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/*
* Originally by Linus Torvalds.
* Smart CONFIG_* processing by Werner Almesberger, Michael Chastain.
*
* Usage: mkdep cflags -- file ...
*
* Read source files and output makefile dependency lines for them.
* I make simple dependency lines for #include <*.h> and #include "*.h".
* I also find instances of CONFIG_FOO and generate dependencies
* like include/config/foo.h.
*
* 1 August 1999, Michael Elizabeth Chastain, <mec@shout.net>
* - Keith Owens reported a bug in smart config processing. There used
* to be an optimization for "#define CONFIG_FOO ... #ifdef CONFIG_FOO",
* so that the file would not depend on CONFIG_FOO because the file defines
* this symbol itself. But this optimization is bogus! Consider this code:
* "#if 0 \n #define CONFIG_FOO \n #endif ... #ifdef CONFIG_FOO". Here
* the definition is inactivated, but I still used it. It turns out this
* actually happens a few times in the kernel source. The simple way to
* fix this problem is to remove this particular optimization.
*
* 2.3.99-pre1, Andrew Morton <andrewm@uow.edu.au>
* - Changed so that 'filename.o' depends upon 'filename.[cS]'. This is so that
* missing source files are noticed, rather than silently ignored.
*
* 2.4.2-pre3, Keith Owens <kaos@ocs.com.au>
* - Accept cflags followed by '--' followed by filenames. mkdep extracts -I
* options from cflags and looks in the specified directories as well as the
* defaults. Only -I is supported, no attempt is made to handle -idirafter,
* -isystem, -I- etc.
*/
#include <ctype.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
char __depname[512] = "\n\t@touch ";
#define depname (__depname+9)
int hasdep;
struct path_struct {
int len;
char *buffer;
};
struct path_struct *path_array;
int paths;
/* Current input file */
static const char *g_filename;
/*
* This records all the configuration options seen.
* In perl this would be a hash, but here it's a long string
* of values separated by newlines. This is simple and
* extremely fast.
*/
char * str_config = NULL;
int size_config = 0;
int len_config = 0;
static void
do_depname(void)
{
if (!hasdep) {
hasdep = 1;
printf("%s:", depname);
if (g_filename)
printf(" %s", g_filename);
}
}
/*
* Grow the configuration string to a desired length.
* Usually the first growth is plenty.
*/
void grow_config(int len)
{
while (len_config + len > size_config) {
if (size_config == 0)
size_config = 2048;
str_config = realloc(str_config, size_config *= 2);
if (str_config == NULL)
{ perror("malloc config"); exit(1); }
}
}
/*
* Lookup a value in the configuration string.
*/
int is_defined_config(const char * name, int len)
{
const char * pconfig;
const char * plast = str_config + len_config - len;
for ( pconfig = str_config + 1; pconfig < plast; pconfig++ ) {
if (pconfig[ -1] == '\n'
&& pconfig[len] == '\n'
&& !memcmp(pconfig, name, len))
return 1;
}
return 0;
}
/*
* Add a new value to the configuration string.
*/
void define_config(const char * name, int len)
{
grow_config(len + 1);
memcpy(str_config+len_config, name, len);
len_config += len;
str_config[len_config++] = '\n';
}
/*
* Clear the set of configuration strings.
*/
void clear_config(void)
{
len_config = 0;
define_config("", 0);
}
/*
* This records all the precious .h filenames. No need for a hash,
* it's a long string of values enclosed in tab and newline.
*/
char * str_precious = NULL;
int size_precious = 0;
int len_precious = 0;
/*
* Grow the precious string to a desired length.
* Usually the first growth is plenty.
*/
void grow_precious(int len)
{
while (len_precious + len > size_precious) {
if (size_precious == 0)
size_precious = 2048;
str_precious = realloc(str_precious, size_precious *= 2);
if (str_precious == NULL)
{ perror("malloc"); exit(1); }
}
}
/*
* Add a new value to the precious string.
