Fix ABI breakage for versioned symbols in 3.2.7

Add 3.2 versions of the symbols whose version was "fixed" in ed7defadd2
(Fix multiple errors in the version script, 2025-01-01), breaking ABI as
they were not available in their old version any more.

Add wxELF_VERSION() macro which allows to define the symbol with the
given ELF version and use it, in conjunction with the existing version
in the version script, to have both WXU_3.2.N and WXU_3.2 versions of
all the symbols affected by the changes in that commit.

Closes #25327.

docs/changes.txt

@@ -257,6 +257,7 @@ All:
 - Allow initializing wxVector<> from std::initializer_list<> (#25290).
 - Update Brazilian Portuguese translations (Felipe).
 - Ensure that all headers are installed by CMake (Maarten Bent, #25266).
+- Fix ABI breakage for versioned symbols in 3.2.7 under Unix (#25327).
 
 All (GUI):
 

include/wx/private/elfversion.h

@@ -0,0 +1,58 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/private/elfversion.h
+// Purpose:     Helper macro for assigning ELF version to a symbol.
+// Author:      Vadim Zeitlin
+// Created:     2025-04-14
+// Copyright:   (c) 2025 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_PRIVATE_ELFVERSION_H_
+#define _WX_PRIVATE_ELFVERSION_H_
+
+// We suppose that if version script is supported, then .symver assembler
+// directive is also supported.
+#ifdef wxHAVE_VERSION_SCRIPT
+    // Prefer to use the attribute if it is available, as it works with LTO,
+    // unlike the assembler directive.
+    #ifdef __has_attribute
+        #if __has_attribute(__symver__)
+            #define wxELF_SYMVER(sym, symver) __attribute__((__symver__(symver)))
+        #endif
+    #endif
+
+    #ifndef wxELF_SYMVER
+        #define wxELF_SYMVER(sym, symver) __asm__(".symver " sym "," symver);
+    #endif
+
+    // Our version tag depends on whether we're using Unicode or not.
+    #if wxUSE_UNICODE
+        #define wxMAKE_ELF_VERSION_TAG(ver) "WXU_" ver
+    #else
+        #define wxMAKE_ELF_VERSION_TAG(ver) "WX_" ver
+    #endif
+
+    // This macro is used to repair ABI compatibility problems with the symbols
+    // versions: unfortunately, some symbols were initially added with the
+    // wrong "3.2" version tag because their definitions in the version script
+    // were erroneous, and, even more unfortunately, they were later corrected
+    // to use a different version tag, which made the symbols with the old
+    // version unavailable in the shared library. This macro allows to define
+    // both the old, compatible version ("3.2") and the new ("3.2.N") one for
+    // the given symbol to restore ABI compatibility with the previous releases
+    // without breaking it with the release containing the corrected version.
+    //
+    // The parameters are the mangled symbol name (the simplest way to get is
+    // probably to use nm or readelf on the object file or library) and the
+    // part of the version after "WX[U]_", i.e. the version number itself.
+    //
+    // Note that this macro takes strings, not symbols, and that it includes
+    // the trailing semicolon for consistency with the empty version below.
+    #define wxELF_VERSION_COMPAT(sym, ver) \
+        wxELF_SYMVER(sym, sym "@" wxMAKE_ELF_VERSION_TAG("3.2")) \
+        wxELF_SYMVER(sym, sym "@@" wxMAKE_ELF_VERSION_TAG(ver))
+#else
+    #define wxELF_VERSION_COMPAT(sym, ver)
+#endif
+
+#endif // _WX_PRIVATE_ELFVERSION_H_

src/common/translation.cpp

@@ -49,6 +49,8 @@
 #include "wx/private/threadinfo.h"
 #include "wx/uilocale.h"
 
+#include "wx/private/elfversion.h"
+
 #ifdef __WINDOWS__
     #include "wx/dynlib.h"
     #include "wx/scopedarray.h"
@@ -1420,11 +1422,13 @@ bool wxTranslations::AddCatalog(const wxString& domain,
 }
 #endif // !wxUSE_UNICODE
 
+wxELF_VERSION_COMPAT("_ZN14wxTranslations19AddAvailableCatalogERK8wxString", "3.2.3")
 bool wxTranslations::AddAvailableCatalog(const wxString& domain)
 {
     return AddAvailableCatalog(domain, wxLANGUAGE_ENGLISH_US);
 }
 
+wxELF_VERSION_COMPAT("_ZN14wxTranslations19AddAvailableCatalogERK8wxString10wxLanguage", "3.2.6")
 bool wxTranslations::AddAvailableCatalog(const wxString& domain, wxLanguage msgIdLanguage)
 {
     return DoAddCatalog(domain, msgIdLanguage) == Translations_Found;
@@ -1563,6 +1567,7 @@ wxString wxTranslations::GetBestTranslation(const wxString& domain,
     return lang;
 }
 
+wxELF_VERSION_COMPAT("_ZN14wxTranslations27GetBestAvailableTranslationERK8wxString", "3.2.3")
 wxString wxTranslations::GetBestAvailableTranslation(const wxString& domain)
 {
     // Determine the best language from the ones with actual translation file:

src/common/uilocale.cpp

@@ -32,6 +32,7 @@
     #include "wx/language.h"
 #endif
 
+#include "wx/private/elfversion.h"
 #include "wx/private/uilocale.h"
 
 #define TRACE_I18N wxS("i18n")
@@ -612,6 +613,7 @@ wxString wxUILocale::GetLocalizedName(wxLocaleName name, wxLocaleForm form) cons
 }
 
