/
reader.c
1691 lines (1471 loc) · 30.4 KB
/
reader.c
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/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Robert Paul Corbett.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)reader.c 5.7 (Berkeley) 1/20/91";
#endif /* not lint */
#include "defs.h"
/* The line size must be a positive integer. One hundred was chosen */
/* because few lines in Yacc input grammars exceed 100 characters. */
/* Note that if a line exceeds LINESIZE characters, the line buffer */
/* will be expanded to accomodate it. */
#define LINESIZE 100
char *cache;
int cinc, cache_size;
int ntags, tagmax;
char **tag_table;
char saw_eof;
char *cptr, *line;
int linesize;
bucket *goal;
int prec;
int gensym;
char last_was_action;
int maxitems;
bucket **pitem;
int maxrules;
bucket **plhs;
int maxmethods;
int name_pool_size;
char *name_pool;
char *line_format = "#line %d \"%s\"\n";
char *default_line_format = "#line default\n";
cachec(c)
int c;
{
assert(cinc >= 0);
if (cinc >= cache_size)
{
cache_size += 256;
cache = REALLOC(cache, cache_size);
if (cache == 0) no_space();
}
cache[cinc] = c;
++cinc;
}
get_line()
{
register FILE *f = input_file;
register int c;
register int i;
if (saw_eof || (c = getc(f)) == EOF)
{
if (line) { FREE(line); line = 0; }
cptr = 0;
saw_eof = 1;
return;
}
if (line == 0 || linesize != (LINESIZE + 1))
{
if (line) FREE(line);
linesize = LINESIZE + 1;
line = MALLOC(linesize);
if (line == 0) no_space();
}
i = 0;
++lineno;
for (;;)
{
line[i] = c;
if (c == '\n') { cptr = line; return; }
if (++i >= linesize)
{
linesize += LINESIZE;
line = REALLOC(line, linesize);
if (line == 0) no_space();
}
c = getc(f);
if (c == EOF)
{
line[i] = '\n';
saw_eof = 1;
cptr = line;
return;
}
}
}
char *
dup_line()
{
register char *p, *s, *t;
if (line == 0) return (0);
s = line;
while (*s != '\n') ++s;
p = MALLOC(s - line + 1);
if (p == 0) no_space();
s = line;
t = p;
while ((*t++ = *s++) != '\n') continue;
return (p);
}
skip_comment()
{
register char *s;
int st_lineno = lineno;
char *st_line = dup_line();
char *st_cptr = st_line + (cptr - line);
s = cptr + 2;
for (;;)
{
if (*s == '*' && s[1] == '/')
{
cptr = s + 2;
FREE(st_line);
return;
}
if (*s == '\n')
{
get_line();
if (line == 0)
unterminated_comment(st_lineno, st_line, st_cptr);
s = cptr;
}
else
++s;
}
}
int
nextc()
{
register char *s;
if (line == 0)
{
get_line();
if (line == 0)
return (EOF);
}
s = cptr;
for (;;)
{
switch (*s)
{
case '\n':
get_line();
if (line == 0) return (EOF);
s = cptr;
break;
case ' ':
case '\t':
case '\f':
case '\r':
case '\v':
case ',':
case ';':
++s;
break;
case '\\':
cptr = s;
return ('%');
case '/':
if (s[1] == '*')
{
cptr = s;
skip_comment();
s = cptr;
break;
}
else if (s[1] == '/')
{
get_line();
if (line == 0) return (EOF);
s = cptr;
break;
}
/* fall through */
default:
cptr = s;
return (*s);
}
}
}
int
keyword()
{
register int c;
char *t_cptr = cptr;
c = *++cptr;
if (isalpha(c))
{
cinc = 0;
for (;;)
{
if (isalpha(c))
{
if (isupper(c)) c = tolower(c);
cachec(c);
}
else if (isdigit(c) || c == '_' || c == '.' || c == '$')
cachec(c);
else
break;
c = *++cptr;
}
cachec(NUL);
if (strcmp(cache, "token") == 0 || strcmp(cache, "term") == 0)
return (TOKEN);
if (strcmp(cache, "type") == 0)
return (TYPE);
if (strcmp(cache, "left") == 0)
return (LEFT);
if (strcmp(cache, "right") == 0)
return (RIGHT);
if (strcmp(cache, "nonassoc") == 0 || strcmp(cache, "binary") == 0)
return (NONASSOC);
if (strcmp(cache, "start") == 0)
return (START);
}
else
{
++cptr;
if (c == '{')
return (TEXT);
