binutils-gdb/gdb/language.c
Andrew Burgess baab375361 gdb: building inferior strings from within GDB
History Of This Patch
=====================

This commit aims to address PR gdb/21699.  There have now been a
couple of attempts to fix this issue.  Simon originally posted two
patches back in 2021:

  https://sourceware.org/pipermail/gdb-patches/2021-July/180894.html
  https://sourceware.org/pipermail/gdb-patches/2021-July/180896.html

Before Pedro then posted a version of his own:

  https://sourceware.org/pipermail/gdb-patches/2021-July/180970.html

After this the conversation halted.  Then in 2023 I (Andrew) also took
a look at this bug and posted two versions:

  https://sourceware.org/pipermail/gdb-patches/2023-April/198570.html
  https://sourceware.org/pipermail/gdb-patches/2023-April/198680.html

The approach taken in my first patch was pretty similar to what Simon
originally posted back in 2021.  My second attempt was only a slight
variation on the first.

Pedro then pointed out his older patch, and so we arrive at this
patch.  The GDB changes here are mostly Pedro's work, but updated by
me (Andrew), any mistakes are mine.

The tests here are a combinations of everyone's work, and the commit
message is new, but copies bits from everyone's earlier work.

Problem Description
===================

Bug PR gdb/21699 makes the observation that using $_as_string with
GDB's printf can cause GDB to print unexpected data from the
inferior.  The reproducer is pretty simple:

  #include <stddef.h>
  static char arena[100];

  /* Override malloc() so value_coerce_to_target() gets a known
     pointer, and we know we"ll see an error if $_as_string() gives
     a string that isn't null terminated. */
  void
  *malloc (size_t size)
  {
      memset (arena, 'x', sizeof (arena));
      if (size > sizeof (arena))
          return NULL;
      return arena;
  }

  int
  main ()
  {
    return 0;
  }

And then in a GDB session:

  $ gdb -q test
  Reading symbols from /tmp/test...
  (gdb) start
  Temporary breakpoint 1 at 0x4004c8: file test.c, line 17.
  Starting program: /tmp/test

  Temporary breakpoint 1, main () at test.c:17
  17        return 0;
  (gdb) printf "%s\n", $_as_string("hello")
  "hello"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  (gdb) quit

The problem above is caused by how value_cstring is used within
py-value.c, but once we understand the issue then it turns out that
value_cstring is used in an unexpected way in many places within GDB.

Within py-value.c we have a null-terminated C-style string.  We then
pass a pointer to this string, along with the length of this
string (so not including the null-character) to value_cstring.

In value_cstring GDB allocates an array value of the given character
type, and copies in requested number of characters.  However
value_cstring does not add a null-character of its own.  This means
that the value created by calling value_cstring is only
null-terminated if the null-character is included in the passed in
length.  In py-value.c this is not the case, and indeed, in most uses
of value_cstring, this is not the case.

When GDB tries to print one of these strings the value contents are
pushed to the inferior, and then read back as a C-style string, that
is, GDB reads inferior memory until it finds a null-terminator.  For
the py-value.c case, no null-terminator is pushed into the inferior,
so GDB will continue reading inferior memory until a null-terminator
is found, with unpredictable results.

Patch Description
=================

The first thing this patch does is better define what the arguments
for the two function value_cstring and value_string should represent.
The comments in the header file are updated to describe whether the
length argument should, or should not, include a null-character.
Also, the data argument is changed to type gdb_byte.  The functions as
they currently exist will handle wide-characters, in which case more
than one 'char' would be needed for each character.  As such using
gdb_byte seems to make more sense.

To avoid adding casts throughout GDB, I've also added an overload that
still takes a 'char *', but asserts that the character type being used
is of size '1'.

The value_cstring function is now responsible for adding a null
character at the end of the string value it creates.

However, once we start looking at how value_cstring is used, we
realise there's another, related, problem.  Not every language's
strings are null terminated.  Fortran and Ada strings, for example,
are just an array of characters, GDB already has the function
value_string which can be used to create such values.

