amxmodx/compiler/libpc300/prefix.c

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2005-07-27 17:28:06 +00:00
/*
* BinReloc - a library for creating relocatable executables
* Written by: Mike Hearn <mike@theoretic.com>
* Hongli Lai <h.lai@chello.nl>
* http://autopackage.org/
*
* This source code is public domain. You can relicense this code
* under whatever license you want.
*
* NOTE: if you're using C++ and are getting "undefined reference
* to br_*", try renaming prefix.c to prefix.cpp
*/
/* WARNING, BEFORE YOU MODIFY PREFIX.C:
*
* If you make changes to any of the functions in prefix.c, you MUST
* change the BR_NAMESPACE macro (in prefix.h).
* This way you can avoid symbol table conflicts with other libraries
* that also happen to use BinReloc.
*
* Example:
* #define BR_NAMESPACE(funcName) foobar_ ## funcName
* --> expands br_locate to foobar_br_locate
*/
#ifndef _PREFIX_C_
#define _PREFIX_C_
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifndef BR_PTHREADS
/* Change 1 to 0 if you don't want pthread support */
#define BR_PTHREADS 1
#endif /* BR_PTHREADS */
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <string.h>
#include "prefix.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
#undef NULL
#define NULL ((void *) 0)
#ifdef __GNUC__
#define br_return_val_if_fail(expr,val) if (!(expr)) {fprintf (stderr, "** BinReloc (%s): assertion %s failed\n", __PRETTY_FUNCTION__, #expr); return val;}
#else
#define br_return_val_if_fail(expr,val) if (!(expr)) return val
#endif /* __GNUC__ */
static br_locate_fallback_func fallback_func = (br_locate_fallback_func) NULL;
static void *fallback_data = NULL;
#ifdef ENABLE_BINRELOC
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <unistd.h>
/**
* br_locate:
* symbol: A symbol that belongs to the app/library you want to locate.
* Returns: A newly allocated string containing the full path of the
* app/library that func belongs to, or NULL on error. This
* string should be freed when not when no longer needed.
*
* Finds out to which application or library symbol belongs, then locate
* the full path of that application or library.
* Note that symbol cannot be a pointer to a function. That will not work.
*
* Example:
* --> main.c
* #include "prefix.h"
* #include "libfoo.h"
*
* int main (int argc, char *argv[]) {
* printf ("Full path of this app: %s\n", br_locate (&argc));
* libfoo_start ();
* return 0;
* }
*
* --> libfoo.c starts here
* #include "prefix.h"
*
* void libfoo_start () {
* --> "" is a symbol that belongs to libfoo (because it's called
* --> from libfoo_start()); that's why this works.
* printf ("libfoo is located in: %s\n", br_locate (""));
* }
*/
char *
br_locate (void *symbol)
{
char line[5000];
FILE *f;
char *path;
br_return_val_if_fail (symbol != NULL, NULL);
f = fopen ("/proc/self/maps", "r");
if (!f) {
if (fallback_func)
return fallback_func(symbol, fallback_data);
else
return NULL;
}
while (!feof (f))
{
unsigned long start, end;
if (!fgets (line, sizeof (line), f))
continue;
if (!strstr (line, " r-xp ") || !strchr (line, '/'))
continue;
sscanf (line, "%lx-%lx ", &start, &end);
if (symbol >= (void *) start && symbol < (void *) end)
{
char *tmp;
size_t len;
/* Extract the filename; it is always an absolute path */
path = strchr (line, '/');
/* Get rid of the newline */
tmp = strrchr (path, '\n');
if (tmp) *tmp = 0;
/* Get rid of "(deleted)" */
len = strlen (path);
if (len > 10 && strcmp (path + len - 10, " (deleted)") == 0)
{
tmp = path + len - 10;
*tmp = 0;
}
fclose(f);
return strdup (path);
}
}
fclose (f);
return NULL;
}
/**
* br_locate_prefix:
* symbol: A symbol that belongs to the app/library you want to locate.
* Returns: A prefix. This string should be freed when no longer needed.
*
* Locates the full path of the app/library that symbol belongs to, and return
* the prefix of that path, or NULL on error.
* Note that symbol cannot be a pointer to a function. That will not work.
*
* Example:
* --> This application is located in /usr/bin/foo
* br_locate_prefix (&argc); --> returns: "/usr"
*/
char *
br_locate_prefix (void *symbol)
{
char *path, *prefix;
br_return_val_if_fail (symbol != NULL, NULL);
path = br_locate (symbol);
if (!path) return NULL;
prefix = br_extract_prefix (path);
free (path);
return prefix;
}
/**
* br_prepend_prefix:
* symbol: A symbol that belongs to the app/library you want to locate.
* path: The path that you want to prepend the prefix to.
* Returns: The new path, or NULL on error. This string should be freed when no
* longer needed.
*
* Gets the prefix of the app/library that symbol belongs to. Prepend that prefix to path.
* Note that symbol cannot be a pointer to a function. That will not work.
