编译原理实验报告(一)-词法分析程序Word下载.doc
《编译原理实验报告(一)-词法分析程序Word下载.doc》由会员分享,可在线阅读,更多相关《编译原理实验报告(一)-词法分析程序Word下载.doc(11页珍藏版)》请在冰点文库上搜索。
![编译原理实验报告(一)-词法分析程序Word下载.doc](https://file1.bingdoc.com/fileroot1/2023-4/29/eeb75ab7-9f30-42f5-adf7-36ada7c2efca/eeb75ab7-9f30-42f5-adf7-36ada7c2efca1.gif)
否
报错
能
判断当前字符是否是文件结束符
是
结束
从源程序中读入一行到数组缓冲区
否
判断当前字符是否是’\n’
是
判断当前字符是否是字母
转关键字和标识符处理
判断当前字符是否是数字
转数字处理
判断当前字符是否是运算符
转运算符处理
【程序调试】
现有源程序a.c清单如下:
#include<
stdio.h>
intmain(intargc,char*argv[])
{charch;
inti;
ch='
a'
;
ch=ch+32;
i=ch;
printf("
%did%c\n"
i,ch);
/*打印*/
return0;
}
运行词法分析程序后,显示如下结果:
after_com.txt文件:
#[p--2]
include[i--0]
<
[p--14]
stdio.h[i--1]
>
[p--16]
int[k--2]
main[i--2]
([p--7]
argc[i--3]
[p--6]
char[k--0]
*[p--9]
argv[i--4]
[[p--18]
][p--21]
)[p--8]
{[p--23]
ch[i--5]
[p--13]
i[i--6]
=[p--15]
'
[p--19]
a[i--7]
+[p--10]
32[c--0]
printf[k--33]
"
[p--1]
%[p--4]
d[i--8]
id[i--9]
c[i--10]
\[p--20]
n[i--11]
return[k--28]
0[c--1]
}[p--25]
key.txt关键字文件:
0char
1short
2int
3unsigned
4long
5float
6double
7struct
8union
9void
10enum
11signed
12const
13volatile
14typedef
15auto
16register
17static
18extem
19break
20case
21continue
22default
23do
24else
25for
26goto
27if
28return
29switch
30while
31sizeof
32txt
33printf
34FILE
35fopen
36NULL
37fclose
38exit
39r
40read
41close
42w
43fprintf
id.txt标识符文件:
0include
1stdio.h
2main
3argc
4argv
5ch
6i
7a
8d
9id
10c
11n
operation.txt运算符文件:
0!
1"
2#
3$
4%
5&
6,
7(
8)
9*
10+
11-
12:
13;
14<
15=
16>
17?
18[
19'
20\
21]
22.
23{
24||
25}
26!
=
27>
28<
29==
30++
31--
32&
&
33/*
34*/
const.txt常量文件:
032
10
结果完全正确。
词法分析程序如下:
#include<
string.h>
stdlib.h>
ctype.h>
#defineSIZE256
#definenull0
intline=0,error=0,mark1=0,mark2=0;
char*sname;
FILE*sfp,*nfp,*ifp,*kfp,*cfp,*pfp;
/*--------------------------------------------------------------------*/
charib[50][20];
charcb[50][10];
charkb[44][10]={"
char"
"
short"
int"
unsigned"
long"
float"
double"
struct"
union"
void"
"
enum"
signed"
const"
volatile"
typedef"
auto"
register"
static"
extem"
break"
case"
continue"
default"
do"
else"
for"
goto"
if"
return"
switch"
while"
sizeof"
txt"
printf"
FILE"
fopen"
NULL"
fclose"
exit"
r"
read"
close"
w"
fprintf"
};
charpb[36][5]={"
!
\"
\#"
\$"
%"
("
)"
*"
+"
-"
:
="
?
["
\\"
]"
."
{"
||"
}"
=="
++"
--"
/*"
*/"
/*----------定义了四个二元数组存放四个表--------------------------------*/
{charsbuff[SIZE];
charnbuff[SIZE];
inti;
/*---------------------------------------------------------------------*/
intnumber(chars[],inti);
intletter(chars[],inti);
intoperation(chars[],inti);
voidseti(chars[]);
voidsetc(chars[]);
voidcfile(chars1[],chars2[],intm);
voiderror2(chars[]);
voiderror1(chars[]);
voiderror3(chars[]);
if(argc!
