mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2025-01-12 12:16:04 +08:00
2a62dfa93f
Consider a variable "PRA" defined as a packed array of packed
records as follow:
subtype Int is Integer range 0 .. 7;
type Packed_Rec is record
X, Y : Int;
W : Integer;
end record;
pragma Pack (Packed_Rec);
type Packed_RecArr is array (Integer range <>) of Packed_Rec;
pragma Pack (Packed_RecArr);
PRA : Packed_RecArr (1 .. 3);
Consider also a variable "PR", which is a Packed_Rec record,
declared as follow:
PR : Packed_Rec := (2, 2, 2);
Trying to assign a new value to PRA using an aggregate expression
where one of the components is our variable PR yields the wrong
result on big-endian machines (e.g. on ppc-linux):
(gdb) p pra := (pr, (2,2,2), (2,2,2))
$6 = ((x => 1, y => 0, w => 8), [...]
On the other hand, replacing "pr" by "(2,2,2)" does work.
I tracked the issue down to the bit offset we use to extract
the value of "PR" and copy it inside PRA. in value_assign_to_component,
we have:
if (gdbarch_bits_big_endian (get_type_arch (value_type (container))))
move_bits ([target buffer], [bit offset in target buffer],
[source buffer where PR is stored],
TYPE_LENGTH (value_type (component)) * TARGET_CHAR_BIT - bits,
bits, 1);
The issue is with the third-to-last argument, which provides the bit
offset where the value of PR is stored relative to its start address,
and therefore the bit offset relative to the start of the source
buffer passed as the previous argument.
In our case, component is a 38bit packed record whose TYPE_LENGTH
is 5 bytes, so the bit-offset that gets calculated is 2 (bits).
However, that formula only really applies to scalars, whereas
in our case, we have a record (struct). The offset in the non-scalar
case should be zero.
gdb/ChangeLog:
* ada-lang.c (value_assign_to_component): In the case of
big-endian targets, extract the bits of the given VAL
using an src_offset of zero if container is not a scalar.
gdb/testsuite/ChangeLog:
* gdb.ada/packed_array_assign: New testcase.
|
||
|---|---|---|
| bfd | ||
| binutils | ||
| config | ||
| contrib | ||
| cpu | ||
| elfcpp | ||
| etc | ||
| gas | ||
| gdb | ||
| gold | ||
| gprof | ||
| include | ||
| intl | ||
| ld | ||
| 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 | ||
| 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.