binutils-gdb/gdb/cli-out.c
Andrew Burgess 1871a62daf gdb: Respect field width and alignment for 'fmt' fields in CLI output
Currently the method 'cli_ui_out::do_field_fmt' has this comment:

  /* This is the only field function that does not align.  */

The reality is even slightly worse, the 'fmt' field type doesn't
respect either the field alignment or the field width.  In at least
one place in GDB we attempt to work around this lack of respect for
field width by adding additional padding manually.  But, as is often
the case, this is leading to knock on problems.

Conside the output for 'info breakpoints' when a breakpoint has
multiple locations.  This example is taken from the testsuite, from
test gdb.opt/inline-break.exp:

  (gdb) info breakpoints
  Num     Type           Disp Enb Address            What
  1       breakpoint     keep y   <MULTIPLE>
  1.1                     y     0x00000000004004ae in func4b at /src/gdb/testsuite/gdb.opt/inline-break.c:64
  1.2                     y     0x0000000000400682 in func4b at /src/gdb/testsuite/gdb.opt/inline-break.c:64

The miss-alignment of the fields shown here is exactly as GDB
currently produces.

With this patch 'fmt' style fields are now first written into a
temporary buffer, and then written out as a 'string' field.  The
result is that the field width, and alignment should now be respected.
With this patch in place the output from GDB now looks like this:

  (gdb) info breakpoints
  Num     Type           Disp Enb Address            What
  1       breakpoint     keep y   <MULTIPLE>
  1.1                         y   0x00000000004004ae in func4b at /src/gdb/testsuite/gdb.opt/inline-break.c:64
  1.2                         y   0x0000000000400682 in func4b at /src/gdb/testsuite/gdb.opt/inline-break.c:64

This patch has been tested on x86-64/Linux with no regressions,
however, the testsuite doesn't always spot broken output formatting or
alignment.  I have also audited all uses of 'fmt' fields that I could
find, and I don't think there are any other places that specifically
try to work around the lack of width/alignment, however, I could have
missed something.

gdb/ChangeLog:

	* breakpoint.c (print_one_breakpoint_location): Reduce whitespace,
	and remove insertion of extra spaces in GDB's output.
	* cli-out.c (cli_ui_out::do_field_fmt): Update header comment.
	Layout field into a temporary buffer, and then output it as a
	string field.

gdb/testsuite/ChangeLog:

	* gdb.opt/inline-break.exp: Add test that info breakpoint output
	is correctly aligned.
2018-11-20 23:01:42 +00:00