 #if wxUSE_DATETIME
+wxELF_VERSION_COMPAT("_ZNK10wxUILocale12GetMonthNameEN10wxDateTime5MonthENS0_9NameFlagsE", "3.2.3")
 wxString wxUILocale::GetMonthName(wxDateTime::Month month, wxDateTime::NameFlags flags) const
 {
     if (!m_impl)
@@ -620,6 +622,7 @@ wxString wxUILocale::GetMonthName(wxDateTime::Month month, wxDateTime::NameFlags
     return m_impl->GetMonthName(month, flags);
 }
 
+wxELF_VERSION_COMPAT("_ZNK10wxUILocale14GetWeekDayNameEN10wxDateTime7WeekDayENS0_9NameFlagsE", "3.2.3")
 wxString wxUILocale::GetWeekDayName(wxDateTime::WeekDay weekday, wxDateTime::NameFlags flags) const
 {
     if (!m_impl)
@@ -677,6 +680,7 @@ wxUILocale::~wxUILocale()
 
 
 /* static */
+wxELF_VERSION_COMPAT("_ZN10wxUILocale17GetSystemLocaleIdEv", "3.2.2")
 wxLocaleIdent wxUILocale::GetSystemLocaleId()
 {
     wxUILocale defaultLocale(wxUILocaleImpl::CreateUserDefault());

src/gtk/filedlg.cpp

@@ -32,6 +32,8 @@
 #include "wx/filefn.h" // ::wxGetCwd
 #include "wx/modalhook.h"
 
+#include "wx/private/elfversion.h"
+
 //-----------------------------------------------------------------------------
 // "clicked" for OK-button
 //-----------------------------------------------------------------------------
@@ -500,6 +502,7 @@ void wxFileDialog::GTKSelectionChanged(const wxString& filename)
     UpdateExtraControlUI();
 }
 
+wxELF_VERSION_COMPAT("_ZN12wxFileDialog11AddShortcutERK8wxStringi", "3.2.1")
 bool wxFileDialog::AddShortcut(const wxString& directory, int WXUNUSED(flags))
 {
     wxGtkError error;

src/unix/glegl.cpp

@@ -28,6 +28,8 @@
 
 #include "wx/scopedptr.h"
 
+#include "wx/private/elfversion.h"
+
 #include "wx/gtk/private/wrapgdk.h"
 #include "wx/gtk/private/backend.h"
 #ifdef GDK_WINDOWING_WAYLAND
@@ -633,6 +635,7 @@ wxGLCanvasEGL::~wxGLCanvasEGL()
     gs_alreadySetSwapInterval.erase(this);
 }
 
+wxELF_VERSION_COMPAT("_ZN13wxGLCanvasEGL23CreateWaylandSubsurfaceEv", "3.2.3")
 void wxGLCanvasEGL::CreateWaylandSubsurface()
 {
 #ifdef GDK_WINDOWING_WAYLAND
@@ -671,6 +674,7 @@ void wxGLCanvasEGL::CreateWaylandSubsurface()
 #endif
 }
 
+wxELF_VERSION_COMPAT("_ZN13wxGLCanvasEGL24DestroyWaylandSubsurfaceEv", "3.2.3")
 void wxGLCanvasEGL::DestroyWaylandSubsurface()
 {
 #ifdef GDK_WINDOWING_WAYLAND

version-script.in

@@ -18,9 +18,10 @@
 #   };
 #
 # If a symbols should have been added in this way, but is forgotten then it
-# cannot be added in the next release. This is because it has already been
-# released with the generic branch version due to the final wildcard below,
-# and once released its version cannot be changed.
+# cannot be added to the next release version tag, but we can workaround the
+# problem by using wxELF_VERSION_COMPAT() macro in the source code. Note that
+# this is why some version tags are defined here even if no symbols are
+# assigned to them: they are used by that macro.
 
 # When adding a new section here, don't forget to modify the version in
 # build/bakefiles/version.bkl to indicate that new APIs have been added and
@@ -36,35 +37,20 @@
 
 # public symbols added in 3.2.6 (please keep in alphabetical order):
 @WX_VERSION_TAG@.6 {
-    extern "C++" {
-        "wxTranslations::AddAvailableCatalog(wxString const&, wxLanguage)";
-    };
 };
 
 # public symbols added in 3.2.3 (please keep in alphabetical order):
 @WX_VERSION_TAG@.3 {
-    extern "C++" {
-        "wxGLCanvasEGL::CreateWaylandSubsurface()";
-        "wxGLCanvasEGL::DestroyWaylandSubsurface()";
-        "wxTranslations::AddAvailableCatalog(wxString const&)";
-        "wxTranslations::GetBestAvailableTranslation(wxString const&)";
-        "wxUILocale::GetMonthName(wxDateTime::Month, wxDateTime::NameFlags) const";
-        "wxUILocale::GetWeekDayName(wxDateTime::WeekDay, wxDateTime::NameFlags) const";
-    };
 };
 
 # public symbols added in 3.2.2 (please keep in alphabetical order):
 @WX_VERSION_TAG@.2 {
-    extern "C++" {
-        "wxUILocale::GetSystemLocaleId()";
-    };
 };
 
 # public symbols added in 3.2.1
 @WX_VERSION_TAG@.1 {
     extern "C++" {
         "wxApp::GTKAllowDiagnosticsControl()";
-        "wxFileDialogBase::AddShortcut(wxString const&, int)";
     };
 };