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| author |   Tom Tromey <tromey@adacore.com> | 2020-09-14 08:30:10 -0600 |
|---|---|---|
| committer | Tom Tromey <tromey@adacore.com> | 2020-09-14 09:46:05 -0600 |
| commit | 3eba3a011a89c75c10bd1860eee4589e65697165 (patch) | |
| tree | 9465ab269218fe38dcdcbabc3220940c25817a1f /gdb/m68k-tdep.h | |
| parent | gdb: remove xfree in xml-support.c (diff) | |
| download | binutils-gdb-3eba3a011a89c75c10bd1860eee4589e65697165.tar.gz binutils-gdb-3eba3a011a89c75c10bd1860eee4589e65697165.tar.bz2 binutils-gdb-3eba3a011a89c75c10bd1860eee4589e65697165.zip | |
Various m68k fixes for gdb
Recently I tried the m68k port of gdb. It had some issues, which are
fixed in this patch.
* Various types of return values were not being handled properly. In
particular:
* arrays are returned by following the same convention as
structures. This matters in languages like Ada, where an array
can in fact be returned as a value.
* "long double" was not being handled correctly in
m68k_svr4_return_value.
* GCC's m68k back end does not return vector types in registers, so
change gdb to follow.
* GCC's m68k back end doesn't faithfully implement the ABI, and so
some objects with unusual size (not possible in C, but possible in
Ada) are not returned correctly.
* gcc implements an m68k ABI variant that it simply describes as
"embedded". This ABI is similar to the SVR4 ABI, but rather than
returning pointer-typed values in %a0, such values are returned in
%d0. To support this, an ELF osabi sniffer is added.
* Commit 85f7484a ("m68k: tag floating-point ABI used") adds an
attribute that can be used to recognize when hard- or soft-float is
in use. gdb can now read this tag and choose the ABI accordingly.
I was unable to run the gdb test suite with this patch. Instead, I
tested it using qemu and the internal AdaCore test suite.
gdb/ChangeLog
2020-09-14 Tom Tromey <tromey@adacore.com>
* m68k-tdep.c (m68k_extract_return_value): Use
pointer_result_regnum.
(m68k_store_return_value): Likewise.
(m68k_reg_struct_return_p): Handle vectors and arrays.
(m68k_return_value): Handle arrays.
(m68k_svr4_return_value): Fix single-element aggregate handling.
Handle long double. Adjust for embedded ABI.
(m68k_svr4_init_abi): Set pointer_result_regnum.
(m68k_embedded_init_abi): New function.
(m68k_gdbarch_init): Handle Tag_GNU_M68K_ABI_FP.
(m68k_osabi_sniffer): New function.
(_initialize_m68k_tdep): Register osabi sniffer.
* m68k-tdep.h (struct gdbarch_tdep) <pointer_result_regnum>: New
member.
Diffstat (limited to 'gdb/m68k-tdep.h')
| -rw-r--r-- | gdb/m68k-tdep.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/gdb/m68k-tdep.h b/gdb/m68k-tdep.h index 1567505abf8..513190fe8cc 100644 --- a/gdb/m68k-tdep.h +++ b/gdb/m68k-tdep.h @@ -79,6 +79,10 @@ struct gdbarch_tdep passed to a function. */ int struct_value_regnum; + /* Register in which a pointer value is returned. In the SVR4 ABI, + this is %a0, but in GCC's "embedded" ABI, this is %d0. */ + int pointer_result_regnum; + /* Convention for returning structures. */ enum struct_return struct_return; |