if (c == '%' || c == '\\')
return (MARK);
if (c == '<')
return (LEFT);
if (c == '>')
return (RIGHT);
if (c == '0')
return (TOKEN);
if (c == '2')
return (NONASSOC);
}
syntax_error(lineno, line, t_cptr);
/*NOTREACHED*/
}
copy_text(f)
FILE *f;
{
register int c;
int quote;
int need_newline = 0;
int t_lineno = lineno;
char *t_line = dup_line();
char *t_cptr = t_line + (cptr - line - 2);
if (*cptr == '\n')
{
get_line();
if (line == 0)
unterminated_text(t_lineno, t_line, t_cptr);
}
fprintf(f, line_format, lineno, input_file_name);
loop:
c = *cptr++;
switch (c)
{
case '\n':
next_line:
putc('\n', f);
need_newline = 0;
get_line();
if (line) goto loop;
unterminated_text(t_lineno, t_line, t_cptr);
case '\'':
case '"':
{
int s_lineno = lineno;
char *s_line = dup_line();
char *s_cptr = s_line + (cptr - line - 1);
quote = c;
putc(c, f);
for (;;)
{
c = *cptr++;
putc(c, f);
if (c == quote)
{
need_newline = 1;
FREE(s_line);
goto loop;
}
if (c == '\n')
unterminated_string(s_lineno, s_line, s_cptr);
if (c == '\\')
{
c = *cptr++;
putc(c, f);
if (c == '\n')
{
get_line();
if (line == 0)
unterminated_string(s_lineno, s_line, s_cptr);
}
}
}
}
case '/':
putc(c, f);
need_newline = 1;
c = *cptr;
if (c == '/')
{
do putc(c, f); while ((c = *++cptr) != '\n');
goto next_line;
}
if (c == '*')
{
int c_lineno = lineno;
char *c_line = dup_line();
char *c_cptr = c_line + (cptr - line - 1);
putc('*', f);
++cptr;
for (;;)
{
c = *cptr++;
putc(c, f);
if (c == '*' && *cptr == '/')
{
putc('/', f);
++cptr;
FREE(c_line);
goto loop;
}
if (c == '\n')
{
get_line();
if (line == 0)
unterminated_comment(c_lineno, c_line, c_cptr);
}
}
}
need_newline = 1;
goto loop;
case '%':
case '\\':
if (*cptr == '}')
{
if (need_newline) putc('\n', f);
++cptr;
FREE(t_line);
return;
}
/* fall through */
default:
putc(c, f);
need_newline = 1;
goto loop;
}
}
int
hexval(c)
int c;
{
if (c >= '0' && c <= '9')
return (c - '0');
if (c >= 'A' && c <= 'F')
return (c - 'A' + 10);
if (c >= 'a' && c <= 'f')
return (c - 'a' + 10);
return (-1);
}
bucket *
get_literal()
{
register int c, quote;
register int i;
register int n;
register char *s;
register bucket *bp;
int s_lineno = lineno;
char *s_line = dup_line();
char *s_cptr = s_line + (cptr - line);
quote = *cptr++;
cinc = 0;
for (;;)
{
c = *cptr++;
if (c == quote) break;
if (c == '\n') unterminated_string(s_lineno, s_line, s_cptr);
if (c == '\\')
{
char *c_cptr = cptr - 1;
c = *cptr++;
switch (c)
{
case '\n':
get_line();
if (line == 0) unterminated_string(s_lineno, s_line, s_cptr);
continue;
case '0': case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
n = c - '0';
c = *cptr;
if (IS_OCTAL(c))
{
n = (n << 3) + (c - '0');
c = *++cptr;
if (IS_OCTAL(c))
{
n = (n << 3) + (c - '0');
++cptr;
}
}
if (n > MAXCHAR) illegal_character(c_cptr);
c = n;
break;
case 'x':
c = *cptr++;
n = hexval(c);
if (n < 0 || n >= 16)
illegal_character(c_cptr);
for (;;)
{
c = *cptr;
i = hexval(c);
if (i < 0 || i >= 16) break;
++cptr;
n = (n << 4) + i;
if (n > MAXCHAR) illegal_character(c_cptr);
}
c = n;
break;
case 'a': c = 7; break;
case 'b': c = '\b'; break;
case 'f': c = '\f'; break;
case 'n': c = '\n'; break;
case 'r': c = '\r'; break;
case 't': c = '\t'; break;
case 'v': c = '\v'; break;
}
}
cachec(c);
}
FREE(s_line);
n = cinc;
s = MALLOC(n);
if (s == 0) no_space();
for (i = 0; i < n; ++i)
s[i] = cache[i];
cinc = 0;
if (n == 1)
cachec('\'');
else
cachec('"');
for (i = 0; i < n; ++i)
{
c = ((unsigned char *)s)[i];
if (c == '\\' || c == cache[0])
{
cachec('\\');
cachec(c);
}
else if (isprint(c))
cachec(c);
