[lldb] TargetList::CreateTargetInternal() selects wrong platform

[slydiman]

The lldb/test/API/python_api/debugger/TestDebuggerAPI.py test failed in case of Windows or Linux x86_64 host and Linux Aarch64 target:

File "llvm-project\lldb\test\API\python_api\debugger\TestDebuggerAPI.py", line 108, in test_CreateTarget_platform
  platform2.GetWorkingDirectory().endswith("bar"),
AttributeError: 'NoneType' object has no attribute 'endswith'

target1 = self.dbg.CreateTarget(exe, None, "remote-linux", False, error) calls TargetList::CreateTargetInternal() in llvm-project/lldb/source/Target/TargetList.cpp, line 76

platform_options contains remote-linux, triple_str is empty, user_exe_path is a path to ELF created from elf.yaml (x86_64).

platform_arch is updated to x86_64 in TargetList.cpp, line 169:

// Only one arch and none was specified.
prefer_platform_arch = true;
platform_arch = matching_module_spec.GetArchitecture();

and platform_sp is updated to host in TargetList.cpp, line 226:

// If "arch" isn't valid, yet "platform_arch" is, it means we have an
// executable file with a single architecture which should be used.
ArchSpec fixed_platform_arch;
if (!platform_sp->IsCompatibleArchitecture(platform_arch, {}, ArchSpec::CompatibleMatch, nullptr)) {
  platform_sp = platform_list.GetOrCreate(platform_arch, {}, &fixed_platform_arch);
  if (platform_sp)
    platform_list.SetSelectedPlatform(platform_sp);
}

Next call target2 = self.dbg.CreateTarget(exe, None, "remote-linux", False, error) will create the platform remote-linux in TargetList.cpp, line 98:

// Create a new platform if a platform was specified in the platform options and doesn't match the selected platform.
if (platform_options && platform_options->PlatformWasSpecified() && !platform_options->PlatformMatches(platform_sp)) {
  const bool select_platform = true;
  platform_sp = platform_options->CreatePlatformWithOptions(debugger.GetCommandInterpreter(), 
      arch, select_platform, error, platform_arch);
  if (!platform_sp)
    return error;
}

If the user specifies an explicit platform in the CreateTarget function, that platform should really take precedence over anything else.

[llvmbot]

@llvm/issue-subscribers-lldb

Author: Dmitry Vasilyev (slydiman)

The `lldb/test/API/python_api/debugger/TestDebuggerAPI.py` test failed in case of Windows host (x86_64) and Linux target (Aarch64). `target1 = self.dbg.CreateTarget(exe, None, "remote-linux", False, error)` calls TargetList::CreateTargetInternal() in llvm-project/lldb/source/Target/TargetList.cpp, line 76 platform_options contains `remote-linux`, `triple_str is empty`, user_exe_path is a path to ELF created from elf.yaml (x86_64). `platform_arch` is updated to `x86_64` in TargetList.cpp, line 169: ``` // Only one arch and none was specified. prefer_platform_arch = true; platform_arch = matching_module_spec.GetArchitecture(); ``` and platform_sp is updated to `host` in TargetList.cpp, line 226: ``` // If "arch" isn't valid, yet "platform_arch" is, it means we have an // executable file with a single architecture which should be used. ArchSpec fixed_platform_arch; if (!platform_sp->IsCompatibleArchitecture(platform_arch, {}, ArchSpec::CompatibleMatch, nullptr)) { platform_sp = platform_list.GetOrCreate(platform_arch, {}, &fixed_platform_arch); if (platform_sp) platform_list.SetSelectedPlatform(platform_sp); } ``` Next call `target2 = self.dbg.CreateTarget(exe, None, "remote-linux", False, error)` will create the platform remote-linux in TargetList.cpp, line 98: ``` // Create a new platform if a platform was specified in the platform options and doesn't match the selected platform. if (platform_options && platform_options->PlatformWasSpecified() && !platform_options->PlatformMatches(platform_sp)) { const bool select_platform = true; platform_sp = platform_options->CreatePlatformWithOptions(debugger.GetCommandInterpreter(), arch, select_platform, error, platform_arch); if (!platform_sp) return error; } ``` If the user specifies an explicit platform in the CreateTarget function, that platform should really take precedence over anything else.