/* Target-dependent code for the Motorola 68000 series.
- Copyright (C) 1990-2018 Free Software Foundation, Inc.
+ Copyright (C) 1990-2022 Free Software Foundation, Inc.
This file is part of GDB.
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
-#include "dwarf2-frame.h"
+#include "dwarf2/frame.h"
#include "frame.h"
#include "frame-base.h"
#include "frame-unwind.h"
#include "target-descriptions.h"
#include "floatformat.h"
#include "target-float.h"
+#include "elf-bfd.h"
+#include "elf/m68k.h"
#include "m68k-tdep.h"
\f
static struct type *
m68k_ps_type (struct gdbarch *gdbarch)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
if (!tdep->m68k_ps_type)
{
static struct type *
m68881_ext_type (struct gdbarch *gdbarch)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
if (!tdep->m68881_ext_type)
tdep->m68881_ext_type
static struct type *
m68k_register_type (struct gdbarch *gdbarch, int regnum)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
if (tdep->fpregs_present)
{
return builtin_type (gdbarch)->builtin_int32;
}
-static const char *m68k_register_names[] = {
+static const char * const m68k_register_names[] = {
"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
"a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp",
"ps", "pc",
static const char *
m68k_register_name (struct gdbarch *gdbarch, int regnum)
{
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
if (regnum < 0 || regnum >= ARRAY_SIZE (m68k_register_names))
internal_error (__FILE__, __LINE__,
_("m68k_register_name: illegal register number %d"),
regnum);
else if (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM
- && gdbarch_tdep (gdbarch)->fpregs_present == 0)
+ && tdep->fpregs_present == 0)
return "";
else
return m68k_register_names[regnum];
m68k_convert_register_p (struct gdbarch *gdbarch,
int regnum, struct type *type)
{
- if (!gdbarch_tdep (gdbarch)->fpregs_present)
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
+ if (!tdep->fpregs_present)
return 0;
return (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FP0_REGNUM + 7
/* We only support floating-point values. */
- && TYPE_CODE (type) == TYPE_CODE_FLT
+ && type->code () == TYPE_CODE_FLT
&& type != register_type (gdbarch, M68K_FP0_REGNUM));
}
gdb_byte from[M68K_MAX_REGISTER_SIZE];
struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM);
- gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+ gdb_assert (type->code () == TYPE_CODE_FLT);
/* Convert to TYPE. */
if (!get_frame_register_bytes (frame, regnum, 0,
- register_size (gdbarch, regnum),
- from, optimizedp, unavailablep))
+ gdb::make_array_view (from,
+ register_size (gdbarch,
+ regnum)),
+ optimizedp, unavailablep))
return 0;
target_float_convert (from, fpreg_type, to, type);
M68K_FP0_REGNUM);
/* We only support floating-point values. */
- if (TYPE_CODE (type) != TYPE_CODE_FLT)
+ if (type->code () != TYPE_CODE_FLT)
{
warning (_("Cannot convert non-floating-point type "
"to floating-point register value."));
The 68020/030/040/060 do support an FPU, either as a coprocessor
(68881/2) or built-in (68040/68060). That's why System V release 4
- (SVR4) instroduces a new calling convention specified by the SVR4
+ (SVR4) introduces a new calling convention specified by the SVR4
psABI. Integer values are returned in %d0/%d1, pointer return
values in %a0 and floating values in %fp0. When calling functions
returning a structure the caller should pass a pointer to a buffer
%d0/%d1 instead of in memory by using -freg-struct-return. This is
the default on NetBSD a.out, OpenBSD and GNU/Linux and several
embedded systems. This convention is implemented by setting the
- struct_return member of `struct gdbarch_tdep' to reg_struct_return. */
+ struct_return member of `struct gdbarch_tdep' to reg_struct_return.
