Program-assigned thread names on Windows

diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 3f67486..6315303 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -174,6 +174,18 @@  static int debug_registers_used;
 static int windows_initialization_done;
 #define DR6_CLEAR_VALUE 0xffff0ff0
 
+/* This exception has no documented name, but MSDN dubs it "MS_VC_EXCEPTION"
+   in one code example. It's thrown by a program to tell the debugger the name
+   of a thread. */
+#define MS_VC_EXCEPTION 0x406d1388
+
+typedef enum
+{
+  HANDLE_EXCEPTION_UNHANDLED = 0,
+  HANDLE_EXCEPTION_HANDLED,
+  HANDLE_EXCEPTION_IGNORED
+} handle_exception_result;
+
 /* The string sent by cygwin when it processes a signal.
    FIXME: This should be in a cygwin include file.  */
 #ifndef _CYGWIN_SIGNAL_STRING
@@ -441,6 +453,7 @@  windows_delete_thread (ptid_t ptid, DWORD exit_code)
     {
       windows_thread_info *here = th->next;
       th->next = here->next;
+      xfree (here->name);
       xfree (here);
     }
 }
@@ -1031,10 +1044,12 @@  display_selectors (char * args, int from_tty)
     host_address_to_string (\
       current_event.u.Exception.ExceptionRecord.ExceptionAddress))
 
-static int
+static handle_exception_result
 handle_exception (struct target_waitstatus *ourstatus)
 {
-  DWORD code = current_event.u.Exception.ExceptionRecord.ExceptionCode;
+  EXCEPTION_RECORD *rec = &current_event.u.Exception.ExceptionRecord;
+  DWORD code = rec->ExceptionCode;
+  handle_exception_result result = HANDLE_EXCEPTION_HANDLED;
 
   ourstatus->kind = TARGET_WAITKIND_STOPPED;
 
@@ -1057,14 +1072,13 @@  handle_exception (struct target_waitstatus *ourstatus)
 	   cygwin-specific-signal.  So, ignore SEGVs if they show up
 	   within the text segment of the DLL itself.  */
 	const char *fn;
-	CORE_ADDR addr = (CORE_ADDR) (uintptr_t)
-	  current_event.u.Exception.ExceptionRecord.ExceptionAddress;
+	CORE_ADDR addr = (CORE_ADDR) (uintptr_t) rec->ExceptionAddress;
 
 	if ((!cygwin_exceptions && (addr >= cygwin_load_start
 				    && addr < cygwin_load_end))
 	    || (find_pc_partial_function (addr, &fn, NULL, NULL)
 		&& startswith (fn, "KERNEL32!IsBad")))
-	  return 0;
+	  return HANDLE_EXCEPTION_UNHANDLED;
       }
 #endif
       break;
@@ -1140,20 +1154,64 @@  handle_exception (struct target_waitstatus *ourstatus)
       DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_NONCONTINUABLE_EXCEPTION");
       ourstatus->value.sig = GDB_SIGNAL_ILL;
       break;
+    case MS_VC_EXCEPTION:
+      if (rec->NumberParameters >= 3
+          && (rec->ExceptionInformation[0] & 0xffffffff) == 0x1000)
+	{
+	  long named_thread_id;
+	  windows_thread_info *named_windows_thread;
+	  CORE_ADDR thread_name_target;
+	  char *thread_name;
+	  int thread_name_len;
+
+	  DEBUG_EXCEPTION_SIMPLE ("MS_VC_EXCEPTION");
+
+	  named_thread_id = (long) (0xffffffff & rec->ExceptionInformation[2]);
+	  thread_name_target = rec->ExceptionInformation[1];
+
+	  if (named_thread_id == (DWORD) -1)
+	    named_thread_id = current_event.dwThreadId;
+
+	  named_windows_thread = thread_rec (named_thread_id, 0);
+
+	  thread_name = NULL;
+	  thread_name_len = 0;
+
+	  if (named_windows_thread != NULL)
+	    thread_name_len = target_read_string (thread_name_target,
+					          &thread_name, 1025, 0);
+
+	  if (thread_name_len > 0 && thread_name != NULL)
+	    {
+	      thread_name[thread_name_len - 1] = '\0';
+	      if (thread_name[0] != '\0')
+		{
+		  xfree (named_windows_thread->name);
+		  named_windows_thread->name = thread_name;
+		}
+	      else
+		{
+		  xfree (thread_name);
+		}
+	    }
+	  ourstatus->value.sig = GDB_SIGNAL_TRAP;
+	  result = HANDLE_EXCEPTION_IGNORED;
+	  break;
+	}
+	/* treat improperly formed exception as unknown, fallthrough */
     default:
       /* Treat unhandled first chance exceptions specially.  */
       if (current_event.u.Exception.dwFirstChance)
-	return 0;
+	return HANDLE_EXCEPTION_UNHANDLED;
       printf_unfiltered ("gdb: unknown target exception 0x%08x at %s\n",
-	(unsigned) current_event.u.Exception.ExceptionRecord.ExceptionCode,
-	host_address_to_string (
-	  current_event.u.Exception.ExceptionRecord.ExceptionAddress));
+	(unsigned) rec->ExceptionCode,
+	host_address_to_string (rec->ExceptionAddress));
       ourstatus->value.sig = GDB_SIGNAL_UNKNOWN;
       break;
     }
   exception_count++;
   last_sig = ourstatus->value.sig;
-  return 1;
+  return result;
 }
 