else
{
cachec('\\');
switch (c)
{
case 7: cachec('a'); break;
case '\b': cachec('b'); break;
case '\f': cachec('f'); break;
case '\n': cachec('n'); break;
case '\r': cachec('r'); break;
case '\t': cachec('t'); break;
case '\v': cachec('v'); break;
default:
cachec(((c >> 6) & 7) + '0');
cachec(((c >> 3) & 7) + '0');
cachec((c & 7) + '0');
break;
}
}
}
if (n == 1)
cachec('\'');
else
cachec('"');
cachec(NUL);
bp = lookup(cache);
bp->class = TERM;
if (n == 1 && bp->value == UNDEFINED)
bp->value = *(unsigned char *)s;
FREE(s);
return (bp);
}
int
is_reserved(name)
char *name;
{
char *s;
if (strcmp(name, ".") == 0 ||
strcmp(name, "$accept") == 0 ||
strcmp(name, "$end") == 0)
return (1);
if (name[0] == '$' && name[1] == '$' && isdigit(name[2]))
{
s = name + 3;
while (isdigit(*s)) ++s;
if (*s == NUL) return (1);
}
return (0);
}
bucket *
get_name()
{
register int c;
cinc = 0;
for (c = *cptr; IS_IDENT(c); c = *++cptr)
cachec(c);
cachec(NUL);
if (is_reserved(cache)) used_reserved(cache);
return (lookup(cache));
}
int
get_number()
{
register int c;
register int n;
n = 0;
for (c = *cptr; isdigit(c); c = *++cptr)
n = 10*n + (c - '0');
return (n);
}
char *
get_tag(int emptyOk)
{
register int c;
register int i;
register char *s;
int t_lineno = lineno;
char *t_line = dup_line();
char *t_cptr = t_line + (cptr - line);
++cptr;
c = nextc();
if (c == EOF) unexpected_EOF();
if (emptyOk && c == '>') {
++cptr; return 0; // 0 indicates empty tag if emptyOk
}
if (!isalpha(c) && c != '_' && c != '$')
illegal_tag(t_lineno, t_line, t_cptr);
cinc = 0;
do { cachec(c); c = *++cptr; } while (IS_IDENT(c));
cachec(NUL);
c = nextc();
if (c == EOF) unexpected_EOF();
if (c != '>')
illegal_tag(t_lineno, t_line, t_cptr);
++cptr;
for (i = 0; i < ntags; ++i)
{
if (strcmp(cache, tag_table[i]) == 0)
return (tag_table[i]);
}
if (ntags >= tagmax)
{
tagmax += 16;
tag_table = (char **)
(tag_table ? REALLOC(tag_table, tagmax*sizeof(char *))
: MALLOC(tagmax*sizeof(char *)));
if (tag_table == 0) no_space();
}
s = MALLOC(cinc);
if (s == 0) no_space();
strcpy(s, cache);
tag_table[ntags] = s;
++ntags;
FREE(t_line);
return (s);
}
declare_tokens(assoc)
int assoc;
{
register int c;
register bucket *bp;
int value;
char *tag = 0;
if (assoc != TOKEN) ++prec;
c = nextc();
if (c == EOF) unexpected_EOF();
if (c == '<')
{
tag = get_tag(0);
c = nextc();
if (c == EOF) unexpected_EOF();
}
for (;;)
{
if (isalpha(c) || c == '_' || c == '.' || c == '$')
bp = get_name();
else if (c == '\'' || c == '"')
bp = get_literal();
else
return;
if (bp == goal) tokenized_start(bp->name);
bp->class = TERM;
if (tag)
{
if (bp->tag && tag != bp->tag)
retyped_warning(bp->name);
bp->tag = tag;
}
if (assoc != TOKEN)
{
if (bp->prec && prec != bp->prec)
reprec_warning(bp->name);
bp->assoc = assoc;
bp->prec = prec;
}
c = nextc();
if (c == EOF) unexpected_EOF();
value = UNDEFINED;
if (isdigit(c))
{
value = get_number();
if (bp->value != UNDEFINED && value != bp->value)
revalued_warning(bp->name);
bp->value = value;
c = nextc();
if (c == EOF) unexpected_EOF();
}
}
}
declare_types()
{
register int c;
register bucket *bp;
char *tag;
c = nextc();
if (c == EOF) unexpected_EOF();
if (c != '<') syntax_error(lineno, line, cptr);
tag = get_tag(0);
for (;;)
{
c = nextc();
if (isalpha(c) || c == '_' || c == '.' || c == '$')
bp = get_name();
else if (c == '\'' || c == '"')
bp = get_literal();
else
return;
if (bp->tag && tag != bp->tag)
retyped_warning(bp->name);
bp->tag = tag;
}
}
declare_start()
{
register int c;
register bucket *bp;
c = nextc();
