Fix pagination crash when the TUI is active

The TUI currently crashes when the user types <return> in response to
a pagination prompt:

  $ gdb --tui ...
  *the TUI is now active*
  (gdb) set height 2
  (gdb) help
  List of classes of commands:

  Program received signal SIGSEGV, Segmentation fault.
  strlen () at ../sysdeps/x86_64/strlen.S:106
  106             movdqu  (%rax), %xmm12

  (top-gdb) bt
  #0  strlen () at ../sysdeps/x86_64/strlen.S:106
  #1  0x000000000086be5f in xstrdup (s=0x0) at ../src/libiberty/xstrdup.c:33
  #2  0x00000000005163f9 in tui_prep_terminal (notused1=1) at ../src/gdb/tui/tui-io.c:296
  #3  0x000000000077a7ee in _rl_callback_newline () at ../src/readline/callback.c:82
  #4  0x000000000077a853 in rl_callback_handler_install (prompt=0x0, linefunc=0x618b60 <command_line_handler>) at ../src/readline/callback.c:102
  #5  0x0000000000718a5c in gdb_readline_wrapper_cleanup (arg=0xfd14d0) at ../src/gdb/top.c:788
  #6  0x0000000000596d08 in do_my_cleanups (pmy_chain=0xcf0b38 <cleanup_chain>, old_chain=0x1043d10) at ../src/gdb/cleanups.c:155
  #7  0x0000000000596d75 in do_cleanups (old_chain=0x1043d10) at ../src/gdb/cleanups.c:177
  #8  0x0000000000718bd9 in gdb_readline_wrapper (prompt=0x7fffffffcfa0 "---Type <return> to continue, or q <return> to quit---")
      at ../src/gdb/top.c:835
  #9  0x000000000071cf74 in prompt_for_continue () at ../src/gdb/utils.c:1894
  #10 0x000000000071d434 in fputs_maybe_filtered (linebuffer=0x1043db0 "List of classes of commands:\n\n", stream=0xf72e20, filter=1)
      at ../src/gdb/utils.c:2111
  #11 0x000000000071da0f in vfprintf_maybe_filtered (stream=0xf72e20, format=0x89aef8 "List of classes of %scommands:\n\n", args=0x7fffffffd118, filter=1)
      at ../src/gdb/utils.c:2339
  #12 0x000000000071da4a in vfprintf_filtered (stream=0xf72e20, format=0x89aef8 "List of classes of %scommands:\n\n", args=0x7fffffffd118)
      at ../src/gdb/utils.c:2347
  #13 0x000000000071dc72 in fprintf_filtered (stream=0xf72e20, format=0x89aef8 "List of classes of %scommands:\n\n") at ../src/gdb/utils.c:2399
  #14 0x00000000004f90ab in help_list (list=0xe6d100, cmdtype=0x89ad8c "", class=all_classes, stream=0xf72e20)
      at ../src/gdb/cli/cli-decode.c:1038
  #15 0x00000000004f8dba in help_cmd (arg=0x0, stream=0xf72e20) at ../src/gdb/cli/cli-decode.c:946

Git 0017922 added:

    @@ -776,6 +777,12 @@ gdb_readline_wrapper_cleanup (void *arg)

     gdb_assert (input_handler == gdb_readline_wrapper_line);
     input_handler = cleanup->handler_orig;
  +
  +  /* Reinstall INPUT_HANDLER in readline, without displaying a
  +     prompt.  */
  +  if (async_command_editing_p)
  +    rl_callback_handler_install (NULL, input_handler);

and tui_prep_terminal simply misses handling the case of a NULL
rl_prompt.

I also checked that readline's sources do similar checks.

gdb/
2014-07-24  Pedro Alves  <palves@redhat.com>

	* tui/tui-io.c (tui_prep_terminal): Handle NULL rl_prompt.
constify cli-dump.c

This does some minor constification in cli-dump.c.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* cli/cli-dump.c (scan_expression_with_cleanup): Return const.
	Make "cmd" const.
	(scan_filename_with_cleanup): Likewise.
	(dump_memory_to_file, dump_value_to_file, restore_binary_file):
	Make arguments const.
	(restore_command): Update.
constify unset_in_environ

This constifies an argument to unset_in_environ.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* environ.c (unset_in_environ): Make "var" const.
	* environ.h (unset_in_environ): Update.
constify inf_child_open_target

This constifies an argument to inf_child_open_target.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* inf-child.c (inf_child_open_target): Make "arg" const.
	* inf-child.h (inf_child_open_target): Update.
constify maint.c

This does a bit of constification in maint.c, making
print_bfd_section_info a bit cleaner in the process.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* maint.c (match_bfd_flags): Make "string" const.
	(print_bfd_section_info): Remove casts.
	(print_objfile_section_info): Make "string" const.
constify monitor_open

