clang broken on current?

[Mark Millard]

On 2019-Feb-10, at 11:24, Steve Kargl <sgk at troutmask.apl.washington.edu> wrote:

> On Sun, Feb 10, 2019 at 11:13:09AM -0800, Mark Millard wrote:
>> 
>> On 2019-Feb-10, at 10:46, Steve Kargl <sgk at troutmask.apl.washington.edu> wrote:
>>> 
>>> On Sun, Feb 10, 2019 at 12:03:55PM +0100, Dimitry Andric wrote:
>>>> On 10 Feb 2019, at 06:00, Steve Kargl <sgk at troutmask.apl.washington.edu> wrote:
>>>> 
>>>> How did you arrive at the conclusion that this has anything to do with
>>>> the specific compiler?  From these errors, I think it is more likely
>>>> something in Qt5 that is erroneously convinced that those qt_memfillXY
>>>> functions exist.  Or they get referenced, but not compiled at all, for
>>>> some reason.
>>>> 
>>> 
>>> If I have "CFLAGS+= -march=i686 -mmmx -msse" in /etc/make.conf
>>> qt5-gui builds without issue.  If I add -msse2 to CFLAGS, then
>>> the build dies.
>>> 
>>> So, either clang is miscompiling qt5-gui with -mmse2 or the
>>> qt5-gui port is being too smart for its own good.
>> 
>> That lead to an old memory of getting results like ((armv6
>> time frame I think, before the armv7 addition to FreeBSD):
>> 
>> image/qimage.cpp:(.text+0x1e14): undefined reference to `qt_memfill32(unsigned int*, unsigned int, int)'
>> image/qimage.cpp:(.text+0x1f34): undefined reference to `qt_memfill32(unsigned int*, unsigned int, int)'
>> 
>> where it turned out that arm NEON was not supported by various
>> parts of qt5.
>> 
> 
> It is definitely some problem between clang and the qt5-gui
> port.  It seems qt5-gui tries to auto-detect sse2.  Don't
> know if qt5-gui has a bogus auto-detect code, clang miscompiles
> the auto-detect code, or FreeBSD is lying about the features
> of my cpu (although x86info says it found sse2).   In poking
> around the qt5-gui sources, I found that configure can be 
> given a -sse2 argument.  I tried to force sse2, but I'm seeing
> qt5-gui is doing
> 
> % find qtbase-everywhere-src-5.12.0 -name config.\* | xargs grep -i sse2
> qtbase-everywhere-src-5.12.0/config.log:Command line: -no-eglfs -sse2 -no-evdev -no-libudev -system-harfbuzz -c++std c++14 -opensource -confirm-license -no-pch -prefix /usr/local -bindir /usr/local/lib/qt5/bin -headerdir /usr/local/include/qt5 -libdir /usr/local/lib/qt5 -plugindir /usr/local/lib/qt5/plugins -importdir /usr/local/lib/qt5/imports -datadir /usr/local/share/qt5 -docdir /usr/local/share/doc/qt5 -translationdir /usr/local/share/qt5/translations -sysconfdir /usr/local/etc/xdg -nomake examples -nomake tests -platform freebsd-clang -archdatadir /usr/local/lib/qt5 -libexecdir /usr/local/libexec/qt5 -qmldir /usr/local/lib/qt5/qml -examplesdir /usr/local/share/examples/qt5 -testsdir /usr/local/share/qt5/tests -no-sse2 -no-use-gold-linker -recheck-all -release -no-separate-debug-info
> qtbase-everywhere-src-5.12.0/config.opt:-sse2
> qtbase-everywhere-src-5.12.0/config.opt:-no-sse2
> 
> Note my -sse2 is followed by a -no-sse2!

FYI: from the "24 May 2015 16:41:17" check in
description:

Qt 5.3 removed runtime detection of SSE2 so it needs to be configured
with -no-sse2 at buildtime on i386.

PR:		198738, 200258
Reported by:	sasamotikomi at gmail.com
Approved by:	maintainer timeout (2 weeks)



===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)