[all-commits] [llvm/llvm-project] 14a1d3: [lldb] Fix TypeSystemClang::GetBasicTypeEnumeratio...

[Matej Košík via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 14a1d3e0aeb7b8fe2cfdb2e8e029ddee8a334d14
      https://github.com/llvm/llvm-project/commit/14a1d3e0aeb7b8fe2cfdb2e8e029ddee8a334d14
  Author: Matej Košík <99839051+sedymrak at users.noreply.github.com>
  Date:   2025-10-13 (Mon, 13 Oct 2025)

  Changed paths:
    M lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
    M lldb/test/API/python_api/sbtype_basic_type/TestSBTypeBasicType.py
    M lldb/unittests/Symbol/TestTypeSystemClang.cpp

  Log Message:
  -----------
  [lldb] Fix TypeSystemClang::GetBasicTypeEnumeration for 128-bit int types (#162278)

When we take the following C program:
```
int main() {
  return 0;
}
```
and create a statically-linked executable from it:
```
clang -static -g -o main main.c
```
Then we can observe the following `lldb` behavior:
```
$ lldb
(lldb) target create main
Current executable set to '.../main' (x86_64).
(lldb) breakpoint set --name main
Breakpoint 1: where = main`main + 11 at main.c:2:3, address = 0x000000000022aa7b
(lldb) process launch
Process 3773637 launched: '/home/me/tmp/built-in/main' (x86_64)
Process 3773637 stopped
* thread #1, name = 'main', stop reason = breakpoint 1.1
    frame #0: 0x000000000022aa7b main`main at main.c:2:3
   1   	int main() {
-> 2   	  return 0;
   3   	}
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("__int128").size
0
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("unsigned __int128").size
0
(lldb) quit
```
The value return by the `SBTarget::FindFirstType` method is wrong for
the `__int128` and `unsigned __int128` basic types.

The proposed changes make the `TypeSystemClang::GetBasicTypeEnumeration`
method consistent with `gcc` and `clang` C [language
extension](https://gcc.gnu.org/onlinedocs/gcc/_005f_005fint128.html)
related to 128-bit integer types as well as with the
`BuiltinType::getName` method in the LLVM codebase itself.

When the above change is applied, the behavior of the `lldb` changes in
the following (desired) way:
```
$ lldb
(lldb) target create main
Current executable set to '.../main' (x86_64).
(lldb) breakpoint set --name main
Breakpoint 1: where = main`main + 11 at main.c:2:3, address = 0x000000000022aa7b
(lldb) process launch
Process 3773637 launched: '/home/me/tmp/built-in/main' (x86_64)
Process 3773637 stopped
* thread #1, name = 'main', stop reason = breakpoint 1.1
    frame #0: 0x000000000022aa7b main`main at main.c:2:3
   1   	int main() {
-> 2   	  return 0;
   3   	}
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("__int128").size
16
(lldb) script lldb.debugger.GetSelectedTarget().FindFirstType("unsigned __int128").size
16
(lldb) quit
```

---------

Co-authored-by: Matej Košík <matej.kosik at codasip.com>



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