WSLA: Add initial wsladiag tool with basic --list command and placeholder ListSessions

CMakeLists.txt

@@ -425,6 +425,7 @@ add_subdirectory(src/windows/wslhost)
 add_subdirectory(src/windows/wslrelay)
 add_subdirectory(src/windows/wslinstall)
 add_subdirectory(src/windows/wslaclient)
+add_subdirectory(src/windows/wsladiag)
 
 if (WSL_BUILD_WSL_SETTINGS)
     add_subdirectory(src/windows/libwsl)

msipackage/CMakeLists.txt

@@ -3,7 +3,7 @@ set(OUTPUT_PACKAGE ${BIN}/wsl.msi)
 set(PACKAGE_WIX_IN ${CMAKE_CURRENT_LIST_DIR}/package.wix.in)
 set(PACKAGE_WIX ${BIN}/package.wix)
 set(CAB_CACHE ${BIN}/cab)
-set(BINARIES wsl.exe;wslg.exe;wslhost.exe;wslrelay.exe;wslservice.exe;wslserviceproxystub.dll;init;initrd.img;wslinstall.dll;wslaserviceproxystub.dll;wslaservice.exe)
+set(BINARIES wsl.exe;wslg.exe;wslhost.exe;wslrelay.exe;wslservice.exe;wslserviceproxystub.dll;init;initrd.img;wslinstall.dll;wslaserviceproxystub.dll;wslaservice.exe;wsladiag.exe)
 
 if (WSL_BUILD_WSL_SETTINGS)
     list(APPEND BINARIES_DEPENDENCIES "wslsettings/wslsettings.dll;wslsettings/wslsettings.exe;libwsl.dll")
@@ -39,7 +39,7 @@ add_custom_command(
 
 add_custom_target(msipackage DEPENDS ${OUTPUT_PACKAGE})
 set_target_properties(msipackage PROPERTIES EXCLUDE_FROM_ALL FALSE SOURCES ${PACKAGE_WIX_IN})
-add_dependencies(msipackage wsl wslg wslservice wslhost wslrelay wslserviceproxystub init initramfs wslinstall msixgluepackage wslaservice wslaserviceproxystub)
+add_dependencies(msipackage wsl wslg wslservice wslhost wslrelay wslserviceproxystub init initramfs wslinstall msixgluepackage wslaservice wslaserviceproxystub wsladiag)
 
 if (WSL_BUILD_WSL_SETTINGS)
     add_dependencies(msipackage wslsettings libwsl)

msipackage/package.wix.in

@@ -27,6 +27,7 @@
                 </File>
 
                 <File Id="wslg.exe" Name="wslg.exe" Source="${BIN}/wslg.exe" />
+                <File Id="wsladiag.exe" Name="wsladiag.exe" Source="${BIN}/wsladiag.exe" />
                 <File Id="wslhost.exe" Name="wslhost.exe" Source="${BIN}/wslhost.exe" />
                 <File Id="wslrelay.exe" Name="wslrelay.exe" Source="${BIN}/wslrelay.exe" />
                 <File Id="wslserviceproxystub.dll" Name="wslserviceproxystub.dll" Source="${BIN}/wslserviceproxystub.dll" />

src/windows/wsladiag/CMakeLists.txt

@@ -0,0 +1,14 @@
+set(SOURCES
+    main.cpp
+)
+
+add_executable(wsladiag ${SOURCES})
+
+target_link_libraries(wsladiag
+    ${COMMON_LINK_LIBRARIES}
+    common
+)
+
+target_precompile_headers(wsladiag REUSE_FROM common)
+
+set_target_properties(wsladiag PROPERTIES FOLDER windows)

src/windows/wsladiag/main.cpp

@@ -0,0 +1,101 @@
+/*++
+
+Copyright (c) Microsoft. All rights reserved.
+
+Module Name:
+
+    main.cpp
+
+Abstract:
+
+    Entry point for the wsladiag tool, performs WSL runtime initialization and parses --list/--help.
+
+--*/
+
+#include "precomp.h"
+#include "CommandLine.h"
+#include "wslutil.h"
+
+using namespace wsl::shared;
+namespace wslutil = wsl::windows::common::wslutil;
+
+int wsladiag_main(std::wstring_view commandLine)
+{
+    //
+    // Standard process initialization (matches other WSL tools)
+    //
+    wslutil::ConfigureCrt();
+    wslutil::InitializeWil();
+
+    WslTraceLoggingInitialize(LxssTelemetryProvider, !wsl::shared::OfficialBuild);
+    auto cleanupTelemetry = wil::scope_exit_log(WI_DIAGNOSTICS_INFO, []()
+    {
+        WslTraceLoggingUninitialize();
+    });
+
+    wslutil::SetCrtEncoding(_O_U8TEXT);
+
+    auto coInit = wil::CoInitializeEx(COINIT_MULTITHREADED);
+    wslutil::CoInitializeSecurity();
+
+    WSADATA data{};
+    THROW_IF_WIN32_ERROR(WSAStartup(MAKEWORD(2, 2), &data));
+    auto wsaCleanup = wil::scope_exit_log(WI_DIAGNOSTICS_INFO, []()
+    {
+        WSACleanup();
+    });
+
+    //
+    // Command-line parsing using ArgumentParser
+    //
+    ArgumentParser parser(std::wstring{commandLine}, L"wsladiag");
+
+    bool help = false;
+    bool list = false;
+
+    parser.AddArgument(list, L"--list");
+    parser.AddArgument(help, L"--help", L'h'); //  short option is a single wide char 
+    parser.Parse();
+
+    auto printUsage = []()
+    {
+        wslutil::PrintMessage(
+            L"wsladiag - WSLA diagnostics tool\n"
+            L"Usage:\n"
+            L"  wsladiag --list    List WSLA sessions\n"
+            L"  wsladiag --help    Show this help",
+            stdout);
+    };
+
+    // Slightly clearer help logic
+    if (help)
+    {
+        printUsage();
+        return 0;
+    }
+
+    if (!list)
+    {
+        // No recognized command → show usage
+        printUsage();
+        return 0;
+    }
+
+    // --list
+    wslutil::PrintMessage(
+        L"[wsladiag] --list: placeholder.\n"
+        L"Next step: call WSLA service ListSessions and display sessions.",
+        stdout);
+    // TODO: call WSLA service COM interface to retrieve and display sessions.
+    return 0;
+}
+
+int wmain(int /*argc*/, wchar_t** /*argv*/)
+{
+    try
+    {
+        // Use the full command line so ArgumentParser sees the raw string
+        return wsladiag_main(GetCommandLineW());
+    }
+    CATCH_RETURN();
+}

src/windows/wslaservice/exe/WSLAUserSession.cpp

@@ -116,8 +116,18 @@ CATCH_RETURN();
 
 HRESULT wsl::windows::service::wsla::WSLAUserSession::ListSessions(WSLA_SESSION_INFORMATION** Sessions, ULONG* SessionsCount)
 {
-    return E_NOTIMPL;
+    if (!Sessions || !SessionsCount)
+    {
+        return E_INVALIDARG;
+    }
+
+    // For now, return an empty list. We'll populate this from m_sessions later.
+    *Sessions = nullptr;
+    *SessionsCount = 0;
+
+    return S_OK;
 }
+
 HRESULT wsl::windows::service::wsla::WSLAUserSession::OpenSession(ULONG Id, IWSLASession** Session)
 {
     return E_NOTIMPL;