Consider this example using current GDB:

  (gdb) set language ada
  (gdb) p $_gdb_setting("arch")
  $1 = (97, 117, 116, 111)
  (gdb) ptype $
  type = array (1 .. 4) of char
  (gdb) p $_gdb_maint_setting("test-settings string")
  $2 = (0)
  (gdb) ptype $
  type = array (1 .. 1) of char

This shows two problems, first, the $_gdb_setting and
$_gdb_maint_setting functions are calling value_cstring using the
builtin_char character, rather than a language appropriate type.  In
the first call, the 'arch' case, the value_cstring call doesn't
include the null character, so the returned array only contains the
expected characters.  But, in the $_gdb_maint_setting example we do
end up including the null-character, even though this is not expected
for Ada strings.

This commit adds a new language method language_defn::value_string,
this function takes a pointer and length and creates a language
appropriate value that represents the string.  For C, C++, etc this
will be a null-terminated string (by calling value_cstring), and for
Fortran and Ada this can be a bounded array of characters with no null
terminator.  Additionally, this new language_defn::value_string
function is responsible for selecting a language appropriate character
type.

After this commit the only calls to value_cstring are from the C
expression evaluator and from the default language_defn::value_string.

And the only calls to value_string are from Fortan, Ada, and ObjectC
related code.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=21699

Co-Authored-By: Simon Marchi <simon.marchi@efficios.com>
Co-Authored-By: Andrew Burgess <aburgess@redhat.com>
Co-Authored-By: Pedro Alves <pedro@palves.net>
Approved-By: Simon Marchi <simon.marchi@efficios.com>
2023-06-05 13:25:08 +01:00

