Allow suppressing GTK log messages

include/wx/gtk/private/log.h

@@ -0,0 +1,135 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/gtk/private/log.h
+// Purpose:     Support for filtering GTK log messages.
+// Author:      Vadim Zeitlin
+// Created:     2022-05-11
+// Copyright:   (c) 2022 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_GTK_PRIVATE_LOG_H_
+#define _WX_GTK_PRIVATE_LOG_H_
+
+#include <glib.h>
+
+// Support for custom log writers is only available in glib 2.50 or later.
+#if GLIB_CHECK_VERSION(2, 50, 0)
+    #define wxHAS_GLIB_LOG_WRITER
+#endif
+
+namespace wxGTKImpl
+{
+
+#ifdef wxHAS_GLIB_LOG_WRITER
+
+// LogFilter is the base class for filtering GTK log messages
+//
+// Note that all members of this class are defined in src/gtk/app.cpp.
+class LogFilter
+{
+public:
+    LogFilter()
+    {
+        m_next = NULL;
+    }
+
+    // Function to call to install this filter as the active one.
+    // Does nothing and just returns false if run-time glib version is too old.
+    bool Install();
+
+protected:
+    // Function to override in the derived class to actually filter: return
+    // true if the message should be suppressed or false if it should be passed
+    // through to the default writer (which may, or not, show it).
+    virtual bool Filter(GLogLevelFlags log_level,
+                        const GLogField* fields,
+                        gsize n_fields) const = 0;
+
+    // Typically called from the derived class dtor to stop using this filter.
+    void Uninstall();
+
+private:
+    // The function used as glib log writer.
+    static GLogWriterOutput
+    wx_log_writer(GLogLevelFlags   log_level,
+                  const GLogField *fields,
+                  gsize            n_fields,
+                  gpointer         user_data);
+
+    // False initially, set to true when we install wx_log_writer() as the log
+    // writer. Once we do it, we never change it any more.
+    static bool ms_installed;
+
+    // We maintain a simple linked list of log filters and this is the head of
+    // this list.
+    static LogFilter* ms_first;
+
+    // Next entry in the linked list, may be null.
+    LogFilter* m_next;
+
+    wxDECLARE_NO_COPY_CLASS(LogFilter);
+};
+
+// LogFilterByLevel filters out all the messages at the specified level.
+class LogFilterByLevel : public LogFilter
+{
+public:
+    LogFilterByLevel() { }
+
+    void SetLevelToIgnore(int flags)
+    {
+        m_logLevelToIgnore = flags;
+    }
+
+protected:
+    bool Filter(GLogLevelFlags log_level,
+                const GLogField* WXUNUSED(fields),
+                gsize WXUNUSED(n_fields)) const wxOVERRIDE
+    {
+        return log_level & m_logLevelToIgnore;
+    }
+
+private:
+    int m_logLevelToIgnore;
+
+    wxDECLARE_NO_COPY_CLASS(LogFilterByLevel);
+};
+
+// LogFilterByMessage filters out all the messages with the specified content.
+class LogFilterByMessage : public LogFilter
+{
+public:
+    // Objects of this class are supposed to be created with literal strings as
+    // argument, so don't bother copying the string but just use the pointer.
+    explicit LogFilterByMessage(const char* message)
+        : m_message(message)
+    {
+        // We shouldn't warn about anything if Install() failed.
+        m_warnNotFiltered = Install();
+    }
+
+    // Remove this filter when the object goes out of scope.
+    //
+    // The dtor also checks if we actually filtered the message and logs a
+    // trace message with the "gtklog" mask if we didn't: this allows checking
+    // if the filter is actually being used.
+    ~LogFilterByMessage();
+
+protected:
+    bool Filter(GLogLevelFlags WXUNUSED(log_level),
+                const GLogField* fields,
+                gsize n_fields) const wxOVERRIDE;
+
+private:
+    const char* const m_message;
+
+    mutable bool m_warnNotFiltered;
+
+    wxDECLARE_NO_COPY_CLASS(LogFilterByMessage);
+};
+
+#endif // wxHAS_GLIB_LOG_WRITER
+
+} // namespace wxGTKImpl
+
+#endif // _WX_GTK_PRIVATE_LOG_H_

src/gtk/app.cpp

@@ -30,6 +30,7 @@
 #include "wx/msgout.h"
 
 #include "wx/gtk/private.h"
+#include "wx/gtk/private/log.h"
 
 #include "wx/gtk/mimetype.h"
 //-----------------------------------------------------------------------------
@@ -178,48 +179,112 @@ bool wxApp::DoIdle()
     return keepSource;
 }
 
