freebsd-dev/usr.sbin/config/lang.l
Kyle Evans 4b09be036d config(8): Allow escape-quoted empty strings
For use with things like BOOT_TAG=\"\" -- there are valid reasons to allow
empty strings, especially as these are usually being passed through as
options. The same argument could perhaps be made for the unquoted
variant in things like MODULES_OVERRIDE="", but it's not immediately clear
that this is an issue so I've left it untouched.

MFC after:	3 days
2018-08-20 22:08:03 +00:00

339 lines
7.3 KiB
Plaintext

%{
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
*
* 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. 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.
*
* @(#)lang.l 8.1 (Berkeley) 6/6/93
* $FreeBSD$
*/
#include <assert.h>
#include <ctype.h>
#include <err.h>
#include <stdlib.h>
#include <string.h>
#include "y.tab.h"
#include "config.h"
/*
* Data for returning to previous files from include files.
*/
struct incl {
struct incl *in_prev; /* previous includes in effect, if any */
YY_BUFFER_STATE in_buf; /* previous lex state */
const char *in_fname; /* previous file name */
int in_lineno; /* previous line number */
int in_ateof; /* token to insert at EOF */
};
static struct incl *inclp;
static const char *lastfile;
/*
* Key word table
*/
struct kt {
const char *kt_name;
int kt_val;
} key_words[] = {
{ "config", CONFIG },
{ "cpu", CPU },
{ "nocpu", NOCPU },
{ "device", DEVICE },
{ "devices", DEVICE },
{ "nodevice", NODEVICE },
{ "nodevices", NODEVICE },
{ "env", ENV },
{ "envvar", ENVVAR },
{ "hints", HINTS },
{ "ident", IDENT },
{ "machine", ARCH }, /* MACHINE is defined in /sys/param.h */
{ "makeoption", MAKEOPTIONS },
{ "makeoptions", MAKEOPTIONS },
{ "nomakeoption", NOMAKEOPTION },
{ "nomakeoptions", NOMAKEOPTION },
{ "maxusers", MAXUSERS },
{ "profile", PROFILE },
{ "option", OPTIONS },
{ "options", OPTIONS },
{ "nooption", NOOPTION },
{ "nooptions", NOOPTION },
{ "include", INCLUDE },
{ "files", FILES },
{ 0, 0 },
};
static int endinclude(void);
int include(const char *, int);
int kw_lookup(char *);
unsigned int octal(const char *);
unsigned int hex(const char *);
int yyerror(const char *);
#define YY_DECL int yylex(void)
%}
%option nounput
%option noinput
ID [A-Za-z_][-A-Za-z_0-9]*
PATH [./][-/.%^A-Za-z_0-9]+
%START TOEOL
%START ENVC
%%
<ENVC>[^#\n]* {
BEGIN 0;
yylval.str = strdup(yytext);
return ENVLINE;
}
{ID} {
int i;
BEGIN 0;
if ((i = kw_lookup(yytext)) == -1)
{
yylval.str = strdup(yytext);
return ID;
}
/* We'll glom onto the rest of an envvar line */
if (i == ENVVAR)
BEGIN ENVC;
return i;
}
\\\"[^"]*\\\" {
BEGIN 0;
yytext[yyleng-2] = '"';
yytext[yyleng-1] = '\0';
yylval.str = strdup(yytext + 1);
return ID;
}
\"[^"]+\" {
BEGIN 0;
yytext[yyleng-1] = '\0';
yylval.str = strdup(yytext + 1);
return ID;
}
<TOEOL>[^# \t\n]* {
BEGIN 0;
yylval.str = strdup(yytext);
return ID;
}
0[0-7]* {
yylval.val = octal(yytext);
return NUMBER;
}
0x[0-9a-fA-F]+ {
yylval.val = hex(yytext);
return NUMBER;
}
-?[1-9][0-9]* {
yylval.val = atoi(yytext);
return NUMBER;
}
"?" {
yylval.val = -1;
return NUMBER;
}
\n/[ \t] {
