PR gdb/15911: "info threads" changes the default source and line (for "break", "list")

"info threads" changes the default source for "break" and "list", to
whatever the location of the first/bottom thread in the thread list
is...

 (gdb) b start
 (gdb) c
 ...
 (gdb) list
 *lists "start"*
 (gdb) b 23
 Breakpoint 3 at 0x400614: file test.c, line 23.
 (gdb) info threads
   Id   Target Id         Frame
 * 2    Thread 0x7ffff7fcb700 (LWP 1760) "test" start (arg=0x0) at test.c:23
   1    Thread 0x7ffff7fcc740 (LWP 1748) "test" 0x000000323dc08e60 in pthread_join (threadid=140737353922304, thread_return=0x0) at pthread_join.c:93
 (gdb) b 23
 Breakpoint 4 at 0x323dc08d90: file pthread_join.c, line 23.
                                    ^^^^^^^^^^^^^^^
 (gdb) list
 93          lll_wait_tid (pd->tid);
 94
 95
 96        /* Restore cancellation mode.  */
 97        CANCEL_RESET (oldtype);
 98
 99        /* Remove the handler.  */
 100       pthread_cleanup_pop (0);
 101
 102

The issue is that print_stack_frame always sets the current sal to the
frame's sal.  print_frame_info (which print_stack_frame calls to do
most of the work) also sets the last displayed sal, but only if
print_what isn't LOCATION.  Now the call in question, from within
thread.c:print_thread_info, does pass in LOCATION as print_what, but
print_stack_frame doesn't have the same check print_frame_info has.
We could consider adding it, but setting these globals depending on
print_what isn't very clean, IMO.  What we have is two logically
distinct operations mixed in the same function(s):

  #1 - print frame, in the format specified by {print_what,
    print_level and print_args}.

  #2 - We're displaying a frame to the user, and I want the default
    sal to point here, because the program stopped here, or the user
    did some context-changing command (up, down, etc.).

So I added a new parameter to print_stack_frame & friends for point
#2, and went through all calls in the tree adjusting as necessary.

Tested on x86_64 Fedora 17.

gdb/
2013-09-17  Pedro Alves  <palves@redhat.com>

	PR gdb/15911
	* ada-tasks.c (task_command_1): Adjust call to print_stack_frame.
	* bsd-kvm.c (bsd_kvm_open, bsd_kvm_proc_cmd, bsd_kvm_pcb_cmd):
	* corelow.c (core_open):
	* frame.h (print_stack_frame, print_frame_info): New
	'set_current_sal' parameter.
	* infcmd.c (finish_command, kill_command): Adjust call to
	print_stack_frame.
	* inferior.c (inferior_command): Likewise.
	* infrun.c (normal_stop): Likewise.
	* linux-fork.c (linux_fork_context): Likewise.
	* record-full.c (record_full_goto_entry, record_full_restore):
	Likewise.
	* remote-mips.c (common_open): Likewise.
	* stack.c (print_stack_frame): New 'set_current_sal' parameter.
	Use it.
	(print_frame_info): New 'set_current_sal' parameter.  Set the last
	displayed sal depending on the new paremeter instead of looking at
	print_what.
	(backtrace_command_1, select_and_print_frame, frame_command)
	(current_frame_command, up_command, down_command): Adjust call to
	print_stack_frame.
	* thread.c (print_thread_info, restore_selected_frame)
	(do_captured_thread_select): Adjust call to print_stack_frame.
	* tracepoint.c (tfind_1): Likewise.
	* mi/mi-cmd-stack.c (mi_cmd_stack_list_frames)
	(mi_cmd_stack_info_frame): Likewise.
	* mi/mi-interp.c (mi_on_normal_stop): Likewise.
	* mi/mi-main.c (mi_cmd_exec_return, mi_cmd_trace_find): Likewise.

	gdb/testsuite/
	* gdb.threads/info-threads-cur-sal-2.c: New file.
	* gdb.threads/info-threads-cur-sal.c: New file.
	* gdb.threads/info-threads-cur-sal.exp: New file.

