📄 pas.c
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/***************************************/
/* pas.c */
/* 高级语言到四元式 */
/***************************************/
#include "stdio.h"
#include "string.h"
#include "globals.h"
#include "symtab.h"
//#include "code.h"
#include "block.h"
#include "cgen.h"
#define ACC -2
/********************************************/
#define sy_if 0
#define sy_then 1
#define sy_else 2
#define sy_while 3
#define sy_begin 4
#define sy_do 5
#define sy_end 6
#define a 7
#define semicolon 8
#define e 9
#define jinghao 10
#define S 11
#define L 12
#define tempsy 15
#define EA 18/*E and*/
#define EO 19/*E or*/
#define plus 34
#define times 36
#define becomes 38
#define op_and 39
#define op_or 40
#define op_not 41
#define rop 42
#define lparent 48
#define rparent 49
#define ident 56
#define intconst 57
/***********************************/
char ch='\0'; //当前字符
int count=0;
static char spelling[10]={""}; //存放识别的字符
static char line[81]={""}; //以行字符缓冲区
char *pline; //字符缓冲区指针
static char ntab1[100][10];
struct ntab
{
int tc;
int fc;
}ntab2[200];
int label=0;
//存放临时变量的表的定义
struct rwords{
char sp[10];
int sy;
};
//存放文件的结构
struct rwords reswords[10]={{"if",sy_if},
{"do",sy_do},
{"else",sy_else},
{"while",sy_while},
{"then",sy_then},
{"begin",sy_begin},
{"end",sy_end},
{"and",op_and},
{"or",op_or},
{"not",op_not}};
struct aa{
int sy1;
int pos;
}buf[1000]; //词法分析结果缓冲区
struct aa n; // 当前字符
struct aa n1; //当前表达式中的字符
struct aa E; //非终结符
struct aa sstack[100];//符号栈
struct aa ibuf[100];
struct aa stack[1000];
struct aa oth;
struct fourexp{
char op[10];
struct aa arg1;
struct aa arg2;
int result;
}fexp[200];
//四元式的结构
int ssp=0; //指向sstack[100]
struct aa *pbuf=buf; //指向词法分析缓冲区
int nlength=0;
int lnum=0; //源程序长度
int tt1=0;
FILE *cfile;
FILE *mfile;
FILE *source;
FILE *code;
int Error=FALSE;
/**********************************************/
int newt=0;
//临时变量
int nxq=100;
//*nxq指向下一个形成的四元式的地址
int lr;
int lr1;
int sp=0;
//状态栈定义
int stack1[100];
int sp1=0;
//状态栈1的定义
int num=0;
struct ll{
int nxq1;
int tc1;
int fc1;
}labelmark[10];
int labeltemp[10];
int pointmark=-1,pointtemp=-1;
int sign=0;
//sign=1,表达式为赋值语句；sign=2,表达式为布尔表达式
/********************************************************/
static int action[19][13]=
/*0*/ {{2,-1,-1,3,4,-1,-1,5,-1,-1,10,1,-1},
/*1*/ {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,ACC,-1,-1},
/*2*/ {-1,-1,-1,-1,-1,-1,-1,-1,-1,6,-1,-1,-1},
/*3*/ {-1,-1,-1,-1,-1,-1,-1,-1,-1,7,-1,-1,-1},
/*4*/ {2,-1,-1,3,4,-1,-1,5,-1,-1,-1,9,8},
/*5*/ {-1,-1,104,-1,-1,-1,104,-1,104,-1,104,-1,-1},
/*6*/ {-1,10,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1},
/*7*/ {-1,-1,-1,-1,-1,11,-1,-1,-1,-1,-1,-1,-1},
/*8*/ {-1,-1,-1,-1,-1,-1,12,-1,-1,-1,-1,-1,-1},
