Moved the execution context that was in the Debugger into

the CommandInterpreter where it was always being used.

Make sure that Modules can track their object file offsets correctly to
allow opening of sub object files (like the "__commpage" on darwin).

Modified the Platforms to be able to launch processes. The first part of this
move is the platform soon will become the entity that launches your program
and when it does, it uses a new ProcessLaunchInfo class which encapsulates
all process launching settings. This simplifies the internal APIs needed for
launching. I want to slowly phase out process launching from the process
classes, so for now we can still launch just as we used to, but eventually
the platform is the object that should do the launching.

Modified the Host::LaunchProcess in the MacOSX Host.mm to correctly be able
to launch processes with all of the new eLaunchFlag settings. Modified any
code that was manually launching processes to use the Host::LaunchProcess
functions.

Fixed an issue where lldb_private::Args had implicitly defined copy 
constructors that could do the wrong thing. This has now been fixed by adding
an appropriate copy constructor and assignment operator.

Make sure we don't add empty ModuleSP entries to a module list.

Fixed the commpage module creation on MacOSX, but we still need to train
the MacOSX dynamic loader to not get rid of it when it doesn't have an entry
in the all image infos.

Abstracted many more calls from in ProcessGDBRemote down into the 
GDBRemoteCommunicationClient subclass to make the classes cleaner and more
efficient.

Fixed the default iOS ARM register context to be correct and also added support
for targets that don't support the qThreadStopInfo packet by selecting the
current thread (only if needed) and then sending a stop reply packet.

Debugserver can now start up with a --unix-socket (-u for short) and can 
then bind to port zero and send the port it bound to to a listening process
on the other end. This allows the GDB remote platform to spawn new GDB server
instances (debugserver) to allow platform debugging.

llvm-svn: 129351

1 files changed, 77 insertions, 9 deletions

diff --git a/lldb/tools/debugserver/source/debugserver.cpp b/lldb/tools/debugserver/source/debugserver.cpp
index 6e08d5dd8dc..12a873ef8e3 100644
--- a/lldb/tools/debugserver/source/debugserver.cpp
+++ b/lldb/tools/debugserver/source/debugserver.cpp
@@ -17,6 +17,12 @@
 #include <string>
 #include <vector>
 #include <asl.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <sys/un.h>
+#include <sys/types.h>
 
 #include "CFString.h"
 #include "DNB.h"
@@ -608,13 +614,68 @@ RNBRunLoopPlatform (RNBRemote *remote)
 // Returns 1 for success 0 for failure.
 //----------------------------------------------------------------------
 
+static void
+PortWasBoundCallback (const void *baton, in_port_t port)
+{
+    //::printf ("PortWasBoundCallback (baton = %p, port = %u)\n", baton, port);
+
+    const char *unix_socket_name = (const char *)baton;
+    
+    if (unix_socket_name && unix_socket_name[0])
+    {
+        // We were given a unix socket name to use to communicate the port
+        // that we ended up binding to back to our parent process
+        struct sockaddr_un saddr_un;
+        int s = ::socket (AF_UNIX, SOCK_STREAM, 0);
+        if (s < 0)
+        {
+            perror("error: socket (AF_UNIX, SOCK_STREAM, 0)");
+            exit(1);
+        }
+        
+        saddr_un.sun_family = AF_UNIX;
+        ::strncpy(saddr_un.sun_path, unix_socket_name, sizeof(saddr_un.sun_path) - 1);
+        saddr_un.sun_path[sizeof(saddr_un.sun_path) - 1] = '\0';
+        saddr_un.sun_len = SUN_LEN (&saddr_un);
+        
+        if (::connect (s, (struct sockaddr *)&saddr_un, SUN_LEN (&saddr_un)) < 0) 
+        {
+            perror("error: connect (socket, &saddr_un, saddr_un_len)");
+            exit(1);
+        }
+        
+        //::printf ("connect () sucess!!\n");
+
+        
+        // We were able to connect to the socket, now write our PID so whomever
+        // launched us will know this process's ID
+        RNBLogSTDOUT ("Listening to port %i...\n", port);
+        
+        char pid_str[64];
+        const int pid_str_len = ::snprintf (pid_str, sizeof(pid_str), "%u", port);
+        const int bytes_sent = ::send (s, pid_str, pid_str_len, 0);
+        
+        if (pid_str_len != bytes_sent)
+        {
+            perror("error: send (s, pid_str, pid_str_len, 0)");
+            exit (1);
+        }
+
+        //::printf ("send () sucess!!\n");
+
+        // We are done with the socket
+        close (s);
+    }
+}
+
 static int
-StartListening (RNBRemote *remote, int listen_port)
+StartListening (RNBRemote *remote, int listen_port, const char *unix_socket_name)
 {
     if (!remote->Comm().IsConnected())
     {
-        RNBLogSTDOUT ("Listening to port %i...\n", listen_port);
-        if (remote->Comm().Listen(listen_port) != rnb_success)
+        if (listen_port != 0)
+            RNBLogSTDOUT ("Listening to port %i...\n", listen_port);
+        if (remote->Comm().Listen(listen_port, PortWasBoundCallback, unix_socket_name) != rnb_success)
         {
             RNBLogSTDERR ("Failed to get connection from a remote gdb process.\n");
             return 0;
@@ -709,6 +770,7 @@ static struct option g_long_options[] =
     { "disable-aslr",       no_argument,        NULL,               'D' },  // Use _POSIX_SPAWN_DISABLE_ASLR to avoid shared library randomization
     { "working-dir",        required_argument,  NULL,               'W' },  // The working directory that the inferior process should have (only if debugserver launches the process)
     { "platform",           required_argument,  NULL,               'p' },  // Put this executable into a remote platform mode
+    { "unix-socket",        required_argument,  NULL,               'u' },  // If we need to handshake with our parent process, an option will be passed down that specifies a unix socket name to use
     { NULL,                 0,                  NULL,               0   }
 };
 
