Commit dee81e988674 ("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@xxxxxxxxxxxxx>
---
Changes in v2:
- Remove #include <sys/mman.h>
scripts/basic/fixdep.c | 56 ++++++++++++++++++++++++++++----------------------
1 file changed, 32 insertions(+), 24 deletions(-)
diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index b9b4bbf..91bb4c1 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -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);
}
+ 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(map, st.st_size);
-
- munmap(map, st.st_size);
+ parse_dep_file(buf);
- close(fd);
+ 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;
}
--
2.7.4
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