linux/tools/perf/util/abspath.c
Ingo Molnar 83a0944fa9 perf: Enable more compiler warnings
Related to a shadowed variable bug fix Valdis Kletnieks noticed
that perf does not get built with -Wshadow, which could have
helped us avoid the bug.

So enable -Wshadow and also enable the following warnings on
perf builds, in addition to the already enabled -Wall -Wextra
-std=gnu99 warnings:

 -Wcast-align
 -Wformat=2
 -Wshadow
 -Winit-self
 -Wpacked
 -Wredundant-decls
 -Wstack-protector
 -Wstrict-aliasing=3
 -Wswitch-default
 -Wswitch-enum
 -Wno-system-headers
 -Wundef
 -Wvolatile-register-var
 -Wwrite-strings
 -Wbad-function-cast
 -Wmissing-declarations
 -Wmissing-prototypes
 -Wnested-externs
 -Wold-style-definition
 -Wstrict-prototypes
 -Wdeclaration-after-statement

And change/fix the perf code to build cleanly under GCC 4.3.2.

The list of warnings enablement is rather arbitrary: it's based
on my (quick) reading of the GCC manpages and trying them on
perf.

I categorized the warnings based on individually enabling them
and looking whether they trigger something in the perf build.
If i liked those warnings (i.e. if they trigger for something
that arguably could be improved) i enabled the warning.

If the warnings seemed to come from language laywers spamming
the build with tons of nuisance warnings i generally kept them
off. Most of the sign conversion related warnings were in
this category. (A second patch enabling some of the sign
warnings might be welcome - sign bugs can be nasty.)

I also kept warnings that seem to make sense from their manpage
description and which produced no actual warnings on our code
base. These warnings might still be turned off if they end up
being a nuisance.

I also left out a few warnings that are not supported in older
compilers.

[ Note that these changes might break the build on older
  compilers i did not test, or on non-x86 architectures that
  produce different warnings, so more testing would be welcome. ]

Reported-by: Valdis.Kletnieks@vt.edu
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-16 10:47:47 +02:00

119 lines
2.7 KiB
C

#include "cache.h"
/*
* Do not use this for inspecting *tracked* content. When path is a
* symlink to a directory, we do not want to say it is a directory when
* dealing with tracked content in the working tree.
*/
static int is_directory(const char *path)
{
struct stat st;
return (!stat(path, &st) && S_ISDIR(st.st_mode));
}
/* We allow "recursive" symbolic links. Only within reason, though. */
#define MAXDEPTH 5
const char *make_absolute_path(const char *path)
{
static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
char cwd[1024] = "";
int buf_index = 1, len;
int depth = MAXDEPTH;
char *last_elem = NULL;
struct stat st;
if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
die ("Too long path: %.*s", 60, path);
while (depth--) {
if (!is_directory(buf)) {
char *last_slash = strrchr(buf, '/');
if (last_slash) {
*last_slash = '\0';
last_elem = xstrdup(last_slash + 1);
} else {
last_elem = xstrdup(buf);
*buf = '\0';
}
}
if (*buf) {
if (!*cwd && !getcwd(cwd, sizeof(cwd)))
die ("Could not get current working directory");
if (chdir(buf))
die ("Could not switch to '%s'", buf);
}
if (!getcwd(buf, PATH_MAX))
die ("Could not get current working directory");
if (last_elem) {
len = strlen(buf);
if (len + strlen(last_elem) + 2 > PATH_MAX)
die ("Too long path name: '%s/%s'",
buf, last_elem);
buf[len] = '/';
strcpy(buf + len + 1, last_elem);
free(last_elem);
last_elem = NULL;
}
if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
len = readlink(buf, next_buf, PATH_MAX);
if (len < 0)
die ("Invalid symlink: %s", buf);
if (PATH_MAX <= len)
die("symbolic link too long: %s", buf);
next_buf[len] = '\0';
buf = next_buf;
buf_index = 1 - buf_index;
next_buf = bufs[buf_index];
} else
break;
}
if (*cwd && chdir(cwd))
die ("Could not change back to '%s'", cwd);
return buf;
}
static const char *get_pwd_cwd(void)
{
static char cwd[PATH_MAX + 1];
char *pwd;
struct stat cwd_stat, pwd_stat;
if (getcwd(cwd, PATH_MAX) == NULL)
return NULL;
pwd = getenv("PWD");
if (pwd && strcmp(pwd, cwd)) {
stat(cwd, &cwd_stat);
if (!stat(pwd, &pwd_stat) &&
pwd_stat.st_dev == cwd_stat.st_dev &&
pwd_stat.st_ino == cwd_stat.st_ino) {
strlcpy(cwd, pwd, PATH_MAX);
}
}
return cwd;
}
const char *make_nonrelative_path(const char *path)
{
static char buf[PATH_MAX + 1];
if (is_absolute_path(path)) {
if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
die("Too long path: %.*s", 60, path);
} else {
const char *cwd = get_pwd_cwd();
if (!cwd)
die("Cannot determine the current working directory");
if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
die("Too long path: %.*s", 60, path);
}
return buf;
}