/*9*/ {-1,-1,-1,-1,-1,-1,105,-1,13,-1,-1,-1,-1},
/*10*/ {2,-1,-1,3,4,-1,-1,5,-1,-1,-1,14,-1},
/*11*/ {2,-1,-1,3,4,-1,-1,5,-1,-1,-115,-1},
/*12*/ {-1,-1,103,-1,-1,-1,103,-1,103,-1,103,-1,-1},
/*13*/ {2,-1,-1,3,4,-1,-1,5,-1,-1,-1,9,16},
/*14*/ {-1,-1,17,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1},
/*15*/ {-1,-1,102,-1,-1,-1,102,-1,102,-1,102,-1,-1},
/*16*/ {-1,-1,-1,-1,-1,-1,106,-1,-1,-1,-1,-1,-1},
/*17*/ {2,-1,-1,3,4,-1,-1,5,-1,-1,-1,18,-1},
/*18*/ {-1,-1,101,-1,-1,-1,101,-1,101,-1,101,-1,-1}};
static int action1[10][7]=
/*0*/ {{3,-1,-1,2,-1,-1,1},
/*1*/ {-1,4,5,-1,-1,ACC,-1},
/*2*/ {3,-1,-1,2,-1,-1,6},
/*3*/ {104,104,104,104,104,104,-1},
/*4*/ {3,-1,-1,2,-1,-1,7},
/*5*/ {3,-1,-1,2,-1,-1,8},
/*6*/ {-1,4,5,-1,9,-1,-1},
/*7*/ {101,101,5,101,101,101,-1},
/*8*/ {102,102,102,102,102,102,-1},
/*9*/ {103,103,103,103,103,103,-1}};
static int action2[16][11]=
/*0*/ {{1,-1,4,-1,5,-1,-1,-1,13,7,8},
/*1*/ {-1,2,-1,101,-1,101,101,101,-1,-1,-1},
/*2*/ {3,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1},
/*3*/ {-1,-1,-1,102,-1,102,102,102,-1,-1,-1},
/*4*/ {1,-1,4,-1,5,-1,-1,-1,11,7,8},
/*5*/ {1,-1,4,-1,5,-1,-1,-1,6,7,8},
/*6*/ {-1,-1,-1,104,-1,9,10,104,-1,-1,-1},
/*7*/ {1,-1,4,-1,5,-1,-1,-1,14,7,8},
/*8*/ {1,-1,4,-1,5,-1,-1,-1,15,7,8},
/*9*/ {105,-1,105,-1,105,-1,-1,105,-1,-1,-1},
/*10*/ {107,-1,107,-1,107,-1,-1,107,-1,-1,-1},
/*11*/ {-1,-1,-1,12,-1,9,10,-1,-1,-1,-1},
/*12*/ {-1,103,-1,103,-1,103,103,103,-1,-1,-1},
/*13*/ {-1,-1,-1,-1,-1,9,10,ACC,-1,-1,-1},
/*14*/ {-1,-1,-1,106,-1,9,10,106,-1,-1,-1},
/*15*/ {-1,-1,-1,108,-1,9,10,108-1,-1,-1}};
/*********************从文件读一行到缓冲区*******************************/
readline()
{
char ch1;
pline=line;
ch1=getc(cfile);
while (ch1!='\n')
{
*pline=ch1;
pline++;
ch1=getc(cfile);
}
*pline='\0';
pline=line;
}
/*******************从缓冲区读一个字符***************/
readch()
{
if(ch=='\0')
{
readline();
lnum++;
}
ch=*pline;
pline++;
}
/**************标志符和关键字的识别***********************/
find(char spel[])
{
int ss1=0;
int ii=0;
while((ss1==0)&&(ii<nlength))
{
if(!strcmp(spel,ntab1[ii])) ss1=1;
ii++;
}
if(ss1==1) return (ii-1);
else return -1;
}
identifier()
{
int iii=0,j,k;
int ss=0;
k=0;
do
{
spelling[k]=ch;
k++;
readch();
}
while(((ch>='a')&&(ch<='z'))||((ch>='0')&&(ch<='9')));
pline--;
spelling[k]='\0';
while((ss==0)&&(iii<10))
{
if(!strcmp(spelling,reswords[iii].sp)) ss=1;
iii++;
}
//关键字匹配
if(ss==1)
{
buf[count].sy1=reswords[iii-1].sy;
}
else
{
buf[count].sy1=ident;
j=find(spelling);
if(j==-1)
{
buf[count].pos=tt1;
strcpy(ntab1[tt1],spelling);
tt1++;
nlength++;
}
else buf[count].pos=j;
}
count++;
for(k=0;k<10;k++)spelling[k]=' ';
}
/*******************数字的识别************************/
number()
{
int ivalue=0;
int digit;
do
{