359 lines
7.2 KiB
C

/* Output generating routines for GDB CLI.
Copyright (C) 1999-2018 Free Software Foundation, Inc.
Contributed by Cygnus Solutions.
Written by Fernando Nasser for Cygnus.
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/>. */
#include "defs.h"
#include "ui-out.h"
#include "cli-out.h"
#include "completer.h"
#include "readline/readline.h"
/* These are the CLI output functions */
/* Mark beginning of a table */
void
cli_ui_out::do_table_begin (int nbrofcols, int nr_rows, const char *tblid)
{
if (nr_rows == 0)
m_suppress_output = true;
else
/* Only the table suppresses the output and, fortunately, a table
is not a recursive data structure. */
gdb_assert (!m_suppress_output);
}
/* Mark beginning of a table body */
void
cli_ui_out::do_table_body ()
{
if (m_suppress_output)
return;
/* first, close the table header line */
text ("\n");
}
/* Mark end of a table */
void
cli_ui_out::do_table_end ()
{
m_suppress_output = false;
}
/* Specify table header */
void
cli_ui_out::do_table_header (int width, ui_align alignment,
const std::string &col_name,
const std::string &col_hdr)
{
if (m_suppress_output)
return;
do_field_string (0, width, alignment, 0, col_hdr.c_str ());
}
/* Mark beginning of a list */
void
cli_ui_out::do_begin (ui_out_type type, const char *id)
{
}
/* Mark end of a list */
void
cli_ui_out::do_end (ui_out_type type)
{
}
/* output an int field */
void
cli_ui_out::do_field_int (int fldno, int width, ui_align alignment,
const char *fldname, int value)
{
char buffer[20]; /* FIXME: how many chars long a %d can become? */
if (m_suppress_output)
return;
xsnprintf (buffer, sizeof (buffer), "%d", value);
do_field_string (fldno, width, alignment, fldname, buffer);
}
/* used to omit a field */
void
cli_ui_out::do_field_skip (int fldno, int width, ui_align alignment,
const char *fldname)
{
if (m_suppress_output)
return;
do_field_string (fldno, width, alignment, fldname, "");
}
/* other specific cli_field_* end up here so alignment and field
separators are both handled by cli_field_string */
void
cli_ui_out::do_field_string (int fldno, int width, ui_align align,
const char *fldname, const char *string)
{
int before = 0;
int after = 0;
if (m_suppress_output)
return;
if ((align != ui_noalign) && string)
{
before = width - strlen (string);
if (before <= 0)
before = 0;
else
{
if (align == ui_right)
after = 0;
else if (align == ui_left)
{
after = before;
before = 0;
}
else
/* ui_center */
{
after = before / 2;
before -= after;
}
}
}
if (before)
spaces (before);
if (string)
fputs_filtered (string, m_streams.back ());
if (after)
spaces (after);
if (align != ui_noalign)
field_separator ();
}
/* Output field containing ARGS using printf formatting in FORMAT. */
void
cli_ui_out::do_field_fmt (int fldno, int width, ui_align align,
const char *fldname, const char *format,
va_list args)
{
if (m_suppress_output)
return;
std::string str = string_vprintf (format, args);
do_field_string (fldno, width, align, fldname, str.c_str ());
}
void
cli_ui_out::do_spaces (int numspaces)
{
if (m_suppress_output)
return;
print_spaces_filtered (numspaces, m_streams.back ());
}
void
cli_ui_out::do_text (const char *string)
{
if (m_suppress_output)
return;
fputs_filtered (string, m_streams.back ());
}
void
cli_ui_out::do_message (const char *format, va_list args)
{
if (m_suppress_output)
return;
vfprintf_unfiltered (m_streams.back (), format, args);
}
void
cli_ui_out::do_wrap_hint (const char *identstring)
{
if (m_suppress_output)
return;
wrap_here (identstring);
}
void
cli_ui_out::do_flush ()
{
gdb_flush (m_streams.back ());
}
/* OUTSTREAM as non-NULL will push OUTSTREAM on the stack of output streams
and make it therefore active. OUTSTREAM as NULL will pop the last pushed
output stream; it is an internal error if it does not exist. */
void
cli_ui_out::do_redirect (ui_file *outstream)
{
if (outstream != NULL)
m_streams.push_back (outstream);
else
m_streams.pop_back ();
}
/* local functions */
void
cli_ui_out::field_separator ()
{
fputc_filtered (' ', m_streams.back ());
}
/* Constructor for cli_ui_out. */
cli_ui_out::cli_ui_out (ui_file *stream, ui_out_flags flags)
: ui_out (flags),
m_suppress_output (false)
{
gdb_assert (stream != NULL);
m_streams.push_back (stream);
}
cli_ui_out::~cli_ui_out ()
{
}
/* Initialize private members at startup. */
cli_ui_out *
cli_out_new (struct ui_file *stream)
{
return new cli_ui_out (stream, ui_source_list);
}
ui_file *
cli_ui_out::set_stream (struct ui_file *stream)
{
ui_file *old;
old = m_streams.back ();
m_streams.back () = stream;
return old;
}
/* CLI interface to display tab-completion matches. */
/* CLI version of displayer.crlf. */
static void
cli_mld_crlf (const struct match_list_displayer *displayer)
{
rl_crlf ();
}
/* CLI version of displayer.putch. */
static void
cli_mld_putch (const struct match_list_displayer *displayer, int ch)
{
putc (ch, rl_outstream);
}
/* CLI version of displayer.puts. */
static void
cli_mld_puts (const struct match_list_displayer *displayer, const char *s)
{
fputs (s, rl_outstream);
}
/* CLI version of displayer.flush. */
static void
cli_mld_flush (const struct match_list_displayer *displayer)
{
fflush (rl_outstream);
}
EXTERN_C void _rl_erase_entire_line (void);
/* CLI version of displayer.erase_entire_line. */
static void
cli_mld_erase_entire_line (const struct match_list_displayer *displayer)
{
_rl_erase_entire_line ();
}
/* CLI version of displayer.beep. */
static void
cli_mld_beep (const struct match_list_displayer *displayer)
{
rl_ding ();
}
/* CLI version of displayer.read_key. */
static int
cli_mld_read_key (const struct match_list_displayer *displayer)
{
return rl_read_key ();
}
/* CLI version of rl_completion_display_matches_hook.
See gdb_display_match_list for a description of the arguments. */
void
cli_display_match_list (char **matches, int len, int max)
{
struct match_list_displayer displayer;
rl_get_screen_size (&displayer.height, &displayer.width);
displayer.crlf = cli_mld_crlf;
displayer.putch = cli_mld_putch;
displayer.puts = cli_mld_puts;
displayer.flush = cli_mld_flush;
displayer.erase_entire_line = cli_mld_erase_entire_line;
displayer.beep = cli_mld_beep;
displayer.read_key = cli_mld_read_key;
gdb_display_match_list (matches, len, max, &displayer);
rl_forced_update_display ();
}