Implement ProcessInfo::Dump(), log gdb-remote stub launch

[tfiala]

Summary

This change implements dumping the executable, triple,
args and environment when using ProcessInfo::Dump().

It also tweaks the way Args::Dump() works so that it prints
a configurable label rather than argv[{index}]={value}. By
default it behaves the same, but if the Dump() method with
the additional arg is provided, it can be overridden. The
environment variables dumped as part of ProcessInfo::Dump()
make use of that.

lldb-server has been modified to dump the gdb-remote stub's
ProcessInfo before launching if the "gdb-remote process" channel
is logged.

[tfiala]

Hang on, this diff is busted. It seems to have a few more changes in it than came from me. (I suspect it is something slightly out of sync between my change branch and trunk... I'll re-upload as soon as I straighten that out).

[tfiala]

Fixed up whatever my arcanist-foo did wrong on the initial 'arc diff' creation of the patch. (The diff I'm putting up is exactly what comes out of 'git diff origin/master', so not sure how this got mutated into the original diff).

[tfiala]

This was the logging I used to discover the breakage in launching debugserver from 'lldb-server platform' on Apple platforms.

[clayborg]

See inlined comments.

include/lldb/Interpreter/Args.h

120

I would make just one Dump function and default the label_name to "argv". No need for two functions.

[tfiala]

include/lldb/Interpreter/Args.h

120

Okay - I wasn't sure if we preferred to avoid default args - they used to sometimes cause problems with stale compilations in some build systems, but we're probably way past that point nowadays.

I'll fix that up. Also, I'll run it through the clang formatter. I kept the formatting of the (unimplemented) header in ProcessInfo, but that was using the non-official space-before-the-paren style.

[tfiala]

Updates per Greg.

• Args::Dump(stream, label) now takes a default label.
• Dropped the Args::Dump(stream) call.
• Converted the Args stream parameter to a ref. It is not valid to call this without a stream.
• Updated in-source docs to reflect changes.

[tfiala]

Marked comments as done.

[tfiala]

Closed by commit r271312.

include/lldb/Interpreter/Args.h

public:
     operator= (const Args &rhs);
 
     //------------------------------------------------------------------
     /// Destructor.
     //------------------------------------------------------------------
     ~Args();
 
     //------------------------------------------------------------------
-    /// Dump all arguments to the stream \a s.
+    /// Dump all entries to the stream \a s using label \a label_name.
+    ///
+    /// If label_name is nullptr, the dump operation is skipped.
     ///
     /// @param[in] s
     ///     The stream to which to dump all arguments in the argument
     ///     vector.
+    /// @param[in] label_name
+    ///     The label_name to use as the label printed for each
+    ///     entry of the args like so:
+    ///       {label_name}[{index}]={value}
     //------------------------------------------------------------------
     void
-    Dump (Stream *s);
+    Dump (Stream &s, const char *label_name = "argv") const;
 
     //------------------------------------------------------------------
     /// Sets the command string contained by this object.
     ///
     /// The command string will be copied and split up into arguments
     /// that can be accessed via the accessor functions.
     ///
     /// @param[in] command
     ///     A command StringRef that will be copied and split up
     ///     into arguments.
     ///
     /// @see Args::GetArgumentCount() const
     /// @see Args::GetArgumentAtIndex (size_t) const
     /// @see Args::GetArgumentVector ()
     /// @see Args::Shift ()
     /// @see Args::Unshift (const char *)
     //------------------------------------------------------------------
     void
     SetCommandString (llvm::StringRef command);
 
     bool

source/Interpreter/Args.cpp

 //----------------------------------------------------------------------
 // Destructor
 //----------------------------------------------------------------------
 Args::~Args ()
 {
 }
 
