DPF

DISTRHO Plugin Framework
Log | Files | Refs | Submodules | README | LICENSE

LibraryUtils.hpp (4104B)

      1 /*
      2  * DISTRHO Plugin Framework (DPF)
      3  * Copyright (C) 2012-2021 Filipe Coelho <falktx@falktx.com>
      4  *
      5  * Permission to use, copy, modify, and/or distribute this software for any purpose with
      6  * or without fee is hereby granted, provided that the above copyright notice and this
      7  * permission notice appear in all copies.
      8  *
      9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
     10  * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
     11  * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
     12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
     13  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
     14  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     15  */
     16 
     17 #ifndef DISTRHO_LIBRARY_UTILS_HPP_INCLUDED
     18 #define DISTRHO_LIBRARY_UTILS_HPP_INCLUDED
     19 
     20 #include "../DistrhoUtils.hpp"
     21 
     22 #ifdef DISTRHO_OS_WINDOWS
     23 # ifndef NOMINMAX
     24 #  define NOMINMAX
     25 # endif
     26 # include <winsock2.h>
     27 # include <windows.h>
     28 typedef HMODULE lib_t;
     29 #else
     30 # include <dlfcn.h>
     31 typedef void* lib_t;
     32 #endif
     33 
     34 START_NAMESPACE_DISTRHO
     35 
     36 // -----------------------------------------------------------------------
     37 // library related calls
     38 
     39 /*
     40  * Open 'filename' library (must not be null).
     41  * May return null, in which case "lib_error" has the error.
     42  */
     43 static inline
     44 lib_t lib_open(const char* const filename) noexcept
     45 {
     46     DISTRHO_SAFE_ASSERT_RETURN(filename != nullptr && filename[0] != '\0', nullptr);
     47 
     48     try {
     49 #ifdef DISTRHO_OS_WINDOWS
     50         return ::LoadLibraryA(filename);
     51 #else
     52         return ::dlopen(filename, RTLD_NOW|RTLD_LOCAL);
     53 #endif
     54     } DISTRHO_SAFE_EXCEPTION_RETURN("lib_open", nullptr);
     55 }
     56 
     57 /*
     58  * Close a previously opened library (must not be null).
     59  * If false is returned, "lib_error" has the error.
     60  */
     61 static inline
     62 bool lib_close(const lib_t lib) noexcept
     63 {
     64     DISTRHO_SAFE_ASSERT_RETURN(lib != nullptr, false);
     65 
     66     try {
     67 #ifdef DISTRHO_OS_WINDOWS
     68         return ::FreeLibrary(lib);
     69 #else
     70         return (::dlclose(lib) == 0);
     71 #endif
     72     } DISTRHO_SAFE_EXCEPTION_RETURN("lib_close", false);
     73 }
     74 
     75 /*
     76  * Get a library symbol (must not be null).
     77  * Returns null if the symbol is not found.
     78  */
     79 template<typename Func>
     80 static inline
     81 Func lib_symbol(const lib_t lib, const char* const symbol) noexcept
     82 {
     83     DISTRHO_SAFE_ASSERT_RETURN(lib != nullptr, nullptr);
     84     DISTRHO_SAFE_ASSERT_RETURN(symbol != nullptr && symbol[0] != '\0', nullptr);
     85 
     86     try {
     87 #ifdef DISTRHO_OS_WINDOWS
     88 # if defined(__GNUC__) && (__GNUC__ >= 9)
     89 #  pragma GCC diagnostic push
     90 #  pragma GCC diagnostic ignored "-Wcast-function-type"
     91 # endif
     92         return (Func)::GetProcAddress(lib, symbol);
     93 # if defined(__GNUC__) && (__GNUC__ >= 9)
     94 #  pragma GCC diagnostic pop
     95 # endif
     96 #else
     97         return (Func)(uintptr_t)::dlsym(lib, symbol);
     98 #endif
     99     } DISTRHO_SAFE_EXCEPTION_RETURN("lib_symbol", nullptr);
    100 }
    101 
    102 /*
    103  * Return the last operation error ('filename' must not be null).
    104  * May return null.
    105  */
    106 static inline
    107 const char* lib_error(const char* const filename) noexcept
    108 {
    109     DISTRHO_SAFE_ASSERT_RETURN(filename != nullptr && filename[0] != '\0', nullptr);
    110 
    111 #ifdef DISTRHO_OS_WINDOWS
    112     static char libError[2048+1];
    113     std::memset(libError, 0, sizeof(libError));
    114 
    115     try {
    116         const DWORD winErrorCode  = ::GetLastError();
    117         const int   winErrorFlags = FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS;
    118         LPVOID      winErrorString;
    119 
    120         ::FormatMessage(winErrorFlags, nullptr, winErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR)&winErrorString, 0, nullptr);
    121 
    122         std::snprintf(libError, 2048, "%s: error code %li: %s", filename, winErrorCode, (const char*)winErrorString);
    123         ::LocalFree(winErrorString);
    124     } DISTRHO_SAFE_EXCEPTION("lib_error");
    125 
    126     return (libError[0] != '\0') ? libError : nullptr;
    127 #else
    128     return ::dlerror();
    129 #endif
    130 }
    131 
    132 // -----------------------------------------------------------------------
    133 
    134 END_NAMESPACE_DISTRHO
    135 
    136 #endif // DISTRHO_LIBRARY_UTILS_HPP_INCLUDED