[Bug pch/71622] gcc 5.3.1 crashes when it tries to compile qtbase [dev]

["thiago at kde dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71622

--- Comment #16 from Thiago Macieira <thiago at kde dot org> ---
(In reply to Markus Trippelsdorf from comment #15)
> All these bogus valgrind warnings can be suppressed if you configure gcc
> with --enable-valgrind-annotations.

That's good to know, but Valgrind didn't report a single erroneous access. And
since there's no actual crash when run inside gdb, I don't think valgrind will
help further.

If I put a breakpoint on tree.c:508 (the line reported in the output), I get:

#0  tree_node_structure_for_code (code=30240) at ../../gcc/tree.c:508
#1  tree_node_structure (t=t@entry=0x7ffff3e27438) at ../../gcc/tree.c:3370
#2  0x0000000000545080 in gt_ggc_mx_lang_tree_node (x_p=<optimized out>) at
./gt-cp-tree.h:243
#3  0x00000000007188c6 in ggc_mark_root_tab (rt=0x10b9d08
<gt_ggc_r_gt_i386_h+40>) at ../../gcc/ggc-common.c:81
#4  0x0000000000718b91 in ggc_mark_roots () at ../../gcc/ggc-common.c:98
#5  0x00000000005d1280 in ggc_collect () at ../../gcc/ggc-page.c:2199
#6  0x000000000087931f in execute_one_pass (pass=pass@entry=0x19920e0) at
../../gcc/passes.c:2371
#7  0x0000000000879646 in execute_pass_list_1 (pass=0x19920e0) at
../../gcc/passes.c:2383
#8  0x0000000000879658 in execute_pass_list_1 (pass=0x1991d20,
pass@entry=0x1991c60) at ../../gcc/passes.c:2384
#9  0x0000000000879699 in execute_pass_list (fn=0x7ffff2f479d8, pass=0x1991c60)
at ../../gcc/passes.c:2394
#10 0x000000000062dc8b in cgraph_node::expand (this=this@entry=0x7ffff2f45498)
at ../../gcc/cgraphunit.c:1896
#11 0x000000000062ef74 in expand_all_functions () at
../../gcc/cgraphunit.c:2032
#12 symbol_table::compile (this=this@entry=0x100478d300) at
../../gcc/cgraphunit.c:2385
#13 0x0000000000630410 in symbol_table::compile (this=0x100478d300) at
../../gcc/timevar.h:110
#14 symbol_table::finalize_compilation_unit (this=0x100478d300) at
../../gcc/cgraphunit.c:2462
#15 0x00000000004ce4d3 in cp_write_global_declarations () at
../../gcc/cp/decl2.c:4849
#16 0x000000000091d763 in compile_file () at ../../gcc/toplev.c:613
#17 0x000000000045f095 in do_compile () at ../../gcc/toplev.c:2067
#18 toplev::main (this=this@entry=0x7fffffffd040, argc=argc@entry=84,
argv=argv@entry=0x7fffffffd148)
    at ../../gcc/toplev.c:2165
#19 0x000000000045fd8a in main (argc=84, argv=0x7fffffffd148) at
../../gcc/main.c:39

It crashes after this.