wxwidgets/include/wx/dynlib.h
Vadim Zeitlin 43ff845e77 Remove Windows XP and Vista support
Supporting XP requires too many hacks, and while it wouldn't be very
difficult to support Vista as long as we support Windows 7, it's still
not worth it because nobody uses this system anyhow.

Remove most of XP-specific code and don't use wxDynamicLibrary for using
the functions not present in it any longer.

Don't use <wspiapi.h> neither as we shouldn't use it any more.

Update some comments to not mention Windows versions not supported any
longer and also remove mentions of "Vista and newer Windows versions"
from the documentation as this is now always the case.

This commit is best viewed ignoring whitespace-only changes.
2022-11-12 16:57:52 +00:00

401 lines
15 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/dynlib.h
// Purpose: Dynamic library loading classes
// Author: Guilhem Lavaux, Vadim Zeitlin, Vaclav Slavik
// Modified by:
// Created: 20/07/98
// Copyright: (c) 1998 Guilhem Lavaux
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DYNLIB_H__
#define _WX_DYNLIB_H__
#include "wx/defs.h"
#if wxUSE_DYNLIB_CLASS
#include "wx/string.h"
#include "wx/dynarray.h"
class WXDLLIMPEXP_FWD_BASE wxDynamicLibraryDetailsCreator;
// ----------------------------------------------------------------------------
// conditional compilation
// ----------------------------------------------------------------------------
#if defined(__WINDOWS__)
typedef WXHMODULE wxDllType;
#elif defined(HAVE_DLOPEN)
#include <dlfcn.h>
typedef void *wxDllType;
#elif defined(__WXMAC__)
#include <CodeFragments.h>
typedef CFragConnectionID wxDllType;
#else
#error "Dynamic Loading classes can't be compiled on this platform, sorry."
#endif
// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------
enum wxDLFlags
{
wxDL_LAZY = 0x00000001, // resolve undefined symbols at first use
// (only works on some Unix versions)
wxDL_NOW = 0x00000002, // resolve undefined symbols on load
// (default, always the case under Win32)
wxDL_GLOBAL = 0x00000004, // export extern symbols to subsequently
// loaded libs.
wxDL_VERBATIM = 0x00000008, // attempt to load the supplied library
// name without appending the usual dll
// filename extension.
// this flag is obsolete, don't use
wxDL_NOSHARE = 0x00000010, // load new DLL, don't reuse already loaded
// (only for wxPluginManager)
wxDL_QUIET = 0x00000020, // don't log an error if failed to load
// this flag is dangerous, for internal use of wxMSW only, don't use at all
// and especially don't use directly, use wxLoadedDLL instead if you really
// do need it
wxDL_GET_LOADED = 0x00000040, // Win32 only: return handle of already
// loaded DLL or nullptr otherwise; Unload()
// should not be called so don't forget to
// Detach() if you use this function
wxDL_DEFAULT = wxDL_NOW // default flags correspond to Win32
};
enum wxDynamicLibraryCategory
{
wxDL_LIBRARY, // standard library
wxDL_MODULE // loadable module/plugin
};
enum wxPluginCategory
{
wxDL_PLUGIN_GUI, // plugin that uses GUI classes
wxDL_PLUGIN_BASE // wxBase-only plugin
};
// ----------------------------------------------------------------------------
// macros
// ----------------------------------------------------------------------------
// when loading a function from a DLL you always have to cast the returned
// "void *" pointer to the correct type and, even more annoyingly, you have to
// repeat this type twice if you want to declare and define a function pointer
// all in one line
//
// this macro makes this slightly less painful by allowing you to specify the
// type only once, as the first parameter, and creating a variable of this type
// called "pfn<name>" initialized with the "name" from the "dynlib"
#define wxDYNLIB_FUNCTION(type, name, dynlib) \
type pfn ## name = (type)(dynlib).GetSymbol(wxT(#name))
// a more convenient function replacing wxDYNLIB_FUNCTION above
//
// it uses the convention that the type of the function is its name suffixed
// with "_t" but it doesn't define a variable but just assigns the loaded value
// to it and also allows to pass it the prefix to be used instead of hardcoding
// "pfn" (the prefix can be "m_" or "gs_pfn" or whatever)
//
// notice that this function doesn't generate error messages if the symbol
// couldn't be loaded, the caller should generate the appropriate message
#define wxDL_INIT_FUNC(pfx, name, dynlib) \
pfx ## name = (name ## _t)(dynlib).RawGetSymbol(#name)
#ifdef __WINDOWS__
// same as wxDL_INIT_FUNC() but appends 'A' or 'W' to the function name, see
// wxDynamicLibrary::GetSymbolAorW()
#define wxDL_INIT_FUNC_AW(pfx, name, dynlib) \