1099 lines
29 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Multiple source language support for GDB.
Copyright (C) 1991-2023 Free Software Foundation, Inc.
Contributed by the Department of Computer Science at the State University
of New York at Buffalo.
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/>. */
/* This file contains functions that return things that are specific
to languages. Each function should examine current_language if necessary,
and return the appropriate result. */
/* FIXME: Most of these would be better organized as macros which
return data out of a "language-specific" struct pointer that is set
whenever the working language changes. That would be a lot faster. */
#include "defs.h"
#include <ctype.h>
#include "symtab.h"
#include "gdbtypes.h"
#include "value.h"
#include "gdbcmd.h"
#include "expression.h"
#include "language.h"
#include "varobj.h"
#include "target.h"
#include "parser-defs.h"
#include "demangle.h"
#include "symfile.h"
#include "cp-support.h"
#include "frame.h"
#include "c-lang.h"
#include <algorithm>
#include "gdbarch.h"
static void set_range_case (void);
/* range_mode ==
range_mode_auto: range_check set automatically to default of language.
range_mode_manual: range_check set manually by user. */
enum range_mode
{
range_mode_auto, range_mode_manual
};
/* case_mode ==
case_mode_auto: case_sensitivity set upon selection of scope.
case_mode_manual: case_sensitivity set only by user. */
enum case_mode
{
case_mode_auto, case_mode_manual
};
/* The current (default at startup) state of type and range checking.
(If the modes are set to "auto", though, these are changed based
on the default language at startup, and then again based on the
language of the first source file. */
static enum range_mode range_mode = range_mode_auto;
enum range_check range_check = range_check_off;
static enum case_mode case_mode = case_mode_auto;
enum case_sensitivity case_sensitivity = case_sensitive_on;
/* The current language and language_mode (see language.h). */
const struct language_defn *current_language = nullptr;
enum language_mode language_mode = language_mode_auto;
/* The language that the user expects to be typing in (the language
of main(), or the last language we notified them about, or C). */
const struct language_defn *expected_language;
/* Define the array containing all languages. */
const struct language_defn *language_defn::languages[nr_languages];
/* The current values of the "set language/range/case-sensitive" enum
commands. */
static const char *range;
static const char *case_sensitive;
/* See language.h. */
const char lang_frame_mismatch_warn[] =
N_("Warning: the current language does not match this frame.");
/* This page contains the functions corresponding to GDB commands
and their helpers. */
/* Show command. Display a warning if the language set
does not match the frame. */
static void
show_language_command (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
enum language flang; /* The language of the frame. */
if (language_mode == language_mode_auto)
gdb_printf (file,
_("The current source language is "
"\"auto; currently %s\".\n"),
current_language->name ());
else
gdb_printf (file,
_("The current source language is \"%s\".\n"),
current_language->name ());
if (has_stack_frames ())
{
frame_info_ptr frame;
frame = get_selected_frame (NULL);
flang = get_frame_language (frame);
if (flang != language_unknown
&& language_mode == language_mode_manual
&& current_language->la_language != flang)
gdb_printf (file, "%s\n", _(lang_frame_mismatch_warn));
}
}
/* Set callback for the "set/show language" setting. */
static void
set_language (const char *language)
{
enum language flang = language_unknown;
/* "local" is a synonym of "auto". */
if (strcmp (language, "auto") == 0
|| strcmp (language, "local") == 0)
{
/* Enter auto mode. Set to the current frame's language, if
known, or fallback to the initial language. */
language_mode = language_mode_auto;
try
{
frame_info_ptr frame;
frame = get_selected_frame (NULL);
flang = get_frame_language (frame);
}
catch (const gdb_exception_error &ex)
{
flang = language_unknown;
}
if (flang != language_unknown)
set_language (flang);
else
set_initial_language ();
expected_language = current_language;
return;
}
/* Search the list of languages for a match. */
for (const auto &lang : language_defn::languages)
{
if (strcmp (lang->name (), language) != 0)
