bug fix for gdb 16039 ( patch resent according Sergion's suggestion)

["Dave.Tian" <xhengdf at gmail dot com>]

1 description: gdb bug 16039 created by me

  Title: gdb next" command stop working when shared library unloaded
  Root Cause: there is "libc++" static linked into the shared library,
and since gdb insert internal breakpoints on
std::terminate/longjump/..
              so after dlclose, the memory address is invalid,
remove_breakpoints/insert_breakpoints failed with EIO error.

  Fix: disable the internal breakpoints when dlclose hit.

2 ChangeLog:

          PR gdb/16039
        * breakpoint.c (set_longjmp_breakpoint): Check if breakpoint's
location address is not in an unloaded shared library.
                       (disable_breakpoints_in_unloaded_shlib):
disable the internal breakpoints in the hook function of shared
library unload.

3 Patch diffs:

--- breakpoint.c.bak	2013-10-12 01:15:09.044081000 -0700
+++ breakpoint.c	2013-10-13 22:56:54.905407000 -0700
@@ -1118,6 +1118,15 @@ is_tracepoint (const struct breakpoint *
   return is_tracepoint_type (b->type);
 }

+static int
+is_internal_breakpoint (const struct breakpoint *b)
+{
+  return (b->type == bp_longjmp_master
+	  || b->type == bp_std_terminate_master
+	  || b->type == bp_exception_master
+	  || b->type == bp_exception);
+}
+
 /* A helper function that validates that COMMANDS are valid for a
    breakpoint.  This function will throw an exception if a problem is
    found.  */
@@ -7147,8 +7156,8 @@ set_longjmp_breakpoint (struct thread_in
      clones of those and enable them for the requested thread.  */
   ALL_BREAKPOINTS_SAFE (b, b_tmp)
     if (b->pspace == current_program_space
-	&& (b->type == bp_longjmp_master
-	    || b->type == bp_exception_master))
+	&& ((b->type == bp_longjmp_master
+	    || b->type == bp_exception_master) && !b->loc->shlib_disabled))
       {
 	enum bptype type = b->type == bp_longjmp_master ? bp_longjmp : bp_exception;
 	struct breakpoint *clone;
@@ -7463,7 +7472,8 @@ disable_breakpoints_in_unloaded_shlib (s
 	      || b->type == bp_hardware_breakpoint)
 	     && (loc->loc_type == bp_loc_hardware_breakpoint
 		 || loc->loc_type == bp_loc_software_breakpoint))
-	    || is_tracepoint (b))
+	    || is_tracepoint (b)
+	    || is_internal_breakpoint (b))
 	&& solib_contains_address_p (solib, loc->address))
       {
 	loc->shlib_disabled = 1;

thank you,
-YT