630 lines
14 KiB
C
630 lines
14 KiB
C
/* Token-reader for Bison's input parser,
|
|
Copyright (C) 1984, 1986, 1989, 1992 Free Software Foundation, Inc.
|
|
|
|
This file is part of Bison, the GNU Compiler Compiler.
|
|
|
|
Bison is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
Bison is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with Bison; see the file COPYING. If not, write to
|
|
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
|
|
/*
|
|
lex is the entry point. It is called from reader.c.
|
|
It returns one of the token-type codes defined in lex.h.
|
|
When an identifier is seen, the code IDENTIFIER is returned
|
|
and the name is looked up in the symbol table using symtab.c;
|
|
symval is set to a pointer to the entry found. */
|
|
|
|
#include <stdio.h>
|
|
#include "system.h"
|
|
#include "files.h"
|
|
#include "getopt.h" /* for optarg */
|
|
#include "symtab.h"
|
|
#include "lex.h"
|
|
#include "alloc.h"
|
|
|
|
/* flags set by % directives */
|
|
extern int definesflag; /* for -d */
|
|
extern int toknumflag; /* for -k */
|
|
extern int noparserflag; /* for -n */
|
|
extern int fixed_outfiles; /* for -y */
|
|
extern int nolinesflag; /* for -l */
|
|
extern int rawtoknumflag; /* for -r */
|
|
extern int verboseflag; /* for -v */
|
|
extern int debugflag; /* for -t */
|
|
extern char *spec_name_prefix; /* for -p */
|
|
extern char *spec_file_prefix; /* for -b */
|
|
/*spec_outfile is declared in files.h, for -o */
|
|
|
|
extern int lineno;
|
|
extern int translations;
|
|
|
|
void init_lex PARAMS((void));
|
|
char *grow_token_buffer PARAMS((char *));
|
|
int skip_white_space PARAMS((void));
|
|
int safegetc PARAMS((FILE *));
|
|
int literalchar PARAMS((char **, int *, char));
|
|
void unlex PARAMS((int));
|
|
int lex PARAMS((void));
|
|
int parse_percent_token PARAMS((void));
|
|
|
|
/* functions from main.c */
|
|
extern char *printable_version PARAMS((int));
|
|
extern void fatal PARAMS((char *));
|
|
extern void warn PARAMS((char *));
|
|
extern void warni PARAMS((char *, int));
|
|
extern void warns PARAMS((char *, char *));
|
|
|
|
/* Buffer for storing the current token. */
|
|
char *token_buffer;
|
|
|
|
/* Allocated size of token_buffer, not including space for terminator. */
|
|
int maxtoken;
|
|
|
|
bucket *symval;
|
|
int numval;
|
|
|
|
static int unlexed; /* these two describe a token to be reread */
|
|
static bucket *unlexed_symval; /* by the next call to lex */
|
|
|
|
|
|
void
|
|
init_lex (void)
|
|
{
|
|
maxtoken = 100;
|
|
token_buffer = NEW2 (maxtoken + 1, char);
|
|
unlexed = -1;
|
|
}
|
|
|
|
|
|
char *
|
|
grow_token_buffer (char *p)
|
|
{
|
|
int offset = p - token_buffer;
|
|
maxtoken *= 2;
|
|
token_buffer = (char *) xrealloc(token_buffer, maxtoken + 1);
|
|
return token_buffer + offset;
|
|
}
|
|
|
|
|
|
int
|
|
skip_white_space (void)
|
|
{
|
|
register int c;
|
|
register int inside;
|
|
|
|
c = getc(finput);
|
|
|
|
for (;;)
|
|
{
|
|
int cplus_comment;
|
|
|
|
switch (c)
|
|
{
|
|
case '/':
|
|
c = getc(finput);
|
|
if (c != '*' && c != '/')
|
|
{
|
|
warn(_("unexpected `/' found and ignored"));
|
|
break;
|
|
}
|
|
cplus_comment = (c == '/');
|
|
|
|
c = getc(finput);
|
|
|
|
inside = 1;
|
|
while (inside)
|
|
{
|
|
if (!cplus_comment && c == '*')
|
|
{
|
|
while (c == '*')
|
|
c = getc(finput);
|
|
|
|
if (c == '/')
|
|
{
|
|
inside = 0;
|
|
c = getc(finput);
|
|
}
|
|
}
|
|
else if (c == '\n')
|
|
{
|
|
lineno++;
|
|
if (cplus_comment)
|
|
inside = 0;
|
|
c = getc(finput);
|
|
}
|
|
else if (c == EOF)
|
|
fatal(_("unterminated comment"));
|
|
else
|
|
c = getc(finput);
|
|
}
|
|
|
|
break;
|
|
|
|
case '\n':
|
|
lineno++;
|
|
|
|
case ' ':
|
|
case '\t':
|
|
case '\f':
|
|
c = getc(finput);
|
|
break;
|
|
|
|
default:
|
|
return (c);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* do a getc, but give error message if EOF encountered */
|
|
int
|
|
safegetc (FILE *f)
|
|
{
|
|
register int c = getc(f);
|
|
if (c == EOF)
|
|
fatal(_("Unexpected end of file"));
|
|
return c;
|
|
}
|
|
|
|
/* read one literal character from finput. process \ escapes.