if (c == EOF) unexpected_EOF();
if (!isalpha(c) && c != '_' && c != '.' && c != '$')
syntax_error(lineno, line, cptr);
bp = get_name();
if (bp->class == TERM)
terminal_start(bp->name);
if (goal && goal != bp)
restarted_warning();
goal = bp;
}
read_declarations()
{
register int c, k;
cache_size = 256;
cache = MALLOC(cache_size);
if (cache == 0) no_space();
for (;;)
{
c = nextc();
if (c == EOF) unexpected_EOF();
if (c != '%') syntax_error(lineno, line, cptr);
switch (k = keyword())
{
case MARK:
return;
case TEXT:
copy_text(prolog_file);
break;
case TOKEN:
case LEFT:
case RIGHT:
case NONASSOC:
declare_tokens(k);
break;
case TYPE:
declare_types();
break;
case START:
declare_start();
break;
}
}
}
initialize_grammar()
{
nitems = 4;
maxitems = 300;
pitem = (bucket **) MALLOC(maxitems*sizeof(bucket *));
if (pitem == 0) no_space();
pitem[0] = 0;
pitem[1] = 0;
pitem[2] = 0;
pitem[3] = 0;
nmethods = 0;
nrules = 3;
maxrules = 100;
plhs = (bucket **) MALLOC(maxrules*sizeof(bucket *));
if (plhs == 0) no_space();
plhs[0] = 0;
plhs[1] = 0;
plhs[2] = 0;
rprec = (short *) MALLOC(maxrules*sizeof(short));
if (rprec == 0) no_space();
rprec[0] = 0;
rprec[1] = 0;
rprec[2] = 0;
rassoc = (char *) MALLOC(maxrules*sizeof(char));
if (rassoc == 0) no_space();
rassoc[0] = TOKEN;
rassoc[1] = TOKEN;
rassoc[2] = TOKEN;
}
expand_items()
{
maxitems += 300;
pitem = (bucket **) REALLOC(pitem, maxitems*sizeof(bucket *));
if (pitem == 0) no_space();
memset(pitem+maxitems-300, 0, 300*sizeof(bucket *));
}
expand_rules()
{
maxrules += 100;
plhs = (bucket **) REALLOC(plhs, maxrules*sizeof(bucket *));
if (plhs == 0) no_space();
rprec = (short *) REALLOC(rprec, maxrules*sizeof(short));
if (rprec == 0) no_space();
rassoc = (char *) REALLOC(rassoc, maxrules*sizeof(char));
if (rassoc == 0) no_space();
}
advance_to_start()
{
register int c;
register bucket *bp;
char *s_cptr;
int s_lineno;
for (;;)
{
c = nextc();
if (c != '%') break;
s_cptr = cptr;
switch (keyword())
{
case MARK:
no_grammar();
case TEXT:
copy_text(local_file);
break;
case START:
declare_start();
break;
default:
syntax_error(lineno, line, s_cptr);
}
}
c = nextc();
if (!isalpha(c) && c != '_' && c != '.' && c != '_')
syntax_error(lineno, line, cptr);
bp = get_name();
if (goal == 0)
{
if (bp->class == TERM)
terminal_start(bp->name);
goal = bp;
}
s_lineno = lineno;
c = nextc();
if (c == EOF) unexpected_EOF();
if (c != ':') syntax_error(lineno, line, cptr);
start_rule(bp, s_lineno);
++cptr;
}
start_rule(bp, s_lineno)
register bucket *bp;
int s_lineno;
{
if (bp->class == TERM)
terminal_lhs(s_lineno);
bp->class = NONTERM;
if (nrules >= maxrules)
expand_rules();
plhs[nrules] = bp;
rprec[nrules] = UNDEFINED;
rassoc[nrules] = TOKEN;
}
end_rule()
{
register int i;
if (nitems >= maxitems) expand_items();
if (!last_was_action && plhs[nrules]->tag)
{
for (i = nitems - 1; pitem[i]; --i) continue;
if (pitem[i+1] == 0 || pitem[i+1]->tag != plhs[nrules]->tag)
default_action_warning(); /** if classes don't match exactly **/
} /** bug: could be superclass... **/
last_was_action = 0;
pitem[nitems] = 0;
++nitems;
++nrules;
}
insert_empty_rule()
{
register bucket *bp, **bpp;
assert(cache);
sprintf(cache, "$$%d", ++gensym);
bp = make_bucket(cache);
last_symbol->next = bp;
last_symbol = bp;
bp->tag = plhs[nrules]->tag;
bp->class = NONTERM;
if ((nitems += 2) > maxitems)
expand_items();
bpp = pitem + nitems - 1;
*bpp-- = bp;
while (bpp[0] = bpp[-1]) --bpp;
if (++nrules >= maxrules)
expand_rules();
plhs[nrules] = plhs[nrules-1];
plhs[nrules-1] = bp;
rprec[nrules] = rprec[nrules-1];