ref: 81c9ede53f6f9ebd67e7134e664c98e08b9fcca6
dir: /sys/src/cmd/acid/lex.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ctype.h>
#include <mach.h>
#define Extern extern
#include "acid.h"
#include "y.tab.h"
struct keywd
{
char *name;
int terminal;
}
keywds[] =
{
"do", Tdo,
"if", Tif,
"then", Tthen,
"else", Telse,
"while", Twhile,
"loop", Tloop,
"head", Thead,
"tail", Ttail,
"append", Tappend,
"defn", Tfn,
"return", Tret,
"local", Tlocal,
"aggr", Tcomplex,
"union", Tcomplex,
"adt", Tcomplex,
"complex", Tcomplex,
"delete", Tdelete,
"whatis", Twhat,
"eval", Teval,
"builtin", Tbuiltin,
0, 0
};
char cmap[256] =
{
['0'] '\0'+1,
['n'] '\n'+1,
['r'] '\r'+1,
['t'] '\t'+1,
['b'] '\b'+1,
['f'] '\f'+1,
['a'] '\a'+1,
['v'] '\v'+1,
['\\'] '\\'+1,
['"'] '"'+1,
};
void
kinit(void)
{
int i;
for(i = 0; keywds[i].name; i++)
enter(keywds[i].name, keywds[i].terminal);
}
typedef struct IOstack IOstack;
struct IOstack
{
char *name;
int line;
char *text;
char *ip;
Biobuf *fin;
IOstack *prev;
};
IOstack *lexio;
void
pushfile(char *file)
{
Biobuf *b;
IOstack *io;
if(file)
b = Bopen(file, OREAD);
else{
b = Bopen("/fd/0", OREAD);
file = "<stdin>";
}
if(b == 0)
error("pushfile: %s: %r", file);
io = malloc(sizeof(IOstack));
if(io == 0)
fatal("no memory");
io->name = strdup(file);
if(io->name == 0)
fatal("no memory");
io->line = line;
line = 1;
io->text = 0;
io->fin = b;
io->prev = lexio;
lexio = io;
}
void
pushstr(Node *s)
{
IOstack *io;
io = malloc(sizeof(IOstack));
if(io == 0)
fatal("no memory");
io->line = line;
line = 1;
io->name = strdup("<string>");
if(io->name == 0)
fatal("no memory");
io->line = line;
line = 1;
io->text = strdup(s->string->string);
if(io->text == 0)
fatal("no memory");
io->ip = io->text;
io->fin = 0;
io->prev = lexio;
lexio = io;
}
void
restartio(void)
{
Bflush(lexio->fin);
Binit(lexio->fin, 0, OREAD);
}
int
popio(void)
{
IOstack *s;
if(lexio == 0)
return 0;
if(lexio->prev == 0){
if(lexio->fin)
restartio();
return 0;
}
if(lexio->fin)
Bterm(lexio->fin);
else
free(lexio->text);
free(lexio->name);
line = lexio->line;
s = lexio;
lexio = s->prev;
free(s);
return 1;
}
int
Lfmt(Fmt *f)
{
int i;
char buf[1024];
IOstack *e;
e = lexio;
if(e) {
i = snprint(buf, sizeof(buf), "%s:%d", e->name, line);
while(e->prev) {
e = e->prev;
if(initialising && e->prev == 0)
break;
i += snprint(buf+i, sizeof(buf)-i, " [%s:%d]", e->name, e->line);
}
} else
snprint(buf, sizeof(buf), "no file:0");
fmtstrcpy(f, buf);
return 0;
}
void
unlexc(int s)
{
if(s == '\n')
line--;
if(lexio->fin)
Bungetc(lexio->fin);
else
lexio->ip--;
}
int
lexc(void)
{
int c;
if(lexio->fin) {
c = Bgetc(lexio->fin);
if(gotint)
error("interrupt");
return c;
}
c = *lexio->ip++;
if(c == 0)
return -1;
return c;
}
int
escchar(char c)
{
int n;
char buf[Strsize];
if(c >= '0' && c <= '9') {
n = 1;
buf[0] = c;
for(;;) {
c = lexc();
if(c == Eof)
error("%d: <eof> in escape sequence", line);
if(strchr("0123456789xX", c) == 0) {
unlexc(c);
break;
}
if(n >= Strsize)
error("string escape too long");
buf[n++] = c;
}
buf[n] = '\0';
return strtol(buf, 0, 0);
}
n = cmap[c];
if(n == 0)
return c;
return n-1;
}
void
eatstring(void)
{
int esc, c, cnt;
char buf[Strsize];
esc = 0;
for(cnt = 0;;) {
c = lexc();
switch(c) {
case Eof:
error("%d: <eof> in string constant", line);
case '\n':
error("newline in string constant");
goto done;
case '\\':
if(esc)
goto Default;
esc = 1;
break;
case '"':
if(esc == 0)
goto done;
/* Fall through */
default:
Default:
if(esc) {
c = escchar(c);
esc = 0;
}
buf[cnt++] = c;
break;
}
if(cnt >= Strsize)
error("string token too long");
}
done:
buf[cnt] = '\0';
