mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-15 04:31:49 +08:00
0e26741636
It was pointed out on IRC that the RISC-V target allocates target descriptions and stores them in a global map, and doesn't delete these target descriptions when GDB shuts down. This isn't a particular problem, the total number of target descriptions we can create is very limited so creating these on demand and holding them for the entire run on GDB seems reasonable. However, not deleting these objects on GDB exit means extra warnings are printed from tools like valgrind, and the address sanitiser, making it harder to spot real issues. As it's reasonably easy to have GDB correctly delete these objects on exit, lets just do that. I started by noticing that we already have a target_desc_up type, a wrapper around unique_ptr that calls a function that will correctly delete target descriptions, so I want to use that, but.... ...that type is declared in gdb/target-descriptions.h. If I try to include that file in gdb/arch/riscv.c I run into a problem, that file is compiled into both GDB and GDBServer. OK, I could guard the include with #ifdef, but surely we can do better. So then I decided to move the target_desc_up type into gdbsupport/tdesc.h, this is the interface file for generic code shared between GDB and GDBserver (relating to target descriptions). The actual implementation for the delete function still lives in gdb/target-description.c, but now gdb/arch/riscv.c can see the declaration. Problem solved.... ... but, though RISC-V doesn't use it I've now exposed the target_desc_up type to gdbserver, so in future someone _might_ start using it, which is fine, except right now there's no definition of the delete function - remember the delete I used is only defined in GDB code. No problem, I add an implementation of the delete operator into gdbserver/tdesc.cc, and all is good..... except.... I start getting this error from GCC: tdesc.cc:109:10: error: deleting object of polymorphic class type ‘target_desc’ which has non-virtual destructor might cause undefined behavior [-Werror=delete-non-virtual-dtor] Which is caused because gdbserver's target_desc type inherits from tdesc_element which has a virtual method, and so GCC worries that target_desc might be used as a base class. The solution is to declare gdbserver's target_desc class as final. This is fine so long as we never intent to inherit from target_desc (in gdbserver). But if we did then we'd want to make target_desc's destructor virtual anyway, so the error above would be resolved, and there wouldn't be an issue. gdb/ChangeLog: * arch/riscv.c (riscv_tdesc_cache): Change map type. (riscv_lookup_target_description): Return pointer out of unique_ptr. * target-descriptions.c (allocate_target_description): Add comment. (target_desc_deleter::operator()): Likewise. * target-descriptions.h (struct target_desc_deleter): Moved to gdbsupport/tdesc.h. (target_desc_up): Likewise. gdbserver/ChangeLog: * tdesc.cc (allocate_target_description): Add header comment. (target_desc_deleter::operator()): New function. * tdesc.h (struct target_desc): Declare as final. gdbsupport/ChangeLog: * tdesc.h (struct target_desc_deleter): Moved here from gdb/target-descriptions.h, extend comment. (target_desc_up): Likewise. |
||
|---|---|---|
| bfd | ||
| binutils | ||
| config | ||
| contrib | ||
| cpu | ||
| elfcpp | ||
| etc | ||
| gas | ||
| gdb | ||
| gdbserver | ||
| gdbsupport | ||
| gnulib | ||
| gold | ||
| gprof | ||
| include | ||
| intl | ||
| ld | ||
| libctf | ||
| libdecnumber | ||
| libiberty | ||
| opcodes | ||
| readline | ||
| sim | ||
| texinfo | ||
| zlib | ||
| .cvsignore | ||
| .gitattributes | ||
| .gitignore | ||
| ar-lib | ||
| ChangeLog | ||
| compile | ||
| config-ml.in | ||
| config.guess | ||
| config.rpath | ||
| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| COPYING3 | ||
| COPYING3.LIB | ||
| COPYING.LIB | ||
| COPYING.LIBGLOSS | ||
| COPYING.NEWLIB | ||
| depcomp | ||
| djunpack.bat | ||
| install-sh | ||
| libtool.m4 | ||
| lt~obsolete.m4 | ||
| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
| ltversion.m4 | ||
| MAINTAINERS | ||
| Makefile.def | ||
| Makefile.in | ||
| Makefile.tpl | ||
| makefile.vms | ||
| missing | ||
| mkdep | ||
| mkinstalldirs | ||
| move-if-change | ||
| multilib.am | ||
| README | ||
| README-maintainer-mode | ||
| setup.com | ||
| src-release.sh | ||
| symlink-tree | ||
| test-driver | ||
| ylwrap | ||
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.