mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2025-01-06 12:09:26 +08:00
d4718d5c9f
Consider the gdb.ada/array_return.exp testcase, and in particular,
consider the following code...
type Small_Float_Vector is array (1 .. 2) of Float;
function Create_Small_Float_Vector return Small_Float_Vector is
begin
return (others => 4.25);
end Create_Small_Float_Vector;
... which declares a type which is an array with 2 floats in it
(floats are 4 bytes on AArch64), trying to get GDB to print
the return value from that function does not work:
(gdb) fin
Run till exit from #0 pck.create_small_float_vector () at /[...]/pck.adb:15
0x000000000000062c in p () at /[...]/p.adb:11
11 Vector := Create_Small_Float_Vector;
Value returned is $1 = (4.25, 0.0)
^^^
|||
We expected the value shown to be:
(gdb) fin
Run till exit from #0 pck.create_small_float_vector () at /[...]/pck.adb:15
0x000000000000062c in p () at /[...]/p.adb:11
11 Vector := Create_Small_Float_Vector;
Value returned is $1 = (4.25, 4.25)
Because the return type is an HFA, it is returned via the first two
SIMD registers. However, what happens is that the current implementation
fails to realize that this is an HFA, and therefore fetches the return
value from the wrong location. And the reason why it fails to realize
this is because it thinks that our array has 8 elements (HFAs have
a maximum of 4). Looking at aapcs_is_vfp_call_or_return_candidate_1,
where this is determined, we can easily see why (looks like a thinko):
| case TYPE_CODE_ARRAY:
| [...]
| struct type *target_type = TYPE_TARGET_TYPE (type);
| int count = aapcs_is_vfp_call_or_return_candidate_1
| (target_type, fundamental_type);
|
| if (count == -1)
| return count;
|
!! -> | count *= TYPE_LENGTH (type);
| return count;
Here, we first determine the count for one element of our array,
and so we should then be multiplying that count by the number
of elements in our array (2 in our case). But instead, we multiply it
by the total size (8). As a result, we do not classify the return
type as an HFA, and thus pick the wrong location for fetching
the return value.
gdb/ChangeLog:
* aarch64-tdep.c (aapcs_is_vfp_call_or_return_candidate_1):
return the correct count for potential HFAs.
Tested on aarch64-linux, fixes:
array_return.exp: value printed by finish of Create_Small_Float_Vector
|
||
|---|---|---|
| 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 | ||
| 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.