/* User functions for run-time dynamic loading. Copyright (C) 1995-2020 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 /* 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 indeces. */ 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, RTLD_DI_MAX = 10 }; /* 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; #endif /* __USE_GNU */ __END_DECLS #endif /* dlfcn.h */