+
+ GCC also has an "embedded" ABI. This works like the SVR4 ABI,
+ except that pointers are returned in %D0. This is implemented by
+ setting the pointer_result_regnum member of `struct gdbarch_tdep'
+ as appropriate. */
/* Read a function return value of TYPE from REGCACHE, and copy that
into VALBUF. */
int len = TYPE_LENGTH (type);
gdb_byte buf[M68K_MAX_REGISTER_SIZE];
- if (len <= 4)
+ if (type->code () == TYPE_CODE_PTR && len == 4)
+ {
+ struct gdbarch *gdbarch = regcache->arch ();
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+ regcache->raw_read (tdep->pointer_result_regnum, valbuf);
+ }
+ else if (len <= 4)
{
regcache->raw_read (M68K_D0_REGNUM, buf);
memcpy (valbuf, buf + (4 - len), len);
{
gdb_byte buf[M68K_MAX_REGISTER_SIZE];
struct gdbarch *gdbarch = regcache->arch ();
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- if (tdep->float_return && TYPE_CODE (type) == TYPE_CODE_FLT)
+ if (tdep->float_return && type->code () == TYPE_CODE_FLT)
{
struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM);
regcache->raw_read (M68K_FP0_REGNUM, buf);
target_float_convert (buf, fpreg_type, valbuf, type);
}
- else if (TYPE_CODE (type) == TYPE_CODE_PTR && TYPE_LENGTH (type) == 4)
- regcache->raw_read (M68K_A0_REGNUM, valbuf);
else
m68k_extract_return_value (type, regcache, valbuf);
}
{
int len = TYPE_LENGTH (type);
- if (len <= 4)
+ if (type->code () == TYPE_CODE_PTR && len == 4)
+ {
+ struct gdbarch *gdbarch = regcache->arch ();
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+ regcache->raw_write (tdep->pointer_result_regnum, valbuf);
+ /* gdb historically also set D0 in the SVR4 case. */
+ if (tdep->pointer_result_regnum != M68K_D0_REGNUM)
+ regcache->raw_write (M68K_D0_REGNUM, valbuf);
+ }
+ else if (len <= 4)
regcache->raw_write_part (M68K_D0_REGNUM, 4 - len, len, valbuf);
else if (len <= 8)
{
const gdb_byte *valbuf)
{
struct gdbarch *gdbarch = regcache->arch ();
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- if (tdep->float_return && TYPE_CODE (type) == TYPE_CODE_FLT)
+ if (tdep->float_return && type->code () == TYPE_CODE_FLT)
{
struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM);
gdb_byte buf[M68K_MAX_REGISTER_SIZE];
target_float_convert (valbuf, type, buf, fpreg_type);
regcache->raw_write (M68K_FP0_REGNUM, buf);
}
- else if (TYPE_CODE (type) == TYPE_CODE_PTR && TYPE_LENGTH (type) == 4)
- {
- regcache->raw_write (M68K_A0_REGNUM, valbuf);
- regcache->raw_write (M68K_D0_REGNUM, valbuf);
- }
else
m68k_store_return_value (type, regcache, valbuf);
}
static int
m68k_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
- enum type_code code = TYPE_CODE (type);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+ enum type_code code = type->code ();
int len = TYPE_LENGTH (type);
gdb_assert (code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION
- || code == TYPE_CODE_COMPLEX);
+ || code == TYPE_CODE_COMPLEX || code == TYPE_CODE_ARRAY);
if (tdep->struct_return == pcc_struct_return)
return 0;
+ const bool is_vector = code == TYPE_CODE_ARRAY && type->is_vector ();
+
+ if (is_vector
+ && check_typedef (TYPE_TARGET_TYPE (type))->code () == TYPE_CODE_FLT)
+ return 0;
+
+ /* According to m68k_return_in_memory in the m68k GCC back-end,
+ strange things happen for small aggregate types. Aggregate types
+ with only one component are always returned like the type of the
+ component. Aggregate types whose size is 2, 4, or 8 are returned
+ in registers if their natural alignment is at least 16 bits.
