[all-commits] [llvm/llvm-project] 9dcaca: [lldb][test] TestConstStaticIntegralMember.py: fix...

[Michael137 via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 9dcaca706841fa38683eee341f24aafb58e6e3e9
      https://github.com/llvm/llvm-project/commit/9dcaca706841fa38683eee341f24aafb58e6e3e9
  Author: Michael Buch <michaelbuch12 at gmail.com>
  Date:   2022-11-10 (Thu, 10 Nov 2022)

  Changed paths:
    M lldb/test/API/lang/cpp/const_static_integral_member/TestConstStaticIntegralMember.py
    M lldb/test/API/lang/cpp/const_static_integral_member/main.cpp

  Log Message:
  -----------
  [lldb][test] TestConstStaticIntegralMember.py: fix for clang-{9,11,13}

**Summary**

The public lldb matrix bot is failing for tests compiled with clang-9, clang-11, clang-13.

This patch addresses these failures by evaluating the enum case that
doesn't cause malformed DWARF in older version of clang.

There was no particular reason we had to use `true` enum case
to reproduce the bug in #58383, so simply switch to use `false`
to get all bots passing again.

**Details**

In older versions of clang, the following snippet:
```
enum EnumBool : bool {
  enum_bool_case1 = false,
  enum_bool_case2 = true,
};

struct A {
  const static EnumBool enum_bool_val = enum_bool_case2;
};
```

…results in following DWARF:
```
0x00000052:   DW_TAG_structure_type
                DW_AT_calling_convention        (DW_CC_pass_by_value)
                DW_AT_name      ("A")
                DW_AT_byte_size (0x01)
                DW_AT_decl_file ("/Users/michaelbuch/Git/llvm-project/lldb/test/API/lang/cpp/const_static_integral_member/repro.cpp")
                DW_AT_decl_line (6)

0x0000005b:     DW_TAG_member
                  DW_AT_name    ("enum_bool_val")
                  DW_AT_type    (0x0000000000000068 "const EnumBool")
                  DW_AT_decl_file       ("/Users/michaelbuch/Git/llvm-project/lldb/test/API/lang/cpp/const_static_integral_member/repro.cpp")
                  DW_AT_decl_line       (7)
                  DW_AT_external        (true)
                  DW_AT_declaration     (true)
                  DW_AT_const_value     (-1)

```

Note the `DW_AT_const_value == -1`

When evaluating `A::enum_bool_val` in the lldb we get:
```
(lldb) p A::enum_bool_val
error: expression failed to parse:
error: Couldn't lookup symbols:
  __ZN1A13enum_bool_valE
```

Enabling the DWARF logs we see:

```
(arm64) clang-13.out: DWARFASTParserClang::ParseTypeFromDWARF (die = 0x00000068, decl_ctx = 0x136ac1e30 (die 0x0000000b)) DW_TAG_const_type name = '(null)')
Failed to add const value to variable A::enum_bool_val: Can't store unsigned value 18446744073709551615 in integer with 1 bits.
```

This occurs because a boolean enum is considered an unsigned integer
type, but we try to initialize it with a `-1`.

**Testing**

- Confirmed locally that top-of-tree lldb correctly
  evaluates the previously failing expression when
  the test program is compiled with clang-13

Differential Revision: https://reviews.llvm.org/D137793