This constifies an argument to monitor_open.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* monitor.c (monitor_open): Make "args" const.
	* monitor.h (monitor_open): Update.
constify remote.c

This does some more constification in remote.c.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* remote.c (remote_serial_open, print_packet, putpkt)
	(putpkt_binary): Constify.
	* remote.h (putpkt): Update.
constify solib_add

This constifies the "pattern" argument to solib_add.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* solib.c (solib_add): Make "pattern" const.
	* solib.h (solib_add): Update.
constify stack.c

This constifies a couple of functions in stack.c.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* stack.c (up_silently_base, down_silently_base): Make argument
	const.
constify help_cmd

This constifies help_cmd.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* cli/cli-decode.c (help_cmd): Make parameter "const".
	* cli/cli-decode.h (help_cmd): Update.
constify deprecate_cmd

This constifies deprecate_cmd and the "replacement" field in struct
cmd_list_element.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* cli/cli-decode.c (deprecate_cmd): Make "replacement" const.
	* cli/cli-decode.h (struct cmd_list_element) <replacement>: Now
	const.
	* command.h (deprecate_cmd): Update.
	* maint.c (maintenance_do_deprecate): Add casts.
constify command prefix

This constifies the "prefix" argument to the various command-adding
functions.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* cli/cli-decode.c (print_help_for_command): Make "prefix" const.
	(add_prefix_cmd, add_abbrev_prefix_cmd, apropos_cmd, help_list)
	(help_cmd_list): Constify.
	(lookup_cmd): Update.
	* cli/cli-decode.h (struct cmd_list_element) <prefixname>: Now
	const.
	(help_cmd_list, apropos_cmd): Update.
	* cli/cli-script.c (show_user): Update.
	* cli/cli-setshow.c (cmd_show_list): Make "prefix" const.
	* cli/cli-setshow.h (cmd_show_list): Update.
	* command.h (add_prefix_cmd, add_abbrev_prefix_cmd, help_list)
	(cmd_show_list): Update.
	* guile/scm-cmd.c (cmdscm_destroyer): Update.
	* python/py-cmd.c (cmdpy_destroyer): Update.
constify command docs

This makes the command "doc" parameter const.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* cli/cli-decode.c (add_cmd, add_prefix_cmd)
	(add_abbrev_prefix_cmd, add_set_or_show_cmd, add_info)
	(add_info_alias, add_com): Make "doc" const.
	(print_doc_line): Make "str" const.
	(delete_cmd): Update.
	* cli/cli-decode.h (struct cmd_list_element) <doc>: Now const.
	(print_doc_line): Update.
	* cli/cli-script.c (document_command): Update.
	* command.h (add_cmd, add_prefix_cmd, add_abbrev_prefix_cmd)
	(add_com, add_info, add_info_alias): Update.
	* guile/scm-cmd.c (cmdscm_destroyer): Update.
	* python/py-cmd.c (cmdpy_destroyer): Update.
constify target fields

This constifies the target_ops fields to_shortname, to_longname, and
to_doc.

2014-07-24  Tom Tromey  <tromey@redhat.com>

	* monitor.c (compile_pattern): Update.
	* target.h (struct target_ops) <to_shortname, to_longname,
	to_doc>: Now const.
daily update
Fix paginate-*.exp races

Jan pointed out in
<https://sourceware.org/ml/gdb-patches/2014-07/msg00553.html> that
these testcases have racy results:

  gdb.base/double-prompt-target-event-error.exp
  gdb.base/paginate-after-ctrl-c-running.exp
  gdb.base/paginate-bg-execution.exp
  gdb.base/paginate-execution-startup.exp
  gdb.base/paginate-inferior-exit.exp

This is easily reproducible with "read1" from:

  [reproducer for races of expect incomplete reads]
  http://sourceware.org/bugzilla/show_bug.cgi?id=12649

The '-notransfer -re "<return>" { exp_continue }' trick in the current
tests doesn't actually work.

The issue that led to the -notransfer trick was that

  "---Type <return> to continue, or q <return> to quit---"

has two "<return>"s.  If one wants gdb_test_multiple to not hit the
built-in "<return>" match that results in FAIL, one has to expect the
pagination prompt in chunks, first up to the first "<return>", then
again, up to the second.  Something around these lines:

  gdb_test_multiple "" $test {
      -re "<return>" {
	  exp_continue
      }
      -re "to quit ---" {
	  pass $test
      }
  }

The intent was for -notransfer+exp_continue to make expect fetch more
input, and rerun the matches against the now potentially fuller
buffer, and then eventually the -re that includes the full pagination
prompt regex would match instead (because it's listed higher up, it
would match first).  But, once that "<return>" -notransfer -re
matches, it keeps re-matching forever.  It seems like with
exp_continue, expect immediately retries matching, instead of first
reading in more data into the buffer, if available.

