src/process_tree-win32.cc

// Copyright 2026 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "process_tree.h"

#ifdef _WIN32
#include <tlhelp32.h>
#include <windows.h>
#endif

#include <stdio.h>

#include "util.h"

// static
std::vector<ProcessTree::ProcessInfo> ProcessTree::GetSystemProcesses() {
  std::vector<ProcessInfo> processes;
#ifdef _WIN32
  // Create a snapshot of all processes in the system.
  HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
  if (snapshot == INVALID_HANDLE_VALUE)
    return processes;

  PROCESSENTRY32W pe32;
  pe32.dwSize = sizeof(PROCESSENTRY32W);

  // Walk the process list using explicit Wide versions to ensure we get
  // WCHAR strings for szExeFile.
  if (Process32FirstW(snapshot, &pe32)) {
    do {
      processes.push_back({ pe32.th32ProcessID,
                            pe32.th32ParentProcessID,
                            ConvertFromUnicodeString(pe32.szExeFile),
                            {} });
    } while (Process32NextW(snapshot, &pe32));
  }

  CloseHandle(snapshot);
#endif
  return processes;
}

// static
void ProcessTree::GetSystemProcessDetails(Pid pid, ProcessDetails* details) {
  // TODO: Implement command line collection for Windows.
  // This typically requires OpenProcess + NtQueryInformationProcess
  // to read the Process Environment Block (PEB).
  details->collected = true;
}