+
+ We reject vectors here, as experimentally this gives the correct
+ answer. */
+ if (!is_vector && (len == 2 || len == 4 || len == 8))
+ return type_align (type) >= 2;
+
return (len == 1 || len == 2 || len == 4 || len == 8);
}
struct type *type, struct regcache *regcache,
gdb_byte *readbuf, const gdb_byte *writebuf)
{
- enum type_code code = TYPE_CODE (type);
+ enum type_code code = type->code ();
/* GCC returns a `long double' in memory too. */
if (((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION
- || code == TYPE_CODE_COMPLEX)
+ || code == TYPE_CODE_COMPLEX || code == TYPE_CODE_ARRAY)
&& !m68k_reg_struct_return_p (gdbarch, type))
|| (code == TYPE_CODE_FLT && TYPE_LENGTH (type) == 12))
{
/* The default on m68k is to return structures in static memory.
- Consequently a function must return the address where we can
- find the return value. */
+ Consequently a function must return the address where we can
+ find the return value. */
if (readbuf)
{
struct type *type, struct regcache *regcache,
gdb_byte *readbuf, const gdb_byte *writebuf)
{
- enum type_code code = TYPE_CODE (type);
+ enum type_code code = type->code ();
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- if ((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION
- || code == TYPE_CODE_COMPLEX)
- && !m68k_reg_struct_return_p (gdbarch, type))
+ /* Aggregates with a single member are always returned like their
+ sole element. */
+ if ((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION)
+ && type->num_fields () == 1)
+ {
+ type = check_typedef (type->field (0).type ());
+ return m68k_svr4_return_value (gdbarch, function, type, regcache,
+ readbuf, writebuf);
+ }
+
+ if (((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION
+ || code == TYPE_CODE_COMPLEX || code == TYPE_CODE_ARRAY)
+ && !m68k_reg_struct_return_p (gdbarch, type))
+ /* GCC may return a `long double' in memory too. */
+ || (!tdep->float_return
+ && code == TYPE_CODE_FLT
+ && TYPE_LENGTH (type) == 12))
{
/* The System V ABI says that:
register %a0."
So the ABI guarantees that we can always find the return
- value just after the function has returned. */
+ value just after the function has returned.
+
+ However, GCC also implements the "embedded" ABI. That ABI
+ does not preserve %a0 across calls, but does write the value
+ back to %d0. */
if (readbuf)
{
ULONGEST addr;
- regcache_raw_read_unsigned (regcache, M68K_A0_REGNUM, &addr);
+ regcache_raw_read_unsigned (regcache, tdep->pointer_result_regnum,
+ &addr);
read_memory (addr, readbuf, TYPE_LENGTH (type));
}
return RETURN_VALUE_ABI_RETURNS_ADDRESS;
}
- /* This special case is for structures consisting of a single
- `float' or `double' member. These structures are returned in
- %fp0. For these structures, we call ourselves recursively,
- changing TYPE into the type of the first member of the structure.
