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/* Source locations within string literals.
Copyright (C) 2016-2022 Free Software Foundation, Inc.
This file is part of GCC.
GCC 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, or (at your option) any later
version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "intl.h"
#include "diagnostic.h"
#include "cpplib.h"
#include "tree.h"
#include "langhooks.h"
#include "substring-locations.h"
#include "gcc-rich-location.h"
/* format_string_diagnostic_t's ctor, giving information for use by
the emit_warning* member functions, as follows:
They attempt to obtain precise location information within a string
literal from FMT_LOC.
Case 1: if substring location is available, and is within the range of
the format string itself, the primary location of the
diagnostic is the substring range obtained from FMT_LOC, with the
caret at the *end* of the substring range.
For example:
test.c:90:10: warning: problem with '%i' here [-Wformat=]
printf ("hello %i", msg);
~^
Case 2: if the substring location is available, but is not within
the range of the format string, the primary location is that of the
format string, and a note is emitted showing the substring location.
For example:
test.c:90:10: warning: problem with '%i' here [-Wformat=]
printf("hello " INT_FMT " world", msg);
^~~~~~~~~~~~~~~~~~~~~~~~~
test.c:19: note: format string is defined here
#define INT_FMT "%i"
~^
Case 3: if precise substring information is unavailable, the primary
location is that of the whole string passed to FMT_LOC's constructor.
For example:
test.c:90:10: warning: problem with '%i' here [-Wformat=]
printf(fmt, msg);
^~~
For each of cases 1-3, if param_loc is not UNKNOWN_LOCATION, then it is used
as a secondary range within the warning. For example, here it
is used with case 1:
test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
printf ("foo %s bar", long_i + long_j);
~^ ~~~~~~~~~~~~~~~
and here with case 2:
test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
printf ("foo " STR_FMT " bar", long_i + long_j);
^~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~
test.c:89:16: note: format string is defined here
#define STR_FMT "%s"
~^
and with case 3:
test.c:90:10: warning: '%i' here, but arg 2 is "const char *' [-Wformat=]
printf(fmt, msg);
^~~ ~~~
If non-NULL, then FMT_LABEL will be used to label the location within the
string for cases 1 and 2; if non-NULL, then PARAM_LABEL will be used to label
the parameter. For example with case 1:
test.c:90:16: warning: '%s' here but arg 2 has 'long' type [-Wformat=]
printf ("foo %s bar", long_i + long_j);
~^ ~~~~~~~~~~~~~~~
|
int
and with case 2:
test.c:90:10: warning: problem with '%i' here [-Wformat=]
printf("hello " INT_FMT " world", msg);
^~~~~~~~~~~~~~~~~~~~~~~~~
test.c:19: note: format string is defined here
#define INT_FMT "%i"
~^
|
int
If CORRECTED_SUBSTRING is non-NULL, use it for cases 1 and 2 to provide
a fix-it hint, suggesting that it should replace the text within the
substring range. For example:
test.c:90:10: warning: problem with '%i' here [-Wformat=]
printf ("hello %i", msg);
~^
%s
*/
format_string_diagnostic_t::
format_string_diagnostic_t (const substring_loc &fmt_loc,
const range_label *fmt_label,
location_t param_loc,
const range_label *param_label,
const char *corrected_substring)
: m_fmt_loc (fmt_loc),
m_fmt_label (fmt_label),
m_param_loc (param_loc),
m_param_label (param_label),
m_corrected_substring (corrected_substring)
{
}
/* Emit a warning governed by option OPT, using SINGULAR_GMSGID as the
format string (or if PLURAL_GMSGID is different from SINGULAR_GMSGID,
using SINGULAR_GMSGID, PLURAL_GMSGID and N as arguments to ngettext)
and AP as its arguments.
