mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2025-01-12 12:16:04 +08:00
52abb4de08
This commit is similar to the previous commit, but in this case GDB is
actually relying on undefined behaviour.
Consider building GDB for all targets on x86-64/GNU-Linux, then doing
this:
(gdb) show mips mask-address
Zeroing of upper 32 bits of 64-bit addresses is auto.
The 32 bit address mask is set automatically. Currently disabled
(gdb)
The 'show mips mask-address' command ends up in show_mask_address in
mips-tdep.c, and this function does this:
mips_gdbarch_tdep *tdep
= (mips_gdbarch_tdep *) gdbarch_tdep (target_gdbarch ());
Later we might pass TDEP to mips_mask_address_p. However, in my
example above, on an x86-64 native target, the current target
architecture will be an x86-64 gdbarch, and the tdep field within the
gdbarch will be of type i386_gdbarch_tdep, not of type
mips_gdbarch_tdep, as a result the cast above was incorrect, and TDEP
is not pointing at what it thinks it is.
I also think the current output is a little confusing, we appear to
have two lines that show the same information, but using different
words.
The first line comes from calling deprecated_show_value_hack, while
the second line is printed directly from show_mask_address. However,
both of these lines are printing the same mask_address_var value. I
don't think the two lines actually adds any value here.
Finally, none of the text in this function is passed through the
internationalisation mechanism.
It would be nice to remove another use of deprecated_show_value_hack
if possible, so this commit does a complete rewrite of
show_mask_address.
After this commit the output of the above example command, still on my
x86-64 native target is:
(gdb) show mips mask-address
Zeroing of upper 32 bits of 64-bit addresses is "auto" (current architecture is not MIPS).
The 'current architecture is not MIPS' text is only displayed when the
current architecture is not MIPS. If the architecture is mips then we
get the more commonly seen 'currently "on"' or 'currently "off"', like
this:
(gdb) set architecture mips
The target architecture is set to "mips".
(gdb) show mips mask-address
Zeroing of upper 32 bits of 64-bit addresses is "auto" (currently "off").
(gdb)
All the text is passed through the internationalisation mechanism, and
we only call gdbarch_tdep when we know the gdbarch architecture is
bfd_arch_mips.
|
||
|---|---|---|
| bfd | ||
| binutils | ||
| config | ||
| contrib | ||
| cpu | ||
| elfcpp | ||
| etc | ||
| gas | ||
| gdb | ||
| gdbserver | ||
| gdbsupport | ||
| gnulib | ||
| gold | ||
| gprof | ||
| gprofng | ||
| include | ||
| intl | ||
| ld | ||
| libbacktrace | ||
| libctf | ||
| libdecnumber | ||
| libiberty | ||
| opcodes | ||
| readline | ||
| sim | ||
| texinfo | ||
| zlib | ||
| .cvsignore | ||
| .editorconfig | ||
| .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.