binutils-gdb/gdb/common/new-op.c
Tom Tromey 94aeb44b00 Make exception handling more efficient
This makes exception handling more efficient in a few spots, through
the use of const- and rvalue-references.

I wrote this patch by commenting out the gdb_exception copy
constructor and then examining the resulting error messages one by
one, introducing the use of std::move where appropriate.

gdb/ChangeLog
2019-04-25  Tom Tromey  <tromey@adacore.com>

	* xml-support.c (struct gdb_xml_parser) <set_error>: Take an
	rvalue reference.
	(gdb_xml_start_element_wrapper, gdb_xml_end_element_wrapper)
	(gdb_xml_parser::parse): Use std::move.
	* python/python-internal.h (gdbpy_convert_exception): Take a const
	reference.
	* python/py-value.c (valpy_getitem, valpy_nonzero): Use
	std::move.
	* python/py-utils.c (gdbpy_convert_exception): Take a const
	reference.
	* python/py-inferior.c (infpy_write_memory, infpy_search_memory):
	Use std::move.
	* python/py-breakpoint.c (bppy_set_condition, bppy_set_commands):
	Use std::move.
	* mi/mi-main.c (mi_print_exception): Take a const reference.
	* main.c (handle_command_errors): Take a const reference.
	* linespec.c (parse_linespec): Use std::move.
	* infcall.c (run_inferior_call): Use std::move.
	(call_function_by_hand_dummy): Use std::move.
	* exec.c (try_open_exec_file): Use std::move.
	* exceptions.h (exception_print, exception_fprintf)
	(exception_print_same): Update.
	* exceptions.c (print_exception, exception_print)
	(exception_fprintf, exception_print_same): Change parameters to
	const reference.
	* event-top.c (gdb_rl_callback_read_char_wrapper): Update.
	* common/new-op.c: Use std::move.
	* common/common-exceptions.h (struct gdb_exception): Add move
	constructor.
	(struct gdb_exception_error, struct gdb_exception_quit, struct
	gdb_quit_bad_alloc): Change constructor to move constructor.
	(throw_exception): Change parameter to rvalue reference.
	* common/common-exceptions.c (throw_exception): Take rvalue
	reference.
	* cli/cli-interp.c (safe_execute_command): Use std::move.
	* breakpoint.c (insert_bp_location, location_to_sals): Use
	std::move.
2019-04-25 12:59:35 -06:00

96 lines
2.9 KiB
C

/* Replace operator new/new[], for GDB, the GNU debugger.
Copyright (C) 2016-2019 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/>. */
/* GCC does not understand __has_feature. */
#if !defined(__has_feature)
# define __has_feature(x) 0
#endif
#if !__has_feature(address_sanitizer) && !defined(__SANITIZE_ADDRESS__)
#include "common-defs.h"
#include "host-defs.h"
#include <new>
/* Override operator new / operator new[], in order to internal_error
on allocation failure and thus query the user for abort/core
dump/continue, just like xmalloc does. We don't do this from a
new-handler function instead (std::set_new_handler) because we want
to catch allocation errors from within global constructors too.
Skip overriding if building with -fsanitize=address though.
Address sanitizer wants to override operator new/delete too in
order to detect malloc+delete and new+free mismatches. Our
versions would mask out ASan's, with the result of losing that
useful mismatch detection.
Note that C++ implementations could either have their throw
versions call the nothrow versions (libstdc++), or the other way
around (clang/libc++). For that reason, we replace both throw and
nothrow variants and call malloc directly. */
void *
operator new (std::size_t sz)
{
/* malloc (0) is unpredictable; avoid it. */
if (sz == 0)
sz = 1;
void *p = malloc (sz); /* ARI: malloc */
if (p == NULL)
{
/* If the user decides to continue debugging, throw a
gdb_quit_bad_alloc exception instead of a regular QUIT
gdb_exception. The former extends both std::bad_alloc and a
QUIT gdb_exception. This is necessary because operator new
can only ever throw std::bad_alloc, or something that extends
it. */
try
{
malloc_failure (sz);
}
catch (gdb_exception &ex)
{
throw gdb_quit_bad_alloc (std::move (ex));
}
}
return p;
}
void *
operator new (std::size_t sz, const std::nothrow_t&) noexcept
{
/* malloc (0) is unpredictable; avoid it. */
if (sz == 0)
sz = 1;
return malloc (sz); /* ARI: malloc */
}
void *
operator new[] (std::size_t sz)
{
return ::operator new (sz);
}
void*
operator new[] (std::size_t sz, const std::nothrow_t&) noexcept
{
return ::operator new (sz, std::nothrow);
}
#endif