- Since that should work for all structures that have only one
- member, we don't bother to check the member's type here. */
- if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1)
- {
- type = check_typedef (TYPE_FIELD_TYPE (type, 0));
- return m68k_svr4_return_value (gdbarch, function, type, regcache,
- readbuf, writebuf);
- }
-
if (readbuf)
m68k_svr4_extract_return_value (type, regcache, readbuf);
if (writebuf)
function_call_return_method return_method,
CORE_ADDR struct_addr)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte buf[4];
int i;
/* Non-scalars bigger than 4 bytes are left aligned, others are
right aligned. */
- if ((TYPE_CODE (value_type) == TYPE_CODE_STRUCT
- || TYPE_CODE (value_type) == TYPE_CODE_UNION
- || TYPE_CODE (value_type) == TYPE_CODE_ARRAY)
+ if ((value_type->code () == TYPE_CODE_STRUCT
+ || value_type->code () == TYPE_CODE_UNION
+ || value_type->code () == TYPE_CODE_ARRAY)
&& len > 4)
offset = 0;
else
offset = container_len - len;
sp -= container_len;
- write_memory (sp + offset, value_contents_all (args[i]), len);
+ write_memory (sp + offset, value_contents_all (args[i]).data (), len);
}
/* Store struct value address. */
static int
m68k_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int num)
{
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
if (num < 8)
/* d0..7 */
return (num - 0) + M68K_D0_REGNUM;
else if (num < 16)
/* a0..7 */
return (num - 8) + M68K_A0_REGNUM;
- else if (num < 24 && gdbarch_tdep (gdbarch)->fpregs_present)
+ else if (num < 24 && tdep->fpregs_present)
/* fp0..7 */
return (num - 16) + M68K_FP0_REGNUM;
else if (num == 25)
struct m68k_frame_cache *cache)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
if (cache->locals >= 0)
{
{
op = read_memory_unsigned_integer (pc, 2, byte_order);
if (op == P_FMOVEMX_SP
- && gdbarch_tdep (gdbarch)->fpregs_present)
+ && tdep->fpregs_present)
{
/* fmovem.x REGS,-(%sp) */
op = read_memory_unsigned_integer (pc + 2, 2, byte_order);
static const struct frame_unwind m68k_frame_unwind =
{
+ "m68k prologue",
NORMAL_FRAME,
default_frame_unwind_stop_reason,
m68k_frame_this_id,
gdb_byte *buf;
CORE_ADDR sp, jb_addr;
struct gdbarch *gdbarch = get_frame_arch (frame);
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
if (tdep->jb_pc < 0)
void
m68k_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
/* SVR4 uses a different calling convention. */
set_gdbarch_return_value (gdbarch, m68k_svr4_return_value);
/* SVR4 uses %a0 instead of %a1. */
tdep->struct_value_regnum = M68K_A0_REGNUM;
+
+ /* SVR4 returns pointers in %a0. */
+ tdep->pointer_result_regnum = M68K_A0_REGNUM;
+}
+
+/* GCC's m68k "embedded" ABI. This is like the SVR4 ABI, but pointer
+ values are returned in %d0, not %a0. */
+
+static void
+m68k_embedded_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+
+ m68k_svr4_init_abi (info, gdbarch);
+ tdep->pointer_result_regnum = M68K_D0_REGNUM;
}
+
\f
/* Function: m68k_gdbarch_init
static struct gdbarch *
m68k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
- struct gdbarch_tdep *tdep = NULL;
struct gdbarch *gdbarch;
struct gdbarch_list *best_arch;
- struct tdesc_arch_data *tdesc_data = NULL;
+ tdesc_arch_data_up tdesc_data;
int i;
enum m68k_flavour flavour = m68k_no_flavour;
int has_fp = 1;
valid_p = 1;
for (i = 0; i <= M68K_PC_REGNUM; i++)
- valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
+ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), i,
m68k_register_names[i]);
if (!valid_p)
- {
- tdesc_data_cleanup (tdesc_data);
- return NULL;
- }
+ return NULL;
feature = tdesc_find_feature (info.target_desc,
"org.gnu.gdb.coldfire.fp");
{
valid_p = 1;
for (i = M68K_FP0_REGNUM; i <= M68K_FPI_REGNUM; i++)