continue;
/* Found it! Go into manual mode, and use this language. */
language_mode = language_mode_manual;
current_language = lang;
set_range_case ();
expected_language = current_language;
return;
}
internal_error ("Couldn't find language `%s' in known languages list.",
language);
}
/* Get callback for the "set/show language" setting. */
static const char *
get_language ()
{
if (language_mode == language_mode_auto)
return "auto";
return current_language->name ();
}
/* Show command. Display a warning if the range setting does
not match the current language. */
static void
show_range_command (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
if (range_mode == range_mode_auto)
{
const char *tmp;
switch (range_check)
{
case range_check_on:
tmp = "on";
break;
case range_check_off:
tmp = "off";
break;
case range_check_warn:
tmp = "warn";
break;
default:
internal_error ("Unrecognized range check setting.");
}
gdb_printf (file,
_("Range checking is \"auto; currently %s\".\n"),
tmp);
}
else
gdb_printf (file, _("Range checking is \"%s\".\n"),
value);
if (range_check == range_check_warn
|| ((range_check == range_check_on)
!= current_language->range_checking_on_by_default ()))
warning (_("the current range check setting "
"does not match the language."));
}
/* Set command. Change the setting for range checking. */
static void
set_range_command (const char *ignore,
int from_tty, struct cmd_list_element *c)
{
if (strcmp (range, "on") == 0)
{
range_check = range_check_on;
range_mode = range_mode_manual;
}
else if (strcmp (range, "warn") == 0)
{
range_check = range_check_warn;
range_mode = range_mode_manual;
}
else if (strcmp (range, "off") == 0)
{
range_check = range_check_off;
range_mode = range_mode_manual;
}
else if (strcmp (range, "auto") == 0)
{
range_mode = range_mode_auto;
set_range_case ();
return;
}
else
{
internal_error (_("Unrecognized range check setting: \"%s\""), range);
}
if (range_check == range_check_warn
|| ((range_check == range_check_on)
!= current_language->range_checking_on_by_default ()))
warning (_("the current range check setting "
"does not match the language."));
}
/* Show command. Display a warning if the case sensitivity setting does
not match the current language. */
static void
show_case_command (struct ui_file *file, int from_tty,
struct cmd_list_element *c, const char *value)
{
if (case_mode == case_mode_auto)
{
const char *tmp = NULL;
switch (case_sensitivity)
{
case case_sensitive_on:
tmp = "on";
break;
case case_sensitive_off:
tmp = "off";
break;
default:
internal_error ("Unrecognized case-sensitive setting.");
}
gdb_printf (file,
_("Case sensitivity in "
"name search is \"auto; currently %s\".\n"),
tmp);
}
else
gdb_printf (file,
_("Case sensitivity in name search is \"%s\".\n"),
value);
if (case_sensitivity != current_language->case_sensitivity ())
warning (_("the current case sensitivity setting does not match "
"the language."));
}
/* Set command. Change the setting for case sensitivity. */
static void
set_case_command (const char *ignore, int from_tty, struct cmd_list_element *c)
{
if (strcmp (case_sensitive, "on") == 0)
{
case_sensitivity = case_sensitive_on;
case_mode = case_mode_manual;
}
else if (strcmp (case_sensitive, "off") == 0)
{
case_sensitivity = case_sensitive_off;
case_mode = case_mode_manual;
}
else if (strcmp (case_sensitive, "auto") == 0)
{
case_mode = case_mode_auto;
set_range_case ();
return;
}
else
{
internal_error ("Unrecognized case-sensitive setting: \"%s\"",
case_sensitive);
}
if (case_sensitivity != current_language->case_sensitivity ())
warning (_("the current case sensitivity setting does not match "
"the language."));
}
/* Set the status of range and type checking and case sensitivity based on
the current modes and the current language.
If SHOW is non-zero, then print out the current language,
type and range checking status. */
static void
set_range_case (void)
{
if (range_mode == range_mode_auto)
range_check = (current_language->range_checking_on_by_default ()
? range_check_on : range_check_off);
if (case_mode == case_mode_auto)
case_sensitivity = current_language->case_sensitivity ();
}
/* See language.h. */
void
set_language (enum language lang)
{
current_language = language_def (lang);
set_range_case ();
}
/* See language.h. */
void
language_info ()
{
if (expected_language == current_language)
return;
expected_language = current_language;
