Sorry, I missed your README.  But a good number of years ago I was in the compiler group for Red Hat and, if I haven't rusted out entirely, I'll take a look at the bug.  No guarantees...

Chris

On 2020-06-27 12:16, Dr. Jürgen Sauermann wrote:
Hi Chris,

this warning is haunting us for quite a while now.

I have written a *README-11-bogus-compiler-warnings* with work-arounds.

Unfortunately the loop below is not entirely bogus (what happens is that for some r the uninitialized value *other.rho[r] *is being copied to the never-used value *rho[r]*).

Unfortunately the obvious fix for the warning has shown to cause significant perfomance impacts because it prevents loop unrolling (and there was a separate trouble report
concerning that performance drop on bug-apl).

At that time I filed a gcc trouble report:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94905

asking to fix this, but I am afraid that this may take some time.
My bug report was merged into a meta-bug which is open since 2005:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24639

Best Regards,
Jürgen


On 6/27/20 5:01 PM, Chris Moller wrote:
Shape.hh: In member function 'Shape Shape::insert_axis(Axis, ShapeItem) const': Shape.hh:69:46: error: ''target_mem_ref' not supported by dump_expr<expression error>' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   69 |      loop(r, MAX_RANK)   rho[r] = other.rho[r];
      | ~~~~~~~~~~~^

Just to finish the build, I patched around the bug by editing out the Wall and the Werror in the Makefile, so:

[moller@hpbox]~tinkering/gnuapl/trunk% apl -v 10:47:53
BUILDTAG:
---------
    Project:        GNU APL
    Version / SVN:  1.8 / 1210
    Build Date:     2019-12-19 17:09:01 UTC
    Build OS:       Linux 4.19.3-200.fc28.x86_64 x86_64
    config.status: 'PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig:/usr/local/lib/pkgconfig:/usr/lib64/pkgconfig:/usr/lib/pkgconfig'
    Archive SVN:    1161

[moller@hpbox]~tinkering/gnuapl/trunk% gcc --version 10:49:35
gcc (GCC) 10.1.1 20200507 (Red Hat 10.1.1-1)

[moller@hpbox]~tinkering/gnuapl/trunk% cat /etc/redhat-release 10:51:45
Fedora release 32 (Thirty Two)

[moller@hpbox]~tinkering/gnuapl/trunk% uname -a 10:52:29
Linux hpbox 5.6.19-300.fc32.x86_64 #1 SMP Wed Jun 17 16:10:48 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux


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