newlib/winsup/cygwin/dlfcn.cc

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2000-02-17 20:38:33 +01:00
/* dlfcn.cc
Copyright 1998, 2000 Cygnus Solutions
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "winsup.h"
#include <ctype.h>
#include "dlfcn.h"
#include "dll_init.h"
#ifdef _MT_SAFE
#define _dl_error _reent_winsup()->_dl_error
#define _dl_buffer _reent_winsup()->_dl_buffer
#else
static int _dl_error = 0;
static char _dl_buffer[256];
#endif
static void __stdcall
set_dl_error (const char *str)
{
__small_sprintf (_dl_buffer, "%s: %E", str);
_dl_error = 1;
}
//
// this function checks for existence of a file specified by the
// directory and name components. If successful, return a pointer
// the full pathname (static buffer), or else return 0.
//
static const char * __stdcall
check_access (const char *dir, const char *name)
{
static char buf[MAX_PATH];
const char *ret = 0;
buf[0] = 0;
strcpy (buf, dir);
strcat (buf, "\\");
strcat (buf, name);
if (!access (buf, F_OK))
ret = buf;
return ret;
}
//
// this function looks for an executable file given the name and the
// environment variable to use for searching (eg., PATH); returns
// the full pathname (static buffer) if found or NULL if not.
//
static const char * __stdcall
check_path_access (const char *mywinenv, const char *name)
{
static char buf[MAX_PATH];
return find_exec (name, buf, mywinenv, TRUE);
}
//
// This function simulates the same search as LoadLibary + check
// environment variable LD_LIBRARY_PATH. If found, return the full
// pathname (static buffer); if illegal, return the input string
// unchanged and let the caller deal with it; return NULL otherwise.
//
// Note that this should never be called with a NULL string, since
// that is the introspective case, and the caller should not call
// this function at all.
//
static const char * __stdcall
get_full_path_of_dll (const char* str)
{
int len = (str) ? strlen (str) : 0;
// NULL or empty string or too long to be legal win32 pathname?
if (len == 0 || len >= MAX_PATH - 1)
return str;
char buf[MAX_PATH];
static char name[MAX_PATH];
const char *ret = 0;
strcpy (name, str);
// add extension if necessary, but leave a trailing '.', if any, alone.
// Files with trailing '.'s are handled differently by win32 API.
if (str[len - 1] != '.')
{
// add .dll only if no extension provided. Handle various cases:
//
// ./shlib --> ./shlib.dll
// ./dir/shlib.so --> ./dir/shlib.so
// shlib --> shlib.dll
// shlib.dll --> shlib.dll
// shlib.so --> shlib.so
//
const char *p = strrchr (str, '.');
if (!p || isdirsep (p[1]))
strcat (name, ".dll");
}
// deal with fully qualified filename right away. Do the actual
// conversion to win32 filename just before returning however.
if (isabspath (str))
ret = name;
// current directory
if (!ret)
{
if (GetCurrentDirectory (MAX_PATH, buf) == 0)
small_printf ("WARNING: get_full_path_of_dll can't get current directory win32 %E\n");
else
ret = check_access (buf, name);
}
// LD_LIBRARY_PATH
if (!ret)
ret = check_path_access ("LD_LIBRARY_PATH=", name);
if (!ret)
{
// system directory
if (GetSystemDirectory (buf, MAX_PATH) == 0)
small_printf ("WARNING: get_full_path_of_dll can't get system directory win32 %E\n");
else
ret = check_access (buf, name);
}
// 16 bits system directory
if (!ret && (os_being_run == winNT))
{
// we assume last dir was xxxxx\SYSTEM32, so we remove 32
len = strlen (buf);
buf[len - 2] = 0;
ret = check_access (buf, name);
}
// windows directory
if (!ret)
{
if (GetWindowsDirectory (buf, MAX_PATH) == 0)
small_printf ("WARNING: get_full_path_of_dll can't get Windows directory win32 %E\n");
else
ret = check_access (buf, name);
}
// PATH
if (!ret)
ret = check_path_access ("PATH=", name);
//
// now do a final conversion to win32 pathname. This step is necessary
// to resolve symlinks etc so that win32 API finds the underlying file.
//
if (ret)
{
path_conv real_filename (ret, SYMLINK_FOLLOW, 1);
if (real_filename.error)
ret = 0;
else
{
strcpy (name, real_filename.get_win32 ());
ret = name;
}
}
return ret;
}
void *
dlopen (const char *name, int)
{
SetResourceLock(LOCK_DLL_LIST,READ_LOCK|WRITE_LOCK," dlopen");
void *ret = 0;
if (!name)
{
// handle for the current module
ret = (void *) GetModuleHandle (0);
}
else
{
// handle for the named library
const char *fullpath = get_full_path_of_dll (name);
DllList::the().currentDlOpenedLib (fullpath);
ret = (void *) LoadLibrary (fullpath);
}
if (!ret)
set_dl_error ("dlopen");
debug_printf ("ret %p", ret);
ReleaseResourceLock(LOCK_DLL_LIST,READ_LOCK|WRITE_LOCK," dlopen");
return ret;
}
void *
dlsym (void *handle, const char *name)
{
void *ret = (void *) GetProcAddress ((HMODULE) handle, name);
if (!ret)
set_dl_error ("dlsym");
debug_printf ("ret %p", ret);
return ret;
}
int
dlclose (void *handle)
{
SetResourceLock(LOCK_DLL_LIST,READ_LOCK|WRITE_LOCK," dlclose");
int ret = -1;
if (FreeLibrary ((HMODULE) handle))
ret = 0;
if (ret)
set_dl_error ("dlclose");
ReleaseResourceLock(LOCK_DLL_LIST,READ_LOCK|WRITE_LOCK," dlclose");
return ret;
}
char *
dlerror ()
{
char *ret = 0;
if (_dl_error)
ret = _dl_buffer;
return ret;
}