yylval.string = strnode(buf);
}
void
eatnl(void)
{
int c;
line++;
for(;;) {
c = lexc();
if(c == Eof)
error("eof in comment");
if(c == '\n')
return;
}
}
int
yylex(void)
{
int c;
extern char vfmt[];
loop:
Bflush(bout);
c = lexc();
switch(c) {
case Eof:
if(gotint) {
gotint = 0;
stacked = 0;
Bprint(bout, "\nacid: ");
goto loop;
}
return Eof;
case '"':
eatstring();
return Tstring;
case ' ':
case '\t':
goto loop;
case '/':
c = lexc();
if(c != '/'){
unlexc(c);
return '/';
}
eatnl();
case '\n':
line++;
if(interactive == 0)
goto loop;
if(stacked) {
print("\t");
goto loop;
}
return ';';
case '.':
c = lexc();
unlexc(c);
if(isdigit(c))
return numsym('.');
return '.';
case '(':
case ')':
case '[':
case ']':
case ';':
case ':':
case ',':
case '~':
case '?':
case '*':
case '@':
case '^':
case '%':
return c;
case '{':
stacked++;
return c;
case '}':
stacked--;
return c;
case '\\':
c = lexc();
if(strchr(vfmt, c) == 0) {
unlexc(c);
return '\\';
}
yylval.ival = c;
return Tfmt;
case '!':
c = lexc();
if(c == '=')
return Tneq;
unlexc(c);
return '!';
case '+':
c = lexc();
if(c == '+')
return Tinc;
unlexc(c);
return '+';
case '\'':
c = lexc();
if(c == '\\')
yylval.ival = escchar(lexc());
else
yylval.ival = c;
c = lexc();
if(c != '\'') {
error("missing '");
unlexc(c);
}
return Tconst;
case '&':
c = lexc();
if(c == '&')
return Tandand;
unlexc(c);
return '&';
case '=':
c = lexc();
if(c == '=')
return Teq;
unlexc(c);
return '=';
case '|':
c = lexc();
if(c == '|')
return Toror;
unlexc(c);
return '|';
case '<':
c = lexc();
if(c == '=')
return Tleq;
if(c == '<')
return Tlsh;
unlexc(c);
return '<';
case '>':
c = lexc();
if(c == '=')
return Tgeq;
if(c == '>')
return Trsh;
unlexc(c);
return '>';
case '-':
c = lexc();
if(c == '>')
return Tindir;
if(c == '-')
return Tdec;
unlexc(c);
return '-';
default:
return numsym(c);
}
}
int
numsym(char first)
{
int c, isbin, isfloat, ishex;
char *sel, *p;
Lsym *s;
symbol[0] = first;
p = symbol;
ishex = 0;
isbin = 0;
isfloat = 0;
if(first == '.')
isfloat = 1;
if(isdigit(*p++) || isfloat) {
for(;;) {
c = lexc();
if(c < 0)
error("%d: <eof> eating symbols", line);
if(c == '\n')
line++;
sel = "01234567890.xb";
if(ishex)
sel = "01234567890abcdefABCDEF";
else if(isbin)
sel = "01";
else if(isfloat)
sel = "01234567890eE-+";
if(strchr(sel, c) == 0) {
unlexc(c);
break;
}
if(c == '.')
isfloat = 1;
if(!isbin && c == 'x')
ishex = 1;
if(!ishex && c == 'b')
isbin = 1;
*p++ = c;
}
*p = '\0';
if(isfloat) {
yylval.fval = atof(symbol);
return Tfconst;
}
if(isbin)
yylval.ival = strtoull(symbol+2, 0, 2);
else
yylval.ival = strtoull(symbol, 0, 0);
return Tconst;
}
for(;;) {
c = lexc();
if(c < 0)
error("%d <eof> eating symbols", line);
if(c == '\n')
line++;
if(c != '_' && c != '$' && c <= '~' && !isalnum(c)) { /* checking against ~ lets UTF names through */
unlexc(c);
break;
}
*p++ = c;
}
*p = '\0';
s = look(symbol);
if(s == 0)
s = enter(symbol, Tid);
yylval.sym = s;
return s->lexval;
}
Lsym*
enter(char *name, int t)
{
Lsym *s;
uint h;
char *p;
Value *v;
h = 0;
for(p = name; *p; p++)
h = h*3 + *p;
h %= Hashsize;
s = gmalloc(sizeof(Lsym));
memset(s, 0, sizeof(Lsym));
s->name = strdup(name);
s->hash = hash[h];
hash[h] = s;
s->lexval = t;
v = gmalloc(sizeof(Value));
memset(v, 0, sizeof(Value));
v->fmt = 'X';
v->type = TINT;
s->v = v;
return s;
}
Lsym*
look(char *name)
{
Lsym *s;
uint h;
char *p;
h = 0;
for(p = name; *p; p++)
h = h*3 + *p;
h %= Hashsize;
for(s = hash[h]; s; s = s->hash)
if(strcmp(name, s->name) == 0)
return s;
return 0;
}
Lsym*
mkvar(char *s)
{
Lsym *l;
l = look(s);
if(l == 0)
l = enter(s, Tid);
return l;
}