|
|
append the normalized string version of the char to *pp.
|
|
assign the character code to *pcode
|
|
return 1 unless the character is an unescaped `term' or \n
|
|
report error for \n
|
|
*/
|
|
int
|
|
literalchar (char **pp, int *pcode, char term)
|
|
{
|
|
register int c;
|
|
register char *p;
|
|
register int code;
|
|
int wasquote = 0;
|
|
|
|
c = safegetc(finput);
|
|
if (c == '\n')
|
|
{
|
|
warn(_("unescaped newline in constant"));
|
|
ungetc(c, finput);
|
|
code = '?';
|
|
wasquote = 1;
|
|
}
|
|
else if (c != '\\')
|
|
{
|
|
code = c;
|
|
if (c == term)
|
|
wasquote = 1;
|
|
}
|
|
else
|
|
{
|
|
c = safegetc(finput);
|
|
if (c == 't') code = '\t';
|
|
else if (c == 'n') code = '\n';
|
|
else if (c == 'a') code = '\007';
|
|
else if (c == 'r') code = '\r';
|
|
else if (c == 'f') code = '\f';
|
|
else if (c == 'b') code = '\b';
|
|
else if (c == 'v') code = '\013';
|
|
else if (c == '\\') code = '\\';
|
|
else if (c == '\'') code = '\'';
|
|
else if (c == '\"') code = '\"';
|
|
else if (c <= '7' && c >= '0')
|
|
{
|
|
code = 0;
|
|
while (c <= '7' && c >= '0')
|
|
{
|
|
code = (code * 8) + (c - '0');
|
|
if (code >= 256 || code < 0)
|
|
{
|
|
warni(_("octal value outside range 0...255: `\\%o'"), code);
|
|
code &= 0xFF;
|
|
break;
|
|
}
|
|
c = safegetc(finput);
|
|
}
|
|
ungetc(c, finput);
|
|
}
|
|
else if (c == 'x')
|
|
{
|
|
c = safegetc(finput);
|
|
code = 0;
|
|
while (1)
|
|
{
|
|
if (c >= '0' && c <= '9')
|
|
code *= 16, code += c - '0';
|
|
else if (c >= 'a' && c <= 'f')
|
|
code *= 16, code += c - 'a' + 10;
|
|
else if (c >= 'A' && c <= 'F')
|
|
code *= 16, code += c - 'A' + 10;
|
|
else
|
|
break;
|
|
if (code >= 256 || code<0)
|
|
{
|
|
warni(_("hexadecimal value above 255: `\\x%x'"), code);
|
|
code &= 0xFF;
|
|
break;
|
|
}
|
|
c = safegetc(finput);
|
|
}
|
|
ungetc(c, finput);
|
|
}
|
|
else
|
|
{
|
|
warns (_("unknown escape sequence: `\\' followed by `%s'"),
|
|
printable_version(c));
|
|
code = '?';
|
|
}
|
|
} /* has \ */
|
|
|
|
/* now fill token_buffer with the canonical name for this character
|
|