Return true if a warning was emitted, false otherwise. */
bool
format_string_diagnostic_t::emit_warning_n_va (int opt,
unsigned HOST_WIDE_INT n,
const char *singular_gmsgid,
const char *plural_gmsgid,
va_list *ap) const
{
bool substring_within_range = false;
location_t primary_loc;
location_t fmt_substring_loc = UNKNOWN_LOCATION;
source_range fmt_loc_range
= get_range_from_loc (line_table, m_fmt_loc.get_fmt_string_loc ());
const char *err = m_fmt_loc.get_location (&fmt_substring_loc);
source_range fmt_substring_range
= get_range_from_loc (line_table, fmt_substring_loc);
if (err)
/* Case 3: unable to get substring location. */
primary_loc = m_fmt_loc.get_fmt_string_loc ();
else
{
if (fmt_substring_range.m_start >= fmt_loc_range.m_start
&& fmt_substring_range.m_start <= fmt_loc_range.m_finish
&& fmt_substring_range.m_finish >= fmt_loc_range.m_start
&& fmt_substring_range.m_finish <= fmt_loc_range.m_finish)
/* Case 1. */
{
substring_within_range = true;
primary_loc = fmt_substring_loc;
}
else
/* Case 2. */
{
substring_within_range = false;
primary_loc = m_fmt_loc.get_fmt_string_loc ();
}
}
/* Only use fmt_label in the initial warning for case 1. */
const range_label *primary_label = NULL;
if (substring_within_range)
primary_label = m_fmt_label;
auto_diagnostic_group d;
gcc_rich_location richloc (primary_loc, primary_label);
if (m_param_loc != UNKNOWN_LOCATION)
richloc.add_range (m_param_loc, SHOW_RANGE_WITHOUT_CARET, m_param_label);
if (!err && m_corrected_substring && substring_within_range)
richloc.add_fixit_replace (fmt_substring_range, m_corrected_substring);
diagnostic_info diagnostic;
if (singular_gmsgid != plural_gmsgid)
{
unsigned long gtn;
if (sizeof n <= sizeof gtn)
gtn = n;
else
/* Use the largest number ngettext can handle, otherwise
preserve the six least significant decimal digits for
languages where the plural form depends on them. */
gtn = n <= ULONG_MAX ? n : n % 1000000LU + 1000000LU;
const char *text = ngettext (singular_gmsgid, plural_gmsgid, gtn);
diagnostic_set_info_translated (&diagnostic, text, ap, &richloc,
DK_WARNING);
}
else
diagnostic_set_info (&diagnostic, singular_gmsgid, ap, &richloc,
DK_WARNING);
diagnostic.option_index = opt;
bool warned = diagnostic_report_diagnostic (global_dc, &diagnostic);
if (!err && fmt_substring_loc && !substring_within_range)
/* Case 2. */
if (warned)
{
/* Use fmt_label in the note for case 2. */
rich_location substring_richloc (line_table, fmt_substring_loc,
m_fmt_label);
if (m_corrected_substring)
substring_richloc.add_fixit_replace (fmt_substring_range,
m_corrected_substring);
inform (&substring_richloc,
"format string is defined here");
}
return warned;
}
/* Singular-only version of the above. */
bool
format_string_diagnostic_t::emit_warning_va (int opt, const char *gmsgid,
va_list *ap) const
{
return emit_warning_n_va (opt, 0, gmsgid, gmsgid, ap);
}
/* Variadic version of the above (singular only). */
bool
format_string_diagnostic_t::emit_warning (int opt, const char *gmsgid,
...) const
{
va_list ap;
va_start (ap, gmsgid);
bool warned = emit_warning_va (opt, gmsgid, &ap);
va_end (ap);
return warned;
}
/* Variadic version of the above (singular vs plural). */
bool
format_string_diagnostic_t::emit_warning_n (int opt, unsigned HOST_WIDE_INT n,
const char *singular_gmsgid,
const char *plural_gmsgid,
...) const
{
va_list ap;
va_start (ap, plural_gmsgid);
bool warned = emit_warning_n_va (opt, n, singular_gmsgid, plural_gmsgid,
&ap);
va_end (ap);
return warned;
}
/* Attempt to determine the source location of the substring.
If successful, return NULL and write the source location to *OUT_LOC.
Otherwise return an error message. Error messages are intended
for GCC developers (to help debugging) rather than for end-users. */
const char *
substring_loc::get_location (location_t *out_loc) const
{
gcc_assert (out_loc);
return lang_hooks.get_substring_location (*this, out_loc);
}