ReturnWType()==$id)
{
this->ConstVar(Token);
i++;
if(Token[i].ReturnWType()==$equal)
{
i++;
if(Token[i].ReturnWType()==$integer)
{
this->ConstDecla(Token);
i++;
return true;
}
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"此处应输入\":=\":第"< → const {,}
{
if(Token[i].ReturnWType()==$const)
{
i++;
if(!ProceConst(Token))
return false;
while(Token[i].ReturnWType()==$and)
{
i++;
if(!ProceConst(Token))
{
Token[i].ReturnXY(bx,ex,y);
cout<<"常量定义出错:第"< → var {,}
{
if(Token[i].ReturnWType()==$var)
{
i++;
if(Token[i].ReturnWType()==$id)
{
this->VarDecla(Token);
i++;
while(Token[i].ReturnWType()==$and)
{
i++;
if(Token[i].ReturnWType()==$id)
{
this->VarDecla(Token);
i++;
}
else
{
i++;
Token[i].ReturnXY(bx,ex,y);
cout<<"\",\"后应当输入变量名:第"< → procedure （{,}）;{;}
{
int tx0;
Table *tb=pl->ChaTable;
pcode *cd=pl->CodeList;
if(Token[i].ReturnWType()==$procedure)
{
i++;
// lev++;
// dx[lev]=3;
tb=pl->ChaTable;
tx0=tb->ReturnIndex();
if(Token[i].ReturnWType()==$id)
{
tb->Enter(procedure,Token);
i++;
if(Token[i].ReturnWType()==$)
{
i++;
if(!ProceBlock(Token))
return false;
while(Token[i].ReturnWType()==$)
{
i++;
if(!ProceProc(Token))
return false;
}
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"缺少\";\":第"< → [][][]
{
Table *tb=pl->ChaTable;
pcode *cd=pl->CodeList;
int cx0,tx0;
lev++;
dx[lev]=3;
tx0=tb->ReturnIndex();
tb->table[tx0].adr=cd->cx;
cd->Gen(JMP,0,0);
if(lev>MAX_LEV)
{
cout<<"超出最高允许嵌套次数！"<code[tb->table[tx0].adr].a=cd->cx;
tb->table[tx0].adr=cd->cx;
tb->table[tx0].size=dx[lev];
cx0=cd->cx;
cd->Gen(INT,0,dx[lev]);
}
if(!ProceBody(Token))
return false;
else
{
cd->Gen(OPR,0,0);
lev--;
}
return true;
}
bool Grammar::ProceProg(Word *Token) // → program ；
{
if(Token[i].ReturnWType()==$program)
{
i++;
if(Token[i].ReturnWType()==$id)
{
i++;
}
else
{
Token[i].ReturnXY(bx,ex,y);
cout<<"第"<