pfx ## name = (name ## _t)(dynlib).GetSymbolAorW(#name)
#endif // __WINDOWS__
// the following macros can be used to redirect a whole library to a class and
// check at run-time if the library is present and contains all required
// methods
//
// notice that they are supposed to be used inside a class which has "m_ok"
// member variable indicating if the library had been successfully loaded
// helper macros constructing the name of the variable storing the function
// pointer and the name of its type from the function name
#define wxDL_METHOD_NAME(name) m_pfn ## name
#define wxDL_METHOD_TYPE(name) name ## _t
// parameters are:
// - rettype: return type of the function, e.g. "int"
// - name: name of the function, e.g. "foo"
// - args: function signature in parentheses, e.g. "(int x, int y)"
// - argnames: the names of the parameters in parentheses, e.g. "(x, y)"
// - defret: the value to return if the library wasn't successfully loaded
#define wxDL_METHOD_DEFINE( rettype, name, args, argnames, defret ) \
typedef rettype (* wxDL_METHOD_TYPE(name)) args ; \
wxDL_METHOD_TYPE(name) wxDL_METHOD_NAME(name); \
rettype name args \
{ return m_ok ? wxDL_METHOD_NAME(name) argnames : defret; }
#define wxDL_VOIDMETHOD_DEFINE( name, args, argnames ) \
typedef void (* wxDL_METHOD_TYPE(name)) args ; \
wxDL_METHOD_TYPE(name) wxDL_METHOD_NAME(name); \
void name args \
{ if ( m_ok ) wxDL_METHOD_NAME(name) argnames ; }
#define wxDL_METHOD_LOAD(lib, name) \
wxDL_METHOD_NAME(name) = \
(wxDL_METHOD_TYPE(name)) lib.GetSymbol(#name, &m_ok); \
if ( !m_ok ) return false
// ----------------------------------------------------------------------------
// wxDynamicLibraryDetails: contains details about a loaded wxDynamicLibrary
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxDynamicLibraryDetails
{
public:
// ctor, normally never used as these objects are only created by
// wxDynamicLibrary::ListLoaded()
wxDynamicLibraryDetails() { m_address = nullptr; m_length = 0; }
// get the (base) name
wxString GetName() const { return m_name; }
// get the full path of this object
wxString GetPath() const { return m_path; }
// get the load address and the extent, return true if this information is
// available
bool GetAddress(void **addr, size_t *len) const
{
if ( !m_address )
return false;
if ( addr )
*addr = m_address;
if ( len )
*len = m_length;
return true;
}
// return the version of the DLL (may be empty if no version info)
wxString GetVersion() const
{
return m_version;
}
private:
wxString m_name,
m_path,
m_version;
void *m_address;
size_t m_length;
friend class wxDynamicLibraryDetailsCreator;
};
WX_DECLARE_USER_EXPORTED_OBJARRAY(wxDynamicLibraryDetails,
wxDynamicLibraryDetailsArray,
WXDLLIMPEXP_BASE);
// ----------------------------------------------------------------------------
// wxDynamicLibrary: represents a handle to a DLL/shared object
// ----------------------------------------------------------------------------
class WXDLLIMPEXP_BASE wxDynamicLibrary
{
public:
// return a valid handle for the main program itself or nullptr if back
// linking is not supported by the current platform (e.g. Win32)
static wxDllType GetProgramHandle();
// return the platform standard DLL extension (with leading dot)
static wxString GetDllExt(wxDynamicLibraryCategory cat = wxDL_LIBRARY);
wxDynamicLibrary() : m_handle(nullptr) { }
wxDynamicLibrary(const wxString& libname, int flags = wxDL_DEFAULT)
: m_handle(nullptr)
{
Load(libname, flags);
}
// NOTE: this class is (deliberately) not virtual, do not attempt
// to use it polymorphically.
~wxDynamicLibrary() { Unload(); }
// return true if the library was loaded successfully
bool IsLoaded() const { return m_handle != nullptr; }
// load the library with the given name (full or not), return true if ok
bool Load(const wxString& libname, int flags = wxDL_DEFAULT);
// raw function for loading dynamic libs: always behaves as if
// wxDL_VERBATIM were specified and doesn't log error message if the
// library couldn't be loaded but simply returns nullptr
static wxDllType RawLoad(const wxString& libname, int flags = wxDL_DEFAULT);
// attach to an existing handle
void Attach(wxDllType h) { Unload(); m_handle = h; }
// detach the library object from its handle, i.e. prevent the object from
// unloading the library in its dtor -- the caller is now responsible for
// doing this
wxDllType Detach() { wxDllType h = m_handle; m_handle = nullptr; return h; }
// unload the given library handle (presumably returned by Detach() before)
static void Unload(wxDllType handle);
// unload the library, also done automatically in dtor
void Unload() { if ( IsLoaded() ) { Unload(m_handle); m_handle = nullptr; } }