gdb_printf (_("Current language: %s\n"), get_language ());
show_language_command (gdb_stdout, 1, NULL, NULL);
}
/* This page contains functions for the printing out of
error messages that occur during type- and range-
checking. */
/* This is called when a language fails a range-check. The
first argument should be a printf()-style format string, and the
rest of the arguments should be its arguments. If range_check is
range_check_on, an error is printed; if range_check_warn, a warning;
otherwise just the message. */
void
range_error (const char *string,...)
{
va_list args;
va_start (args, string);
switch (range_check)
{
case range_check_warn:
vwarning (string, args);
break;
case range_check_on:
verror (string, args);
break;
case range_check_off:
/* FIXME: cagney/2002-01-30: Should this function print anything
when range error is off? */
gdb_vprintf (gdb_stderr, string, args);
gdb_printf (gdb_stderr, "\n");
break;
default:
internal_error (_("bad switch"));
}
va_end (args);
}
/* This page contains miscellaneous functions. */
/* Return the language enum for a given language string. */
enum language
language_enum (const char *str)
{
for (const auto &lang : language_defn::languages)
if (strcmp (lang->name (), str) == 0)
return lang->la_language;
return language_unknown;
}
/* Return the language struct for a given language enum. */
const struct language_defn *
language_def (enum language lang)
{
const struct language_defn *l = language_defn::languages[lang];
gdb_assert (l != nullptr);
return l;
}
/* Return the language as a string. */
const char *
language_str (enum language lang)
{
return language_def (lang)->name ();
}
/* Build and install the "set language LANG" command. */
static void
add_set_language_command ()
{
static const char **language_names;
/* Build the language names array, to be used as enumeration in the
"set language" enum command. +3 for "auto", "local" and NULL
termination. */
language_names = new const char *[ARRAY_SIZE (language_defn::languages) + 3];
/* Display "auto", "local" and "unknown" first, and then the rest,
alpha sorted. */
const char **language_names_p = language_names;
*language_names_p++ = "auto";
*language_names_p++ = "local";
*language_names_p++ = language_def (language_unknown)->name ();
const char **sort_begin = language_names_p;
for (const auto &lang : language_defn::languages)
{
/* Already handled above. */
if (lang->la_language == language_unknown)
continue;
*language_names_p++ = lang->name ();
}
*language_names_p = NULL;
std::sort (sort_begin, language_names_p, compare_cstrings);
/* Add the filename extensions. */
for (const auto &lang : language_defn::languages)
for (const char * const &ext : lang->filename_extensions ())
add_filename_language (ext, lang->la_language);
/* Build the "help set language" docs. */
string_file doc;
doc.printf (_("Set the current source language.\n"
"The currently understood settings are:\n\nlocal or "
"auto Automatic setting based on source file"));
for (const auto &lang : language_defn::languages)
{
/* Already dealt with these above. */
if (lang->la_language == language_unknown)
continue;
/* Note that we add the newline at the front, so we don't wind
up with a trailing newline. */
doc.printf ("\n%-16s Use the %s language",
lang->name (),
lang->natural_name ());
}
add_setshow_enum_cmd ("language", class_support,
language_names,
doc.c_str (),
_("Show the current source language."),
NULL,
set_language,
get_language,
show_language_command,
&setlist, &showlist);
}
/* Iterate through all registered languages looking for and calling
any non-NULL struct language_defn.skip_trampoline() functions.
Return the result from the first that returns non-zero, or 0 if all
`fail'. */
CORE_ADDR
skip_language_trampoline (const frame_info_ptr &frame, CORE_ADDR pc)
{
for (const auto &lang : language_defn::languages)
{
CORE_ADDR real_pc = lang->skip_trampoline (frame, pc);
if (real_pc != 0)
return real_pc;
}
return 0;
}
/* Return information about whether TYPE should be passed
(and returned) by reference at the language level. */
struct language_pass_by_ref_info
language_pass_by_reference (struct type *type)
{
return current_language->pass_by_reference_info (type);
}
/* Return the default string containing the list of characters
delimiting words. This is a reasonable default value that
most languages should be able to use. */
const char *
default_word_break_characters (void)
