binutils-gdb/gdb/annotate.h
Andrew Burgess 7c13f4e875 gdb: Restore old annotations behaviour when printing frame info
This undoes most of the changes from these commits:

  commit ec8e2b6d30
  Date:   Fri Jun 14 23:43:00 2019 +0100

      gdb: Don't allow annotations to influence what else GDB prints

  commit 0d3abd8cc9
  Date:   Wed Jun 12 22:34:26 2019 +0100

      gdb: Remove an update of current_source_line and current_source_symtab

as a result of the discussion here:

  https://sourceware.org/pipermail/gdb/2020-April/048468.html

Having taken time to reflect on the discussion, and reading the
documentation again I believe we should revert GDB's behaviour back to
how it used to be.

The original concern that triggered the initial patch was that when
annotations were on the current source and line were updated (inside
the annotation code), while when annotations are off this update would
not occur.  This was incorrect, as printing the source with the call
to print_source_lines does also update the current source and line.

Further, the documentation here:
  https://sourceware.org/gdb/current/onlinedocs/gdb/Source-Annotations.html#Source-Annotations

Clearly states:

  "The following annotation is used instead of displaying source code:

   ^Z^Zsource filename:line:character:middle:addr

   ..."

So it is documented that the 'source' annotation is a replacement for,
and not in addition to, actually printing the source lie.

There are still a few issues that I can see, these are:

  1. In source.c:info_line_command, when annotations are on we call
  annotate_source_line, however, if annotations are off then there is
  no corresponding call to print the source line.  This means that a
  if a user uses 'info line ...' with annotations on, and then does a
  'list', they will get different results than if they had done this
  with annotations off.

  2. It bothers me that the call to annotate_source_line returns a
  boolean, and that this controls a call to print_source_line (in
  stack.c:print_frame_info).

  The reason for this is that the source line annotation will only
  print something if the file is found, and the line number is in
  range for the file.

  It seems to me like an annotation should always be printed, either
  one that identifies the file and line, or one that identifies the
  file and line GDB would like to access, but couldn't.

  I considered changing this, but in the end decided not too, if I
  extend the existing 'source' annotation to print something in all
  cases then I risk breaking existing UIs that rely on the file and
  line always being valid.  If I add a new annotation then this might
  also break existing UIs that rely on GDB itself printing the error
  from within print_source_line.

Given that annotations is deprecated (as I understand it) mechanism
for UIs to interact with GDB (in favour of MI) I figure we should just
restore the old behaviour, and leave the mini-bugs in until someone
actually complains.

This isn't a straight revert of the two commits mentioned above.  I've
left annotate_source_line instead of going back to the original
identify_source_line, which lived in source.c, but was really
annotation related.  The API for setting the current source and line
has changed since the original patches, so I updated for that change
too.  Finally I wrote the code in stack.c so that we avoided an extra
level of indentation, which I felt made things easier to read.

gdb/ChangeLog:

	* annotate.c (annotate_source_line): Update return type, add call
	to update current symtab and line.
	* annotate.h (annotate_source_line): Update return type, and
	extend header comment.
	* source.c (info_line_command): Check annotation_level before
	calling annotate_source_line.
	* stack.c (print_frame_info): If calling annotate_source_line
	returns true, then don't print any other source line information.

gdb/testsuite/ChangeLog:

	* gdb.base/annota1.exp: Update expected results.
	* gdb.cp/annota2.exp: Update expected results, remove duplicate
	test name.
	* gdb.cp/annota3.exp: Update expected results.
2020-05-22 13:39:50 +01:00

136 lines
4.9 KiB
C

/* Annotation routines for GDB.
Copyright (C) 1986-2020 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef ANNOTATE_H
#define ANNOTATE_H
#include "symtab.h"
#include "gdbtypes.h"
extern void annotate_breakpoint (int);
extern void annotate_catchpoint (int);
extern void annotate_watchpoint (int);
extern void annotate_starting (void);
extern void annotate_stopped (void);
extern void annotate_exited (int);
extern void annotate_signalled (void);
extern void annotate_signal_name (void);
extern void annotate_signal_name_end (void);
extern void annotate_signal_string (void);
extern void annotate_signal_string_end (void);
extern void annotate_signal (void);
extern void annotate_breakpoints_headers (void);
extern void annotate_field (int);
extern void annotate_breakpoints_table (void);
extern void annotate_record (void);
extern void annotate_breakpoints_table_end (void);
extern void annotate_frames_invalid (void);
extern void annotate_new_thread (void);
extern void annotate_thread_changed (void);
extern void annotate_display_prompt (void);
struct type;
extern void annotate_field_begin (struct type *);
extern void annotate_field_name_end (void);
extern void annotate_field_value (void);
extern void annotate_field_end (void);
extern void annotate_quit (void);
extern void annotate_error (void);
extern void annotate_error_begin (void);
extern void annotate_value_history_begin (int, struct type *);
extern void annotate_value_begin (struct type *);
extern void annotate_value_history_value (void);
extern void annotate_value_history_end (void);
extern void annotate_value_end (void);
extern void annotate_display_begin (void);
extern void annotate_display_number_end (void);
extern void annotate_display_format (void);
extern void annotate_display_expression (void);
extern void annotate_display_expression_end (void);
extern void annotate_display_value (void);
extern void annotate_display_end (void);
extern void annotate_arg_begin (void);
extern void annotate_arg_name_end (void);
extern void annotate_arg_value (struct type *);
extern void annotate_arg_end (void);
/* Wrap calls to annotate_arg_begin and annotate_arg_end in an RAII
class. */
struct annotate_arg_emitter
{
annotate_arg_emitter () { annotate_arg_begin (); }
~annotate_arg_emitter () { annotate_arg_end (); }
DISABLE_COPY_AND_ASSIGN (annotate_arg_emitter);
};
/* If annotations are turned on then print annotation describing the full
name of the source file S and the line number LINE and its corresponding
character position.
MID_STATEMENT is nonzero if the PC is not at the beginning of that
line.
The current symtab and line is updated to reflect S and LINE.
Return true if the annotation was printed and the current symtab and
line were updated, otherwise return false, which can happen if the
source file for S can't be found, or LINE is out of range.
This does leave GDB in the weird situation where, even when annotations
are on, we only sometimes print the annotation, and only sometimes
update the current symtab and line. However, this particular annotation
has behaved this way for some time, and front ends that still use
annotations now depend on this behaviour. */
extern bool annotate_source_line (struct symtab *s, int line,
int mid_statement, CORE_ADDR pc);
extern void annotate_frame_begin (int, struct gdbarch *, CORE_ADDR);
extern void annotate_function_call (void);
extern void annotate_signal_handler_caller (void);
extern void annotate_frame_address (void);
extern void annotate_frame_address_end (void);
extern void annotate_frame_function_name (void);
extern void annotate_frame_args (void);
extern void annotate_frame_source_begin (void);
extern void annotate_frame_source_file (void);
extern void annotate_frame_source_file_end (void);
extern void annotate_frame_source_line (void);
extern void annotate_frame_source_end (void);
extern void annotate_frame_where (void);
extern void annotate_frame_end (void);
extern void annotate_array_section_begin (int, struct type *);
extern void annotate_elt_rep (unsigned int);
extern void annotate_elt_rep_end (void);
extern void annotate_elt (void);
extern void annotate_array_section_end (void);
extern void (*deprecated_annotate_signalled_hook) (void);
extern void (*deprecated_annotate_signal_hook) (void);
#endif /* ANNOTATE_H */