acid

src/cmd/acid/lex.c

@@ -0,0 +1,661 @@
+#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
+setacidfile(void)
+{
+	char *name;
+	Lsym *l;
+
+	if(lexio)
+		name = lexio->name;
+	else
+		name = "";
+	l = mkvar("acidfile");
+	l->v->set = 1;
+	l->v->store.fmt = 's';
+	l->v->type = TSTRING;
+	l->v->store.u.string = strnode(name);
+}
+
+void
+pushfile(char *file)
+{
+	Biobuf *b;
+	IOstack *io;
+
+	if(file)
+		b = Bopen(file, OREAD);
+	else{
+		b = Bopen(unsharp("#d/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;
+	setacidfile();
+}
+
+void
+pushfd(int fd)
+{
+	pushfile("/dev/null");
+	close(lexio->fin->fid);
+	free(lexio->name);
+	lexio->name = smprint("<fd#d>", fd);
+	lexio->fin->fid = fd;
+}
+
+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->store.u.string->string);
+	if(io->text == 0)
+		fatal("no memory");
+	io->ip = io->text;
+	io->fin = 0;
+	io->prev = lexio;
+	lexio = io;
+	setacidfile();
+}
+
+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);
+	setacidfile();
+	return 1;
+}
+
+int
+Zfmt(Fmt *f)
+{
+	int i;
+	char buf[1024];
+	IOstack *e;
+
+	e = lexio;
+	if(e) {
+		i = sprint(buf, "%s:%d", e->name, line);
+		while(e->prev) {
+			e = e->prev;
+			if(initialising && e->prev == 0)
+				break;
+			i += sprint(buf+i, " [%s:%d]", e->name, e->line);
+		}
+	} else
+		sprint(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;
+			}
+			buf[n++] = c;
+		}
+		buf[n] = '\0';
+		return strtol(buf, 0, 0);
+	}
+
+	n = cmap[(unsigned char)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 '\n':
+		line++;
+		if(interactive == 0)
+			goto loop;
+		if(stacked) {
+			print("\t");
+			goto loop;
+		}
+		nlcount++;
+		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 == '/') {
+			eatnl();
+			goto loop;
+		}
+		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 = strtoul(symbol+2, 0, 2);
+		else
+			yylval.ival = strtoul(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;
+	ulong 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));
+	s->v = v;
+
+	v->store.fmt = 'X';
+	v->type = TINT;
+	memset(v, 0, sizeof(Value));
+
+	return s;
+}
+
+void
+delsym(Lsym *s)
+{
+	char *q;
+	ulong h;
+	Lsym *p;
+
+	h = 0;
+	for(q = s->name; *q; q++)
+		h = h*3 + *q;
+	h %= Hashsize;
+	
+	if(hash[h] == s)
+		hash[h] = s->hash;
+	else{
+		for(p=hash[h]; p && p->hash != s; p=p->hash)
+			;
+		if(p)
+			p->hash = s->hash;
+	}
+	s->hash = nil;
+}
+
+Lsym*
+look(char *name)
+{
+	Lsym *s;
+	ulong 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;
+}