as a literal token. Do not use what the user typed,
|
|
so that `\012' and `\n' can be interchangeable. */
|
|
|
|
p = *pp;
|
|
if (code == term && wasquote)
|
|
*p++ = code;
|
|
else if (code == '\\') {*p++ = '\\'; *p++ = '\\';}
|
|
else if (code == '\'') {*p++ = '\\'; *p++ = '\'';}
|
|
else if (code == '\"') {*p++ = '\\'; *p++ = '\"';}
|
|
else if (code >= 040 && code < 0177)
|
|
*p++ = code;
|
|
else if (code == '\t') {*p++ = '\\'; *p++ = 't';}
|
|
else if (code == '\n') {*p++ = '\\'; *p++ = 'n';}
|
|
else if (code == '\r') {*p++ = '\\'; *p++ = 'r';}
|
|
else if (code == '\v') {*p++ = '\\'; *p++ = 'v';}
|
|
else if (code == '\b') {*p++ = '\\'; *p++ = 'b';}
|
|
else if (code == '\f') {*p++ = '\\'; *p++ = 'f';}
|
|
else
|
|
{
|
|
*p++ = '\\';
|
|
*p++ = code / 0100 + '0';
|
|
*p++ = ((code / 010) & 07) + '0';
|
|
*p++ = (code & 07) + '0';
|
|
}
|
|
*pp = p;
|
|
*pcode = code;
|
|
return ! wasquote;
|
|
}
|
|
|
|
|
|
void
|
|
unlex (int token)
|
|
{
|
|
unlexed = token;
|
|
unlexed_symval = symval;
|
|
}
|
|
|
|
|
|
int
|
|
lex (void)
|
|
{
|
|
register int c;
|
|
char *p;
|
|
|
|
if (unlexed >= 0)
|
|
{
|
|
symval = unlexed_symval;
|
|
c = unlexed;
|
|
unlexed = -1;
|
|
return (c);
|
|
}
|
|
|
|
c = skip_white_space();
|
|
*token_buffer = c; /* for error messages (token buffer always valid) */
|
|
token_buffer[1] = 0;
|
|
|
|
switch (c)
|
|
{
|
|
case EOF:
|
|
strcpy(token_buffer, "EOF");
|
|
return (ENDFILE);
|
|
|
|
case 'A': case 'B': case 'C': case 'D': case 'E':
|
|
case 'F': case 'G': case 'H': case 'I': case 'J':
|
|
case 'K': case 'L': case 'M': case 'N': case 'O':
|
|
case 'P': case 'Q': case 'R': case 'S': case 'T':
|
|
case 'U': case 'V': case 'W': case 'X': case 'Y':
|
|
case 'Z':
|
|
case 'a': case 'b': case 'c': case 'd': case 'e':
|
|
case 'f': case 'g': case 'h': case 'i': case 'j':
|
|
case 'k': case 'l': case 'm': case 'n': case 'o':
|
|
case 'p': case 'q': case 'r': case 's': case 't':
|
|
case 'u': case 'v': case 'w': case 'x': case 'y':
|
|
case 'z':
|
|
case '.': case '_':
|
|
p = token_buffer;
|
|
while (isalnum(c) || c == '_' || c == '.')