// Return the raw handle from dlopen and friends.
wxDllType GetLibHandle() const { return m_handle; }
// check if the given symbol is present in the library, useful to verify if
// a loadable module is our plugin, for example, without provoking error
// messages from GetSymbol()
bool HasSymbol(const wxString& name) const
{
bool ok;
DoGetSymbol(name, &ok);
return ok;
}
// resolve a symbol in a loaded DLL, such as a variable or function name.
// 'name' is the (possibly mangled) name of the symbol. (use extern "C" to
// export unmangled names)
//
// Since it is perfectly valid for the returned symbol to actually be null,
// that is not always indication of an error. Pass and test the parameter
// 'success' for a true indication of success or failure to load the
// symbol.
//
// Returns a pointer to the symbol on success, or nullptr if an error occurred
// or the symbol wasn't found.
void *GetSymbol(const wxString& name, bool *success = nullptr) const;
// low-level version of GetSymbol()
static void *RawGetSymbol(wxDllType handle, const wxString& name);
void *RawGetSymbol(const wxString& name) const
{
return RawGetSymbol(m_handle, name);
}
#ifdef __WINDOWS__
// This function is misnamed now as it always loads "W" symbol because we
// always use Unicode now, but keeps its old name for compatibility.
static void *RawGetSymbolAorW(wxDllType handle, const wxString& name)
{
return RawGetSymbol
(
handle,
name + L'W'
);
}
void *GetSymbolAorW(const wxString& name) const
{
return RawGetSymbolAorW(m_handle, name);
}
#endif // __WINDOWS__
// return all modules/shared libraries in the address space of this process
//
// returns an empty array if not implemented or an error occurred
static wxDynamicLibraryDetailsArray ListLoaded();
// return platform-specific name of dynamic library with proper extension
// and prefix (e.g. "foo.dll" on Windows or "libfoo.so" on Linux)
static wxString CanonicalizeName(const wxString& name,
wxDynamicLibraryCategory cat = wxDL_LIBRARY);
// return name of wxWidgets plugin (adds compiler and version info
// to the filename):
static wxString
CanonicalizePluginName(const wxString& name,
wxPluginCategory cat = wxDL_PLUGIN_GUI);
// return plugin directory on platforms where it makes sense and empty
// string on others:
static wxString GetPluginsDirectory();
// Return the load address of the module containing the given address or
// nullptr if not found.
//
// If path output parameter is non-null, fill it with the full path to this
// module disk file on success.
static void* GetModuleFromAddress(const void* addr, wxString* path = nullptr);
#ifdef __WINDOWS__
// return the handle (HMODULE/HINSTANCE) of the DLL with the given name
// and/or containing the specified address: if a valid address is
// specified, it is used and then name is ignored, but if the address is
// null, the name (which may be either a full path to the DLL or just its
// base name, possibly even without extension) is used
//
// the returned handle reference count is not incremented so it doesn't
// need to be freed using FreeLibrary() but it also means that it can
// become invalid if the DLL is unloaded
static WXHMODULE MSWGetModuleHandle(const wxString& name, void *addr);
#endif // __WINDOWS__
protected:
// common part of GetSymbol() and HasSymbol()
void* DoGetSymbol(const wxString& name, bool* success = nullptr) const;
// log the error after an OS dynamic library function failure
static void ReportError(const wxString& msg,
const wxString& name = wxString());
// the handle to DLL or nullptr
wxDllType m_handle;
// no copy ctor/assignment operators (or we'd try to unload the library
// twice)
wxDECLARE_NO_COPY_CLASS(wxDynamicLibrary);
};
#ifdef __WINDOWS__
// ----------------------------------------------------------------------------
// wxLoadedDLL is a MSW-only internal helper class allowing to dynamically bind
// to a DLL already loaded into the project address space
// ----------------------------------------------------------------------------
class wxLoadedDLL : public wxDynamicLibrary
{
public:
wxLoadedDLL(const wxString& dllname)
: wxDynamicLibrary(dllname, wxDL_GET_LOADED | wxDL_VERBATIM | wxDL_QUIET)
{
}
~wxLoadedDLL()
{
Detach();
}
};
#endif // __WINDOWS__
// ----------------------------------------------------------------------------
// Interesting defines
// ----------------------------------------------------------------------------
#define WXDLL_ENTRY_FUNCTION() \
extern "C" WXEXPORT const wxClassInfo *wxGetClassFirst(); \
const wxClassInfo *wxGetClassFirst() { \
return wxClassInfo::GetFirst(); \
}
#endif // wxUSE_DYNLIB_CLASS
#endif // _WX_DYNLIB_H__