 void
-Args::Dump (Stream *s)
+Args::Dump (Stream &s, const char *label_name) const
 {
+    if (!label_name)
+        return;
+
     const size_t argc = m_argv.size();
     for (size_t i=0; i<argc; ++i)
     {
-        s->Indent();
+        s.Indent();
         const char *arg_cstr = m_argv[i];
         if (arg_cstr)
-            s->Printf("argv[%zi]=\"%s\"\n", i, arg_cstr);
+            s.Printf("%s[%zi]=\"%s\"\n", label_name, i, arg_cstr);
         else
-            s->Printf("argv[%zi]=NULL\n", i);
+            s.Printf("%s[%zi]=NULL\n", label_name, i);
     }
-    s->EOL();
+    s.EOL();
 }
 
 bool
 Args::GetCommandString (std::string &command) const
 {
     command.clear();
     const size_t argc = GetArgumentCount();
     for (size_t i=0; i<argc; ++i)

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

 GDBRemoteCommunication::StartDebugserverProcess (const char *url,
                                                  Platform *platform,
                                                  ProcessLaunchInfo &launch_info,
                                                  uint16_t *port,
                                                  const Args& inferior_args)
 {
     Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PROCESS));
     if (log)
-        log->Printf ("GDBRemoteCommunication::%s(url=%s, port=%" PRIu16, __FUNCTION__, url ? url : "<empty>", port ? *port : uint16_t(0));
+        log->Printf ("GDBRemoteCommunication::%s(url=%s, port=%" PRIu16 ")", __FUNCTION__, url ? url : "<empty>", port ? *port : uint16_t(0));
 
     Error error;
     // If we locate debugserver, keep that located version around
     static FileSpec g_debugserver_file_spec;
     
     char debugserver_path[PATH_MAX];
     FileSpec &debugserver_file_spec = launch_info.GetExecutableFile();
     
#endif
         launch_info.AppendCloseFileAction (STDIN_FILENO);
         launch_info.AppendCloseFileAction (STDOUT_FILENO);
         launch_info.AppendCloseFileAction (STDERR_FILENO);
 
         // Redirect STDIN, STDOUT and STDERR to "/dev/null".
         launch_info.AppendSuppressFileAction (STDIN_FILENO, true, false);
         launch_info.AppendSuppressFileAction (STDOUT_FILENO, false, true);
         launch_info.AppendSuppressFileAction (STDERR_FILENO, false, true);
-        
+        if (log)
+        {
+            StreamString string_stream;
+            Platform *const platform = nullptr;
+            launch_info.Dump(string_stream, platform);
+            log->Printf("launch info for gdb-remote stub:\n%s", string_stream.GetString().c_str());
+        }
         error = Host::LaunchProcess(launch_info);
         
         if (error.Success() &&
             launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID)
         {
             if (named_pipe_path.size() > 0)
             {
                 error = socket_pipe.OpenAsReader(named_pipe_path, false);

source/Target/ProcessInfo.cpp

 // C Includes
 // C++ Includes
 #include <climits>
 
 // Other libraries and framework includes
 // Project includes
 #include "lldb/Target/ProcessInfo.h"
 
+#include "lldb/Core/Stream.h"
+
 using namespace lldb;
 using namespace lldb_private;
 
 ProcessInfo::ProcessInfo () :
     m_executable (),
     m_arguments (),
     m_environment (),
     m_uid (UINT32_MAX),

 
 size_t
 ProcessInfo::GetNameLength() const
 {
     return m_executable.GetFilename().GetLength();
 }
 
 void
+ProcessInfo::Dump (Stream &s, Platform *platform) const
+{
+    s << "Executable: " << GetName() << "\n";
+    s << "Triple: ";
+    m_arch.DumpTriple(s);
+    s << "\n";
+
+    s << "Arguments:\n";
+    m_arguments.Dump(s);
+
+    s << "Environment:\n";
+    m_environment.Dump(s, "env");
+}
+
+void
 ProcessInfo::SetExecutableFile (const FileSpec &exe_file, bool add_exe_file_as_first_arg)
 {
     if (exe_file)
     {
         m_executable = exe_file;
         if (add_exe_file_as_first_arg)
         {
             char filename[PATH_MAX];