{
return " \t\n!@#$%^&*()+=|~`}{[]\"';:?/>.<,-";
}
/* See language.h. */
void
language_defn::print_array_index (struct type *index_type, LONGEST index,
struct ui_file *stream,
const value_print_options *options) const
{
struct value *index_value = value_from_longest (index_type, index);
gdb_printf (stream, "[");
value_print (index_value, stream, options);
gdb_printf (stream, "] = ");
}
/* See language.h. */
gdb::unique_xmalloc_ptr<char>
language_defn::watch_location_expression (struct type *type,
CORE_ADDR addr) const
{
/* Generates an expression that assumes a C like syntax is valid. */
type = check_typedef (check_typedef (type)->target_type ());
std::string name = type_to_string (type);
return xstrprintf ("* (%s *) %s", name.c_str (), core_addr_to_string (addr));
}
/* See language.h. */
void
language_defn::value_print (struct value *val, struct ui_file *stream,
const struct value_print_options *options) const
{
return c_value_print (val, stream, options);
}
/* See language.h. */
int
language_defn::parser (struct parser_state *ps) const
{
return c_parse (ps);
}
/* See language.h. */
void
language_defn::value_print_inner
(struct value *val, struct ui_file *stream, int recurse,
const struct value_print_options *options) const
{
return c_value_print_inner (val, stream, recurse, options);
}
/* See language.h. */
void
language_defn::print_typedef (struct type *type, struct symbol *new_symbol,
struct ui_file *stream) const
{
c_print_typedef (type, new_symbol, stream);
}
/* See language.h. */
bool
language_defn::is_string_type_p (struct type *type) const
{
return c_is_string_type_p (type);
}
/* See language.h. */
std::unique_ptr<compile_instance>
language_defn::get_compile_instance () const
{
return {};
}
/* The default implementation of the get_symbol_name_matcher_inner method
from the language_defn class. Matches with strncmp_iw. */
static bool
default_symbol_name_matcher (const char *symbol_search_name,
const lookup_name_info &lookup_name,
completion_match_result *comp_match_res)
{
gdb::string_view name = lookup_name.name ();
completion_match_for_lcd *match_for_lcd
= (comp_match_res != NULL ? &comp_match_res->match_for_lcd : NULL);
strncmp_iw_mode mode = (lookup_name.completion_mode ()
? strncmp_iw_mode::NORMAL
: strncmp_iw_mode::MATCH_PARAMS);
if (strncmp_iw_with_mode (symbol_search_name, name.data (), name.size (),
mode, language_minimal, match_for_lcd) == 0)
{
if (comp_match_res != NULL)
comp_match_res->set_match (symbol_search_name);
return true;
}
else
return false;
}
/* See language.h. */
symbol_name_matcher_ftype *
language_defn::get_symbol_name_matcher
(const lookup_name_info &lookup_name) const
{
/* If currently in Ada mode, and the lookup name is wrapped in
'<...>', hijack all symbol name comparisons using the Ada
matcher, which handles the verbatim matching. */
if (current_language->la_language == language_ada
&& lookup_name.ada ().verbatim_p ())
return current_language->get_symbol_name_matcher_inner (lookup_name);
return this->get_symbol_name_matcher_inner (lookup_name);
}
/* See language.h. */
symbol_name_matcher_ftype *
language_defn::get_symbol_name_matcher_inner
(const lookup_name_info &lookup_name) const
{
return default_symbol_name_matcher;
}
/* See language.h. */
const struct lang_varobj_ops *
language_defn::varobj_ops () const
{
/* The ops for the C language are suitable for the vast majority of the
supported languages. */
return &c_varobj_ops;
}
/* Class representing the "unknown" language. */
class unknown_language : public language_defn
{
public:
unknown_language () : language_defn (language_unknown)
{ /* Nothing. */ }
/* See language.h. */
void language_arch_info (struct gdbarch *gdbarch,
struct language_arch_info *lai) const override
{
lai->set_string_char_type (builtin_type (gdbarch)->builtin_char);
lai->set_bool_type (builtin_type (gdbarch)->builtin_int);
}
/* See language.h. */
void print_type (struct type *type, const char *varstring,
struct ui_file *stream, int show, int level,
const struct type_print_options *flags) const override
{
error (_("type printing not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
gdb::unique_xmalloc_ptr<char> demangle_symbol (const char *mangled,
int options) const override
{
/* The auto language just uses the C++ demangler. */
return gdb_demangle (mangled, options);
}
/* See language.h. */
void value_print (struct value *val, struct ui_file *stream,
