https://github.com/Nerixyz created https://github.com/llvm/llvm-project/pull/141290
When running a process that would exit before LLDB could stop the target, it would try to interpret (and subsequently format) the exit code as a Win32 error. However, processes on Windows won't return Win32 errors in that case. They will often return an [NTSTATUS](https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/596a1078-e883-4972-9bbc-49e60bebca55). One common case for this to occur is when a DLL is missing. In that case, the process will start successfully, but it will exit with `STATUS_DLL_NOT_FOUND`. LLDB would previously return "unknown error", because it tried to [`FormatMessage`](https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-formatmessage) `0xC0000135` which doesn't work, so it fell back to "unknown error". This PR changes the error to be the string "Process prematurely exited with {0:x}" and doesn't try to format the exit code. One could `FormatMessage` an `NTSTATUS` by passing `FORMAT_MESSAGE_FROM_HMODULE` and a handle to `ntdll.dll`, however, I don't think we can get the required format arguments (e.g. the missing DLL name - `%hs`). >From 31aab0ad4b134925b702fa24fedf48880c108f06 Mon Sep 17 00:00:00 2001 From: Nerixyz <nerix...@outlook.de> Date: Fri, 23 May 2025 21:47:40 +0200 Subject: [PATCH] [LLDB] Show exit code on Windows if process can't launch --- .../Windows/Common/ProcessDebugger.cpp | 3 ++- .../API/windows/launch/missing-dll/Makefile | 5 +++++ .../launch/missing-dll/TestMissingDll.py | 22 +++++++++++++++++++ .../windows/launch/missing-dll/dummy_dll.c | 1 + .../API/windows/launch/missing-dll/main.c | 6 +++++ 5 files changed, 36 insertions(+), 1 deletion(-) create mode 100644 lldb/test/API/windows/launch/missing-dll/Makefile create mode 100644 lldb/test/API/windows/launch/missing-dll/TestMissingDll.py create mode 100644 lldb/test/API/windows/launch/missing-dll/dummy_dll.c create mode 100644 lldb/test/API/windows/launch/missing-dll/main.c diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp index bde72d61b0fee..a0f622fd69902 100644 --- a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp +++ b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp @@ -483,7 +483,8 @@ void ProcessDebugger::OnExitProcess(uint32_t exit_code) { // of the error otherwise WaitForDebuggerConnection() will be blocked. // An example of this issue is when a process fails to load a dependent DLL. if (m_session_data && !m_session_data->m_initial_stop_received) { - Status error(exit_code, eErrorTypeWin32); + Status error = Status::FromErrorStringWithFormatv( + "Process prematurely exited with {0:x}", exit_code); OnDebuggerError(error, 0); } } diff --git a/lldb/test/API/windows/launch/missing-dll/Makefile b/lldb/test/API/windows/launch/missing-dll/Makefile new file mode 100644 index 0000000000000..43e02d1d8f22b --- /dev/null +++ b/lldb/test/API/windows/launch/missing-dll/Makefile @@ -0,0 +1,5 @@ +C_SOURCES := main.c +DYLIB_C_SOURCES := dummy_dll.c +DYLIB_NAME := dummy_dll + +include Makefile.rules diff --git a/lldb/test/API/windows/launch/missing-dll/TestMissingDll.py b/lldb/test/API/windows/launch/missing-dll/TestMissingDll.py new file mode 100644 index 0000000000000..b47040fbf794b --- /dev/null +++ b/lldb/test/API/windows/launch/missing-dll/TestMissingDll.py @@ -0,0 +1,22 @@ +import lldb +from lldbsuite.test.decorators import * +from lldbsuite.test.lldbtest import * +from lldbsuite.test import lldbutil + + +class MissingDllTestCase(TestBase): + @skipUnlessWindows + def test(self): + self.build() + exe = self.getBuildArtifact("a.out") + dll = self.getBuildArtifact("dummy_dll.dll") + self.assertTrue(remove_file(dll)) + target = self.dbg.CreateTarget(exe) + self.assertTrue(target, VALID_TARGET) + + launch_info = lldb.SBLaunchInfo(None) + launch_info.SetWorkingDirectory(self.get_process_working_directory()) + + error = lldb.SBError() + target.Launch(launch_info, error) + self.assertFailure(error, "Process prematurely exited with 0xc0000135") diff --git a/lldb/test/API/windows/launch/missing-dll/dummy_dll.c b/lldb/test/API/windows/launch/missing-dll/dummy_dll.c new file mode 100644 index 0000000000000..61bde26534966 --- /dev/null +++ b/lldb/test/API/windows/launch/missing-dll/dummy_dll.c @@ -0,0 +1 @@ +__declspec(dllexport) void SomeFunction(void) {} diff --git a/lldb/test/API/windows/launch/missing-dll/main.c b/lldb/test/API/windows/launch/missing-dll/main.c new file mode 100644 index 0000000000000..c1e0d3222c48b --- /dev/null +++ b/lldb/test/API/windows/launch/missing-dll/main.c @@ -0,0 +1,6 @@ +__declspec(dllimport) void SomeFunction(void); + +int main(void) { + SomeFunction(); + return 0; +} _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
