[Bug lto/58084] [4.9 Regression] FAIL: gcc.dg/torture/pr8081.c -O2 -flto -fno-use-linker-plugin -flto-partition=none (internal compiler error)

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58084

--- Comment #7 from Hans-Peter Nilsson <hp at gcc dot gnu.org> ---
For the record, I'm logging the following regression for cris-axis-elf in this
PR as well, because:
1: It's lto
2: The regression is observed introduced in the same interval locally:
(201466:201470]
3: While likely reproducible with a complete toolchain, last I looked
-save-temps didn't do much to help lto debuggability, nor was there equivalent
machinery, so not seeing it as helpful in a separate PR.

I'll make it a separate PR if I see separate changes in behavior (like
torture/pr8081.c fixed but torture/pr48661.C not).

Running /tmp/hpautotest-gcc0/gcc/gcc/testsuite/g++.dg/torture/dg-torture.exp
...
FAIL: g++.dg/torture/pr48661.C  -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (internal compiler error)
FAIL: g++.dg/torture/pr48661.C  -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (test for excess errors)
FAIL: g++.dg/torture/pr48661.C  -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (internal compiler error)
FAIL: g++.dg/torture/pr48661.C  -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)
WARNING: g++.dg/torture/pr48661.C  -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  compilation failed to produce executable

In g++.log:
Executing on host:
/tmp/hpautotest-gcc1/cris-elf/gccobj/gcc/testsuite/g++/../../xg++
-B/tmp/hpautotest-gcc1/cris-elf/gccobj/gcc/testsuite/g++/../../
/tmp/hpautotest-gcc1/gcc/gcc/testsuite/g++.dg/torture/pr48661.C 
-fno-diagnostics-show-caret -fdiagnostics-color=never  -nostdinc++
-I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include/cris-elf
-I/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/libstdc++-v3/include
-I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/libsupc++
-I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/include/backward
-I/tmp/hpautotest-gcc1/gcc/libstdc++-v3/testsuite/util -fmessage-length=0  -O2
-flto -fno-use-linker-plugin -flto-partition=none      -isystem
/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib/targ-include -isystem
/tmp/hpautotest-gcc1/gcc/newlib/libc/include
-B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris/
-L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libgloss/cris
-L/tmp/hpautotest-gcc1/gcc/libgloss/cris 
-B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib/
-L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./newlib -sim3  
-L/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libstdc++-v3/src/.libs 
-B/tmp/hpautotest-gcc1/cris-elf/gccobj/cris-elf/./libstdc++-v3/src/.libs  -lm  
-o ./pr48661.exe    (timeout = 300)
In member function '_ZTv0_n12_NK1D1mEv':
lto1: internal compiler error: Segmentation fault
0x7ea965 crash_signal
        /tmp/hpautotest-gcc1/gcc/gcc/toplev.c:335
0x524936 contains_struct_check
        /tmp/hpautotest-gcc1/gcc/gcc/tree.h:3803
0x524936 fold_build_pointer_plus_loc
        /tmp/hpautotest-gcc1/gcc/gcc/tree.h:5860
0x524936 thunk_adjust
        /tmp/hpautotest-gcc1/gcc/gcc/cgraphunit.c:1297
0x5264c3 expand_thunk(cgraph_node*)
        /tmp/hpautotest-gcc1/gcc/gcc/cgraphunit.c:1440
0x526d5b assemble_thunks_and_aliases
        /tmp/hpautotest-gcc1/gcc/gcc/cgraphunit.c:1549
0x526daa assemble_thunks_and_aliases
        /tmp/hpautotest-gcc1/gcc/gcc/cgraphunit.c:1565
0x526f42 expand_function
        /tmp/hpautotest-gcc1/gcc/gcc/cgraphunit.c:1675
0x527cb0 expand_all_functions
        /tmp/hpautotest-gcc1/gcc/gcc/cgraphunit.c:1717
0x527cb0 compile()
        /tmp/hpautotest-gcc1/gcc/gcc/cgraphunit.c:2054
0x4acbd6 lto_main()
        /tmp/hpautotest-gcc1/gcc/gcc/lto/lto.c:3843

$ c++filt _ZTv0_n12_NK1D1mEv
virtual thunk to D::m() const

(Shouldn't the "In member function" error message refer to the demangled name?)