LLDB: reference to std::pmr::deque<> incorrectly shows size zero

[ByunghoonKim]

Hi,
LLDB does not seem to recognize std::pmr::deque<>. The symptom is identical to what is described in #62153.
Tested on MacBook Pro M1 Pro,

lldb-1500.0.22.8
Apple Swift version 5.9 (swiftlang-5.9.0.128.108 clang-1500.0.40.1)

❯ cat testing.cxx
#include <cstdio>
#include <memory_resource>
#include <deque>
typedef std::pmr::deque<int> int_deq;

int main() {
  char buffer[1024];
  std::pmr::monotonic_buffer_resource buf{buffer, 1024};

  int_deq numbers{&buf};
  printf("break here");

  (numbers.push_back(1));
  printf("break here");

  (numbers.push_back(12));
  (numbers.push_back(123));
  (numbers.push_back(1234));
  (numbers.push_back(12345));
  (numbers.push_back(123456));
  (numbers.push_back(1234567));

  numbers.clear();
  printf("break here");

  return 0;
}
❯ lldb a.out
(lldb) target create "a.out"
Current executable set to '(**blurred**)/a.out' (arm64).
(lldb) breakpoint set --line 14
Breakpoint 1: where = a.out`main + 136 at testing.cxx:14:3, address = 0x0000000100003d38
(lldb) run
Process 56671 launched: '(**blurred**)/a.out' (arm64)
Process 56671 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x0000000100003d38 a.out`main at testing.cxx:14:3
   11  	 printf("break here");
   12  	
   13  	 (numbers.push_back(1));
-> 14  	 printf("break here");
   15  	
   16  	 (numbers.push_back(12));
   17  	 (numbers.push_back(123));
Target 0: (a.out) stopped.
(lldb) expr numbers
(int_deq) $0 = size=0 {}
(lldb) expr numbers.size()
(std::deque<int, std::pmr::polymorphic_allocator<int> >::size_type) $1 = 1
(lldb) 

[llvmbot]

@llvm/issue-subscribers-lldb

Hi, LLDB does not seem to recognize std::pmr::deque<>. The symptom is identical to what is described in #62153. Tested on MacBook Pro M1 Pro, ``` lldb-1500.0.22.8 Apple Swift version 5.9 (swiftlang-5.9.0.128.108 clang-1500.0.40.1) ``` ``` ❯ cat testing.cxx #include <cstdio> #include <memory_resource> #include <deque> typedef std::pmr::deque<int> int_deq;

int main() {
char buffer[1024];
std::pmr::monotonic_buffer_resource buf{buffer, 1024};

int_deq numbers{&buf};
printf("break here");

(numbers.push_back(1));
printf("break here");

(numbers.push_back(12));
(numbers.push_back(123));
(numbers.push_back(1234));
(numbers.push_back(12345));
(numbers.push_back(123456));
(numbers.push_back(1234567));

numbers.clear();
printf("break here");

return 0;
}
❯ lldb a.out
(lldb) target create "a.out"
Current executable set to '(blurred)/a.out' (arm64).
(lldb) breakpoint set --line 14
Breakpoint 1: where = a.out`main + 136 at testing.cxx:14:3, address = 0x0000000100003d38
(lldb) run
Process 56671 launched: '(blurred)/a.out' (arm64)
Process 56671 stopped

• thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
  frame #0: 0x0000000100003d38 a.out`main at testing.cxx:14:3
  11 printf("break here");
  12
  13 (numbers.push_back(1));
  -> 14 printf("break here");
  15
  16 (numbers.push_back(12));
  17 (numbers.push_back(123));
  Target 0: (a.out) stopped.
  (lldb) expr numbers
  (int_deq) $0 = size=0 {}
  (lldb) expr numbers.size()
  (std::deque<int, std::pmr::polymorphic_allocator<int> >::size_type) $1 = 1
  (lldb)

</details>

[Michael137]

As with #62153, std::pmr::deque uses the python formatter in synthetic applied to (int_deq) numbers is: Python class lldb.formatters.cpp.libcxx.stddeque_SynthProvider.

Looks like _get_value_of_compressed_pair isn't implemented correctly for compressed pairs instantiated with a pmr allocator

[Michael137]

Apparently the problem is that with the allocator we now have an extra __compressed_pair_elem base also with a __value_ member. So when we do TypeSystemClang::GetIndexOfChildMemberWithName, we fail to find the __value_ in one of the bases, and then throw all results away because we deem it an invalid query. Will have to check why one of the base path queries fails

[xgupta]

It is working on linux -

(lldb) expr numbers
(int_deq) $2 = size=1 {
  [0] = 1
}
(lldb) expr numbers.size()
(size_type) $3 = 1