- valid_p &= tdesc_numbered_register (feature, tdesc_data, i,
+ valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), i,
m68k_register_names[i]);
if (!valid_p)
- {
- tdesc_data_cleanup (tdesc_data);
- return NULL;
- }
+ return NULL;
}
else
has_fp = 0;
flavour = m68k_coldfire_flavour;
}
+ /* Try to figure out if the arch uses floating registers to return
+ floating point values from functions. On ColdFire, floating
+ point values are returned in D0. */
+ int float_return = 0;
+ if (has_fp && flavour != m68k_coldfire_flavour)
+ float_return = 1;
+#ifdef HAVE_ELF
+ if (info.abfd && bfd_get_flavour (info.abfd) == bfd_target_elf_flavour)
+ {
+ int fp_abi = bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_GNU,
+ Tag_GNU_M68K_ABI_FP);
+ if (fp_abi == 1)
+ float_return = 1;
+ else if (fp_abi == 2)
+ float_return = 0;
+ }
+#endif /* HAVE_ELF */
+
/* If there is already a candidate, use it. */
for (best_arch = gdbarch_list_lookup_by_info (arches, &info);
best_arch != NULL;
best_arch = gdbarch_list_lookup_by_info (best_arch->next, &info))
{
- if (flavour != gdbarch_tdep (best_arch->gdbarch)->flavour)
+ m68k_gdbarch_tdep *tdep
+ = (m68k_gdbarch_tdep *) gdbarch_tdep (best_arch->gdbarch);
+
+ if (flavour != tdep->flavour)
continue;
- if (has_fp != gdbarch_tdep (best_arch->gdbarch)->fpregs_present)
+ if (has_fp != tdep->fpregs_present)
+ continue;
+
+ if (float_return != tdep->float_return)
continue;
break;
}
if (best_arch != NULL)
- {
- if (tdesc_data != NULL)
- tdesc_data_cleanup (tdesc_data);
- return best_arch->gdbarch;
- }
+ return best_arch->gdbarch;
- tdep = XCNEW (struct gdbarch_tdep);
+ m68k_gdbarch_tdep *tdep = new m68k_gdbarch_tdep;
gdbarch = gdbarch_alloc (&info, tdep);
tdep->fpregs_present = has_fp;
+ tdep->float_return = float_return;
tdep->flavour = flavour;
if (flavour == m68k_coldfire_flavour || flavour == m68k_fido_flavour)
if (has_fp)
set_gdbarch_fp0_regnum (gdbarch, M68K_FP0_REGNUM);
- /* Try to figure out if the arch uses floating registers to return
- floating point values from functions. */
- if (has_fp)
- {
- /* On ColdFire, floating point values are returned in D0. */
- if (flavour == m68k_coldfire_flavour)
- tdep->float_return = 0;
- else
- tdep->float_return = 1;
- }
- else
- {
- /* No floating registers, so can't use them for returning values. */
- tdep->float_return = 0;
- }
-
/* Function call & return. */
set_gdbarch_push_dummy_call (gdbarch, m68k_push_dummy_call);
set_gdbarch_return_value (gdbarch, m68k_return_value);
#else
tdep->jb_pc = -1;
#endif
+ tdep->pointer_result_regnum = M68K_D0_REGNUM;
tdep->struct_value_regnum = M68K_A1_REGNUM;
tdep->struct_return = reg_struct_return;
frame_unwind_append_unwinder (gdbarch, &m68k_frame_unwind);
- if (tdesc_data)
- tdesc_use_registers (gdbarch, info.target_desc, tdesc_data);
+ if (tdesc_data != nullptr)
+ tdesc_use_registers (gdbarch, info.target_desc, std::move (tdesc_data));
return gdbarch;
}
static void
m68k_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file)
{
- struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
if (tdep == NULL)
return;
}
+/* OSABI sniffer for m68k. */
+
+static enum gdb_osabi
+m68k_osabi_sniffer (bfd *abfd)
+{
+ unsigned int elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
+
+ if (elfosabi == ELFOSABI_NONE)
+ return GDB_OSABI_SVR4;
+
+ return GDB_OSABI_UNKNOWN;
+}
+
+void _initialize_m68k_tdep ();
void
-_initialize_m68k_tdep (void)
+_initialize_m68k_tdep ()
{
gdbarch_register (bfd_arch_m68k, m68k_gdbarch_init, m68k_dump_tdep);
+
+ gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_elf_flavour,
+ m68k_osabi_sniffer);
+ gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_SVR4,
+ m68k_embedded_init_abi);
}