-// Custom Glib log writer: setting it is only possible with glib 2.50 or later.
-#if GLIB_CHECK_VERSION(2, 50, 0)
-extern "C" {
-static GLogWriterOutput
-wx_log_writer(GLogLevelFlags   log_level,
-              const GLogField *fields,
-              gsize            n_fields,
-              gpointer         user_data)
+#ifdef wxHAS_GLIB_LOG_WRITER
+
+namespace wxGTKImpl
 {
-    const wxUIntPtr log_mask = reinterpret_cast<wxUIntPtr>(user_data);
 
-    GLogWriterOutput result;
-    if (log_level & log_mask)
+bool LogFilter::ms_installed = false;
+LogFilter* LogFilter::ms_first = NULL;
+
+/* static */
+GLogWriterOutput
+LogFilter::wx_log_writer(GLogLevelFlags   log_level,
+                         const GLogField *fields,
+                         gsize            n_fields,
+                         gpointer         WXUNUSED(user_data))
+{
+    for ( const LogFilter* lf = LogFilter::ms_first; lf; lf = lf->m_next )
     {
-        result = G_LOG_WRITER_HANDLED;
+        if ( lf->Filter(log_level, fields, n_fields) )
+            return G_LOG_WRITER_HANDLED;
     }
-    else
+
+    return g_log_writer_default(log_level, fields, n_fields, NULL);
+}
+
+bool LogFilter::Install()
+{
+    if ( !ms_installed )
     {
-        result = g_log_writer_default(log_level, fields, n_fields, NULL);
+        if ( glib_check_version(2, 50, 0) != 0 )
+        {
+            // No runtime support for log callback, we can't do anything.
+            return false;
+        }
+
+        g_log_set_writer_func(LogFilter::wx_log_writer, NULL, NULL);
+        ms_installed = true;
     }
-    return result;
+
+    // Put this object in front of the linked list.
+    m_next = ms_first;
+    ms_first = this;
+
+    return true;
 }
+
+void LogFilter::Uninstall()
+{
+    if ( !ms_installed )
+    {
+        // We don't do anything at all in this case.
+        return;
+    }
+
+    // We should be uninstalling only the currently installed filter.
+    wxASSERT( ms_first == this );
+
+    ms_first = m_next;
 }
 
-/* static */
-void wxApp::GTKSuppressDiagnostics(int flags)
+bool LogFilterByMessage::Filter(GLogLevelFlags WXUNUSED(log_level),
+                                const GLogField* fields,
+                                gsize n_fields) const
 {
-    if (glib_check_version(2, 50, 0) == 0)
+    for ( gsize n = 0; n < n_fields; ++n )
     {
-        g_log_set_writer_func(
-            wx_log_writer,
-            (wxUIntToPtr)(flags == -1 ? G_LOG_LEVEL_MASK : flags),
-            NULL);
+        const GLogField& f = fields[n];
+        if ( strcmp(f.key, "MESSAGE") == 0 )
+        {
+            if ( strcmp(static_cast<const char*>(f.value), m_message) == 0 )
+            {
+                // This is the message we want to filter.
+                m_warnNotFiltered = false;
+                return true;
+            }
+        }
     }
+
+    return false;
+}
+
+LogFilterByMessage::~LogFilterByMessage()
+{
+    Uninstall();
+
+    if ( m_warnNotFiltered )
+    {
+        wxLogTrace("gtklog", "Message \"%s\" wasn't logged.", m_message);
+    }
+}
+
+} // namespace wxGTKImpl
+
+/* static */
+void wxApp::GTKSuppressDiagnostics(int flags)
+{
+    static wxGTKImpl::LogFilterByLevel s_logFilter;
+    s_logFilter.SetLevelToIgnore(flags);
+    s_logFilter.Install();
 }
-#else // glib < 2.50
+#else // !wxHAS_GLIB_LOG_WRITER
 /* static */
 void wxApp::GTKSuppressDiagnostics(int WXUNUSED(flags))
 {
     // We can't do anything here.
 }
-#endif // glib >=/< 2.50
+#endif // wxHAS_GLIB_LOG_WRITER/!wxHAS_GLIB_LOG_WRITER
 
 //-----------------------------------------------------------------------------
 // wxApp

src/gtk/notebook.cpp

@@ -26,6 +26,7 @@
 
 #include "wx/gtk/private.h"
 #include "wx/gtk/private/image.h"
+#include "wx/gtk/private/log.h"
 #include "wx/gtk/private/stylecontext.h"
 
 //-----------------------------------------------------------------------------
@@ -426,6 +427,12 @@ wxNotebookPage *wxNotebook::DoRemovePage( size_t page )
     if ( !client )
         return NULL;
 
+    // Suppress bogus assertion failures happening deel inside ATK that can't
+    // be avoided in any other way, see #22176.
+    wxGTKImpl::LogFilterByMessage filterLog(
+        "gtk_notebook_get_tab_label: assertion 'list != NULL' failed"
+    );
+
     // we don't need to unparent the client->m_widget; GTK+ will do
     // that for us (and will throw a warning if we do it!)
     gtk_notebook_remove_page( GTK_NOTEBOOK(m_widget), page );