*/
void define_precious(const char * filename)
{
int len = strlen(filename);
grow_precious(len + 4);
*(str_precious+len_precious++) = '\t';
memcpy(str_precious+len_precious, filename, len);
len_precious += len;
memcpy(str_precious+len_precious, " \\\n", 3);
len_precious += 3;
}
/*
* Handle an #include line.
*/
void handle_include(int start, const char * name, int len)
{
struct path_struct *path;
int i;
if (len == 14 && !memcmp(name, "linux/config.h", len))
return;
if (len >= 7 && !memcmp(name, "config/", 7))
define_config(name+7, len-7-2);
for (i = start, path = path_array+start; i < paths; ++i, ++path) {
memcpy(path->buffer+path->len, name, len);
path->buffer[path->len+len] = '\0';
if (access(path->buffer, F_OK) == 0) {
do_depname();
printf(" \\\n %s", path->buffer);
return;
}
}
}
/*
* Add a path to the list of include paths.
*/
void add_path(const char * name)
{
struct path_struct *path;
char resolved_path[PATH_MAX+1];
const char *name2;
if (strcmp(name, ".")) {
name2 = realpath(name, resolved_path);
if (!name2) {
fprintf(stderr, "realpath(%s) failed, %m\n", name);
exit(1);
}
}
else {
name2 = "";
}
path_array = realloc(path_array, (++paths)*sizeof(*path_array));
if (!path_array) {
fprintf(stderr, "cannot expand path_arry\n");
exit(1);
}
path = path_array+paths-1;
path->len = strlen(name2);
path->buffer = malloc(path->len+1+256+1);
if (!path->buffer) {
fprintf(stderr, "cannot allocate path buffer\n");
exit(1);
}
strcpy(path->buffer, name2);
if (path->len && *(path->buffer+path->len-1) != '/') {
*(path->buffer+path->len) = '/';
*(path->buffer+(++(path->len))) = '\0';
}
}
/*
* Record the use of a CONFIG_* word.
*/
void use_config(const char * name, int len)
{
char *pc;
int i;
pc = path_array[paths-1].buffer + path_array[paths-1].len;
memcpy(pc, "config/", 7);
pc += 7;
for (i = 0; i < len; i++) {
char c = name[i];
if (isupper(c)) c = tolower(c);
if (c == '_') c = '/';
pc[i] = c;
}
pc[len] = '\0';
if (is_defined_config(pc, len))
return;
define_config(pc, len);
do_depname();
printf(" \\\n $(wildcard %s.h)", path_array[paths-1].buffer);
}
/*
* Macros for stunningly fast map-based character access.
* __buf is a register which holds the current word of the input.
* Thus, there is one memory access per sizeof(unsigned long) characters.
*/
#if defined(__alpha__) || defined(__i386__) || defined(__ia64__) || defined(__x86_64__) || defined(__MIPSEL__) \
|| defined(__arm__)
#define LE_MACHINE
#endif
#ifdef LE_MACHINE
#define next_byte(x) (x >>= 8)
#define current ((unsigned char) __buf)
#else
#define next_byte(x) (x <<= 8)
#define current (__buf >> 8*(sizeof(unsigned long)-1))
#endif
#define GETNEXT { \
next_byte(__buf); \
if ((unsigned long) next % sizeof(unsigned long) == 0) { \
if (next >= end) \
break; \
__buf = * (unsigned long *) next; \
} \
next++; \
}
/*
* State machine macros.
*/
#define CASE(c,label) if (current == c) goto label
#define NOTCASE(c,label) if (current != c) goto label
/*
* Yet another state machine speedup.
