darling-gdb/gdb/source.h
Pedro Alves 5166082f5f PR gdb/13860: make -interpreter-exec console "list" behave more like "list".
I noticed that "list" behaves differently in CLI vs MI.  Particularly:

  $ ./gdb -nx -q ./testsuite/gdb.mi/mi-cli
  Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli...done.
  (gdb) start
  Temporary breakpoint 1 at 0x40054d: file ../../../src/gdb/testsuite/gdb.mi/basics.c, line 62.
  Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli

  Temporary breakpoint 1, main () at ../../../src/gdb/testsuite/gdb.mi/basics.c:62
  62        callee1 (2, "A string argument.", 3.5);
  (gdb) list
  57      {
  58      }
  59
  60      main ()
  61      {
  62        callee1 (2, "A string argument.", 3.5);
  63        callee1 (2, "A string argument.", 3.5);
  64
  65        do_nothing (); /* Hello, World! */
  66
  (gdb)

Note the list started at line 57.  IOW, the program stopped at line
62, and GDB centered the list on that.

compare with:

  $ ./gdb -nx -q ./testsuite/gdb.mi/mi-cli -i=mi
  =thread-group-added,id="i1"
  ~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli..."
  ~"done.\n"
  (gdb)
  start
  &"start\n"
...
 ~"\nTemporary breakpoint "
  ~"1, main () at ../../../src/gdb/testsuite/gdb.mi/basics.c:62\n"
  ~"62\t  callee1 (2, \"A string argument.\", 3.5);\n"
  *stopped,reason="breakpoint-hit",disp="del",bkptno="1",frame={addr="0x000000000040054d",func="main",args=[],file="../../../src/gdb/testsuite/gdb.mi/basics.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/basics.c",line="62"},thread-id="1",stopped-threads="all",core="0"
  =breakpoint-deleted,id="1"
  (gdb)
  -interpreter-exec console list
  ~"62\t  callee1 (2, \"A string argument.\", 3.5);\n"
  ~"63\t  callee1 (2, \"A string argument.\", 3.5);\n"
  ~"64\t\n"
  ~"65\t  do_nothing (); /* Hello, World! */\n"
  ~"66\t\n"
  ~"67\t  callme (1);\n"
  ~"68\t  callme (2);\n"
  ~"69\t\n"
  ~"70\t  return 0;\n"
  ~"71\t}\n"
  ^done
  (gdb)

Here the list starts at line 62, where the program was stopped.

This happens because print_stack_frame, called from both normal_stop
and mi_on_normal_stop, is the function responsible for setting the
current sal from the selected frame, overrides the PRINT_WHAT
argument, and only after that does it decide whether to center the
current sal line or not, based on the overridden value, and it will
always decide false.

(The print_stack_frame call in mi_on_normal_stop is a little different
from the call in normal_stop, in that it is an unconditional
SRC_AND_LOC call.  A future patch will make those uniform.)

A previous version of this patch made MI uniform with CLI here, by
making print_stack_frame also center when MI is active.  That changed
the output of a "list" command in mi-cli.exp, to expect line 57
instead of 62, as per the example above.

However, looking deeper, that list in question is the first "list"
after the program stops, and right after the stop, before the "list",
the test did "set listsize 1".  Let's try the same thing with the CLI:

 (gdb) start
 62        callee1 (2, "A string argument.", 3.5);
 (gdb) set listsize 1
 (gdb) list
 57      {

Huh, that's unexpected.  Why the 57?  It's because print_stack_frame,
called in reaction to the breakpoint stop, expecting the next "list"
to show 10 lines (the listsize at the time) around line 62, sets the
lines listed range to 57-67 (62 +/- 5).  If the user changes the
listsize before "list", why would we still show that range?  Looks
bogus to me.

So the fix for this whole issue should be delay trying to center the
listing to until actually listing, so that the correct listsize can be
taken into account.  This makes MI and CLI uniform too, as it deletes
the center code from print_stack_frame.

A series of tests are added to list.exp to cover this.  mi-cli.exp was
after all correct all along, but it now gains an additional test that
lists lines with listsize 10, to ensure the centering is consistent
with CLI's.

One related Python test changed related output -- it's a test that
prints the line number after stopping for a breakpoint, similar to the
new list.exp tests.  Previously we'd print the stop line minus 5 (due
to the premature centering), now we print the stop line.  I think
that's a good change.

