Add wxDynamicLibrary::GetModuleFromAddress().

Use dladdr() under Unix, if available, to provide the same functionality as we
get from GetModuleHandleEx() under MSW and export it in a new public function.

Closes #15248.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76114 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

configure

@@ -33348,6 +33348,63 @@ fi
 
 
 
+fi
+done
+
+                for ac_func in dladdr
+do :
+  ac_fn_c_check_func "$LINENO" "dladdr" "ac_cv_func_dladdr"
+if test "x$ac_cv_func_dladdr" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_DLADDR 1
+_ACEOF
+ $as_echo "#define HAVE_DLADDR 1" >>confdefs.h
+
+else
+
+                        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for dladdr in -ldl" >&5
+$as_echo_n "checking for dladdr in -ldl... " >&6; }
+if ${ac_cv_lib_dl_dladdr+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-ldl  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char dladdr ();
+int
+main ()
+{
+return dladdr ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_dl_dladdr=yes
+else
+  ac_cv_lib_dl_dladdr=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_dl_dladdr" >&5
+$as_echo "$ac_cv_lib_dl_dladdr" >&6; }
+if test "x$ac_cv_lib_dl_dladdr" = xyes; then :
+  $as_echo "#define HAVE_DLADDR 1" >>confdefs.h
+
+fi
+
+
+
 fi
 done
 

configure.in

@@ -5442,6 +5442,12 @@ if test "$TOOLKIT" != "MSW" -a "$USE_OS2" != 1; then
                         AC_CHECK_LIB(dl, dlerror, AC_DEFINE(HAVE_DLERROR))
                     ]
                 )
+                AC_CHECK_FUNCS(dladdr,
+                    AC_DEFINE(HAVE_DLADDR),
+                    [
+                        AC_CHECK_LIB(dl, dladdr, AC_DEFINE(HAVE_DLADDR))
+                    ]
+                )
             fi
         fi
 

docs/changes.txt

@@ -22,6 +22,7 @@ All:
 
 - Allow iterating over wxCmdLineParser arguments in order (Armel Asselin).
 - Add wxScopedArray ctor taking the number of elements to allocate.
+- Add wxDynamicLibrary::GetModuleFromAddress() (Luca Bacci).
 
 All (GUI):
 

include/wx/dynlib.h

@@ -347,6 +347,12 @@ class WXDLLIMPEXP_BASE wxDynamicLibrary
     // string on others:
     static wxString GetPluginsDirectory();
 
+    // Return the load address of the module containing the given address or
+    // NULL 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 = NULL);
 
 #ifdef __WINDOWS__
     // return the handle (HMODULE/HINSTANCE) of the DLL with the given name

interface/wx/dynlib.h

@@ -195,6 +195,21 @@ class wxDynamicLibrary
     */
     static wxDynamicLibraryDetailsArray ListLoaded();
 
+    /**
+        Returns the load address of the module containing the specified address
+        or @NULL if not found.
+
+        If the second argument @a path is not @NULL, it is filled with the full
+        path to the file the module was loaded from upon a successful return.
+
+        This method is implemented under MSW and Unix platforms providing
+        `dladdr()` call (which include Linux and various BSD systems) and
+        always returns @NULL elsewhere.
+
+        @since 3.1.0
+    */
+    static void* GetModuleFromAddress(const void* addr, wxString* path = NULL);
+
     /**
         Loads DLL with the given @a name into memory. The @a flags argument can
         be a combination of the styles outlined in the class description.

setup.h.in

@@ -1071,6 +1071,9 @@
 /* Define if you have the dlerror function.  */
 #undef HAVE_DLERROR
 
+/* Define if you have the dladdr function.  */
+#undef HAVE_DLADDR
+
 /* Define if you have Posix fnctl() function. */
 #undef HAVE_FCNTL
 

setup.h_vms

@@ -1177,6 +1177,9 @@ typedef pid_t GPid;
 /* Define if you have the dlerror function.  */
 #define HAVE_DLERROR 1
 
+/* Define if you have the dladdr function.  */
+#undef HAVE_DLADDR
+
 /* Define if you have Posix fnctl() function. */
 #define HAVE_FCNTL 1
 

src/msw/dlmsw.cpp

@@ -297,40 +297,89 @@ wxDynamicLibraryDetailsArray wxDynamicLibrary::ListLoaded()
     return dlls;
 }
 
-/* static */
-WXHMODULE wxDynamicLibrary::MSWGetModuleHandle(const wxString& name, void *addr)
+// ----------------------------------------------------------------------------
+// Getting the module from an address inside it
+// ----------------------------------------------------------------------------
+
+namespace
 {
-    // we want to use GetModuleHandleEx() instead of usual GetModuleHandle()
-    // because the former works correctly for comctl32.dll while the latter
-    // returns NULL when comctl32.dll version 6 is used under XP (note that
-    // GetModuleHandleEx() is only available under XP and later, coincidence?)
 
