/* User functions for run-time dynamic loading.
Copyright (C) 1995-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _DLFCN_H
#define _DLFCN_H 1
#include <features.h>
#define __need_size_t
#include <stddef.h>
/* Collect various system dependent definitions and declarations. */
#include <bits/dlfcn.h>
#ifdef __USE_GNU
#include <bits/dl_find_object.h>
/* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
the run-time address of the symbol called NAME in the next shared
object is returned. The "next" relation is defined by the order
the shared objects were loaded. */
# define RTLD_NEXT ((void *) -1l)
/* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
the run-time address of the symbol called NAME in the global scope
is returned. */
# define RTLD_DEFAULT ((void *) 0)
/* Type for namespace indices. */
typedef long int Lmid_t;
/* Special namespace ID values. */
# define LM_ID_BASE 0 /* Initial namespace. */
# define LM_ID_NEWLM -1 /* For dlmopen: request new namespace. */
#endif
__BEGIN_DECLS
/* Open the shared object FILE and map it in; return a handle that can be
passed to `dlsym' to get symbol values from it. */
extern void *dlopen (const char *__file, int __mode) __THROWNL;
/* Unmap and close a shared object opened by `dlopen'.
The handle cannot be used again after calling `dlclose'. */
extern int dlclose (void *__handle) __THROWNL __nonnull ((1));
/* Find the run-time address in the shared object HANDLE refers to
of the symbol called NAME. */
extern void *dlsym (void *__restrict __handle,
const char *__restrict __name) __THROW __nonnull ((2));
#ifdef __USE_GNU
/* Like `dlopen', but request object to be allocated in a new namespace. */
extern void *dlmopen (Lmid_t __nsid, const char *__file, int __mode) __THROWNL;
/* Find the run-time address in the shared object HANDLE refers to
of the symbol called NAME with VERSION. */
extern void *dlvsym (void *__restrict __handle,
const char *__restrict __name,
const char *__restrict __version)
__THROW __nonnull ((2, 3));
#endif
/* When any of the above functions fails, call this function
to return a string describing the error. Each call resets
the error string so that a following call returns null. */
extern char *dlerror (void) __THROW;
#ifdef __USE_GNU
/* Structure containing information about object searched using
`dladdr'. */
typedef struct
{
const char *dli_fname; /* File name of defining object. */
void *dli_fbase; /* Load address of that object. */
const char *dli_sname; /* Name of nearest symbol. */
void *dli_saddr; /* Exact value of nearest symbol. */
} Dl_info;
/* Fill in *INFO with the following information about ADDRESS.
Returns 0 iff no shared object's segments contain that address. */
extern int dladdr (const void *__address, Dl_info *__info)
__THROW __nonnull ((2));
/* Same as `dladdr', but additionally sets *EXTRA_INFO according to FLAGS. */
extern int dladdr1 (const void *__address, Dl_info *__info,
void **__extra_info, int __flags) __THROW __nonnull ((2));
/* These are the possible values for the FLAGS argument to `dladdr1'.
This indicates what extra information is stored at *EXTRA_INFO.
It may also be zero, in which case the EXTRA_INFO argument is not used. */
enum
{
/* Matching symbol table entry (const ElfNN_Sym *). */
RTLD_DL_SYMENT = 1,
/* The object containing the address (struct link_map *). */
RTLD_DL_LINKMAP = 2
};
/* Get information about the shared object HANDLE refers to.
REQUEST is from among the values below, and determines the use of ARG.
On success, returns zero. On failure, returns -1 and records an error
message to be fetched with `dlerror'. */
extern int dlinfo (void *__restrict __handle,
int __request, void *__restrict __arg)
__THROW __nonnull ((1, 3));
/* These are the possible values for the REQUEST argument to `dlinfo'. */
enum
{
/* Treat ARG as `lmid_t *'; store namespace ID for HANDLE there. */
RTLD_DI_LMID = 1,
/* Treat ARG as `struct link_map **';
store the `struct link_map *' for HANDLE there. */
RTLD_DI_LINKMAP = 2,
RTLD_DI_CONFIGADDR = 3, /* Unsupported, defined by Solaris. */
/* Treat ARG as `Dl_serinfo *' (see below), and fill in to describe the
directories that will be searched for dependencies of this object.