|
|
{
|
|
if (p == token_buffer + maxtoken)
|
|
p = grow_token_buffer(p);
|
|
|
|
*p++ = c;
|
|
c = getc(finput);
|
|
}
|
|
|
|
*p = 0;
|
|
ungetc(c, finput);
|
|
symval = getsym(token_buffer);
|
|
return (IDENTIFIER);
|
|
|
|
case '0': case '1': case '2': case '3': case '4':
|
|
case '5': case '6': case '7': case '8': case '9':
|
|
{
|
|
numval = 0;
|
|
|
|
p = token_buffer;
|
|
while (isdigit(c))
|
|
{
|
|
if (p == token_buffer + maxtoken)
|
|
p = grow_token_buffer(p);
|
|
|
|
*p++ = c;
|
|
numval = numval*10 + c - '0';
|
|
c = getc(finput);
|
|
}
|
|
*p = 0;
|
|
ungetc(c, finput);
|
|
return (NUMBER);
|
|
}
|
|
|
|
case '\'':
|
|
|
|
/* parse the literal token and compute character code in code */
|
|
|
|
translations = -1;
|
|
{
|
|
int code, discode;
|
|
char discard[10], *dp;
|
|
|
|
p = token_buffer;
|
|
*p++ = '\'';
|
|
literalchar(&p, &code, '\'');
|
|
|
|
c = getc(finput);
|
|
if (c != '\'')
|
|
{
|
|
warn(_("use \"...\" for multi-character literal tokens"));
|
|
while (1)
|
|
{
|
|
dp = discard;
|
|
if (! literalchar(&dp, &discode, '\''))
|
|
break;
|
|
}
|
|
}
|
|
*p++ = '\'';
|
|
*p = 0;
|
|
symval = getsym(token_buffer);
|
|
symval->class = STOKEN;
|
|
if (! symval->user_token_number)
|
|
symval->user_token_number = code;
|
|
return (IDENTIFIER);
|
|
}
|
|
|
|
case '\"':
|
|
|
|
/* parse the literal string token and treat as an identifier */
|
|
|
|
translations = -1;
|
|
{
|
|
int code; /* ignored here */
|
|
p = token_buffer;
|
|
*p++ = '\"';
|
|
while (literalchar(&p, &code, '\"')) /* read up to and including " */
|
|
{
|
|
if (p >= token_buffer + maxtoken - 4)
|
|
p = grow_token_buffer(p);
|
|
}
|
|
*p = 0;
|
|
|
|
symval = getsym(token_buffer);
|
|
symval->class = STOKEN;
|
|
|
|
return (IDENTIFIER);
|
|
}
|
|
|
|
case ',':
|
|
return (COMMA);
|
|
|
|
case ':':
|
|
return (COLON);
|
|
|
|
case ';':
|
|
return (SEMICOLON);
|
|
|
|
case '|':
|
|
return (BAR);
|
|
|
|
case '{':
|
|
return (LEFT_CURLY);
|
|
|
|
case '=':
|
|
do
|
|
{
|
|
c = getc(finput);
|
|
if (c == '\n') lineno++;
|
|
}
|
|
while(c==' ' || c=='\n' || c=='\t');
|
|
|
|
if (c == '{')
|
|
{
|
|
strcpy(token_buffer, "={");
|
|
return(LEFT_CURLY);
|
|
}
|
|
else
|
|
{
|
|
ungetc(c, finput);
|
|
return(ILLEGAL);
|
|
}
|
|
|
|
case '<':
|
|
p = token_buffer;
|
|
c = getc(finput);
|
|
while (c != '>')
|
|
{
|
|
if (c == EOF)
|
|
fatal(_("unterminated type name at end of file"));
|
|
if (c == '\n')
|
|
{
|
|
warn(_("unterminated type name"));
|
|
ungetc(c, finput);
|
|
break;
|
|
}
|
|
|
|
if (p == token_buffer + maxtoken)
|
|
p = grow_token_buffer(p);
|
|
|
|
*p++ = c;
|
|
c = getc(finput);
|
|
}
|
|
*p = 0;
|
|
return (TYPENAME);
|
|
|
|
|
|
case '%':
|
|
return (parse_percent_token());
|
|
|
|
default:
|
|
return (ILLEGAL);
|
|
}
|
|
}
|
|
|
|
/* the following table dictates the action taken for the various
|
|
% directives. A setflag value causes the named flag to be
|
|
set. A retval action returns the code.
