Re: Undesirable entries in typedefs list

On 2018-03-24 10:41:40 -0700, Andres Freund wrote:
> I'm about to head out, but afterwards I'm going to check what the
> typedefs collected actually are when LLVM is enabled.

It's indeed from llvm:

<3><5201>: Abbrev Number: 4 (DW_TAG_typedef)
<5202> DW_AT_name : (indirect string, offset: 0x8a0a4): string
<5206> DW_AT_decl_file : 13
<5207> DW_AT_decl_line : 74
<5208> DW_AT_type : <0x3896>

which basically references std::string

<3><3896>: Abbrev Number: 24 (DW_TAG_class_type)
<3897> DW_AT_name : (indirect string, offset: 0x2db87): basic_string<char, std::char_traits<char>, std::allocator<char> >
<389b> DW_AT_byte_size : 32
<389c> DW_AT_decl_file : 12
<389d> DW_AT_decl_line : 77
<389e> DW_AT_sibling : <0x51fc>

Given that the PG code shouldn't refer to this, I think we might be able
to limit things by specifying --dwarf-depth=3 to the objdump output.

I've attached the difference between a objdump typedefs list roughly
equivalent to what the buildfarm uses. There's no difference when not
using llvm.

I'm a bit uncomfortable relying --dwarf-depth=3, with 3 being determined
purely experimentally though.

Greetings,

Andres Freund