/*
* PL/0 complier program for win32 platform (implemented in C)
*
* The program has been test on Visual C++ 6.0, Visual C++.NET and
* Visual C++.NET 2003, on Win98, WinNT, Win2000, WinXP and Win2003
*
* 使用方法：
* 运行后输入PL/0源程序文件?
* 回答是否输出虚拟机代码
* 回答是否输出名字表
* fa.tmp输出虚拟机代码
* fa1.tmp输出源文件及其各行对应的首地址
* fa2.tmp输出结?
* fas.tmp输出名字表
*/
#include <stdio.h>
#include "pl0.h"
#include "string.h"
/* 解释执行时使用的栈 */
#define stacksize 500
int main()
{
bool nxtlev[symnum];
printf("Input pl/0 file? ");
scanf("%s", fname); /* 输入文件名 */
fin = fopen(fname, "r");
if (fin)
{
printf("List object code?(Y/N)"); /* 是否输出虚拟机代码 */
scanf("%s", fname);
listswitch = (fname[0] == 'y' || fname[0] == 'Y');
printf("List symbol table?(Y/N)"); /* 是否输出名字表 */
scanf("%s", fname);
tableswitch = (fname[0] == 'y' || fname[0] == 'Y');
fa1 = fopen("fa1.tmp", "w");
fprintf(fa1, "Input pl/0 file? ");
fprintf(fa1, "%s\n", fname);
init(); /* 初始化 */
err = 0;
cc = cx = ll = 0;
ch = ' ';
if (-1 != getsym())
{
fa = fopen("fa.tmp", "w");
fas = fopen("fas.tmp", "w");
addset(nxtlev, declbegsys, statbegsys, symnum);
nxtlev[period] = true;
if (-1 == block(0, 0, nxtlev)) /* 调用编译程序 */
{
fclose(fa);
fclose(fa1);
fclose(fas);
fclose(fin);
printf("\n");
return 0;
}
fclose(fa);
fclose(fa1);
fclose(fas);
if (sym != period)
{
error(9);
}
if (err == 0)
{
fa2 = fopen("fa2.tmp", "w");
interpret(); /* 调用解释执行程序 */
fclose(fa2);
}
else
{
printf("Errors in pl/0 program");
}
}
fclose(fin);
}
else
{
printf("Can't open file!\n");
}
printf("\n");
return 0;
}
/*
* 初始化
*/
void init()
{
int i;
/* 设置单字符符号 */
for (i = 0; i <= 255; i++)
{
ssym[i] = nul;
}
ssym['+'] = plus;
ssym['-'] = minus;
ssym['*'] = times;
ssym['/'] = slash;
ssym['('] = lparen;
ssym[')'] = rparen;
ssym['='] = eql;
ssym[','] = comma;
ssym['.'] = period;
ssym['#'] = neq;
ssym[';'] = semicolon;
/* 设置保留字名字,按照字母顺序，便于折半查找 */
strcpy(&(word[0][0]), "begin");
strcpy(&(word[1][0]), "call");
strcpy(&(word[2][0]), "const");
strcpy(&(word[3][0]), "do");
strcpy(&(word[4][0]), "else");
strcpy(&(word[5][0]), "end");
strcpy(&(word[6][0]), "for");
strcpy(&(word[7][0]), "if");
strcpy(&(word[8][0]), "odd");
strcpy(&(word[9][0]), "procedure");
strcpy(&(word[10][0]), "read");
strcpy(&(word[11][0]), "repeat");
strcpy(&(word[12][0]), "then");
strcpy(&(word[13][0]), "to");
strcpy(&(word[14][0]), "until");
strcpy(&(word[15][0]), "var");
strcpy(&(word[16][0]), "while");
strcpy(&(word[17][0]), "write");
/* 设置保留字符号 */
wsym[0] = beginsym;
wsym[1] = callsym;
wsym[2] = constsym;
wsym[3] = dosym;
wsym[4] = elsesym;
wsym[5] = endsym;
wsym[6] = forsym;
wsym[7] = ifsym;
wsym[8] = oddsym;
wsym[9] = procsym;
wsym[10] = readsym;
wsym[11] = repeatsym;
wsym[12] = thensym;
wsym[13] = tosym;
wsym[14] = untilsym;
wsym[15] = varsym;
wsym[16] = whilesym;
wsym[17] = writesym;
/* 设置指令名称 */
strcpy(&(mnemonic[lit][0]), "lit");
strcpy(&(mnemonic[opr][0]), "opr");
strcpy(&(mnemonic[lod][0]), "lod");
strcpy(&(mnemonic[sto][0]), "sto");
strcpy(&(mnemonic[cal][0]), "cal");
strcpy(&(mnemonic[inte][0]), "int");
strcpy(&(mnemonic[jmp][0]), "jmp");
strcpy(&(mnemonic[jpc][0]), "jpc");
/* 设置符号集 */
for (i = 0; i<symnum; i++)
{
