[Bug c++/67834] New: [5 Regression] Local references inside comdat groups

["danglin at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67834

            Bug ID: 67834
           Summary: [5 Regression] Local references inside comdat groups
           Product: gcc
           Version: 5.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: danglin at gcc dot gnu.org
  Target Milestone: ---
              Host: hppa-unknown-linux-gnu
            Target: hppa-unknown-linux-gnu
             Build: hppa-unknown-linux-gnu

Created attachment 36442
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36442&action=edit
Preprocessed source

With the switch to gcc-5 on Debian, we are seeing a number of c++ packages
fail to build with the following error:

_ZXXX referenced in section `.data.rel.ro.local' of YYY: defined in discarded
section `.text._ZXXX

Here is the assembler code for _ZN3uhd9transport3sphL19handle_overflow_nopEv:

       .section       
.text._ZN3uhd9transport3sphL19handle_overflow_nopEv,"axG",@progbits,_ZN3uhd9transport3sph19recv_packet_handler6resizeEj,comdat
       .align 4        .type   _ZN3uhd9transport3sphL19handle_overflow_nopEv,
@function
.LFB8296:
       .file 6
"/home/dave/debian/uhd/uhd-3.9.1/host/lib/usrp/usrp1/../../transport/super_recv_packet_handler.hpp"
       .loc 6 61 0
       .cfi_startproc
_ZN3uhd9transport3sphL19handle_overflow_nopEv:
       .PROC
       .CALLINFO FRAME=0,NO_CALLS
       .ENTRY
       bv,n %r0(%r2)
       .EXIT
       .PROCEND        .cfi_endproc
.LFE8296:
       .size   _ZN3uhd9transport3sphL19handle_overflow_nopEv,
.-_ZN3uhd9transport3sphL19handle_overflow_nopEv

Subsequently, there is a reference from a plabel in .data.rel.ro.local:

       .section        .data.rel.ro.local
       .align 4
.LC135:
       .word   P%_ZN3uhd9transport3sphL19handle_overflow_nopEv

COMDAT group section [   10] `.group'
[_ZN3uhd9transport3sph19recv_packet_handler6resizeEj] contains 2 sections:
   [Index]    Name
   [  581]   .text._ZN3uhd9transport3sphL19handle_overflow_nopEv
   [ 1282]   .text._ZN3uhd9transport3sph19recv_packet_handler6resizeEj

It is my understanding that local references into COMDAT groups are not
allowed.
HPPA is probably particularly sensitive to this because of the "P" PLABEL32
reloc.

Compile command:
/usr/bin/c++   -DHAVE_CONFIG_H -DIHEX_USE_STDBOOL -DUHD_DLL_EXPORTS
-DUHD_IMAGES_DIR=OFF -DUHD_VERSION=30901 -g -O2 -Wformat
-Werror=format-security -D_FORTIFY_SOURCE=2  -fvisibility=hidden
-fvisibility-inlines-hidden -fPIC
-I/home/dave/debian/uhd/uhd-3.9.1/build/include
-I/home/dave/debian/uhd/uhd-3.9.1/host/include
-I/home/dave/debian/uhd/uhd-3.9.1/build/lib/ic_reg_maps
-I/home/dave/debian/uhd/uhd-3.9.1/host/lib/convert
-I/home/dave/debian/uhd/uhd-3.9.1/build/lib/convert
-I/home/dave/debian/uhd/uhd-3.9.1/build/lib/transport/nirio/lvbitx
-I/usr/include/libusb-1.0 -I/home/dave/debian/uhd/uhd-3.9.1/host/lib/usrp
-I/home/dave/debian/uhd/uhd-3.9.1/host/lib/usrp/cores
-I/home/dave/debian/uhd/uhd-3.9.1/host/../firmware/fx2/common
-I/home/dave/debian/uhd/uhd-3.9.1/host/lib/usrp/common
-I/home/dave/debian/uhd/uhd-3.9.1/host/lib/usrp/common/ad9361_driver    -Wall
-Wextra -Wsign-compare -o CMakeFiles/uhd.dir/usrp/usrp1/io_impl.cpp.o -c
/home/dave/debian/uhd/uhd-3.9.1/host/lib/usrp/usrp1/io_impl.cpp