testing new non-autotools build system

[chaz/yoink] / src / stlplus / portability / dynaload.cpp

diff --git a/src/stlplus/portability/dynaload.cpp b/src/stlplus/portability/dynaload.cpp
new file mode 100644 (file)
index 0000000..cdd1848
--- /dev/null
+++ b/src/stlplus/portability/dynaload.cpp
@@ -0,0 +1,184 @@
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+//   Author:    Andy Rushton\r
+//   Copyright: (c) Southampton University 1999-2004\r
+//              (c) Andy Rushton           2004-2009\r
+//   License:   BSD License, see ../docs/license.html\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+#include "dynaload.hpp"\r
+\r
+#ifdef MSWINDOWS\r
+#include <windows.h>\r
+#else\r
+#include <dlfcn.h>\r
+#endif\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+#ifdef MSWINDOWS\r
+\r
+static std::string last_error(void)\r
+{\r
+  // get the last error code - if none, return the empty string\r
+  DWORD err = GetLastError();\r
+  if (err == 0) return std::string();\r
+  // get the system message for this error code\r
+  char* message;\r
+  FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,\r
+                0,\r
+                err,\r
+                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),\r
+                (LPTSTR)&message,\r
+                0,0);\r
+  std::string result = message;\r
+  LocalFree(message);\r
+  // the error message is for some perverse reason newline terminated - remove this\r
+  if (result[result.size()-1] == '\n')\r
+    result.erase(result.end()-1);\r
+  if (result[result.size()-1] == '\r')\r
+    result.erase(result.end()-1);\r
+  return result;\r
+}\r
+\r
+#else\r
+\r
+static std::string last_error(void)\r
+{\r
+  return std::string(dlerror());\r
+}\r
+\r
+#endif\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+namespace stlplus\r
+{\r
+\r
+  ////////////////////////////////////////////////////////////////////////////////\r
+  // library management\r
+\r
+  // construct the object but do not load\r
+  dynaload::dynaload(void) : m_handle(0) \r
+  {\r
+  }\r
+\r
+  // construct and load\r
+  dynaload::dynaload(const std::string& library) : m_handle(0)\r
+  {\r
+    load(library);\r
+  }\r
+\r
+  // destroy and unload if loaded\r
+  dynaload::~dynaload(void)\r
+  {\r
+    unload();\r
+  }\r
+\r
+  // load the library - return success or fail\r
+  bool dynaload::load(const std::string& library)\r
+  {\r
+#ifdef MSWINDOWS\r
+    m_handle = (void*)LoadLibrary(library.c_str());\r
+#elif defined(CYGWIN)\r
+    m_handle = dlopen(library.c_str(),RTLD_NOW);\r
+#else\r
+    std::string full_library = std::string("lib") + library + std::string(".so");\r
+    m_handle = dlopen(full_library.c_str(),RTLD_NOW);\r
+#endif\r
+    if (!m_handle)\r
+    {\r
+      m_error = load_error;\r
+      m_text = last_error();\r
+    }\r
+    return loaded();\r
+  }\r
+\r
+  // unload the library if loaded\r
+  bool dynaload::unload(void)\r
+  {\r
+    if (!loaded()) return false;\r
+#ifdef MSWINDOWS\r
+    int status = FreeLibrary((HINSTANCE)m_handle) ? 0 : 1;\r
+#else\r
+    int status = dlclose(m_handle);\r
+#endif\r
+    if (status != 0)\r
+    {\r
+      m_error = unload_error;\r
+      m_text = last_error();\r
+    }\r
+    return status == 0;\r
+  }\r
+\r
+  // test whether the library is loaded\r
+  bool dynaload::loaded(void) const\r
+  {\r
+    return m_handle != 0;\r
+  }\r
+\r
+  ////////////////////////////////////////////////////////////////////////////\r
+  // symbol management\r
+\r
+  // test whether a function is exported by the library\r
+  // does not set the error flag if fails\r
+  bool dynaload::present(const std::string& name)\r
+  {\r
+    if (!loaded()) return false;\r
+#ifdef MSWINDOWS\r
+    void* fn = (void*)GetProcAddress((HINSTANCE)m_handle,name.c_str());\r
+#else\r
+    void* fn = dlsym(m_handle,name.c_str());\r
+#endif\r
+    return fn != 0;\r
+  }\r
+\r
+  // get the function as a generic pointer\r
+  void* dynaload::symbol(const std::string& name)\r
+  {\r
+    if (!loaded()) return 0;\r
+#ifdef MSWINDOWS\r
+    void* fn = (void*)GetProcAddress((HINSTANCE)m_handle,name.c_str());\r
+#else\r
+    void* fn = dlsym(m_handle,name.c_str());\r
+#endif\r
+    if (!fn)\r
+    {\r
+      m_error = symbol_error;\r
+      m_text = last_error();\r
+    }\r
+    return fn;\r
+  }\r
+\r
+  ////////////////////////////////////////////////////////////////////////////\r
+  // error management\r
+\r
+  // test whether there has been an error\r
+  bool dynaload::error(void) const\r
+  {\r
+    return m_error != no_error;\r
+  }\r
+\r
+  // clear an error once it has been handled (or ignored)\r
+  void dynaload::clear_error(void)\r
+  {\r
+    m_error = no_error;\r
+    m_text = std::string();\r
+  }\r
+\r
+  // get the type of the error as indicated by the enum error_t\r
+  dynaload::error_t dynaload::error_type(void) const\r
+  {\r
+    return m_error;\r
+  }\r
+\r
+  // get the text of the error as provided by the OS\r
+  std::string dynaload::error_text(void) const\r
+  {\r
+    return m_text;\r
+  }\r
+\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+} // end namespace stlplus\r