declbegsys[i] = false;
statbegsys[i] = false;
facbegsys[i] = false;
}
/* 设置声明开始符号集 */
declbegsys[constsym] = true;
declbegsys[varsym] = true;
declbegsys[procsym] = true;
/* 设置语句开始符号集 */
statbegsys[beginsym] = true;
statbegsys[callsym] = true;
statbegsys[ifsym] = true;
statbegsys[whilesym] = true;
/* 设置因子开始符号集 */
facbegsys[ident] = true;
facbegsys[number] = true;
facbegsys[lparen] = true;
}
/*
* 用数组实现集合的集合运算
*/
int inset(int e, bool* s)
{
return s[e];
}
int addset(bool* sr, bool* s1, bool* s2, int n)
{
int i;
for (i = 0; i<n; i++)
{
sr[i] = s1[i] || s2[i];
}
return 0;
}
int subset(bool* sr, bool* s1, bool* s2, int n)
{
int i;
for (i = 0; i<n; i++)
{
sr[i] = s1[i] && (!s2[i]);
}
return 0;
}
int mulset(bool* sr, bool* s1, bool* s2, int n)
{
int i;
for (i = 0; i<n; i++)
{
sr[i] = s1[i] && s2[i];
}
return 0;
}
/*
* 出错处理，打印出错位置和错误编码
*/
void error(int n)
{
char space[81];
memset(space, 32, 81);
space[cc - 1] = 0; //出错时当前符号已经读完，所以cc-1
printf("****%s!%d\n", space, n);
fprintf(fa1, "****%s!%d\n", space, n);
err++;
}
/*
* 漏掉空格，读取一个字符。
*
* 每次读一行，存入line缓冲区，line被getsym取空后再读一行
*
* 被函数getsym调用。
*/
int getch()
{
if (cc == ll)
{
if (feof(fin))
{
printf("program incomplete");
return -1;
}
ll = 0;
cc = 0;
printf("%d ", cx);
fprintf(fa1, "%d ", cx);
ch = ' ';
while (ch != 10)
{
//fscanf(fin,"%c", &ch)
//richard
if (EOF == fscanf(fin, "%c", &ch))
{
line[ll] = 0;
break;
}
//end richard
printf("%c", ch);
fprintf(fa1, "%c", ch);
line[ll] = ch;
ll++;
}
printf("\n");
fprintf(fa1, "\n");
}
ch = line[cc];
cc++;
return 0;
}
/*
* 词法分析，获取一个符号
*/
int getsym()
{
int i, j, k;
/* the original version lacks "\r", thanks to foolevery */
while (ch == ' ' || ch == 10 || ch == 13 || ch == 9) /* 忽略空格、换行、回车和TAB */
{
getchdo;
}
if (ch >= 'a' && ch <= 'z')
{ /* 名字或保留字以a..z开头 */
k = 0;
do {
if (k<al)
{
a[k] = ch;
k++;
}
getchdo;
} while (ch >= 'a' && ch <= 'z' || ch >= '0' && ch <= '9');
a[k] = 0;
strcpy(id, a);
i = 0;
j = norw - 1;
do { /* 搜索当前符号是否为保留字 */
k = (i + j) / 2;
if (strcmp(id, word[k]) <= 0)
{
j = k - 1;
}
if (strcmp(id, word[k]) >= 0)
{
i = k + 1;
}
} while (i <= j);
if (i - 1 > j)
{
sym = wsym[k];
}
else
{
sym = ident; /* 搜索失败则，是名字或数字 */
}
}
else
{
if (ch >= '0' && ch <= '9')
{ /* 检测是否为数字：以0..9开头 */
k = 0;
num = 0;
sym = number;
do {
num = 10 * num + ch - '0';
k++;
getchdo;
} while (ch >= '0' && ch <= '9'); /* 获取数字的值 */
k--;
if (k > nmax)
{
error(30);
}
}
else
{
if (ch == ':') /* 检测赋值符号 */
{
getchdo;
if (ch == '=')
{
sym = becomes;
getchdo;
}
else
{
sym = nul; /* 不能识别的符号 */
}
}
else
{
if (ch == '<') /* 检测小于或小于等于符号 */
{
getchdo;
if (ch == '=')
{
sym = leq;
getchdo;
}
else
{
sym = lss;
}
}
else
{
if (ch == '>') /* 检测大于或大于等于符号 */
{
getchdo;
if (ch == '=')
{
sym = geq;
getchdo;
}
else
{
sym = gtr;
}
}
else
{
sym = ssym[ch]; /* 当符号不满足上述条件时，全部按照单字符符号处理 */
//getchdo;
//richard
if (sym != period)
{
getchdo;
}
//end richard
}
}
}
}
}
return 0;
}
/*
* 生成虚拟机代码
*
* x: instruction.f;
* y: instruction.l;
* z: instruction.a;
*/
int gen(enum fct x, int y, int z)
{
if (cx >= cxmax)
{
printf("Program too long"); /* 程序过长 */
return -1;
}
code[cx].f = x;
code[cx].l = y;
code[cx].a = z;
cx++;
return 0;
}
/*
* 测试当前符号是否合�
