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fixdep: use malloc() and read() to load dep_file to buffer 

Commit dee81e9886 ("fixdep: faster CONFIG_ search") changed how to
read files in which CONFIG options are searched.  It used malloc()
and read() instead of mmap() because it needed to zero-terminate the
buffer in order to use strstr().  print_deps() was left untouched
since there was no reason to change it.

Now, I have two motivations to change it in the same way.

 - do_config_file() and print_deps() do quite similar things; they
   open a file, load it onto memory, and pass it to a parser function.
   If we use malloc() and read() for print_deps() too, we can factor
   out the common code.  (I will do this in the next commit.)

 - parse_dep_file() copies each token to a temporary buffer because
   it needs to zero-terminate it to be passed to printf().  It is not
   possible to modify the buffer directly because it is mmap'ed with
   O_RDONLY.  If we load the file content into a malloc'ed buffer, we
   can insert '\0' after each token, and save memcpy().  (I will do
   this in the commit after next.)

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
hifive-unleashed-5.1
Masahiro Yamada 2018-01-11 22:05:41 +09:00
parent 41f92cffba
commit 01b5cbe701
1 changed files with 33 additions and 25 deletions
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58
scripts/basic/fixdep.c
View File

@ -104,7 +104,6 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
@ -308,24 +307,27 @@ static void do_config_file(const char *filename)
* assignments are parsed not only by make, but also by the rather simple
* parser in scripts/mod/sumversion.c.
*/
static void parse_dep_file(void *map, size_t len)
static void parse_dep_file(char *m)
{
char *m = map;
char *end = m + len;
char *p;
char s[PATH_MAX];
int is_target;
int is_last, is_target;
int saw_any_target = 0;
int is_first_dep = 0;
while (m < end) {
while (1) {
/* Skip any "white space" */
while (m < end && (*m == ' ' || *m == '\\' || *m == '\n'))
while (*m == ' ' || *m == '\\' || *m == '\n')
m++;
if (!*m)
break;
/* Find next "white space" */
p = m;
while (p < end && *p != ' ' && *p != '\\' && *p != '\n')
while (*p && *p != ' ' && *p != '\\' && *p != '\n')
p++;
is_last = (*p == '\0');
/* Is the token we found a target name? */
is_target = (*(p-1) == ':');
/* Don't write any target names into the dependency file */
@ -373,6 +375,10 @@ static void parse_dep_file(void *map, size_t len)
do_config_file(s);
}
}
if (is_last)
break;
/*
* Start searching for next token immediately after the first
* "whitespace" character that follows this token.
@ -391,40 +397,42 @@ static void parse_dep_file(void *map, size_t len)
printf("$(deps_%s):\n", target);
}
static void print_deps(void)
static void print_deps(const char *filename)
{
struct stat st;
int fd;
void *map;
char *buf;
fd = open(depfile, O_RDONLY);
fd = open(filename, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "fixdep: error opening depfile: ");
perror(depfile);
perror(filename);
exit(2);
}
if (fstat(fd, &st) < 0) {
fprintf(stderr, "fixdep: error fstat'ing depfile: ");
perror(depfile);
perror(filename);
exit(2);
}
if (st.st_size == 0) {
fprintf(stderr,"fixdep: %s is empty\n",depfile);
close(fd);
return;
}
map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
if ((long) map == -1) {
perror("fixdep: mmap");
close(fd);
return;
buf = malloc(st.st_size + 1);
if (!buf) {
perror("fixdep: malloc");
exit(2);
}
parse_dep_file(map, st.st_size);
munmap(map, st.st_size);
if (read(fd, buf, st.st_size) != st.st_size) {
perror("fixdep: read");
exit(2);
}
buf[st.st_size] = '\0';
close(fd);
parse_dep_file(buf);
free(buf);
}
int main(int argc, char *argv[])
@ -440,7 +448,7 @@ int main(int argc, char *argv[])
cmdline = argv[3];
print_cmdline();
print_deps();
print_deps(depfile);
return 0;
}