ceph/src/boost/libs/dll/include/boost/dll/detail/posix/path_from_handle.hpp

   1 // Copyright 2014-2015 Renato Tegon Forti, Antony Polukhin.
   2 //
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See accompanying file LICENSE_1_0.txt
   5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_DLL_DETAIL_POSIX_PATH_FROM_HANDLE_HPP
   8 #define BOOST_DLL_DETAIL_POSIX_PATH_FROM_HANDLE_HPP
   9
  10 #include <boost/config.hpp>
  11 #include <boost/dll/detail/system_error.hpp>
  12 #include <boost/dll/detail/posix/program_location_impl.hpp>
  13 #include <boost/filesystem/path.hpp>
  14 #include <boost/predef/os.h>
  15
  16 #ifdef BOOST_HAS_PRAGMA_ONCE
  17 # pragma once
  18 #endif
  19
  20 #if BOOST_OS_MACOS || BOOST_OS_IOS
  21
  22 #   include <mach-o/dyld.h>
  23 #   include <mach-o/nlist.h>
  24 #   include <cstddef> // for std::ptrdiff_t
  25
  26 namespace boost { namespace dll { namespace detail {
  27     inline void* strip_handle(void* handle) BOOST_NOEXCEPT {
  28         return reinterpret_cast<void*>(
  29             (reinterpret_cast<std::ptrdiff_t>(handle) >> 2) << 2
  30         );
  31     }
  32
  33     inline boost::filesystem::path path_from_handle(void* handle, boost::system::error_code &ec) {
  34         handle = strip_handle(handle);
  35
  36         // Iterate through all images currently in memory
  37         // https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man3/dyld.3.html
  38         const std::size_t count = _dyld_image_count(); // not thread safe: other thread my [un]load images
  39         for (std::size_t i = 0; i <= count; ++i) {
  40             // on last iteration `i` is equal to `count` which is out of range, so `_dyld_get_image_name`
  41             // will return NULL. `dlopen(NULL, RTLD_LAZY)` call will open the current executable.
  42             const char* image_name = _dyld_get_image_name(i);
  43
  44             // dlopen/dlclose must not affect `_dyld_image_count()`, because libraries are already loaded and only the internal counter is affected
  45             void* probe_handle = dlopen(image_name, RTLD_LAZY);
  46             dlclose(probe_handle);
  47
  48             // If the handle is the same as what was passed in (modulo mode bits), return this image name
  49             if (handle == strip_handle(probe_handle)) {
  50                 boost::dll::detail::reset_dlerror();
  51                 return image_name;
  52             }
  53         }
  54
  55         boost::dll::detail::reset_dlerror();
  56         ec = boost::system::error_code(
  57             boost::system::errc::bad_file_descriptor,
  58             boost::system::generic_category()
  59         );
  60
  61         return boost::filesystem::path();
  62     }
  63
  64 }}} // namespace boost::dll::detail
  65
  66 #elif BOOST_OS_ANDROID
  67
  68 #include <boost/dll/runtime_symbol_info.hpp>
  69
  70 namespace boost { namespace dll { namespace detail {
  71
  72     struct soinfo {
  73         // if defined(__work_around_b_24465209__), then an array of char[128] goes here.
  74         // Unfortunately, __work_around_b_24465209__ is visible only during compilation of Android's linker
  75         const void* phdr;
  76         size_t      phnum;
  77         void*       entry;
  78         void*       base;
  79         // ...          // Ignoring remaning parts of the structure
  80     };
  81
  82     inline boost::filesystem::path path_from_handle(const void* handle, boost::system::error_code &ec) {
  83         static const std::size_t work_around_b_24465209__offset = 128;
  84         const struct soinfo* si = reinterpret_cast<const struct soinfo*>(
  85             static_cast<const char*>(handle) + work_around_b_24465209__offset
  86         );
  87         boost::filesystem::path ret = boost::dll::detail::symbol_location_impl(si->base, ec);
  88
  89         if (ec) {
  90             ec.clear();
  91             si = static_cast<const struct soinfo*>(handle);
  92             return boost::dll::detail::symbol_location_impl(si->base, ec);
  93         }
  94
  95         return ret;
  96     }
  97
  98 }}} // namespace boost::dll::detail
  99
 100 #else // #if BOOST_OS_MACOS || BOOST_OS_IOS || BOOST_OS_ANDROID
 101
 102 // for dlinfo
 103 #include <dlfcn.h>
 104
 105 #if BOOST_OS_QNX
 106 // QNX's copy of <elf.h> and <link.h> reside in sys folder
 107 #   include <sys/link.h>
 108 #else
 109 #   include <link.h>    // struct link_map
 110 #endif
 111
 112 namespace boost { namespace dll { namespace detail {
 113
 114 #if BOOST_OS_QNX
 115     // Android and QNX miss struct link_map. QNX misses ElfW macro, so avoiding it.
 116     struct link_map {
 117         void *l_addr;   // Base address shared object is loaded at
 118         char *l_name;   // Absolute file name object was found in
 119         // ...          // Ignoring remaning parts of the structure
 120     };
 121 #endif // #if BOOST_OS_QNX
 122
 123     inline boost::filesystem::path path_from_handle(void* handle, boost::system::error_code &ec) {
 124         // RTLD_DI_LINKMAP (RTLD_DI_ORIGIN returns only folder and is not suitable for this case)
 125         // Obtain the Link_map for the handle  that  is  specified.
 126         // The  p  argument  points to a Link_map pointer (Link_map
 127         // **p). The actual storage for the Link_map  structure  is
 128         // maintained by ld.so.1.
 129         //
 130         // Unfortunately we can not use `dlinfo(handle, RTLD_DI_LINKMAP, &link_map) < 0`
 131         // because it is not supported on MacOS X 10.3, NetBSD 3.0, OpenBSD 3.8, AIX 5.1,
 132         // HP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin, mingw, Interix 3.5, BeOS.
 133         // Fortunately investigating the sources of open source projects brought the understanding, that
 134         // `handle` is just a `struct link_map*` that contains full library name.
 135
 136         const struct link_map* link_map = 0;
 137 #if BOOST_OS_BSD_FREE
 138         // FreeBSD has it's own logic http://code.metager.de/source/xref/freebsd/libexec/rtld-elf/rtld.c
 139         // Fortunately it has the dlinfo call.
 140         if (dlinfo(handle, RTLD_DI_LINKMAP, &link_map) < 0) {
 141             link_map = 0;
 142         }
 143 #else
 144         link_map = static_cast<const struct link_map*>(handle);
 145 #endif
 146         if (!link_map) {
 147             boost::dll::detail::reset_dlerror();
 148             ec = boost::system::error_code(
 149                 boost::system::errc::bad_file_descriptor,
 150                 boost::system::generic_category()
 151             );
 152
 153             return boost::filesystem::path();
 154         }
 155
 156         if (!link_map->l_name || *link_map->l_name == '\0') {
 157             return program_location_impl(ec);
 158         }
 159
 160         return boost::filesystem::path(link_map->l_name);
 161     }
 162
 163 }}} // namespace boost::dll::detail
 164
 165 #endif // #if BOOST_OS_MACOS || BOOST_OS_IOS
 166
 167 #endif // BOOST_DLL_DETAIL_POSIX_PATH_FROM_HANDLE_HPP
 168
 169