=2)
{printf("
Pleaseinputthefileyouwanttocompile:
\n"
);
exit
(1);
}
else
sname=argv[1];
sfp=fopen(argv[1],"
openall();
i=0;
while(i<
50)
{strcpy(ib[i],"
"
strcpy(cb[i],"
i++;
}
while(fgets(sbuff,SIZE,sfp))
{
i=0;
line++;
/*以行的方式读取源代码进行编译*/
while(sbuff[i]!
='
\n'
)
{
if(isalpha(sbuff[i]))/*处理关键字和标识符*/
i=letter(sbuff,i);
elseif(isdigit(sbuff[i]))
i=number(sbuff,i);
/*处理数字常量*/
else
i=operation(sbuff,i);
/*处理运算符*/
}
fputc('
nfp);
}
if(error)
printf("
Thereare%derrors."
error);
/*最后错误个数报告*/
else
Successtocompilethefile."
writeall();
closeall();
return0;
}
/*$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$*/
voidopenall()/*打开所有必需的文件*/
{
kfp=fopen("
key.txt"
w+"
/*打开关键字表*/
pfp=fopen("
operation.txt"
/*打开运算符表*/
cfp=fopen("
const.txt"
/*打开常量文件*/
ifp=fopen("
id.txt"
/*打开标识符文件*/
nfp=fopen("
after_com.txt"
/*打开编译后会产生的文件*/
if(kfp==NULL||cfp==NULL||ifp==NULL||pfp==NULL||nfp==NULL)
{printf("
Cannotopenthesefiles"
/*打开文件有错,退出程序*/
exit(0);
/*-----------------------------------------------------------------*/
voidwriteall()
{intm=0;
while(m<
36&
pb[m]!
{
fprintf(pfp,"
%d%s%s\n"
m,"
"
pb[m]);
m++;
}
m=0;
while(m<
44&
kb[m]!
fprintf(kfp,"
kb[m]);
while(m<
mark2&
cb[m]!
{
fprintf(cfp,"
cb[m]);
mark1&
ib[m]!
fprintf(ifp,"
ib[m]);
/*-------------------------------------------------------------------*/
voidcloseall()/*关闭所有文件*/
fclose(kfp);
fclose(pfp);
fclose(cfp);
fclose(ifp);
fclose(nfp);
intletter(charsbuff[],inti)
{charstr[10];
voidcfile(chars1[],chars2[],intm);
voidseti(chars[]);
voidsetc(chars[]);
intm=0,n=0;
str[n]=sbuff[i];
while(isalnum(sbuff[i])||sbuff[i]=='
.'
{str[n++]=sbuff[i++];
str[n]='
\0'
while(m<
(strcmp(str,kb[m])!
=0))
{m++;
}
if(m<
44)
{
cfile(str,"
k"
m);
}
else
{m=0;
while(m<
50&
(strcmp(str,ib[m])!
{m++;
}
if(m<
50)
{
cfile(str,"
i"
}
elseseti(str);
}
returni;
/*-----------------------------------------------------------------------*/
intnumber(charsbuff[],inti)
{chars[2],str[10];
voidcfile(chars1[],chars2[],intm);
voidseti(chars[]);
voidsetc(chars[]);
intm=0,n=0;
str[n]=sbuff[i];
i++;
n++;
if(sbuff[i]=='
{str[n]=sbuff[i];
if((sbuff[i]=='
E'
||sbuff[i]=='
e'
)&
(sbuff[i+1]=='
+'
||sbuff[i+1]=='
-'
||isdigit(sbuff[i+1])))
str[n++]=sbuff[i++];
while(isdigit(sbuff[i]))
{str[n++]=sbuff[i++];
}
/*对可能出现的十进制数的处理*/
str[n++]='
while(m<
(strcmp(str,cb[m])!
if(isalpha(sbuff[i]))
{error2(str);
else
{
{
cfile(str,"
c"
}
elsesetc(str);
/*------------------------------------------------------------------------------*/
intoperation(charsbuff[],inti)
{voiderror3(chars[]);
voidcfile(chars1[],chars2[],intm);
voidsetc(chars[]);
intk=0,m=0;
chars[4];
if(sbuff[i]=='
/'
sbuff[i+1]=='
*'
{i=i+2;
while(!
(sbuff[i]=='
))
{i++;
}
i=i+2;
}/*若为注释则跳过*/
else
{
'
{
whil