merge changes from the defunct ubot

ext/crlib/cr-library.h

@@ -0,0 +1,130 @@
+//
+// CRLib - Simple library for STL replacement in private projects.
+// Copyright © 2020 YaPB Development Team <team@yapb.ru>.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program 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 General Public License for more details.
+// 
+
+#pragma once
+
+#include <crlib/cr-basic.h>
+#include <crlib/cr-string.h>
+
+#if defined (CR_LINUX) || defined (CR_OSX)
+#  include <dlfcn.h>
+#  include <errno.h>
+#  include <fcntl.h>
+#  include <sys/stat.h>
+#  include <unistd.h>
+#endif
+
+CR_NAMESPACE_BEGIN
+
+// handling dynamic library loading
+class SharedLibrary final : public DenyCopying {
+public:
+   using Handle = void *;
+
+private:
+   Handle handle_ = nullptr;
+
+public:
+   explicit SharedLibrary () = default;
+
+   SharedLibrary (StringRef file) {
+      if (file.empty ()) {
+         return;
+      }
+      load (file);
+   }
+
+   ~SharedLibrary () {
+      unload ();
+   }
+
+public:
+   bool load (StringRef file) noexcept {
+      if (*this) {
+         unload ();
+      }
+
+#if defined (CR_WINDOWS)
+      handle_ = LoadLibraryA (file.chars ());
+#else
+      handle_ = dlopen (file.chars (), RTLD_LAZY);
+#endif
+      return handle_ != nullptr;
+   }
+
+   bool locate (Handle address) {
+#if defined (CR_WINDOWS)
+      MEMORY_BASIC_INFORMATION mbi;
+
+      if (!VirtualQuery (address, &mbi, sizeof (mbi))) {
+         return false;
+      }
+
+      if (mbi.State != MEM_COMMIT) {
+         return false;
+      }
+      handle_ = reinterpret_cast <Handle> (mbi.AllocationBase);
+#else
+      Dl_info dli;
+      plat.bzero (&dli, sizeof (dli));
+
+      if (dladdr (address, &dli)) {
+         return load (dli.dli_fname);
+      }
+#endif
+      return handle_ != nullptr;
+   }
+
+   void unload () noexcept {
+      if (!*this) {
+         return;
+      }
+#if defined (CR_WINDOWS)
+      FreeLibrary (static_cast <HMODULE> (handle_));
+#else
+      dlclose (handle_);
+#endif
+      handle_ = nullptr;
+   }
+
+   template <typename R> R resolve (const char *function) const {
+      if (!*this) {
+         return nullptr;
+      }
+      return SharedLibrary::getSymbol <R> (handle (), function);
+   }
+
+   Handle handle () const {
+      return handle_;
+   }
+
+public:
+   explicit operator bool () const {
+      return handle_ != nullptr;
+   }
+
+public:
+  template <typename R> static inline  R CR_STDCALL getSymbol (Handle module, const char *function) {
+      return reinterpret_cast <R> (
+#if defined (CR_WINDOWS)
+         GetProcAddress (static_cast <HMODULE> (module), function)
+#else
+         dlsym (module, function)
+#endif
+         );
+   }
+};
+
+CR_NAMESPACE_END