Since we use obstacks with objects that are not default constructible, we sometimes need to manually call the constructor by hand using placement new: foo *f = obstack_alloc (obstack, sizeof (foo)); f = new (f) foo; It's possible to use allocate_on_obstack instead, but there are types that we sometimes want to allocate on an obstack, and sometimes on the regular heap. This patch introduces a utility to make this pattern simpler if allocate_on_obstack is not an option: foo *f = obstack_new<foo> (obstack); Right now there's only one usage (in tdesc_data_init). To help catch places where we would forget to call new when allocating such an object on an obstack, this patch also poisons some other methods of allocating an instance of a type on an obstack: - OBSTACK_ZALLOC/OBSTACK_CALLOC - XOBNEW/XOBNEW - GDBARCH_OBSTACK_ZALLOC/GDBARCH_OBSTACK_CALLOC Unfortunately, there's no way to catch wrong usages of obstack_alloc. By pulling on that string though, it tripped on allocating struct template_symbol using OBSTACK_ZALLOC. The criterion currently used to know whether it's safe to "malloc" an instance of a struct is whether it is a POD. Because it inherits from struct symbol, template_symbol is not a POD. This criterion is a bit too strict however, it should still safe to allocate memory for a template_symbol and memset it to 0. We didn't use is_trivially_constructible as the criterion in the first place only because it is not available in gcc < 5. So here I considered two alternatives: 1. Relax that criterion to use std::is_trivially_constructible and add a bit more glue code to make it work with gcc < 5 2. Continue pulling on the string and change how the symbol structures are allocated and initialized I managed to do both, but I decided to go with #1 to keep this patch simpler and more focused. When building with a compiler that does not have is_trivially_constructible, the check will just not be enforced. gdb/ChangeLog: * common/traits.h (HAVE_IS_TRIVIALLY_COPYABLE): Define if compiler supports std::is_trivially_constructible. * common/poison.h: Include obstack.h. (IsMallocable): Define to is_trivially_constructible if the compiler supports it, define to true_type otherwise. (xobnew): New. (XOBNEW): Redefine. (xobnewvec): New. (XOBNEWVEC): Redefine. * gdb_obstack.h (obstack_zalloc): New. (OBSTACK_ZALLOC): Redefine. (obstack_calloc): New. (OBSTACK_CALLOC): Redefine. (obstack_new): New. * gdbarch.sh: Include gdb_obstack in gdbarch.h. (gdbarch_obstack): New declaration in gdbarch.h, definition in gdbarch.c. (GDBARCH_OBSTACK_CALLOC, GDBARCH_OBSTACK_ZALLOC): Use obstack_calloc/obstack_zalloc. (gdbarch_obstack_zalloc): Remove. * target-descriptions.c (tdesc_data_init): Use obstack_new. |
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bfd | ||
binutils | ||
config | ||
cpu | ||
elfcpp | ||
etc | ||
gas | ||
gdb | ||
gold | ||
gprof | ||
include | ||
intl | ||
ld | ||
libdecnumber | ||
libiberty | ||
opcodes | ||
readline | ||
sim | ||
texinfo | ||
zlib | ||
.cvsignore | ||
.gitattributes | ||
.gitignore | ||
COPYING | ||
COPYING.LIB | ||
COPYING.LIBGLOSS | ||
COPYING.NEWLIB | ||
COPYING3 | ||
COPYING3.LIB | ||
ChangeLog | ||
MAINTAINERS | ||
Makefile.def | ||
Makefile.in | ||
Makefile.tpl | ||
README | ||
README-maintainer-mode | ||
compile | ||
config-ml.in | ||
config.guess | ||
config.rpath | ||
config.sub | ||
configure | ||
configure.ac | ||
depcomp | ||
djunpack.bat | ||
install-sh | ||
libtool.m4 | ||
ltgcc.m4 | ||
ltmain.sh | ||
ltoptions.m4 | ||
ltsugar.m4 | ||
ltversion.m4 | ||
lt~obsolete.m4 | ||
makefile.vms | ||
missing | ||
mkdep | ||
mkinstalldirs | ||
move-if-change | ||
setup.com | ||
src-release.sh | ||
symlink-tree | ||
ylwrap |
README
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.