yyline++;
}
\n {
yyline++;
return SEMICOLON;
}
#.* { /* Ignored (comment) */; }
[ \t\f]* { /* Ignored (white space) */; }
";" { return SEMICOLON; }
"," { return COMMA; }
"=" { BEGIN TOEOL; return EQUALS; }
"+=" { BEGIN TOEOL; return PLUSEQUALS; }
<<EOF>> {
int tok;
if (inclp == NULL)
return YY_NULL;
tok = endinclude();
if (tok != 0)
return tok;
/* otherwise continue scanning */
}
{PATH} {
BEGIN 0;
yylval.str = strdup(yytext);
return PATH;
}
. { return yytext[0]; }
%%
/*
* kw_lookup
* Look up a string in the keyword table. Returns a -1 if the
* string is not a keyword otherwise it returns the keyword number
*/
int
kw_lookup(char *word)
{
struct kt *kp;
for (kp = key_words; kp->kt_name != 0; kp++)
if (eq(word, kp->kt_name))
return kp->kt_val;
return -1;
}
/*
* Number conversion routines
*/
unsigned int
octal(const char *str)
{
unsigned int num;
(void) sscanf(str, "%o", &num);
return num;
}
unsigned int
hex(const char *str)
{
unsigned int num;
(void) sscanf(str+2, "%x", &num);
return num;
}
void
cfgfile_add(const char *fname)
{
struct cfgfile *cf;
cf = calloc(1, sizeof(*cf));
if (cf == NULL)
err(EXIT_FAILURE, "calloc");
assert(cf != NULL);
asprintf(&cf->cfg_path, "%s", fname);
STAILQ_INSERT_TAIL(&cfgfiles, cf, cfg_next);
}
void
cfgfile_removeall(void)
{
struct cfgfile *cf;
while (!STAILQ_EMPTY(&cfgfiles)) {
cf = STAILQ_FIRST(&cfgfiles);
STAILQ_REMOVE_HEAD(&cfgfiles, cfg_next);
if (cf->cfg_path != NULL)
free(cf->cfg_path);
free(cf);
}
}
/*
* Open the named file for inclusion at the current point. Returns 0 on
* success (file opened and previous state pushed), nonzero on failure
* (fopen failed, complaint made). The `ateof' parameter controls the
* token to be inserted at the end of the include file. If ateof == 0,
* then nothing is inserted.
*/
int
include(const char *fname, int ateof)
{
FILE *fp;
struct incl *in;
struct includepath* ipath;
char *fnamebuf;
fnamebuf = NULL;
fp = fopen(fname, "r");
if (fp == NULL && fname[0] != '.' && fname[0] != '/') {
asprintf(&fnamebuf, "../../conf/%s", fname);
if (fnamebuf != NULL) {
fp = fopen(fnamebuf, "r");
if (fp == NULL)
free(fnamebuf);
}
}
if (fp == NULL) {
SLIST_FOREACH(ipath, &includepath, path_next) {
asprintf(&fnamebuf, "%s/%s", ipath->path, fname);
if (fnamebuf != NULL) {
fp = fopen(fnamebuf, "r");
}
if (fp != NULL)
break;
free(fnamebuf);
}
}
if (fp == NULL) {
yyerror("cannot open included file");
return (-1);
}
cfgfile_add(fnamebuf == NULL ? fname : fnamebuf);
in = malloc(sizeof(*in));
assert(in != NULL);
in->in_prev = inclp;
in->in_buf = YY_CURRENT_BUFFER;
in->in_fname = yyfile;
in->in_lineno = yyline;
in->in_ateof = ateof;
inclp = in;
yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
yyfile = fname;
yyline = 0;
return (0);
}
/*
* Terminate the most recent inclusion.
*/
static int
endinclude(void)
{
struct incl *in;
int ateof;
in = inclp;
assert(in != NULL);
inclp = in->in_prev;
lastfile = yyfile;
yy_delete_buffer(YY_CURRENT_BUFFER);
(void)fclose(yyin);
yy_switch_to_buffer(in->in_buf);
yyfile = in->in_fname;
yyline = in->in_lineno;
ateof = in->in_ateof;
free(in);
return (ateof);
}