|
|
*/
|
|
struct percent_table_struct {
|
|
char *name;
|
|
void *setflag;
|
|
int retval;
|
|
} percent_table[] =
|
|
{
|
|
{"token", NULL, TOKEN},
|
|
{"term", NULL, TOKEN},
|
|
{"nterm", NULL, NTERM},
|
|
{"type", NULL, TYPE},
|
|
{"guard", NULL, GUARD},
|
|
{"union", NULL, UNION},
|
|
{"expect", NULL, EXPECT},
|
|
{"thong", NULL, THONG},
|
|
{"start", NULL, START},
|
|
{"left", NULL, LEFT},
|
|
{"right", NULL, RIGHT},
|
|
{"nonassoc", NULL, NONASSOC},
|
|
{"binary", NULL, NONASSOC},
|
|
{"semantic_parser", NULL, SEMANTIC_PARSER},
|
|
{"pure_parser", NULL, PURE_PARSER},
|
|
{"prec", NULL, PREC},
|
|
|
|
{"no_lines", &nolinesflag, NOOP}, /* -l */
|
|
{"raw", &rawtoknumflag, NOOP}, /* -r */
|
|
{"token_table", &toknumflag, NOOP}, /* -k */
|
|
|
|
#if 0
|
|
/* These can be utilized after main is reoganized so
|
|
open_files() is deferred 'til after read_declarations().
|
|
But %{ and %union both put information into files
|
|
that have to be opened before read_declarations().
|
|
*/
|
|
{"yacc", &fixed_outfiles, NOOP}, /* -y */
|
|
{"fixed_output_files", &fixed_outfiles, NOOP}, /* -y */
|
|
{"defines", &definesflag, NOOP}, /* -d */
|
|
{"no_parser", &noparserflag, NOOP}, /* -n */
|
|
{"output_file", &spec_outfile, SETOPT}, /* -o */
|
|
{"file_prefix", &spec_file_prefix, SETOPT}, /* -b */
|
|
{"name_prefix", &spec_name_prefix, SETOPT}, /* -p */
|
|
|
|
/* These would be acceptable, but they do not affect processing */
|
|
{"verbose", &verboseflag, NOOP}, /* -v */
|
|
{"debug", &debugflag, NOOP}, /* -t */
|
|
/* {"help", <print usage stmt>, NOOP},*/ /* -h */
|
|
/* {"version", <print version number> , NOOP},*/ /* -V */
|
|
#endif
|
|
|
|
{NULL, NULL, ILLEGAL}
|
|
};
|
|
|
|
/* Parse a token which starts with %.
|
|
Assumes the % has already been read and discarded. */
|
|
|
|
int
|
|
parse_percent_token (void)
|
|
{
|
|
register int c;
|
|
register char *p;
|
|
register struct percent_table_struct *tx;
|
|
|
|
p = token_buffer;
|
|
c = getc(finput);
|
|
*p++ = '%';
|
|
*p++ = c; /* for error msg */
|
|
*p = 0;
|
|
|
|
switch (c)
|
|
{
|
|
case '%':
|
|
return (TWO_PERCENTS);
|
|
|
|
case '{':
|
|
return (PERCENT_LEFT_CURLY);
|
|
|
|
case '<':
|
|
return (LEFT);
|
|
|
|
case '>':
|
|
return (RIGHT);
|
|
|
|
case '2':
|
|
return (NONASSOC);
|
|
|
|
case '0':
|
|
return (TOKEN);
|
|
|
|
case '=':
|
|
return (PREC);
|
|
}
|
|
if (!isalpha(c))
|
|
return (ILLEGAL);
|
|
|
|
p = token_buffer;
|
|
*p++ = '%';
|
|
while (isalpha(c) || c == '_' || c == '-')
|
|
{
|
|
if (p == token_buffer + maxtoken)
|
|
p = grow_token_buffer(p);
|
|
|
|
if (c == '-') c = '_';
|
|
*p++ = c;
|
|
c = getc(finput);
|
|
}
|
|
|
|
ungetc(c, finput);
|
|
|
|
*p = 0;
|
|
|
|
/* table lookup % directive */
|
|
for (tx = percent_table; tx->name; tx++)
|
|
if (strcmp(token_buffer+1, tx->name) == 0)
|
|
break;
|
|
if (tx->retval == SETOPT)
|
|
{
|
|
*((char **)(tx->setflag)) = optarg;
|
|
return NOOP;
|
|
}
|
|
if (tx->setflag)
|
|
{
|
|
*((int *)(tx->setflag)) = 1;
|
|
return NOOP;
|
|
}
|
|
return tx->retval;
|
|
}
|