const struct value_print_options *options) const override
{
error (_("value printing not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
void value_print_inner
(struct value *val, struct ui_file *stream, int recurse,
const struct value_print_options *options) const override
{
error (_("inner value printing not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
int parser (struct parser_state *ps) const override
{
error (_("expression parsing not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
void emitchar (int ch, struct type *chtype,
struct ui_file *stream, int quoter) const override
{
error (_("emit character not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
void printchar (int ch, struct type *chtype,
struct ui_file *stream) const override
{
error (_("print character not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
void printstr (struct ui_file *stream, struct type *elttype,
const gdb_byte *string, unsigned int length,
const char *encoding, int force_ellipses,
const struct value_print_options *options) const override
{
error (_("print string not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
void print_typedef (struct type *type, struct symbol *new_symbol,
struct ui_file *stream) const override
{
error (_("print typedef not implemented for language \"%s\""),
natural_name ());
}
/* See language.h. */
bool is_string_type_p (struct type *type) const override
{
type = check_typedef (type);
while (type->code () == TYPE_CODE_REF)
{
type = type->target_type ();
type = check_typedef (type);
}
return (type->code () == TYPE_CODE_STRING);
}
/* See language.h. */
const char *name_of_this () const override
{ return "this"; }
/* See language.h. */
const char *name () const override
{ return "unknown"; }
/* See language.h. */
const char *natural_name () const override
{ return "Unknown"; }
/* See language.h. */
bool store_sym_names_in_linkage_form_p () const override
{ return true; }
};
/* Single instance of the unknown language class. */
static unknown_language unknown_language_defn;
/* Per-architecture language information. */
struct language_gdbarch
{
/* A vector of per-language per-architecture info. Indexed by "enum
language". */
struct language_arch_info arch_info[nr_languages];
};
static const registry<gdbarch>::key<language_gdbarch> language_gdbarch_data;
static language_gdbarch *
get_language_gdbarch (struct gdbarch *gdbarch)
{
struct language_gdbarch *l = language_gdbarch_data.get (gdbarch);
if (l == nullptr)
{
l = new struct language_gdbarch;
for (const auto &lang : language_defn::languages)
{
gdb_assert (lang != nullptr);
lang->language_arch_info (gdbarch, &l->arch_info[lang->la_language]);
}
language_gdbarch_data.set (gdbarch, l);
}
return l;
}
/* See language.h. */
struct type *
language_string_char_type (const struct language_defn *la,
struct gdbarch *gdbarch)
{
struct language_gdbarch *ld = get_language_gdbarch (gdbarch);
return ld->arch_info[la->la_language].string_char_type ();
}
/* See language.h. */
struct value *
language_defn::value_string (struct gdbarch *gdbarch,
const char *ptr, ssize_t len) const
{
struct type *type = language_string_char_type (this, gdbarch);
return value_cstring (ptr, len, type);
}
/* See language.h. */
struct type *
language_bool_type (const struct language_defn *la,
struct gdbarch *gdbarch)
{
struct language_gdbarch *ld = get_language_gdbarch (gdbarch);
return ld->arch_info[la->la_language].bool_type ();
}
/* See language.h. */
struct type *
language_arch_info::bool_type () const
{
if (m_bool_type_name != nullptr)
{
struct symbol *sym;
sym = lookup_symbol (m_bool_type_name, NULL, VAR_DOMAIN, NULL).symbol;
if (sym != nullptr)
{
struct type *type = sym->type ();
if (type != nullptr && type->code () == TYPE_CODE_BOOL)
return type;
}
}
return m_bool_type_default;
}
/* See language.h. */
struct symbol *
language_arch_info::type_and_symbol::alloc_type_symbol
(enum language lang, struct type *type)
{
struct symbol *symbol;
struct gdbarch *gdbarch;
gdb_assert (!type->is_objfile_owned ());
gdbarch = type->arch_owner ();
symbol = new (gdbarch_obstack (gdbarch)) struct symbol ();
symbol->m_name = type->name ();
symbol->set_language (lang, nullptr);
symbol->owner.arch = gdbarch;
symbol->set_is_objfile_owned (0);
symbol->set_section_index (0);
symbol->set_type (type);
symbol->set_domain (VAR_DOMAIN);
symbol->set_aclass_index (LOC_TYPEDEF);
