Create a process launcher abstraction.

This implements Host::LaunchProcess for windows, and in doing so
does some minor refactor to move towards a more modular process
launching design.

The original motivation for this is that launching processes on
windows needs some very windows specific code, which would live
most appropriately in source/Host/windows somewhere.  However,
there is already some common code that all platforms use when
launching a process before delegating to the platform specific
stuff, which lives in source/Host/common/Host.cpp which would
be nice to reuse without duplicating.

This commonality has been abstracted into MonitoringProcessLauncher,
a class which abstracts out the notion of launching a process using
an arbitrary algorithm, and then monitoring it for state changes.

The windows specific launching code lives in ProcessLauncherWindows,
and the posix specific launching code lives in ProcessLauncherPosix.
When launching a process MonitoringProcessLauncher is created, and
then an appropriate delegate launcher is created and given to the
MonitoringProcessLauncher.

Reviewed by: Greg Clayton
Differential Revision: http://reviews.llvm.org/D5781

llvm-svn: 219731

1 files changed, 102 insertions, 0 deletions

diff --git a/lldb/source/Host/common/MonitoringProcessLauncher.cpp b/lldb/source/Host/common/MonitoringProcessLauncher.cpp
new file mode 100644
index 00000000000..3b0078474b0
--- /dev/null
+++ b/lldb/source/Host/common/MonitoringProcessLauncher.cpp
@@ -0,0 +1,102 @@
+//===-- ProcessLauncherWindows.cpp ------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Core/Error.h"
+#include "lldb/Core/Log.h"
+#include "lldb/Core/Module.h"
+#include "lldb/Host/HostProcess.h"
+#include "lldb/Host/MonitoringProcessLauncher.h"
+#include "lldb/Target/Platform.h"
+#include "lldb/Target/Process.h"
+#include "lldb/Target/ProcessLaunchInfo.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+MonitoringProcessLauncher::MonitoringProcessLauncher(std::unique_ptr<ProcessLauncher> delegate_launcher)
+    : m_delegate_launcher(std::move(delegate_launcher))
+{
+}
+
+HostProcess
+MonitoringProcessLauncher::LaunchProcess(const ProcessLaunchInfo &launch_info, Error &error)
+{
+    ProcessLaunchInfo resolved_info(launch_info);
+
+    error.Clear();
+    char exe_path[PATH_MAX];
+
+    PlatformSP host_platform_sp(Platform::GetHostPlatform());
+
+    const ArchSpec &arch_spec = resolved_info.GetArchitecture();
+
+    FileSpec exe_spec(resolved_info.GetExecutableFile());
+
+    FileSpec::FileType file_type = exe_spec.GetFileType();
+    if (file_type != FileSpec::eFileTypeRegular)
+    {
+        lldb::ModuleSP exe_module_sp;
+        error = host_platform_sp->ResolveExecutable(exe_spec, arch_spec, exe_module_sp, NULL);
+
+        if (error.Fail())
+            return HostProcess();
+
+        if (exe_module_sp)
+            exe_spec = exe_module_sp->GetFileSpec();
+    }
+
+    if (exe_spec.Exists())
+    {
+        exe_spec.GetPath(exe_path, sizeof(exe_path));
+    }
+    else
+    {
+        resolved_info.GetExecutableFile().GetPath(exe_path, sizeof(exe_path));
+        error.SetErrorStringWithFormat("executable doesn't exist: '%s'", exe_path);
+        return HostProcess();
+    }
+
+    resolved_info.SetExecutableFile(exe_spec, false);
+    assert(!resolved_info.GetFlags().Test(eLaunchFlagLaunchInTTY));
+
+    ::pid_t pid = LLDB_INVALID_PROCESS_ID;
+
+    HostProcess process = m_delegate_launcher->LaunchProcess(resolved_info, error);
+
+    if (process.GetProcessId() != LLDB_INVALID_PROCESS_ID)
+    {
+        Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
+
+        Host::MonitorChildProcessCallback callback = launch_info.GetMonitorProcessCallback();
+
+        void *baton = nullptr;
+        bool monitor_signals = false;
+        if (callback)
+        {
+            // If the ProcessLaunchInfo specified a callback, use that.
+            baton = launch_info.GetMonitorProcessBaton();
+            monitor_signals = launch_info.GetMonitorSignals();
+        }
+        else
+        {
+            callback = Process::SetProcessExitStatus;
+        }
+
+        process.StartMonitoring(callback, baton, monitor_signals);
+        if (log)
+            log->PutCString("started monitoring child process.");
+    }
+    else
+    {
+        // Invalid process ID, something didn't go well
+        if (error.Success())
+            error.SetErrorString("process launch failed for unknown reasons");
+    }
+    return process;
+}