Enable lldb-server on Windows

Summary:
This commit contains three small changes to enable lldb-server on Windows.

- Add lldb-server for Windows to the build
- Disable pty redirection on Windows for the initial lldb-server bring up
- Add a support to get the parent pid for a process on Windows
- Ifdef some signals which aren't supported on Windows

Thanks to Hui Huang for the help with this patch!

Reviewers: labath

Reviewed By: labath

Subscribers: JDevlieghere, compnerd, Hui, amccarth, xiaobai, srhines, mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D61686

llvm-svn: 368774

lldb/cmake/modules/LLDBConfig.cmake

@@ -408,7 +408,7 @@ list(APPEND system_libs ${CMAKE_DL_LIBS})
 
 # Figure out if lldb could use lldb-server.  If so, then we'll
 # ensure we build lldb-server when an lldb target is being built.
-if (CMAKE_SYSTEM_NAME MATCHES "Android|Darwin|FreeBSD|Linux|NetBSD")
+if (CMAKE_SYSTEM_NAME MATCHES "Android|Darwin|FreeBSD|Linux|NetBSD|Windows")
   set(LLDB_CAN_USE_LLDB_SERVER ON)
 else()
   set(LLDB_CAN_USE_LLDB_SERVER OFF)

lldb/source/Host/windows/Host.cpp

@@ -169,7 +169,23 @@ bool Host::GetProcessInfo(lldb::pid_t pid, ProcessInstanceInfo &process_info) {
   GetProcessExecutableAndTriple(handle, process_info);
 
   // Need to read the PEB to get parent process and command line arguments.
-  return true;
+
+  AutoHandle snapshot(CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0));
+  if (!snapshot.IsValid())
+    return false;
+
+  PROCESSENTRY32W pe;
+  pe.dwSize = sizeof(PROCESSENTRY32W);
+  if (Process32FirstW(snapshot.get(), &pe)) {
+    do {
+      if (pe.th32ProcessID == pid) {
+        process_info.SetParentProcessID(pe.th32ParentProcessID);
+        return true;
+      }
+    } while (Process32NextW(snapshot.get(), &pe));
+  }
+
+  return false;
 }
 
 llvm::Expected<HostThread> Host::StartMonitoringChildProcess(

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp

@@ -39,6 +39,8 @@
 
 #if defined(__APPLE__)
 #define DEBUGSERVER_BASENAME "debugserver"
+#elif defined(_WIN32)
+#define DEBUGSERVER_BASENAME "lldb-server.exe"
 #else
 #define DEBUGSERVER_BASENAME "lldb-server"
 #endif

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp

@@ -217,8 +217,13 @@ Status GDBRemoteCommunicationServerLLGS::LaunchProcess() {
   m_process_launch_info.GetFlags().Set(eLaunchFlagDebug);
 
   if (should_forward_stdio) {
+    // Temporarily relax the following for Windows until we can take advantage
+    // of the recently added pty support. This doesn't really affect the use of 
+    // lldb-server on Windows.
+#if !defined(_WIN32)
     if (llvm::Error Err = m_process_launch_info.SetUpPtyRedirection())
       return Status(std::move(Err));
+#endif
   }
 
   {

lldb/tools/lldb-server/lldb-gdbserver.cpp

@@ -514,7 +514,7 @@ int main_gdbserver(int argc, char *argv[]) {
     handle_launch(gdb_server, argc, argv);
 
   // Print version info.
-  printf("%s-%s", LLGS_PROGRAM_NAME, LLGS_VERSION_STR);
+  printf("%s-%s\n", LLGS_PROGRAM_NAME, LLGS_VERSION_STR);
 
   ConnectToRemote(mainloop, gdb_server, reverse_connect, host_and_port,
                   progname, subcommand, named_pipe_path.c_str(), 

lldb/tools/lldb-server/lldb-platform.cpp

@@ -15,8 +15,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#if !defined(_WIN32)
 #include <sys/wait.h>
-
+#endif
 #include <fstream>
 
 #include "llvm/Support/FileSystem.h"
@@ -67,6 +68,7 @@ static struct option g_long_options[] = {
 #define HIGH_PORT (49151u)
 #endif
 
+#if !defined(_WIN32)
 // Watch for signals
 static void signal_handler(int signo) {
   switch (signo) {
@@ -81,6 +83,7 @@ static void signal_handler(int signo) {
     break;
   }
 }
+#endif
 
 static void display_usage(const char *progname, const char *subcommand) {
   fprintf(stderr, "Usage:\n  %s %s [--log-file log-file-name] [--log-channels "
@@ -131,8 +134,10 @@ int main_platform(int argc, char *argv[]) {
   const char *subcommand = argv[1];
   argc--;
   argv++;
+#if !defined(_WIN32)
   signal(SIGPIPE, SIG_IGN);
   signal(SIGHUP, signal_handler);
+#endif
   int long_option_index = 0;
   Status error;
   std::string listen_host_port;
@@ -309,8 +314,10 @@ int main_platform(int argc, char *argv[]) {
     printf("Connection established.\n");
     if (g_server) {
       // Collect child zombie processes.
+#if !defined(_WIN32)
       while (waitpid(-1, nullptr, WNOHANG) > 0)
         ;
+#endif
       if (fork()) {
         // Parent doesn't need a connection to the lldb client
         delete conn;