[Bug debug/86523] [9 Regression] ICE in gen_member_die, at dwarf2out.c:24933 starting from r262560

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86523

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2018-07-16
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Martin Liška from comment #1)
> One more test-case with a bit different BT:
> 
> $  cat ice.ii
> namespace {
> class a typedef b;
> class a {};
> } // namespace
> class c {
>   struct C {
>     b d;
>   };
>   C e() const;
> };
> c::C c::e() const {
>   C g;
>   struct h {
>     C g;
>     h(C *) {}
>   } f(&g);
> }
> 
> $ g++ ice.ii -O2 -flto=8 -g -shared
> ice.ii: In member function ‘c::C c::e() const’:
> ice.ii:17:1: warning: no return statement in function returning non-void
> [-Wreturn-type]
>  }
>  ^
> 
> lto1: internal compiler error: in dwarf2out_finish, at dwarf2out.c:31107
> 0x5c87cd dwarf2out_finish
> 	/home/marxin/Programming/gcc/gcc/dwarf2out.c:31107
> Please submit a full bug report,
> with preprocessed source if appropriate.
> Please include the complete backtrace with any bug report.
> See <https://gcc.gnu.org/bugs/> for instructions.
> make: *** [/tmp/cc5TI8Oi.mk:2: /tmp/ccQqbTv7.ltrans0.ltrans.o] Error 1
> lto-wrapper: fatal error: make returned 2 exit status
> compilation terminated.
> /usr/bin/ld: error: lto-wrapper failed
> collect2: error: ld returned 1 exit status

We generate a DECL_ASSEMBLER_NAME for <type_decl 0x7ffff6a822f8 b> through

#0  0x00000000009e1269 in add_linkage_name_raw (
    die=<dw_die_ref 0x7ffff6a85af0 DW_TAG_structure_type <parent=0x7ffff6a850f0
DW_TAG_namespace>>, decl=<type_decl 0x7ffff6a822f8 b>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:21233
#1  0x00000000009ec5df in gen_typedef_die (decl=<type_decl 0x7ffff6a822f8 b>, 
    context_die=<dw_die_ref 0x7ffff6a850f0 DW_TAG_namespace
<parent=0x7ffff6a85000 DW_TAG_compile_unit>>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25251
#2  0x00000000009ef609 in gen_decl_die (decl=<type_decl 0x7ffff6a822f8 b>, 
    origin=<tree 0x0>, ctx=0x0, 
    context_die=<dw_die_ref 0x7ffff6a850f0 DW_TAG_namespace
<parent=0x7ffff6a85000 DW_TAG_compile_unit>>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:26229
#3  0x00000000009ecd95 in gen_type_die_with_usage (
    type=<record_type 0x7ffff6a863f0 b>, 
    context_die=<dw_die_ref 0x7ffff6a850f0 DW_TAG_namespace
<parent=0x7ffff6a85000 DW_TAG_compile_unit>>, usage=DINFO_USAGE_DIR_USE)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25394
#4  0x00000000009ed695 in gen_type_die (type=<record_type 0x7ffff6a863f0 b>, 
    context_die=<dw_die_ref 0x7ffff6a85a50 DW_TAG_structure_type
<parent=0x7ffff6a85a00 DW_TAG_structure_type>>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25578
#5  0x00000000009ef8c6 in gen_decl_die (decl=<field_decl 0x7ffff6a82390 d>, 
    origin=<tree 0x0>, ctx=0x7fffffffcdc0, 
    context_die=<dw_die_ref 0x7ffff6a85a50 DW_TAG_structure_type
<parent=0x7ffff6a85a00 DW_TAG_structure_type>>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:26297
#6  0x00000000009eb81f in gen_member_die (type=<record_type 0x7ffff6a86498 C>, 
    context_die=<dw_die_ref 0x7ffff6a85a50 DW_TAG_structure_type
<parent=0x7ffff6a85a00 DW_TAG_structure_type>>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25032
#7  0x00000000009ebf69 in gen_struct_or_union_type_die (
    type=<record_type 0x7ffff6a86498 C>, 
    context_die=<dw_die_ref 0x7ffff6a85a00 DW_TAG_structure_type
<parent=0x7ffff6a85000 DW_TAG_compile_unit>>, usage=DINFO_USAGE_DIR_USE)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25128
#8  0x00000000009eca10 in gen_tagged_type_die (
    type=<record_type 0x7ffff6a86498 C>, 
    context_die=<dw_die_ref 0x7ffff6a85a00 DW_TAG_structure_type
<parent=0x7ffff6a85000 DW_TAG_compile_unit>>, usage=DINFO_USAGE_DIR_USE)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25329
#9  0x00000000009ed321 in gen_type_die_with_usage (
    type=<record_type 0x7ffff6a86498 C>, 
    context_die=<dw_die_ref 0x7ffff6a859b0 DW_TAG_structure_type
<parent=0x7ffff6a85190 DW_TAG_subprogram>>, usage=DINFO_USAGE_DIR_USE)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25524
...
#18 0x00000000009eea5f in force_type_die (type=<record_type 0x7ffff6a867e0 h>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25973
#19 0x00000000009ee6d7 in get_context_die (
    context=<record_type 0x7ffff6a867e0 h>)
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:25888
#20 0x00000000009fa4c9 in flush_limbo_die_list ()
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:31053
#21 0x00000000009fa5dc in dwarf2out_finish ()
    at /space/rguenther/src/gcc-sccvn/gcc/dwarf2out.c:31093

where the limbo DIE is

$8 = {die = <dw_die_ref 0x7ffff6a852d0 DW_TAG_subprogram>, 
  created_for = <function_decl 0x7ffff6a81e00 __ct_base >, 
  next = 0x7ffff6a7c510}

DIE    0: DW_TAG_subprogram (0x7ffff6a852d0)
  abbrev id: 0 offset: 0 mark: 0
  DW_AT_abstract_origin: die -> label: t.ii.e437cd39 + 316 (0x7ffff6a85320)

so the issue here is that the context is a RECORD_TYPE which context is
$12 = <function_decl 0x7ffff6a81b00 e>
but at the time of dwarf2out_register_external_die it isn't assigned the
proper parent.

So the real bug is that we do this "inclusive":

      else if (TREE_CODE (ctx) == FUNCTION_DECL
               && TREE_CODE (decl) != PARM_DECL
               && TREE_CODE (decl) != BLOCK)
        /* Leave function local entities parent determination to when
           we process scope vars.  */
        ;

including != FUNCTION_DECL makes both testcases work, another somewhat
obvious addition would be RESULT_DECL.