Tested on x86_64 Fedora 20.

gdb/
2014-05-21  Pedro Alves  <palves@redhat.com>

	* cli/cli-cmds.c (list_command): Handle the first "list" after the
	current source line having changed.
	* frame.h (set_current_sal_from_frame): Remove 'center' parameter.
	* infrun.c (normal_stop): Adjust call to
	set_current_sal_from_frame.
	* source.c (clear_lines_listed_range): New function.
	(set_current_source_symtab_and_line, identify_source_line): Clear
	the lines listed range.
	(line_info): Handle the first "info line" after the current source
	line having changed.
	* stack.c (print_stack_frame): Remove center handling.
	(set_current_sal_from_frame): Remove 'center' parameter.  Don't
	center sal.line.

gdb/testsuite/
2014-05-21  Pedro Alves  <palves@redhat.com>

	* gdb.base/list.exp (build_pattern, test_list): New procedures.
	Use them to test variations of "list" after reaching a breakpoint.
	* gdb.mi/mi-cli.exp (line_main_callme_2): New global.
	Test "list" with listsize 10 after reaching a breakpoint.
	* gdb.python/python.exp (decode_line current location line
	number): Adjust expected line number.
2014-05-21 23:15:27 +01:00

102 lines
4.4 KiB
C

/* List lines of source files for GDB, the GNU debugger.
Copyright (C) 1999-2014 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 SOURCE_H
#define SOURCE_H
struct symtab;
/* This function is capable of finding the absolute path to a
source file, and opening it, provided you give it a FILENAME. Both the
DIRNAME and FULLNAME are only added suggestions on where to find the file.
FILENAME should be the filename to open.
DIRNAME is the compilation directory of a particular source file.
Only some debug formats provide this info.
FULLNAME can be the last known absolute path to the file in question.
Space for the path must have been malloc'd. If a path substitution
is applied we free the old value and set a new one.
On Success
A valid file descriptor is returned (the return value is positive).
FULLNAME is set to the absolute path to the file just opened.
The caller is responsible for freeing FULLNAME.
On Failure
An invalid file descriptor is returned (the return value is negative).
FULLNAME is set to NULL. */
extern int find_and_open_source (const char *filename,
const char *dirname,
char **fullname);
/* Open a source file given a symtab S. Returns a file descriptor or
negative number for error. */
extern int open_source_file (struct symtab *s);
extern char *rewrite_source_path (const char *path);
extern const char *symtab_to_fullname (struct symtab *s);
/* Returns filename without the compile directory part, basename or absolute
filename. It depends on 'set filename-display' value. */
extern const char *symtab_to_filename_for_display (struct symtab *symtab);
/* Create and initialize the table S->line_charpos that records the
positions of the lines in the source file, which is assumed to be
open on descriptor DESC. All set S->nlines to the number of such
lines. */
extern void find_source_lines (struct symtab *s, int desc);
/* Return the first line listed by print_source_lines. Used by
command interpreters to request listing from a previous point. If
0, then no source lines have yet been listed since the last time
the current source line was changed. */
extern int get_first_line_listed (void);
/* Return the default number of lines to print with commands like the
cli "list". The caller of print_source_lines must use this to
calculate the end line and use it in the call to print_source_lines
as it does not automatically use this value. */
extern int get_lines_to_list (void);
/* Return the current source file for listing and next line to list.
NOTE: The returned sal pc and end fields are not valid. */
extern struct symtab_and_line get_current_source_symtab_and_line (void);
/* If the current source file for listing is not set, try and get a default.
Usually called before get_current_source_symtab_and_line() is called.
It may err out if a default cannot be determined.
We must be cautious about where it is called, as it can recurse as the
process of determining a new default may call the caller!
Use get_current_source_symtab_and_line only to get whatever
we have without erroring out or trying to get a default. */
extern void set_default_source_symtab_and_line (void);
/* Return the current default file for listing and next line to list
(the returned sal pc and end fields are not valid.)
and set the current default to whatever is in SAL.
NOTE: The returned sal pc and end fields are not valid. */
extern struct symtab_and_line set_current_source_symtab_and_line (const struct symtab_and_line *);
/* Reset any information stored about a default file and line to print. */
extern void clear_current_source_symtab_and_line (void);
/* Add a source path substitution rule. */
extern void add_substitute_path_rule (char *, char *);
#endif