Fix this like I should have done in the first place.  There's actually
no good reason for gdb_test_multiple to only match "<return>".  We can
make gdb_test_multiple expect the whole pagination prompt text
instead, which is store in the 'pagination_prompt' global (similar to
'gdb_prompt').  Then a gdb_test_multiple caller that doesn't want the
default match to trigger, because it wants to see one pagination
prompt, does simply:

  gdb_test_multiple "" $test {
      -re "$pagination_prompt$" {
	  pass $test
      }
  }

which is just like when we don't want the default $gdb_prompt match
within gdb_test_multiple to trigger, like:

  gdb_test_multiple "" $test {
      -re "$gdb_prompt $" {
	  pass $test
      }
  }

Tested on x86_64 Fedora 20.  In addition, I've let the racy tests run
all in parallel in a loop for 30 minutes, and they never failed.

gdb/testsuite/
2014-07-25  Pedro Alves  <palves@redhat.com>

	* gdb.base/double-prompt-target-event-error.exp
	(cancel_pagination_in_target_event): Remove '-notransfer <return>'
	match.
	(cancel_pagination_in_target_event): Rework double prompt
	detection.
	* gdb.base/paginate-after-ctrl-c-running.exp
	(test_ctrlc_while_target_running_paginates): Remove '-notransfer
	<return>' match.
	* gdb.base/paginate-bg-execution.exp
	(test_bg_execution_pagination_return)
	(test_bg_execution_pagination_cancel): Remove '-notransfer
	<return>' matches.
	* gdb.base/paginate-execution-startup.exp
	(test_fg_execution_pagination_return)
	(test_fg_execution_pagination_cancel): Remove '-notransfer
	<return>' matches.
	* gdb.base/paginate-inferior-exit.exp
	(test_paginate_inferior_exited): Remove '-notransfer <return>'
	match.
	* lib/gdb-utils.exp (string_to_regexp): Move here from lib/gdb.exp.
	* lib/gdb.exp (pagination_prompt): Run text through
	string_to_regexp.
	(gdb_test_multiple): Match $pagination_prompt instead of
	"<return>".
	(string_to_regexp): Move to lib/gdb-utils.exp.
Make all source files include defs.h or server.h first

This commit makes all source files under gdb/ that include headers
from gdb/ include either defs.h or server.h before any other code.
This ensures that definitions and macros from the two config.h files
are always in place for our code.  An exception has been made for
gdb/gdbserver/gdbreplay.c which seems to be a special case.

gdb/
2014-07-25  Gary Benson  <gbenson@redhat.com>

	* btrace.c: Include defs.h.
	* common/ptid.c: Include defs.h or server.h as appropriate.
	* nat/mips-linux-watch.c: Likewise.

gdb/gdbserver/
2014-07-25  Gary Benson  <gbenson@redhat.com>

	* hostio-errno.c: Move server.h to top of includes list.
	* inferiors.c: Likewise.
	* linux-x86-low.c: Likewise.
	* notif.c: Include server.h.
Do not include common.h directly

All source files under gdb/ that include headers from gdb/ include
either defs.h or server.h before any other code.  Both defs.h and
server.h include both our and gnulib's config.h files as their first
non-comment line, so no other file ever needs to include any config.h
apart from gdb/gdbserver/gdbreplay.c which seems to be a special case.
This commit removes the other two direct config.h includes.

gdb/
2014-07-25  Gary Benson  <gbenson@redhat.com>

	* common/common-utils.h: Do not include config.h.
	* nat/linux-btrace.h: Likewise.
Introduce common/common-defs.h

This commit creates a new header, common/common-defs.h, to hold
hold definitions common to all code under gdb/.  Both gdb/defs.h
and gdb/gdbserver/server.h are modified to include common-defs.h
as their first non-comment line; all code under gdb/ includes
either defs.h or server.h as appropriate, so common-defs.h will
be the first actual code the compiler sees.

For this initial commit common-defs.h includes only the two
config.h files.  Future commits will move more code currently
duplicated across defs.h and server.h such that shared code in
gdb/{common,target,nat} can be modified to include common-defs.h
rather than defs.h or server.h.

gdb/
2014-07-25  Gary Benson  <gbenson@redhat.com>

	* common/common-defs.h: New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add common/common-defs.h.
	* defs.h: Include common-defs.h.
	Do not include config.h or build-gnulib/config.h.

gdb/gdbserver/
2014-07-25  Gary Benson  <gbenson@redhat.com>

	* server.h: Include common-defs.h.
	Do not include config.h or build-gnulib-gdbserver/config.h.