Allow no debuginfo to be found when (trying to) produce the help msg
for activating the host visibility in gdbsrv


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14227 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/m_gdbserver/server.c b/coregrind/m_gdbserver/server.c
index 72d6660..5346401 100644
--- a/coregrind/m_gdbserver/server.c
+++ b/coregrind/m_gdbserver/server.c
@@ -327,16 +327,20 @@
             hostvisibility = True;
          }
          if (hostvisibility) {
-            const DebugInfo *tooldi = VG_(find_DebugInfo) ((Addr)handle_gdb_valgrind_command);
-            vg_assert(tooldi);
-            const NSegment *toolseg = VG_(am_find_nsegment)
-               (VG_(DebugInfo_get_text_avma) (tooldi));
-            vg_assert(toolseg);
+            const DebugInfo *tooldi 
+               = VG_(find_DebugInfo) ((Addr)handle_gdb_valgrind_command);
+            const NSegment *toolseg 
+               = tooldi ?
+                 VG_(am_find_nsegment) (VG_(DebugInfo_get_text_avma) (tooldi))
+                 : NULL;
             VG_(gdb_printf) 
                ("Enabled access to Valgrind memory/status by GDB\n"
                 "If not yet done, tell GDB which valgrind file(s) to use, "
                 "typically:\n"
-                "add-symbol-file %s %p\n", VG_(am_get_filename)(toolseg), (void*) toolseg->start);
+                "add-symbol-file %s %p\n", 
+                toolseg ? VG_(am_get_filename)(toolseg)
+                : "<toolfile> <address> e.g.",
+                toolseg ? (void*)toolseg->start : (void*)0x38000000);
          } else
             VG_(gdb_printf)
                ("Disabled access to Valgrind memory/status by GDB\n");