digit=ch-'0';
ivalue=ivalue*10+digit;
readch();
}
while((ch>='0')&&(ch<='9'));
buf[count].sy1=intconst;
buf[count].pos=ivalue;
count++;
pline--;
}
/***********************扫描主函数*************************/
scan()
{
//int i;
while(!feof(cfile))
{
switch(ch)
{
case ' ':
break;
case 'a':
case 'b':
case 'c':
case 'd':
case 'e':
case 'f':
case 'g':
case 'h':
case 'i':
case 'j':
case 'k':
case 'l':
case 'm':
case 'n':
case 'o':
case 'p':
case 'q':
case 'r':
case 's':
case 't':
case 'u':
case 'v':
case 'w':
case 'x':
case 'y':
case 'z':
identifier();
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
number();
break;
case '<':
readch();
if(ch=='=')
{
buf[count].pos=0;
}
else
{
if(ch=='>')buf[count].pos=4;
else
{
buf[count].pos=1;
pline--;
}
}
buf[count].sy1=rop;
count++;
break;
case '>':
readch();
if(ch=='=')
{
buf[count].pos=2;
}
else
{
buf[count].pos=3;
pline--;
}
buf[count].sy1=rop;
count++;
break;
case '(':
buf[count].sy1=lparent;
count++;
break;
case ')':
buf[count].sy1=rparent;
count++;
break;
case '#':
buf[count].sy1=jinghao;
count++;
break;
case '+':
buf[count].sy1=plus;
count++;
break;
case '*':
buf[count].sy1=times;
count++;
break;
case ':':
readch();
if(ch=='=')
buf[count].sy1=becomes;
count++;
break;
case '=':
buf[count].sy1=rop;
buf[count].pos=5;
count++;
break;
case ';':
buf[count].sy1=semicolon;
count++;
break;
}
readch();
}
buf[count].sy1=-1;
}
/****************************************************************/
readnu()
{
if(pbuf->sy1>=0)
{
n.sy1=pbuf->sy1;
n.pos=pbuf->pos;
pbuf++;
}
}
/*****************************中间变量的生成*************************/
newtemp()
{
newt++;
return newt;
}
/*********************生成四元式**************************/
gen(char op1[],struct aa arg11,struct aa arg22,int result1)
{
strcpy(fexp[nxq].op,op1);
fexp[nxq].arg1.sy1=arg11.sy1;
fexp[nxq].arg1.pos=arg11.pos;
fexp[nxq].arg2.sy1=arg22.sy1;
fexp[nxq].arg2.pos=arg22.pos;
fexp[nxq].result=result1;
nxq++;
return nxq-1;
}
/*****************布尔表达式的匹配***********************/
merg(int p1,int p2)
{
int p;
if(p2==0) return p1;
else
{
p=p2;
while(fexp[p].result!=0) p=fexp[p].result;
fexp[p].result=p1;
return p2;
}
}
backpatch(int p,int t)
{
int tempq;
int q;
q=p;
while(q!=0)
{
tempq=fexp[q].result;
fexp[q].result=t;
q=tempq;
}
}
/************************************************************/
change1(int chan)
{
switch(chan)
{
case ident:
case intconst:
return 0;
case plus:
return 1;
case times:
return 2;
case lparent:
return 3;
case rparent:
return 4;
case jinghao:
return 5;
case tempsy:
return 6;
}
}
change2(int chan)
{
switch(chan)
{
case ident:
case intconst:
return 0;
case rop:
return 1;
case lparent:
return 2;
case rparent:
return 3;
case op_not:
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