*
* Example:
* --> The application is /usr/bin/foo
* br_prepend_prefix (&argc, "/share/foo/data.png"); --> Returns "/usr/share/foo/data.png"
*/
char *
br_prepend_prefix (void *symbol, char *path)
{
char *tmp, *newpath;
br_return_val_if_fail (symbol != NULL, NULL);
br_return_val_if_fail (path != NULL, NULL);
tmp = br_locate_prefix (symbol);
if (!tmp) return NULL;
if (strcmp (tmp, "/") == 0)
newpath = strdup (path);
else
newpath = br_strcat (tmp, path);
/* Get rid of compiler warning ("br_prepend_prefix never used") */
if (0) br_prepend_prefix (NULL, NULL);
free (tmp);
return newpath;
}
#endif /* ENABLE_BINRELOC */
/* Pthread stuff for thread safetiness */
#if BR_PTHREADS && defined(ENABLE_BINRELOC)
#include <pthread.h>
static pthread_key_t br_thread_key;
static pthread_once_t br_thread_key_once = PTHREAD_ONCE_INIT;
static void
br_thread_local_store_fini ()
{
char *specific;
specific = (char *) pthread_getspecific (br_thread_key);
if (specific)
{
free (specific);
pthread_setspecific (br_thread_key, NULL);
}
pthread_key_delete (br_thread_key);
br_thread_key = 0;
}
static void
br_str_free (void *str)
{
if (str)
free (str);
}
static void
br_thread_local_store_init ()
{
if (pthread_key_create (&br_thread_key, br_str_free) == 0)
atexit (br_thread_local_store_fini);
}
#else /* BR_PTHREADS */
#ifdef ENABLE_BINRELOC
static char *br_last_value = (char *) NULL;
static void
br_free_last_value ()
{
if (br_last_value)
free (br_last_value);
}
#endif /* ENABLE_BINRELOC */
#endif /* BR_PTHREADS */
#ifdef ENABLE_BINRELOC
/**
* br_thread_local_store:
* str: A dynamically allocated string.
* Returns: str. This return value must not be freed.
*
* Store str in a thread-local variable and return str. The next
* you run this function, that variable is freed too.
* This function is created so you don't have to worry about freeing
* strings. Just be careful about doing this sort of thing:
*
* some_function( BR_DATADIR("/one.png"), BR_DATADIR("/two.png") )
*
* Examples:
* char *foo;
* foo = br_thread_local_store (strdup ("hello")); --> foo == "hello"
* foo = br_thread_local_store (strdup ("world")); --> foo == "world"; "hello" is now freed.
*/
const char *
br_thread_local_store (char *str)
{
#if BR_PTHREADS
char *specific;
pthread_once (&br_thread_key_once, br_thread_local_store_init);
specific = (char *) pthread_getspecific (br_thread_key);
br_str_free (specific);
pthread_setspecific (br_thread_key, str);
#else /* BR_PTHREADS */
static int initialized = 0;
if (!initialized)
{
atexit (br_free_last_value);
initialized = 1;
}
if (br_last_value)
free (br_last_value);
br_last_value = str;
#endif /* BR_PTHREADS */
return (const char *) str;
}
#endif /* ENABLE_BINRELOC */
/**
* br_strcat:
* str1: A string.
* str2: Another string.
* Returns: A newly-allocated string. This string should be freed when no longer needed.
*
* Concatenate str1 and str2 to a newly allocated string.
*/
char *
br_strcat (const char *str1, const char *str2)
{
char *result;
size_t len1, len2;
if (!str1) str1 = "";
if (!str2) str2 = "";
len1 = strlen (str1);
len2 = strlen (str2);
result = (char *) malloc (len1 + len2 + 1);
memcpy (result, str1, len1);
memcpy (result + len1, str2, len2);
result[len1 + len2] = '\0';
return result;
}
/* Emulates glibc's strndup() */
static char *
br_strndup (char *str, size_t size)
{
char *result = (char *) NULL;
size_t len;
br_return_val_if_fail (str != (char *) NULL, (char *) NULL);
len = strlen (str);
if (!len) return strdup ("");
if (size > len) size = len;
result = (char *) calloc (sizeof (char), len + 1);
memcpy (result, str, size);
return result;
}
/**
* br_extract_dir:
* path: A path.
* Returns: A directory name. This string should be freed when no longer needed.
*
* Extracts the directory component of path. Similar to g_dirname() or the dirname
* commandline application.
*
* Example:
* br_extract_dir ("/usr/local/foobar"); --> Returns: "/usr/local"
*/
char *
br_extract_dir (const char *path)
{
char *end, *result;
br_return_val_if_fail (path != (char *) NULL, (char *) NULL);
end = strrchr (path, '/');
if (!end) return strdup (".");
while (end > path && *end == '/')
end--;
result = br_strndup ((char *) path, end - path + 1);
if (!*result)
{
free (result);
return strdup ("/");
} else
return result;
}
/**
* br_extract_prefix:
* path: The full path of an executable or library.
* Returns: The prefix, or NULL on error. This string should be freed when no longer needed.
*
* Extracts the prefix from path. This function assumes that your executable
* or library is installed in an LSB-compatible directory structure.
*
* Example:
* br_extract_prefix ("/usr/bin/gnome-panel"); --> Returns "/usr"
* br_extract_prefix ("/usr/local/lib/libfoo.so"); --> Returns "/usr/local"
* br_extract_prefix ("/usr/local/libfoo.so"); --> Returns "/usr"
*/
char *
br_extract_prefix (const char *path)
{
char *end, *tmp, *result;
br_return_val_if_fail (path != (char *) NULL, (char *) NULL);
if (!*path) return strdup ("/");
end = strrchr (path, '/');
if (!end) return strdup (path);
tmp = br_strndup ((char *) path, end - path);
if (!*tmp)
{
free (tmp);
return strdup ("/");
}
end = strrchr (tmp, '/');
if (!end) return tmp;
result = br_strndup (tmp, end - tmp);
free (tmp);
if (!*result)
{
free (result);
result = strdup ("/");
}
return result;
}
/**
* br_set_fallback_function:
* func: A function to call to find the binary.
* data: User data to pass to func.
*
* Sets a function to call to find the path to the binary, in
* case "/proc/self/maps" can't be opened. The function set should
* return a string that is safe to free with free().
*/
void
br_set_locate_fallback_func (br_locate_fallback_func func, void *data)
{
fallback_func = func;
fallback_data = data;
}
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _PREFIX_C */