*/
#define MAX2(a,b) ((a)>(b)?(a):(b))
#define MIN2(a,b) ((a)<(b)?(a):(b))
#define MAX5(a,b,c,d,e) (MAX2(a,MAX2(b,MAX2(c,MAX2(d,e)))))
#define MIN5(a,b,c,d,e) (MIN2(a,MIN2(b,MIN2(c,MIN2(d,e)))))
/*
* The state machine looks for (approximately) these Perl regular expressions:
*
* m|\/\*.*?\*\/|
* m|\/\/.*|
* m|'.*?'|
* m|".*?"|
* m|#\s*include\s*"(.*?)"|
* m|#\s*include\s*<(.*?>"|
* m|#\s*(?define|undef)\s*CONFIG_(\w*)|
* m|(?!\w)CONFIG_|
*
* About 98% of the CPU time is spent here, and most of that is in
* the 'start' paragraph. Because the current characters are
* in a register, the start loop usually eats 4 or 8 characters
* per memory read. The MAX5 and MIN5 tests dispose of most
* input characters with 1 or 2 comparisons.
*/
void state_machine(const char * map, const char * end)
{
const char * next = map;
const char * map_dot;
unsigned long __buf = 0;
for (;;) {
start:
GETNEXT
__start:
if (current > MAX5('/','\'','"','#','C')) goto start;
if (current < MIN5('/','\'','"','#','C')) goto start;
CASE('/', slash);
CASE('\'', squote);
CASE('"', dquote);
CASE('#', pound);
CASE('C', cee);
goto start;
/* // */
slash_slash:
GETNEXT
CASE('\n', start);
NOTCASE('\\', slash_slash);
GETNEXT
goto slash_slash;
/* / */
slash:
GETNEXT
CASE('/', slash_slash);
NOTCASE('*', __start);
slash_star_dot_star:
GETNEXT
__slash_star_dot_star:
NOTCASE('*', slash_star_dot_star);
GETNEXT
NOTCASE('/', __slash_star_dot_star);
goto start;
/* '.*?' */
squote:
GETNEXT
CASE('\'', start);
NOTCASE('\\', squote);
GETNEXT
goto squote;
/* ".*?" */
dquote:
GETNEXT
CASE('"', start);
NOTCASE('\\', dquote);
GETNEXT
goto dquote;
/* #\s* */
pound:
GETNEXT
CASE(' ', pound);
CASE('\t', pound);
CASE('i', pound_i);
CASE('d', pound_d);
CASE('u', pound_u);
goto __start;
/* #\s*i */
pound_i:
GETNEXT NOTCASE('n', __start);
GETNEXT NOTCASE('c', __start);
GETNEXT NOTCASE('l', __start);
GETNEXT NOTCASE('u', __start);
GETNEXT NOTCASE('d', __start);
GETNEXT NOTCASE('e', __start);
goto pound_include;
/* #\s*include\s* */
pound_include:
GETNEXT
CASE(' ', pound_include);
CASE('\t', pound_include);
map_dot = next;
CASE('"', pound_include_dquote);
CASE('<', pound_include_langle);
goto __start;
/* #\s*include\s*"(.*)" */
pound_include_dquote:
GETNEXT
CASE('\n', start);
NOTCASE('"', pound_include_dquote);
handle_include(0, map_dot, next - map_dot - 1);
goto start;
/* #\s*include\s*<(.*)> */
pound_include_langle:
GETNEXT
CASE('\n', start);
NOTCASE('>', pound_include_langle);
handle_include(1, map_dot, next - map_dot - 1);
goto start;
/* #\s*d */
pound_d:
GETNEXT NOTCASE('e', __start);
GETNEXT NOTCASE('f', __start);
GETNEXT NOTCASE('i', __start);
GETNEXT NOTCASE('n', __start);
GETNEXT NOTCASE('e', __start);
goto pound_define_undef;
/* #\s*u */
pound_u:
GETNEXT NOTCASE('n', __start);
GETNEXT NOTCASE('d', __start);
GETNEXT NOTCASE('e', __start);
GETNEXT NOTCASE('f', __start);
goto pound_define_undef;
/*
* #\s*(define|undef)\s*CONFIG_(\w*)
*