 /* Resume thread specified by ID, or all artificially suspended
@@ -1510,10 +1568,19 @@  get_windows_debug_event (struct target_ops *ops,
 		     "EXCEPTION_DEBUG_EVENT"));
       if (saw_create != 1)
 	break;
-      if (handle_exception (ourstatus))
-	thread_id = current_event.dwThreadId;
-      else
-	continue_status = DBG_EXCEPTION_NOT_HANDLED;
+      switch (handle_exception (ourstatus))
+	{
+	case HANDLE_EXCEPTION_UNHANDLED:
+	default:
+	  continue_status = DBG_EXCEPTION_NOT_HANDLED;
+	  break;
+	case HANDLE_EXCEPTION_HANDLED:
+	  thread_id = current_event.dwThreadId;
+	  break;
+	case HANDLE_EXCEPTION_IGNORED:
+	  continue_status = DBG_CONTINUE;
+	  break;
+	}
       break;
 
     case OUTPUT_DEBUG_STRING_EVENT:	/* Message from the kernel.  */
@@ -2514,6 +2581,31 @@  windows_get_ada_task_ptid (struct target_ops *self, long lwp, long thread)
   return ptid_build (ptid_get_pid (inferior_ptid), 0, lwp);
 }
 
+static const char *
+windows_get_thread_name (struct target_ops *self, struct thread_info *thr)
+{
+  struct thread_info *threadinfo;
+  windows_thread_info *windows_threadinfo;
+  DWORD id = ptid_get_tid (thr->ptid);
+  char *name;
+
+  name = NULL;
+  threadinfo = find_thread_ptid (thr->ptid);
+
+  if (threadinfo != NULL)
+    name = threadinfo->name;
+
+  if (name == NULL && id != 0)
+    {
+      windows_threadinfo = thread_rec (id, 0);
+
+      if (windows_threadinfo != NULL)
+        name = windows_threadinfo->name;
+    }
+
+  return (const char *) name;
+}
+
 static struct target_ops *
 windows_target (void)
 {
@@ -2538,6 +2630,7 @@  windows_target (void)
   t->to_pid_to_exec_file = windows_pid_to_exec_file;
   t->to_get_ada_task_ptid = windows_get_ada_task_ptid;
   t->to_get_tib_address = windows_get_tib_address;
+  t->to_thread_name = windows_get_thread_name;
 
   return t;
 }