1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

CMake/ELF: hide all Standard Library symbols

Browse Source 
We've had issues in the past where Standard Library constructs either
with or without a Qt type mangled in the middle get exported from our
ABI and thus get marked with the Qt version numbers. For example, I can
see in our libraries:

  517: 000000000010e608     24 OBJECT  GLOBAL DEFAULT       22 typeinfo for std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>@@Qt_6
  615: 00000000000eb2a0     47 OBJECT  GLOBAL DEFAULT       17 typeinfo name for std::_Mutex_base<(__gnu_cxx::_Lock_policy)2>@@Qt_6
  706: 000000000010e5f8     16 OBJECT  GLOBAL DEFAULT       22 typeinfo for std::_Mutex_base<(__gnu_cxx::_Lock_policy)2>@@Qt_6
  750: 00000000000ed5f0     16 OBJECT  GLOBAL DEFAULT       17 std::_Sp_make_shared_tag::_S_ti()::__tag@@Qt_6
  754: 00000000000da408      1 OBJECT  GLOBAL DEFAULT       17 std::piecewise_construct@@Qt_6

This causes user content to break when an update to Qt stops exporting
such symbols, either because of code changes or because of changes to
the compiler and its optimizer.

In fact, this commit will cause that, for the symbols above. But this
will no longer be random-looking.

[ChangeLog][Important ABI Changes] On ELF-based platforms (e.g., Linux,
FreeBSD), the linking process has been updated to exclude Standard
Library symbols from getting the "Qt_6" ELF version. This solves the
problem of applications and libraries breaking arbitrarily after Qt
updates, but will cause such breakages right now. Content built with
older versions of Qt may need to be relinked.

Change-Id: I5acc02341c5940499682fffd1775edce0021ce6d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
This commit is contained in:
Thiago Macieira 2023-07-27 21:31:44 -07:00
parent 167d28e77a
commit 946f15efb7
1 changed files with 4 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
cmake/QtFlagHandlingHelpers.cmake
View File

@ -23,7 +23,10 @@ function(qt_internal_add_linker_version_script target)
endif()
if(TEST_ld_version_script)
set(contents "Qt_${PROJECT_VERSION_MAJOR}_PRIVATE_API {\n qt_private_api_tag*;\n")
set(contents "NonQt { local:\n")
string(APPEND contents " _ZT?S*;\n") # {typeinfo {,name},vtable,VTT} for std::
string(APPEND contents " extern \"C++\" { std::*; };\n")
string(APPEND contents "};\nQt_${PROJECT_VERSION_MAJOR}_PRIVATE_API { qt_private_api_tag*;\n")
if(arg_PRIVATE_HEADERS)
foreach(ph ${arg_PRIVATE_HEADERS})
string(APPEND contents " @FILE:${ph}@\n")