RTLD_DI_SERINFOSIZE fills in just the `dls_cnt' and `dls_size'
entries to indicate the size of the buffer that must be passed to
RTLD_DI_SERINFO to fill in the full information. */
RTLD_DI_SERINFO = 4,
RTLD_DI_SERINFOSIZE = 5,
/* Treat ARG as `char *', and store there the directory name used to
expand $ORIGIN in this shared object's dependency file names. */
RTLD_DI_ORIGIN = 6,
RTLD_DI_PROFILENAME = 7, /* Unsupported, defined by Solaris. */
RTLD_DI_PROFILEOUT = 8, /* Unsupported, defined by Solaris. */
/* Treat ARG as `size_t *', and store there the TLS module ID
of this object's PT_TLS segment, as used in TLS relocations;
store zero if this object does not define a PT_TLS segment. */
RTLD_DI_TLS_MODID = 9,
/* Treat ARG as `void **', and store there a pointer to the calling
thread's TLS block corresponding to this object's PT_TLS segment.
Store a null pointer if this object does not define a PT_TLS
segment, or if the calling thread has not allocated a block for it. */
RTLD_DI_TLS_DATA = 10,
/* Treat ARG as const ElfW(Phdr) **, and store the address of the
program header array at that location. The dlinfo call returns
the number of program headers in the array. */
RTLD_DI_PHDR = 11,
/* Treat ARG as `const char **' and at that location, store the address
of the directory name used to expand $ORIGIN in this shared object's
dependency file names. */
RTLD_DI_ORIGIN_PATH = 12,
RTLD_DI_MAX = 12
};
/* This is the type of elements in `Dl_serinfo', below.
The `dls_name' member points to space in the buffer passed to `dlinfo'. */
typedef struct
{
char *dls_name; /* Name of library search path directory. */
unsigned int dls_flags; /* Indicates where this directory came from. */
} Dl_serpath;
/* This is the structure that must be passed (by reference) to `dlinfo' for
the RTLD_DI_SERINFO and RTLD_DI_SERINFOSIZE requests. */
typedef struct
{
size_t dls_size; /* Size in bytes of the whole buffer. */
unsigned int dls_cnt; /* Number of elements in `dls_serpath'. */
# if __GNUC_PREREQ (3, 0)
/* The zero-length array avoids an unwanted array subscript check by
the compiler, while the surrounding anonymous union preserves the
historic size of the type. At the time of writing, GNU C does
not support structs with flexible array members in unions. */
__extension__ union
{
Dl_serpath dls_serpath[0]; /* Actually longer, dls_cnt elements. */
Dl_serpath __dls_serpath_pad[1];
};
# else
Dl_serpath dls_serpath[1]; /* Actually longer, dls_cnt elements. */
# endif
} Dl_serinfo;
struct dl_find_object
{
__extension__ unsigned long long int dlfo_flags;
void *dlfo_map_start; /* Beginning of mapping containing address. */
void *dlfo_map_end; /* End of mapping. */
struct link_map *dlfo_link_map;
void *dlfo_eh_frame; /* Exception handling data of the object. */
# if DLFO_STRUCT_HAS_EH_DBASE
void *dlfo_eh_dbase; /* Base address for DW_EH_PE_datarel. */
# if __WORDSIZE == 32
unsigned int __dlfo_eh_dbase_pad;
# endif
# endif
# if DLFO_STRUCT_HAS_EH_COUNT
int dlfo_eh_count; /* Number of exception handling entries. */
unsigned int __dlfo_eh_count_pad;
# endif
__extension__ unsigned long long int __dflo_reserved[7];
};
/* If ADDRESS is found in an object, fill in *RESULT and return 0.
Otherwise, return -1. */
int _dl_find_object (void *__address, struct dl_find_object *__result) __THROW;
#endif /* __USE_GNU */
__END_DECLS
#endif /* dlfcn.h */