1 files changed, 15 insertions, 11 deletions

diff --git a/gdb/stack.c b/gdb/stack.c
index 16a03eb..cd4ac7a 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -154,7 +154,8 @@ frame_show_address (struct frame_info *frame,
 
 void
 print_stack_frame (struct frame_info *frame, int print_level,
-		   enum print_what print_what)
+		   enum print_what print_what,
+		   int set_current_sal)
 {
   volatile struct gdb_exception e;
 
@@ -166,8 +167,10 @@ print_stack_frame (struct frame_info *frame, int print_level,
     {
       int center = (print_what == SRC_LINE || print_what == SRC_AND_LOC);
 
-      print_frame_info (frame, print_level, print_what, 1 /* print_args */);
-      set_current_sal_from_frame (frame, center);
+      print_frame_info (frame, print_level, print_what, 1 /* print_args */,
+			set_current_sal);
+      if (set_current_sal)
+	set_current_sal_from_frame (frame, center);
     }
 }
 
@@ -780,7 +783,8 @@ do_gdb_disassembly (struct gdbarch *gdbarch,
 
 void
 print_frame_info (struct frame_info *frame, int print_level,
-		  enum print_what print_what, int print_args)
+		  enum print_what print_what, int print_args,
+		  int set_current_sal)
 {
   struct gdbarch *gdbarch = get_frame_arch (frame);
   struct symtab_and_line sal;
@@ -905,7 +909,7 @@ print_frame_info (struct frame_info *frame, int print_level,
 	do_gdb_disassembly (get_frame_arch (frame), -1, sal.pc, sal.end);
     }
 
-  if (print_what != LOCATION)
+  if (set_current_sal)
     {
       CORE_ADDR pc;
 
@@ -1787,7 +1791,7 @@ backtrace_command_1 (char *count_exp, int show_locals, int no_filters,
 	     hand, perhaps the code does or could be fixed to make sure
 	     the frame->prev field gets set to NULL in that case).  */
 
-	  print_frame_info (fi, 1, LOCATION, 1);
+	  print_frame_info (fi, 1, LOCATION, 1, 0);
 	  if (show_locals)
 	    {
 	      struct frame_id frame_id = get_frame_id (fi);
@@ -2184,7 +2188,7 @@ select_and_print_frame (struct frame_info *frame)
 {
   select_frame (frame);
   if (frame)
-    print_stack_frame (frame, 1, SRC_AND_LOC);
+    print_stack_frame (frame, 1, SRC_AND_LOC, 1);
 }
 
 /* Return the symbol-block in which the selected frame is executing.
@@ -2262,7 +2266,7 @@ static void
 frame_command (char *level_exp, int from_tty)
 {
   select_frame_command (level_exp, from_tty);
-  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
+  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
 }
 
 /* The XDB Compatibility command to print the current frame.  */
@@ -2270,7 +2274,7 @@ frame_command (char *level_exp, int from_tty)
 static void
 current_frame_command (char *level_exp, int from_tty)
 {
-  print_stack_frame (get_selected_frame (_("No stack.")), 1, SRC_AND_LOC);
+  print_stack_frame (get_selected_frame (_("No stack.")), 1, SRC_AND_LOC, 1);
 }
 
 /* Select the frame up one or COUNT_EXP stack levels from the
@@ -2301,7 +2305,7 @@ static void
 up_command (char *count_exp, int from_tty)
 {
   up_silently_base (count_exp);
-  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
+  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
 }
 
 /* Select the frame down one or COUNT_EXP stack levels from the previously
@@ -2340,7 +2344,7 @@ static void
 down_command (char *count_exp, int from_tty)
 {
   down_silently_base (count_exp);
-  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC);
+  print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1);
 }