@@ -757,7 +819,8 @@ main (int argc, char *argv[])
     std::string waitfor_pid_name;           // Wait for a process that starts with this name
     std::string attach_pid_name;
     std::string arch_name;
-    std::string working_dir;          // The new working directory to use for the inferior
+    std::string working_dir;                // The new working directory to use for the inferior
+    std::string unix_socket_name;           // If we need to handshake with our parent process, an option will be passed down that specifies a unix socket name to use
     useconds_t waitfor_interval = 1000;     // Time in usecs between process lists polls when waiting for a process by name, default 1 msec.
     useconds_t waitfor_duration = 0;        // Time in seconds to wait for a process by name, 0 means wait forever.
     bool no_stdio = false;
@@ -768,7 +831,7 @@ main (int argc, char *argv[])
 
     RNBRunLoopMode start_mode = eRNBRunLoopModeExit;
 
-    while ((ch = getopt_long(argc, argv, "a:A:d:gi:vktl:f:w:x:rs:n", g_long_options, &long_option_index)) != -1)
+    while ((ch = getopt_long(argc, argv, "a:A:d:gi:vktl:f:w:x:rs:nu:", g_long_options, &long_option_index)) != -1)
     {
         DNBLogDebug("option: ch == %c (0x%2.2x) --%s%c%s\n",
                     ch, (uint8_t)ch,
@@ -967,6 +1030,11 @@ main (int argc, char *argv[])
             case 'p':
                 start_mode = eRNBRunLoopModePlatformMode;
                 break;
+
+            case 'u':
+                unix_socket_name.assign (optarg);
+                break;
+                
         }
     }
     
@@ -1171,7 +1239,7 @@ main (int argc, char *argv[])
 #endif
                 if (listen_port != INT32_MAX)
                 {
-                    if (!StartListening (remote, listen_port))
+                    if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
                         mode = eRNBRunLoopModeExit;
                 }
                 else if (str[0] == '/')
@@ -1282,7 +1350,7 @@ main (int argc, char *argv[])
                 {
                     if (listen_port != INT32_MAX)
                     {
-                        if (!StartListening (remote, listen_port))
+                        if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
                             mode = eRNBRunLoopModeExit;
                     }
                     else if (str[0] == '/')
@@ -1307,7 +1375,7 @@ main (int argc, char *argv[])
                     {
                         if (listen_port != INT32_MAX)
                         {
-                            if (!StartListening (remote, listen_port))
+                            if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
                                 mode = eRNBRunLoopModeExit;
                         }
                         else if (str[0] == '/')
@@ -1334,7 +1402,7 @@ main (int argc, char *argv[])
             case eRNBRunLoopModePlatformMode:
                 if (listen_port != INT32_MAX)
                 {
-                    if (!StartListening (remote, listen_port))
+                    if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
                         mode = eRNBRunLoopModeExit;
                 }
                 else if (str[0] == '/')