https://github.com/charles-zablit created https://github.com/llvm/llvm-project/pull/173015
This patch adds the _attach by name_ feature to lldb/lldb-dap on Windows. Using the [`CreateToolhelp32Snapshot `](https://learn.microsoft.com/en-us/windows/win32/api/tlhelp32/nf-tlhelp32-createtoolhelp32snapshot) API and by iterating over the processes in the snapshot, lldb returns the pid of the first match, if any. This implementation is based on: https://learn.microsoft.com/en-us/windows/win32/toolhelp/taking-a-snapshot-and-viewing-processes >From 40f3dc018772d1bf58319f1df959f5c75c70c863 Mon Sep 17 00:00:00 2001 From: Charles Zablit <[email protected]> Date: Fri, 19 Dec 2025 15:10:36 +0000 Subject: [PATCH] [lldb][windows] add attach by name capability --- .../Process/Windows/Common/ProcessWindows.cpp | 52 +++++++++++++++++++ .../Process/Windows/Common/ProcessWindows.h | 19 +++++++ .../tools/lldb-dap/attach/TestDAP_attach.py | 1 - 3 files changed, 71 insertions(+), 1 deletion(-) diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp index 127dd0f59e9ae..19b895cda77d9 100644 --- a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp +++ b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp @@ -10,6 +10,7 @@ // Windows includes #include "lldb/Host/windows/windows.h" +#include <TlHelp32.h> #include <psapi.h> #include "lldb/Breakpoint/Watchpoint.h" @@ -35,6 +36,7 @@ #include "lldb/Utility/Log.h" #include "lldb/Utility/State.h" +#include "llvm/ADT/ScopeExit.h" #include "llvm/Support/ConvertUTF.h" #include "llvm/Support/Format.h" #include "llvm/Support/Threading.h" @@ -227,6 +229,56 @@ ProcessWindows::DoAttachToProcessWithID(lldb::pid_t pid, return error; } +Status ProcessWindows::DoAttachToProcessWithName( + const char *process_name, const ProcessAttachInfo &attach_info) { + Status error; + Clear(); + + if (!process_name || process_name[0] == '\0') { + error = Status::FromErrorString("Invalid process name"); + return error; + } + + lldb::pid_t pid = FindProcessByName(process_name, error); + + if (pid == LLDB_INVALID_PROCESS_ID) { + error = Status::FromErrorStringWithFormatv("Unable to find process '%s'", + process_name); + return error; + } + + return DoAttachToProcessWithID(pid, attach_info); +} + +lldb::pid_t ProcessWindows::FindProcessByName(const char *process_name, + Status &error) { + HANDLE hProcessSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0); + if (hProcessSnap == INVALID_HANDLE_VALUE) { + error = Status(GetLastError(), eErrorTypeWin32); + return LLDB_INVALID_PROCESS_ID; + } + auto cleanup = llvm::make_scope_exit([&] { CloseHandle(hProcessSnap); }); + + llvm::StringRef process_filename = llvm::sys::path::filename(process_name); + + PROCESSENTRY32W pe32; + pe32.dwSize = sizeof(PROCESSENTRY32W); + if (!Process32FirstW(hProcessSnap, &pe32)) { + error = Status(GetLastError(), eErrorTypeWin32); + return LLDB_INVALID_PROCESS_ID; + } + + do { + std::string exe_name; + llvm::convertWideToUTF8(pe32.szExeFile, exe_name); + + if (exe_name == process_filename) + return pe32.th32ProcessID; + } while (Process32NextW(hProcessSnap, &pe32)); + + return LLDB_INVALID_PROCESS_ID; +} + Status ProcessWindows::DoResume(RunDirection direction) { Log *log = GetLog(WindowsLog::Process); llvm::sys::ScopedLock lock(m_mutex); diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h index 33e4de6b85932..be861db31ba36 100644 --- a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h +++ b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h @@ -49,6 +49,9 @@ class ProcessWindows : public Process, public ProcessDebugger { Status DoAttachToProcessWithID( lldb::pid_t pid, const lldb_private::ProcessAttachInfo &attach_info) override; + Status + DoAttachToProcessWithName(const char *process_name, + const ProcessAttachInfo &attach_info) override; Status DoResume(lldb::RunDirection direction) override; Status DoDestroy() override; Status DoHalt(bool &caused_stop) override; @@ -101,6 +104,22 @@ class ProcessWindows : public Process, public ProcessDebugger { void SetPseudoConsoleHandle(const std::shared_ptr<PseudoConsole> &pty) override; + /// Finds the pid matching the process_name. + /// + /// If there are multiple processes with the same name, this method will + /// return the first one. + /// + /// \param[in] process_name + /// The name of the process to find. + /// + /// \param[out] error + /// An error that indicates the success or failure of the search. + /// + /// \return + /// Returns the pid of the process if a match was found. Returns \code + /// LLDB_INVALID_PROCESS otherwise. + lldb::pid_t FindProcessByName(const char *process_name, Status &error); + protected: ProcessWindows(lldb::TargetSP target_sp, lldb::ListenerSP listener_sp); diff --git a/lldb/test/API/tools/lldb-dap/attach/TestDAP_attach.py b/lldb/test/API/tools/lldb-dap/attach/TestDAP_attach.py index d9acd0a4cae01..d6287397a93b0 100644 --- a/lldb/test/API/tools/lldb-dap/attach/TestDAP_attach.py +++ b/lldb/test/API/tools/lldb-dap/attach/TestDAP_attach.py @@ -59,7 +59,6 @@ def test_by_name(self): self.attach(program=program) self.continue_and_verify_pid() - @expectedFailureWindows def test_by_name_waitFor(self): """ Tests waiting for, and attaching to a process by process name that _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
