[Bug tree-optimization/65337] [5/6 Regression] bootstrap-lto gnat1 linktime ICE: gcc/ada/exp_aggr.adb:6570:0: internal compiler error: in forward_edge_to_pdom, at tree-ssa-dce.c:1086

["steven at uplinklabs dot net" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65337

--- Comment #9 from Steven Noonan <steven at uplinklabs dot net> ---
Sure.

$ gdb --args
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/./prev-gcc/xgcc
-B/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/./prev-gcc/
-B/usr/x86_64-unknown-linux-gnu/bin/ -B/usr/x86_64-unknown-linux-gnu/bin/
-B/usr/x86_64-unknown-linux-gnu/lib/ -isystem
/usr/x86_64-unknown-linux-gnu/include -isystem
/usr/x86_64-unknown-linux-gnu/sys-include    -c -g -O2 -flto=jobserver
-frandom-seed=1  -gnatpg  -W -Wall -nostdinc -I- -I. -Iada/generated -Iada
-I/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/ada
-I/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/ada/gcc-interface
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/ada/comperr.adb
-o ada/comperr.o
GNU gdb (GDB) 7.9.1
Copyright (C) 2015 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/./prev-gcc/xgcc...done.
warning: File
"/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/gcc/.gdbinit"
auto-loading has been declined by your `auto-load safe-path' set to
"$debugdir:$datadir/auto-load".
To enable execution of this file add
        add-auto-load-safe-path
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/gcc/.gdbinit
line to your configuration file "/home/snoonan/.gdbinit".
To completely disable this security protection add
        set auto-load safe-path /
line to your configuration file "/home/snoonan/.gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:
        info "(gdb)Auto-loading safe path"
(gdb) set follow-fork-mode child
(gdb) run
Starting program:
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/prev-gcc/xgcc
-B/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/./prev-gcc/
-B/usr/x86_64-unknown-linux-gnu/bin/ -B/usr/x86_64-unknown-linux-gnu/bin/
-B/usr/x86_64-unknown-linux-gnu/lib/ -isystem
/usr/x86_64-unknown-linux-gnu/include -isystem
/usr/x86_64-unknown-linux-gnu/sys-include -c -g -O2 -flto=jobserver
-frandom-seed=1 -gnatpg -W -Wall -nostdinc -I- -I. -Iada/generated -Iada
-I/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/ada
-I/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/ada/gcc-interface
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/ada/comperr.adb
-o ada/comperr.o
[New process 16017]
process 16017 is executing new program:
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-build/prev-gcc/gnat1

Program received signal SIGSEGV, Segmentation fault.
[Switching to process 16017]
0x0000000000c354ed in ei_edge (i=...) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/basic-block.h:460
460       return EDGE_I (ei_container (i), i.index);
(gdb) thread apply all bt full

Thread 2 (process 16017):
#0  0x0000000000c354ed in ei_edge (i=...) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/basic-block.h:460
No locals.
#1  0x0000000000c376cf in inverted_post_order_compute (post_order=0x2e3d9a0,
start_points=0x2bb0858 <bb_contains_live_stmts>) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/cfganal.c:837
        ei = {
          index = 0, 
          container = 0x7ffff68543a8
        }
        pred = 0x7ffff6c8b8be <malloc+110>
        has_unvisited_bb = false
        bb = 0x0
        stack = 0x2e1e740
        sp = 171
        post_order_num = 0
        visited = 0x2decb40
        __FUNCTION__ = "inverted_post_order_compute"
#2  0x00000000011ddcdc in remove_dead_stmt (i=0x7fffffffc950,
bb=0x7ffff5ad07b8) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/tree-ssa-dce.c:1076
        postorder = 0x2e3d9a0
        postorder_num = 0
        ei = {
          index = 4121675328, 
          container = 0x7fffffffc860
        }
        e = 0x0
        e2 = 0xdc9474 <gimple_call_flags(gimple_statement_base const*)+47>
        stmt = 0x7ffff5abc640
        __FUNCTION__ = "remove_dead_stmt"
#3  0x00000000011de918 in eliminate_unnecessary_stmts () at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/tree-ssa-dce.c:1360
        something_changed = true
        bb = 0x7ffff5ad07b8
        gsi = {
          ptr = 0x7ffff5abc640, 
          seq = 0x7ffff5ad07f8, 
          bb = 0x7ffff5ad07b8
        }
        psi = {
          ptr = 0x0, 
          seq = 0x7ffff5ad07f8, 
          bb = 0x7ffff5ad07b8
        }
        stmt = 0x7ffff5abc640
        call = 0x0
        h = {
          m_vec = 0x2e407b0
        }
        __FUNCTION__ = "eliminate_unnecessary_stmts"
#4  0x00000000011df279 in perform_tree_ssa_dce (aggressive=true) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/tree-ssa-dce.c:1629
        something_changed = false
#5  0x00000000011df35a in tree_ssa_cd_dce () at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/tree-ssa-dce.c:1670
No locals.
#6  0x00000000011df4c7 in (anonymous namespace)::pass_cd_dce::execute
(this=0x2c14da0) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/tree-ssa-dce.c:1735
No locals.
#7  0x0000000000fdf3b5 in execute_one_pass (pass=0x2c14da0) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/passes.c:2330
        todo_after = 0
        gate_status = true
        __FUNCTION__ = "execute_one_pass"
#8  0x0000000000fdf5ef in execute_pass_list_1 (pass=0x2c14da0) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/passes.c:2382
        __FUNCTION__ = "execute_pass_list_1"
#9  0x0000000000fdf620 in execute_pass_list_1 (pass=0x2c149e0) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/passes.c:2383
        __FUNCTION__ = "execute_pass_list_1"
#10 0x0000000000fdf660 in execute_pass_list (fn=0x7ffff59fc7e0, pass=0x2c14860)
at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/passes.c:2393
No locals.
#11 0x0000000000fddfe3 in do_per_function_toporder (callback=0xfdf638
<execute_pass_list(function*, opt_pass*)>, data=0x2c14860) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/passes.c:1728
        node = 0x7ffff685ac40
        hook = 0x2c04f40
        order_idx = 0x7fffffffcb00
        i = 0
        __FUNCTION__ = "do_per_function_toporder"
#12 0x0000000000fe0200 in execute_ipa_pass_list (pass=0x2c14800) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/passes.c:2736
        __FUNCTION__ = "execute_ipa_pass_list"
#13 0x0000000000c87712 in ipa_passes () at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/cgraphunit.c:2171
        passes = 0x2c13500
#14 0x0000000000c87b0e in symbol_table::compile (this=0x7ffff684f000) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/cgraphunit.c:2312
No locals.
#15 0x0000000000c87d86 in symbol_table::finalize_compilation_unit
(this=0x7ffff684f000) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/cgraphunit.c:2461
No locals.
#16 0x00000000007f007e in gnat_write_global_declarations () at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/ada/gcc-interface/utils.c:5217
        i = 339
        iter = 0x0
#17 0x00000000010ca5da in compile_file () at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/toplev.c:608
No locals.
#18 0x00000000010cc9a3 in do_compile () at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/toplev.c:2076
        i = 1
#19 0x00000000010ccbd3 in toplev::main (this=0x7fffffffcdb0, argc=34,
argv=0x7fffffffceb8) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/toplev.c:2174
No locals.
#20 0x000000000199b8f4 in main (argc=34, argv=0x7fffffffceb8) at
/home/snoonan/Development/ec2-packages/gcc-multilib/src/gcc-5-20150602/gcc/main.c:39
        toplev = {
          m_use_TV_TOTAL = true, 
          m_init_signals = true
        }
(gdb)