Bugs in LLDB

Comparing lldb::SBType objects representing the same type doesn't always work

>>> v = lldb.frame.FindVariable('x')
>>> v.GetType().GetName()
'int'
>>> lldb.target.GetBasicType(lldb.eBasicTypeInt).GetName()
'int'
>>> v.GetType() == lldb.target.GetBasicType(lldb.eBasicTypeInt)
False

Discussion on #lldb channel -- https://discord.com/channels/636084430946959380/636732809708306432/800681526198272010

Workaround in lldb-eval -- https://github.com/google/lldb-eval/blob/5add7abc740ceeb43db4ab7c644248dbeb2908c1/lldb-eval/value.cc#L163

Inconsistent global variable names for Linux and Windows

# Definitions
int array2d[10][10];
namespace abc { int array2d[10][10]; }

# Windows
>>> lldb.target.FindFirstGlobalVariable("array2d").GetName()
'int (*array2d)[10]'
>>> lldb.target.FindFirstGlobalVariable("abc::array2d").GetName()
'int (*abc::array2d)[10]'

# Linux
>>> lldb.target.FindFirstGlobalVariable("array2d").GetName()
'::array2d'
>>> lldb.target.FindFirstGlobalVariable("abc::array2d").GetName()
'abc::array2d'

Discussion on #lldb channel -- https://discord.com/channels/636084430946959380/636732809708306432/819528095496667156

Dereferencing a value canonizes the type

>>> x_ref = lldb.frame.FindVariable('x_ref')
>>> x_ref.type.name
'myint &'
>>> x_ref.type.GetDereferencedType().name
'myint'
>>> x_ref.Dereference().type.name
'int'

Current workaround in lldb-eval -- https://github.com/google/lldb-eval/commit/c914f65702714b90565b5df5450eadd0fd617658

lldb::SBValue::Persist() doesn't work for “ephemeral” values

>>> v = lldb.target.CreateValueFromData(...)
>>> vp = v.Persist()
>>> vp.value
'42'
>>> vp.name
'$0'
>>> lldb.frame.EvaluateExpression('$0').value
'42'
>>> lldb.frame.EvaluateExpression('++$0').value
'43'
>>> lldb.frame.EvaluateExpression('++$0').value
'44'
>>> vp.value
'42'

Discussion in Phabricator -- https://reviews.llvm.org/D98370

Incorrect integral promotions for enumerations

enum E : uint8_t {
  eZero,
};

* thread #1, name = 'a.out', stop reason = step in
    frame #0: 0x0000000000401124 a.out`main at enum.cc:9:3
   6   
   7    int main() {
   8      auto x = E::eZero << 1;
-> 9      return 0;
   10   }
(lldb) p x
(int) $0 = 0
(lldb) p E::eZero << 1
(unsigned int) $1 = 0

uint8_t should be promoted to int, but the expression evaluator returns unsigned int.

Discussion on #lldb channel -- https://discord.com/channels/636084430946959380/636732809708306432/860112842266640424