* this does not define the word, because it could be inside another
* conditional (#if 0). But I do parse the word so that this instance
* does not count as a use. -- mec
*/
pound_define_undef:
GETNEXT
CASE(' ', pound_define_undef);
CASE('\t', pound_define_undef);
NOTCASE('C', __start);
GETNEXT NOTCASE('O', __start);
GETNEXT NOTCASE('N', __start);
GETNEXT NOTCASE('F', __start);
GETNEXT NOTCASE('I', __start);
GETNEXT NOTCASE('G', __start);
GETNEXT NOTCASE('_', __start);
map_dot = next;
pound_define_undef_CONFIG_word:
GETNEXT
if (isalnum(current) || current == '_')
goto pound_define_undef_CONFIG_word;
goto __start;
/* \<CONFIG_(\w*) */
cee:
if (next >= map+2 && (isalnum(next[-2]) || next[-2] == '_'))
goto start;
GETNEXT NOTCASE('O', __start);
GETNEXT NOTCASE('N', __start);
GETNEXT NOTCASE('F', __start);
GETNEXT NOTCASE('I', __start);
GETNEXT NOTCASE('G', __start);
GETNEXT NOTCASE('_', __start);
map_dot = next;
cee_CONFIG_word:
GETNEXT
if (isalnum(current) || current == '_')
goto cee_CONFIG_word;
use_config(map_dot, next - map_dot - 1);
goto __start;
}
}
/*
* Generate dependencies for one file.
*/
void do_depend(const char * filename, const char * command)
{
int mapsize;
int pagesizem1 = getpagesize()-1;
int fd;
struct stat st;
char * map;
fd = open(filename, O_RDONLY);
if (fd < 0) {
perror(filename);
return;
}
fstat(fd, &st);
if (st.st_size == 0) {
fprintf(stderr,"%s is empty\n",filename);
close(fd);
return;
}
mapsize = st.st_size;
mapsize = (mapsize+pagesizem1) & ~pagesizem1;
map = mmap(NULL, mapsize, PROT_READ, MAP_PRIVATE, fd, 0);
if ((long) map == -1) {
perror("mkdep: mmap");
close(fd);
return;
}
if ((unsigned long) map % sizeof(unsigned long) != 0)
{
fprintf(stderr, "do_depend: map not aligned\n");
exit(1);
}
hasdep = 0;
clear_config();
state_machine(map, map+st.st_size);
if (hasdep) {
puts(command);
if (*command)
define_precious(filename);
}
munmap(map, mapsize);
close(fd);
}
/*
* Generate dependencies for all files.
*/
int main(int argc, char **argv)
{
int len;
const char *hpath;
hpath = getenv("HPATH");
if (!hpath) {
fputs("mkdep: HPATH not set in environment. "
"Don't bypass the top level Makefile.\n", stderr);
return 1;
}
add_path("."); /* for #include "..." */
while (++argv, --argc > 0) {
if (strncmp(*argv, "-I", 2) == 0) {
if (*((*argv)+2)) {
add_path((*argv)+2);
}
else {
++argv;
--argc;
add_path(*argv);
}
}
else if (strcmp(*argv, "--") == 0) {
break;
}
}
add_path(hpath); /* must be last entry, for config files */
while (--argc > 0) {
const char * filename = *++argv;
const char * command = __depname;
g_filename = 0;
len = strlen(filename);
memcpy(depname, filename, len+1);
if (len > 2 && filename[len-2] == '.') {
if (filename[len-1] == 'c' || filename[len-1] == 'S') {
depname[len-1] = 'o';
g_filename = filename;
command = "";
}
}
do_depend(filename, command);
}
if (len_precious) {
*(str_precious+len_precious) = '\0';
printf(".PRECIOUS:%s\n", str_precious);
}
return 0;
}
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