linux/tools/perf/util/exec_cmd.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

168 lines
3.2 KiB
C

#include "cache.h"
#include "exec_cmd.h"
#include "quote.h"
#include <string.h>
#define MAX_ARGS 32
static const char *argv_exec_path;
static const char *argv0_path;
const char *system_path(const char *path)
{
#ifdef RUNTIME_PREFIX
static const char *prefix;
#else
static const char *prefix = PREFIX;
#endif
struct strbuf d = STRBUF_INIT;
if (is_absolute_path(path))
return path;
#ifdef RUNTIME_PREFIX
assert(argv0_path);
assert(is_absolute_path(argv0_path));
if (!prefix &&
!(prefix = strip_path_suffix(argv0_path, PERF_EXEC_PATH)) &&
!(prefix = strip_path_suffix(argv0_path, BINDIR)) &&
!(prefix = strip_path_suffix(argv0_path, "perf"))) {
prefix = PREFIX;
fprintf(stderr, "RUNTIME_PREFIX requested, "
"but prefix computation failed. "
"Using static fallback '%s'.\n", prefix);
}
#endif
strbuf_addf(&d, "%s/%s", prefix, path);
path = strbuf_detach(&d, NULL);
return path;
}
const char *perf_extract_argv0_path(const char *argv0)
{
const char *slash;
if (!argv0 || !*argv0)
return NULL;
slash = argv0 + strlen(argv0);
while (argv0 <= slash && !is_dir_sep(*slash))
slash--;
if (slash >= argv0) {
argv0_path = xstrndup(argv0, slash - argv0);
return slash + 1;
}
return argv0;
}
void perf_set_argv_exec_path(const char *exec_path)
{
argv_exec_path = exec_path;
/*
* Propagate this setting to external programs.
*/
setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
}
/* Returns the highest-priority, location to look for perf programs. */
const char *perf_exec_path(void)
{
const char *env;
if (argv_exec_path)
return argv_exec_path;
env = getenv(EXEC_PATH_ENVIRONMENT);
if (env && *env) {
return env;
}
return system_path(PERF_EXEC_PATH);
}
static void add_path(struct strbuf *out, const char *path)
{
if (path && *path) {
if (is_absolute_path(path))
strbuf_addstr(out, path);
else
strbuf_addstr(out, make_nonrelative_path(path));
strbuf_addch(out, PATH_SEP);
}
}
void setup_path(void)
{
const char *old_path = getenv("PATH");
struct strbuf new_path = STRBUF_INIT;
add_path(&new_path, perf_exec_path());
add_path(&new_path, argv0_path);
if (old_path)
strbuf_addstr(&new_path, old_path);
else
strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
setenv("PATH", new_path.buf, 1);
strbuf_release(&new_path);
}
const char **prepare_perf_cmd(const char **argv)
{
int argc;
const char **nargv;
for (argc = 0; argv[argc]; argc++)
; /* just counting */
nargv = malloc(sizeof(*nargv) * (argc + 2));
nargv[0] = "perf";
for (argc = 0; argv[argc]; argc++)
nargv[argc + 1] = argv[argc];
nargv[argc + 1] = NULL;
return nargv;
}
int execv_perf_cmd(const char **argv) {
const char **nargv = prepare_perf_cmd(argv);
/* execvp() can only ever return if it fails */
execvp("perf", (char **)nargv);
free(nargv);
return -1;
}
int execl_perf_cmd(const char *cmd,...)
{
int argc;
const char *argv[MAX_ARGS + 1];
const char *arg;
va_list param;
va_start(param, cmd);
argv[0] = cmd;
argc = 1;
while (argc < MAX_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_ARGS <= argc)
return error("too many args to run %s", cmd);
argv[argc] = NULL;
return execv_perf_cmd(argv);
}