int main(int argc, char **argv){
if (argc > 1) {
yyin = fopen(argv[1], "r");
}
else{
char FILENAME[30];
printf("Please enter the file name:\n");
scanf("%s",FILENAME);
if( (yyin = fopen(FILENAME,"r")) == NULL){
printf("Can not open the file!\n");
return 1;
}
}
init();
my_yylloc.first_line = 1;
if (yyparse() == 0){
printf("\n\n中间代码\n\n");
listcode();
int i = tx;
printf("\n\n符号表\n\n");
for(;i > 0 ; i--)
printf("%s %d %d\n",table[i].name,table[i].kind,table[i].val);
//interpret();
}
}
int main()
{
long i;
globalinit();
printf("please input source program file name: ");
//scanf("%s",infilename);
printf("\n");
//if((infile=fopen(infilename,"r"))==NULL)
if((infile=fopen("test1.pl0","r"))==NULL)
{
printf("File %s can't be opened.\n", infilename);
exit(1);
}
getsym();
block(declbegsys|statbegsys|period);
if(sym!=period)
{
error(9);
}
fclose(infile);
if(err==0)
{
listcode(0);
interpret();
}
else
{
printf("%3ld errors in PL/0 program\n",err);
}
return (0);
}
void block(unsigned long fsys) {
long tx0; // initial table index
long cx0; // initial code index
long tx1; // save current table index before processing nested procedures
long dx1; // save data allocation index
dx = 3; tx0 = tx; table[tx].addr = cx; gen(jmp, 0, 0);
if (lev > levmax) {
error(32);
}
do {
if (sym == constsym) {
getsym();
do {
constdeclaration();
while (sym == comma) {
getsym(); constdeclaration();
}
if (sym == semicolon) {
getsym();
}
else {
error(5);
}
} while (sym == ident);
}
if (sym == varsym) {
getsym();
do {
vardeclaration();
while (sym == comma) {
getsym(); vardeclaration();
}
if (sym == semicolon) {
getsym();
}
else {
error(5);
}
} while (sym == ident);
}
while (sym == procsym) {
getsym();
if (sym == ident) {
enter(proc); getsym();
}
else {
error(4);
}
if (sym == semicolon) {
getsym();
}
else {
error(5);
}
lev = lev + 1; tx1 = tx; dx1 = dx;
block(fsys | semicolon);
lev = lev - 1; tx = tx1; dx = dx1;
if (sym == semicolon) {
getsym();
//printf("this sym is %d\n",sym);
test(statbegsys | ident | procsym, fsys, 6);
}
else {
error(5);
}
}
test(statbegsys | ident, declbegsys, 7);
} while (sym&declbegsys);
code[table[tx0].addr].a = cx;
table[tx0].addr = cx; // start addr of code
cx0 = cx; gen(Int, 0, dx);
statement(fsys | semicolon | endsym);
gen(opr, 0, 0); // return
test(fsys, 0, 8);
listcode(cx0);
}
