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Issue 857277 link

Starred by 2 users
Status: Fixed
Owner:
joedow@chromium.org
Closed: Jun 2018
Components:
EstimatedDays: ----
NextAction: ----
OS: Windows
Pri: 1
Type: Bug

Blocking:
issue 832811



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ODR violation - two copies of ui::GenerateDomKeyboardLayoutMap on Windows builds

Project Member Reported by brucedaw...@chromium.org, Jun 28 2018 
While doing some test linking with use_lld=false I hit this warning:

[352 processes, 11477/36375 @ 150.2/s : 76.409s ] LIB obj/ui/events/dom_keyboard_layout.lib
dom_keyboard_layout_map_ozone.obj : warning LNK4006: "class base::flat_map<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct std::less<void> > __cdecl ui::GenerateDomKeyboardLayoutMap(void)" (?GenerateDomKeyboardLayoutMap@ui@@YA?AV?$flat_map@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V12@U?$less@X@2@@base@@XZ) already defined in dom_keyboard_layout_map_win.obj; second definition ignored

Investigation showed that, indeed, there are two functions called ui::GenerateDomKeyboardLayoutMap, one in ui\events\keycodes\dom\dom_keyboard_layout_map_win.cc and the other in ui\events\keycodes\dom\dom_keyboard_layout_map_ozone.cc

This is a One Definition Rule violation and it is undefined which one of these functions will be pulled in. I'm not sure what the fix is - perhaps adding an ifdef so that the ozone version doesn't get compiled on Windows?

Comment 1 by brucedaw...@chromium.org, Jun 28 2018 

It looks like the bug is that the ozone.cc source file is being compiled on Windows at all. I looked through my .ninja_log files to see how many other .obj files with ozone in the path are being generated on a Windows builds:

obj/ui/events/ozone/events_ozone_layout/no_keyboard_layout_engine.obj
obj/ui/events/ozone/events_ozone_layout/keyboard_layout_engine_manager.obj
obj/ui/events/ozone/events_ozone_layout/layout_util.obj
obj/ui/events/ozone/events_ozone_layout/stub_keyboard_layout_engine.obj
obj/ui/events/dom_keyboard_layout/dom_keyboard_layout_map_ozone.obj

I verified that *ozone.cc is not used for automatic source filtering (as done with set_sources_assignment_filter in build\config\BUILDCONFIG.gn) so dom_keyboard_layout_map_ozone.cc needs to be manually filtered out. Prototype CL is in crrev.com/c/1117865
Project Member

Comment 2 by bugdroid1@chromium.org, Jun 30 2018 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1f2706b35e5382d6d095673ec4755d279f110f02

commit 1f2706b35e5382d6d095673ec4755d279f110f02
Author: Bruce Dawson <brucedawson@chromium.org>
Date: Sat Jun 30 00:34:23 2018

Don't compile ozone file for Windows or Mac

While testing with link.exe on Windows I hit a warning about duplicate
definitions of ui::GenerateDomKeyboardLayoutMap. This is because this
function is defined in three source files - *_win.cc, *_mac.mm, and
*_ozone.cc, and the *_ozone.cc file is always compiled. This means that
it is undefined which version the linker will select when building for
Windows and Mac. This ODR violation appeared in crrev.com/c/1093891

Bug:  857277 
Change-Id: I05e9a3216a5e9c2c0925bd83267b03e6cb9aa2f6
Reviewed-on: https://chromium-review.googlesource.com/1117865
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Bruce Dawson <brucedawson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571720}
[modify] https://crrev.com/1f2706b35e5382d6d095673ec4755d279f110f02/ui/events/BUILD.gn

Comment 3 by brucedaw...@chromium.org, Jun 30 2018

Status: Fixed (was: Assigned)

Comment 4 by brucedaw...@chromium.org, Jun 30 2018 

See also bug 726071 which covers ODR detection with lld.
►

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