-    // check if we can use GetModuleHandleEx
+// Tries to dynamically load GetModuleHandleEx() from kernel32.dll and call it
+// to get the module handle from the given address. Returns NULL if it fails to
+// either resolve the function (which can only happen on pre-Vista systems
+// normally) or if the function itself failed.
+HMODULE CallGetModuleHandleEx(const void* addr)
+{
     typedef BOOL (WINAPI *GetModuleHandleEx_t)(DWORD, LPCTSTR, HMODULE *);
-
     static const GetModuleHandleEx_t INVALID_FUNC_PTR = (GetModuleHandleEx_t)-1;
 
     static GetModuleHandleEx_t s_pfnGetModuleHandleEx = INVALID_FUNC_PTR;
     if ( s_pfnGetModuleHandleEx == INVALID_FUNC_PTR )
     {
         wxDynamicLibrary dll(wxT("kernel32.dll"), wxDL_VERBATIM);
-        s_pfnGetModuleHandleEx =
-            (GetModuleHandleEx_t)dll.GetSymbolAorW(wxT("GetModuleHandleEx"));
+
+        wxDL_INIT_FUNC_AW(s_pfn, GetModuleHandleEx, dll);
 
         // dll object can be destroyed, kernel32.dll won't be unloaded anyhow
     }
 
-    // get module handle from its address
-    if ( s_pfnGetModuleHandleEx )
+    if ( !s_pfnGetModuleHandleEx )
+        return NULL;
+
+    // flags are GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT |
+    //           GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
+    HMODULE hmod;
+    if ( !s_pfnGetModuleHandleEx(6, (LPCTSTR)addr, &hmod) )
+        return NULL;
+
+    return hmod;
+}
+
+} // anonymous namespace
+
+/* static */
+void* wxDynamicLibrary::GetModuleFromAddress(const void* addr, wxString* path)
+{
+    HMODULE hmod = CallGetModuleHandleEx(addr);
+    if ( !hmod )
+    {
+        wxLogLastError(wxT("GetModuleHandleEx"));
+        return NULL;
+    }
+
+    if ( path )
     {
-        // flags are GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT |
-        //           GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
-        HMODULE hmod;
-        if ( s_pfnGetModuleHandleEx(6, (LPCTSTR)addr, &hmod) && hmod )
-            return hmod;
+        TCHAR libname[MAX_PATH];
+        if ( !::GetModuleFileName(hmod, libname, MAX_PATH) )
+        {
+            // GetModuleFileName could also return extended-length paths (paths
+            // prepended with "//?/", maximum length is 32767 charachters) so,
+            // in principle, MAX_PATH could be unsufficient and we should try
+            // increasing the buffer size here.
+            wxLogLastError(wxT("GetModuleFromAddress"));
+            return NULL;
+        }
+
+        libname[MAX_PATH-1] = wxT('\0');
+
+        *path = libname;
     }
 
-    return ::GetModuleHandle(name.t_str());
+    // In Windows HMODULE is actually the base address of the module so we
+    // can just cast it to the address.
+    return reinterpret_cast<void *>(hmod);
+}
+
+/* static */
+WXHMODULE wxDynamicLibrary::MSWGetModuleHandle(const wxString& name, void *addr)
+{
+    // we want to use GetModuleHandleEx() instead of usual GetModuleHandle()
+    // because the former works correctly for comctl32.dll while the latter
+    // returns NULL when comctl32.dll version 6 is used under XP (note that
+    // GetModuleHandleEx() is only available under XP and later, coincidence?)
+    HMODULE hmod = CallGetModuleHandleEx(addr);
+
+    return hmod ? hmod : ::GetModuleHandle(name.t_str());
 }
 
 #endif // wxUSE_DYNLIB_CLASS

src/unix/dlunix.cpp

@@ -280,5 +280,25 @@ wxDynamicLibraryDetailsArray wxDynamicLibrary::ListLoaded()
     return dlls;
 }
 
+
+/* static */
+void* wxDynamicLibrary::GetModuleFromAddress(const void* addr, wxString* path)
+{
+#ifdef HAVE_DLADDR
+    Dl_info di = { 0 };
+
+    if ( dladdr(addr, &di) == 0 )
+        return NULL;
+
+    if ( path )
+        *path = di.dli_fname;
+
+    return di.dli_fbase;
+#endif // HAVE_DLADDR
+
+    return NULL;
+}
+
+
 #endif // wxUSE_DYNLIB_CLASS