edc73c5492
RTLD_DEFAULT/RTLD_NEXT already linked to the functions, but the functions should link to the constants too. Change-Id: I854b632092f077d71918e99b3caec874e1df1ef3
184 lines
7 KiB
C
184 lines
7 KiB
C
/*
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* Copyright (C) 2008 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#pragma once
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#include <stdint.h>
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#include <sys/cdefs.h>
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__BEGIN_DECLS
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/**
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* dladdr() returns information using this structure.
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*/
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typedef struct {
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/** Pathname of the shared object that contains the given address. */
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const char* _Nullable dli_fname;
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/** Address at which the shared object is loaded. */
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void* _Nullable dli_fbase;
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/** Name of the nearest symbol with an address lower than the given address. */
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const char* _Nullable dli_sname;
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/** Exact address of the symbol named in `dli_sname`. */
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void* _Nullable dli_saddr;
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} Dl_info;
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/**
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* [dlopen(3)](http://man7.org/linux/man-pages/man3/dlopen.3.html)
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* loads the given shared library.
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*
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* Returns a pointer to an opaque handle for use with other <dlfcn.h> functions
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* on success, and returns NULL on failure, in which case dlerror() can be used
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* to retrieve the specific error.
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*/
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void* _Nullable dlopen(const char* _Nullable __filename, int __flag);
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/**
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* [dlclose(3)](http://man7.org/linux/man-pages/man3/dlclose.3.html)
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* decrements the reference count for the given shared library (and
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* any libraries brought in by that library's DT_NEEDED entries).
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*
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* If a library's reference count hits zero, it may be unloaded.
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* Code that relies on this is not portable, and may not work on
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* future versions of Android.
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*
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* dlclose() is dangerous because function pointers may or may not
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* be rendered invalid, global data may or may not be rendered invalid,
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* and memory may or may not leak. Code with global constructors is
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* especially problematic. Instead of dlclose, prefer to leave the
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* library open or, if cleanup is necessary, dlopen() the library in
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* a child process which can later be killed by the parent or call
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* exit() itself.
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*
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* Note also that dlclose() interacts badly with thread local variables
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* with non-trivial destructors, with the
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* (exact behavior varying by API level)[https://android.googlesource.com/platform/bionic/+/main/android-changes-for-ndk-developers.md#dlclose-interacts-badly-with-thread-local-variables-with-non_trivial-destructors].
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*
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* Returns 0 on success, and returns -1 on failure, in which case
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* dlerror() can be used to retrieve the specific error.
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*/
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int dlclose(void* _Nonnull __handle);
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/**
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* [dlerror(3)](http://man7.org/linux/man-pages/man3/dlerror.3.html)
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* returns a human-readable error message describing the most recent
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* failure from one of the <dlfcn.h> functions on the calling thread.
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*
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* This function also clears the error, so a second call (or a call
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* before any failure) will return NULL.
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*
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* Returns a pointer to an error on success, and returns NULL if no
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* error is pending.
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*/
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char* _Nullable dlerror(void);
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/**
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* [dlsym(3)](http://man7.org/linux/man-pages/man3/dlsym.3.html)
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* returns a pointer to the symbol with the given name in the shared
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* library represented by the given handle. The handle may have been
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* returned from dlopen(), or can be RTLD_DEFAULT or RTLD_NEXT.
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*
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* Returns the address of the symbol on success, and returns NULL on failure,
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* in which case dlerror() can be used to retrieve the specific error.
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*/
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void* _Nullable dlsym(void* __BIONIC_COMPLICATED_NULLNESS __handle, const char* _Nullable __symbol);
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/**
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* [dlvsym(3)](http://man7.org/linux/man-pages/man3/dlvsym.3.html)
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* returns a pointer to the symbol with the given name and version in the shared
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* library represented by the given handle. The handle may have been
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* returned from dlopen(), or can be RTLD_DEFAULT or RTLD_NEXT.
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*
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* Returns the address of the symbol on success, and returns NULL on failure,
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* in which case dlerror() can be used to retrieve the specific error.
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*/
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void* _Nullable dlvsym(void* __BIONIC_COMPLICATED_NULLNESS __handle, const char* _Nullable __symbol, const char* _Nullable __version) __INTRODUCED_IN(24);
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/**
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* [dladdr(3)](http://man7.org/linux/man-pages/man3/dladdr.3.html)
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* returns information about the symbol at the given address.
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*
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* Returns non-zero on success, and returns 0 on failure. Note that unlike
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* the other <dlfcn.h> functions, in this case dlerror() will _not_ have
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* more information.
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*/
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int dladdr(const void* _Nonnull __addr, Dl_info* _Nonnull __info);
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/**
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* A dlsym()/dlvsym() handle that returns the first symbol found in any
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* shared library using the default search order.
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*/
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#define RTLD_DEFAULT __BIONIC_CAST(reinterpret_cast, void*, 0)
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/**
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* A dlsym()/dlvsym() handle that returns the first symbol found in any
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* shared library that appears _after_ the object containing the caller.
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*/
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#define RTLD_NEXT __BIONIC_CAST(reinterpret_cast, void*, -1L)
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/**
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* A dlopen() flag to not make symbols from this library available to later
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* libraries. See also RTLD_GLOBAL.
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*/
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#define RTLD_LOCAL 0
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/** Not supported on Android; Android always uses RTLD_NOW. */
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#define RTLD_LAZY 0x00001
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/** A dlopen() flag to resolve all undefined symbols before dlopen() returns. */
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#define RTLD_NOW 0x00002
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/**
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* A dlopen() flag to not actually load the given library;
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* used to test whether the library is already loaded.
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*/
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#define RTLD_NOLOAD 0x00004
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/**
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* A dlopen() flag to make symbols from this library available to later
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* libraries. See also RTLD_LOCAL.
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*/
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#define RTLD_GLOBAL 0x00100
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/**
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* A dlopen() flag to ignore later dlclose() calls on this library.
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*/
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#define RTLD_NODELETE 0x01000
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/* LP32 has historical ABI breakage. */
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#if !defined(__LP64__)
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#undef RTLD_DEFAULT
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#define RTLD_DEFAULT __BIONIC_CAST(reinterpret_cast, void*, 0xffffffff)
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#undef RTLD_NEXT
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#define RTLD_NEXT __BIONIC_CAST(reinterpret_cast, void*, 0xfffffffe)
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#undef RTLD_NOW
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#define RTLD_NOW 0x00000
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#undef RTLD_GLOBAL
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#define RTLD_GLOBAL 0x00002
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#endif
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__END_DECLS
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