LLDB gcc std lib data formatters

Hi,

Apologies if this is the wrong forum for this question - redirection to the correct place would be appreciated…

I am running

lldb --version
lldb-900.0.64
Swift-4.0

with binaries compiled using g++

g+±5 --version
g+±5 (Homebrew GCC 5.5.0_2) 5.5.0
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.(although I have tried a build from repo as well)

The website implies that gcc std library formatters should be available:

By default, several categories are created in LLDB:

  • default: this is the category where every formatter ends up, unless another category is specified
  • objc: formatters for basic and common Objective-C types that do not specifically depend on Mac OS X
  • gnu-libstdc++: formatters for std::string, std::vector, std::list and std::map as implemented by libstdcpp
    However I see:

(lldb) type category list Category: default (enabled)
Category: VectorTypes (enabled, applicable for language(s): objective-c++)
Category: runtime-synthetics (enabled, applicable for language(s): objective-c++, swift)
Category: system (enabled, applicable for language(s): objective-c++)
(lldb) type category enable gnu-libstdc++ warning: empty category enabled (typo?)

And the std containers do not print nicely:

containerTest: cat main.cpp
#include
#include

using namespace std;

int main()
{
auto v = vector< unsigned >{ 0, 1, 2, 3, 4, 5, 6, 7, 9 };

for( auto i : v )
{
cout << i << “\n”;
}

return( 0 );
}
containerTest: g+±5 -g -std=c++11 main.cpp
/var/folders/2_/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:157:11: warning: section “__textcoal_nt” is deprecated
.section _TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/2
/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:157:11: note: change section name to “__text”
.section _TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/2
/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:386:11: warning: section “__textcoal_nt” is deprecated
.section _TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/2
/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:386:11: note: change section name to “__text”
.section _TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/2
/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:430:11: warning: section “__textcoal_nt” is deprecated
.section _TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/2
/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:430:11: note: change section name to “__text”
.section _TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/2
/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:683:11: warning: section “__textcoal_nt” is deprecated
.section _TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
/var/folders/2
/07xjgwq904376gst9m3ddb100000gn/T//cctjpiwL.s:683:11: note: change section name to “__text”
.section __TEXT,__textcoal_nt,coalesced,pure_instructions
^ ~~~~~~~~~~~~~
containerTest: lldb ./a.out
(lldb) target create “./a.out”
Current executable set to ‘./a.out’ (x86_64).
(lldb) b main
Breakpoint 1: where = a.out`main + 13 at main.cpp:8, address = 0x0000000100001673
(lldb) run
Process 98294 launched: ‘./a.out’ (x86_64)
Process 98294 stopped

  • thread #1, queue = ‘com.apple.main-thread’, stop reason = breakpoint 1.1
    frame #0: 0x0000000100001673 a.out`main at main.cpp:8
    5
    6 int main()
    7 {
    → 8 auto v = vector< unsigned >{ 0, 1, 2, 3, 4, 5, 6, 7, 9 };
    9
    10 for( auto i : v )
    11 {
    Target 0: (a.out) stopped.
    (lldb) n
    Process 98294 stopped
  • thread #1, queue = ‘com.apple.main-thread’, stop reason = step over
    frame #0: 0x00000001000016bd a.out`main at main.cpp:10
    7 {
    8 auto v = vector< unsigned >{ 0, 1, 2, 3, 4, 5, 6, 7, 9 };
    9
    → 10 for( auto i : v )
    11 {
    12 cout << i << “\n”;
    13 }
    Target 0: (a.out) stopped.
    (lldb) p v
    (vector<unsigned int, allocator >) $0 = {
    _Vector_base<unsigned int, allocator > = {
    _M_impl = {
    _M_start = 0x0000000100402050
    _M_finish = 0x0000000100402074
    _M_end_of_storage = 0x0000000100402074
    }
    }
    }
    (lldb)

Anyone able to point me at either a python pretty printer or solution to this?

Cheers, Bryan.

why is the “std::” missing from the typename (“vector<unsigned int, allocator >”) above? That is why the formatters aren’t kicking in.

Ah, ok so the default DWARF version for g++ 5 (and 6) is 2, compiling with -gdwarf-3 solves my problem.

Thanks for the help,

Bryan.