return symbol;
}
/* See language.h. */
language_arch_info::type_and_symbol *
language_arch_info::lookup_primitive_type_and_symbol (const char *name)
{
for (struct type_and_symbol &tas : primitive_types_and_symbols)
{
if (strcmp (tas.type ()->name (), name) == 0)
return &tas;
}
return nullptr;
}
/* See language.h. */
struct type *
language_arch_info::lookup_primitive_type (const char *name)
{
type_and_symbol *tas = lookup_primitive_type_and_symbol (name);
if (tas != nullptr)
return tas->type ();
return nullptr;
}
/* See language.h. */
struct type *
language_arch_info::lookup_primitive_type
(gdb::function_view<bool (struct type *)> filter)
{
for (struct type_and_symbol &tas : primitive_types_and_symbols)
{
if (filter (tas.type ()))
return tas.type ();
}
return nullptr;
}
/* See language.h. */
struct symbol *
language_arch_info::lookup_primitive_type_as_symbol (const char *name,
enum language lang)
{
type_and_symbol *tas = lookup_primitive_type_and_symbol (name);
if (tas != nullptr)
return tas->symbol (lang);
return nullptr;
}
/* Helper for the language_lookup_primitive_type overloads to forward
to the corresponding language's lookup_primitive_type overload. */
template<typename T>
static struct type *
language_lookup_primitive_type_1 (const struct language_defn *la,
struct gdbarch *gdbarch,
T arg)
{
struct language_gdbarch *ld = get_language_gdbarch (gdbarch);
return ld->arch_info[la->la_language].lookup_primitive_type (arg);
}
/* See language.h. */
struct type *
language_lookup_primitive_type (const struct language_defn *la,
struct gdbarch *gdbarch,
const char *name)
{
return language_lookup_primitive_type_1 (la, gdbarch, name);
}
/* See language.h. */
struct type *
language_lookup_primitive_type (const struct language_defn *la,
struct gdbarch *gdbarch,
gdb::function_view<bool (struct type *)> filter)
{
return language_lookup_primitive_type_1 (la, gdbarch, filter);
}
/* See language.h. */
struct symbol *
language_lookup_primitive_type_as_symbol (const struct language_defn *la,
struct gdbarch *gdbarch,
const char *name)
{
struct language_gdbarch *ld = get_language_gdbarch (gdbarch);
struct language_arch_info *lai = &ld->arch_info[la->la_language];
symbol_lookup_debug_printf
("language = \"%s\", gdbarch @ %s, type = \"%s\")",
la->name (), host_address_to_string (gdbarch), name);
struct symbol *sym
= lai->lookup_primitive_type_as_symbol (name, la->la_language);
symbol_lookup_debug_printf ("found symbol @ %s",
host_address_to_string (sym));
/* Note: The result of symbol lookup is normally a symbol *and* the block
it was found in. Builtin types don't live in blocks. We *could* give
them one, but there is no current need so to keep things simple symbol
lookup is extended to allow for BLOCK_FOUND to be NULL. */
return sym;
}
/* Initialize the language routines. */
void _initialize_language ();
void
_initialize_language ()
{
static const char *const type_or_range_names[]
= { "on", "off", "warn", "auto", NULL };
static const char *const case_sensitive_names[]
= { "on", "off", "auto", NULL };
/* GDB commands for language specific stuff. */
set_show_commands setshow_check_cmds
= add_setshow_prefix_cmd ("check", no_class,
_("Set the status of the type/range checker."),
_("Show the status of the type/range checker."),
&setchecklist, &showchecklist,
&setlist, &showlist);
add_alias_cmd ("c", setshow_check_cmds.set, no_class, 1, &setlist);
add_alias_cmd ("ch", setshow_check_cmds.set, no_class, 1, &setlist);
add_alias_cmd ("c", setshow_check_cmds.show, no_class, 1, &showlist);
add_alias_cmd ("ch", setshow_check_cmds.show, no_class, 1, &showlist);
range = type_or_range_names[3];
gdb_assert (strcmp (range, "auto") == 0);
add_setshow_enum_cmd ("range", class_support, type_or_range_names,
&range,
_("Set range checking (on/warn/off/auto)."),
_("Show range checking (on/warn/off/auto)."),
NULL, set_range_command,
show_range_command,
&setchecklist, &showchecklist);
case_sensitive = case_sensitive_names[2];
gdb_assert (strcmp (case_sensitive, "auto") == 0);
add_setshow_enum_cmd ("case-sensitive", class_support, case_sensitive_names,
&case_sensitive, _("\
Set case sensitivity in name search (on/off/auto)."), _("\
Show case sensitivity in name search (on/off/auto)."), _("\
For Fortran the default is off; for other languages the default is on."),
set_case_command,
show_case_command,
&setlist, &showlist);
add_set_language_command ();
}