newlib/winsup/cygwin/dlfcn.cc

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/* 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 "winsup.h"
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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include "dlfcn.h"
#include "dll_init.h"
#define _dl_error _reent_winsup()->_dl_error
#define _dl_buffer _reent_winsup()->_dl_buffer
static void __stdcall
set_dl_error (const char *str)
{
__small_sprintf (_dl_buffer, "%s: %E", str);
_dl_error = 1;
}
/* Check for existence of a file specified by the directory
and name components. If successful, return a pointer the
full pathname (static buffer), else return 0. */
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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;
}
/* Look 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. */
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static const char * __stdcall
check_path_access (const char *mywinenv, const char *name)
{
path_conv buf;
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return find_exec (name, buf, mywinenv, TRUE);
}
/* Simulate 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. */
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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? */
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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. */
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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 */
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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. */
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if (isabspath (str))
ret = name;
/* current directory */
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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 */
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if (!ret)
ret = check_path_access ("LD_LIBRARY_PATH=", name);
if (!ret)
{
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 */
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if (!ret && (os_being_run == winNT))
{
/* we assume last dir was xxxxx\SYSTEM32, so we remove 32 */
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len = strlen (buf);
buf[len - 2] = 0;
ret = check_access (buf, name);
}
/* windows directory */
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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 */
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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. */
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if (ret)
{
path_conv real_filename (ret, PC_SYM_FOLLOW | PC_FULL);
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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 (NULL);
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}
else
{
/* handle for the named library */
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const char *fullpath = get_full_path_of_dll (name);
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;
}