/* Dummy function calls. */
-/* Return non-zero if TYPE is an integer-like type, zero otherwise.
- "Integer-like" types are those that should be passed the way
- integers are: integers, enums, ranges, characters, and booleans. */
-static int
-is_integer_like (struct type *type)
-{
- enum type_code code = TYPE_CODE (type);
-
- return (code == TYPE_CODE_INT
- || code == TYPE_CODE_ENUM
- || code == TYPE_CODE_RANGE
- || code == TYPE_CODE_CHAR
- || code == TYPE_CODE_BOOL);
-}
-
-/* Return non-zero if TYPE is a pointer-like type, zero otherwise.
- "Pointer-like" types are those that should be passed the way
- pointers are: pointers and references. */
-static int
-is_pointer_like (struct type *type)
-{
- enum type_code code = TYPE_CODE (type);
-
- return (code == TYPE_CODE_PTR
- || code == TYPE_CODE_REF);
-}
-
-
-/* Return non-zero if TYPE is a `float singleton' or `double
- singleton', zero otherwise.
-
- A `T singleton' is a struct type with one member, whose type is
- either T or a `T singleton'. So, the following are all float
- singletons:
+/* Unwrap any single-field structs in TYPE and return the effective
+ "inner" type. E.g., yield "float" for all these cases:
- struct { float x };
- struct { struct { float x; } x; };
- struct { struct { struct { float x; } x; } x; };
+ float x;
+ struct { float x };
+ struct { struct { float x; } x; };
+ struct { struct { struct { float x; } x; } x; }; */
- ... and so on.
-
- All such structures are passed as if they were floats or doubles,
- as the (revised) ABI says. */
-static int
-is_float_singleton (struct type *type)
+static struct type *
+s390_effective_inner_type (struct type *type)
{
- if (TYPE_CODE (type) == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1)
- {
- struct type *singleton_type = TYPE_FIELD_TYPE (type, 0);
- CHECK_TYPEDEF (singleton_type);
-
- return (TYPE_CODE (singleton_type) == TYPE_CODE_FLT
- || TYPE_CODE (singleton_type) == TYPE_CODE_DECFLOAT
- || is_float_singleton (singleton_type));
- }
-
- return 0;
+ while (TYPE_CODE (type) == TYPE_CODE_STRUCT
+ && TYPE_NFIELDS (type) == 1)
+ type = check_typedef (TYPE_FIELD_TYPE (type, 0));
+ return type;
}
+/* Return non-zero if TYPE should be passed like "float" or
+ "double". */
-/* Return non-zero if TYPE is a struct-like type, zero otherwise.
- "Struct-like" types are those that should be passed as structs are:
- structs and unions.
-
- As an odd quirk, not mentioned in the ABI, GCC passes float and
- double singletons as if they were a plain float, double, etc. (The
- corresponding union types are handled normally.) So we exclude
- those types here. *shrug* */
static int
-is_struct_like (struct type *type)
+s390_function_arg_float (struct type *type)
{
- enum type_code code = TYPE_CODE (type);
-
- return (code == TYPE_CODE_UNION
- || (code == TYPE_CODE_STRUCT && ! is_float_singleton (type)));
-}
-
+ /* Note that long double as well as complex types are intentionally
+ excluded. */
+ if (TYPE_LENGTH (type) > 8)
+ return 0;
-/* Return non-zero if TYPE is a float-like type, zero otherwise.
- "Float-like" types are those that should be passed as
- floating-point values are.
+ /* A struct containing just a float or double is passed like a float
+ or double. */
+ type = s390_effective_inner_type (type);
- You'd think this would just be floats, doubles, long doubles, etc.
- But as an odd quirk, not mentioned in the ABI, GCC passes float and
- double singletons as if they were a plain float, double, etc. (The
- corresponding union types are handled normally.) So we include
- those types here. *shrug* */
-static int
-is_float_like (struct type *type)
-{
return (TYPE_CODE (type) == TYPE_CODE_FLT
- || TYPE_CODE (type) == TYPE_CODE_DECFLOAT
- || is_float_singleton (type));
+ || TYPE_CODE (type) == TYPE_CODE_DECFLOAT);
}
/* Determine whether N is a power of two. */
return n && ((n & (n - 1)) == 0);
}
-/* Return non-zero if TYPE should be passed as a pointer to a copy,
- zero otherwise. */
-static int
-s390_function_arg_pass_by_reference (struct type *type)
-{
- if (TYPE_LENGTH (type) > 8)
- return 1;
-
- return (is_struct_like (type) && !is_power_of_two (TYPE_LENGTH (type)))
- || TYPE_CODE (type) == TYPE_CODE_COMPLEX
- || (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type));
-}
+/* For an argument whose type is TYPE and which is not passed like a
+ float, return non-zero if it should be passed like "int" or "long
+ long". */
-/* Return non-zero if TYPE should be passed in a float register
- if possible. */
-static int
-s390_function_arg_float (struct type *type)
-{
- if (TYPE_LENGTH (type) > 8)
- return 0;
-
- return is_float_like (type);
-}
-
-/* Return non-zero if TYPE should be passed in an integer register
- (or a pair of integer registers) if possible. */
static int
s390_function_arg_integer (struct type *type)
{
+ enum type_code code = TYPE_CODE (type);
+
if (TYPE_LENGTH (type) > 8)
return 0;
- return is_integer_like (type)
- || is_pointer_like (type)
- || (is_struct_like (type) && is_power_of_two (TYPE_LENGTH (type)));
+ if (code == TYPE_CODE_INT
+ || code == TYPE_CODE_ENUM
+ || code == TYPE_CODE_RANGE
+ || code == TYPE_CODE_CHAR
+ || code == TYPE_CODE_BOOL
+ || code == TYPE_CODE_PTR
+ || code == TYPE_CODE_REF)
+ return 1;
+
+ return ((code == TYPE_CODE_UNION || code == TYPE_CODE_STRUCT)
+ && is_power_of_two (TYPE_LENGTH (type)));
}
-/* Return ARG, a `SIMPLE_ARG', sign-extended or zero-extended to a full
- word as required for the ABI. */
-static LONGEST
-extend_simple_arg (struct gdbarch *gdbarch, struct value *arg)
-{
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- struct type *type = check_typedef (value_type (arg));
+/* Argument passing state: Internal data structure passed to helper
+ routines of s390_push_dummy_call. */
- /* Even structs get passed in the least significant bits of the
- register / memory word. It's not really right to extract them as
- an integer, but it does take care of the extension. */
- if (TYPE_UNSIGNED (type))
- return extract_unsigned_integer (value_contents (arg),
- TYPE_LENGTH (type), byte_order);
- else
- return extract_signed_integer (value_contents (arg),
- TYPE_LENGTH (type), byte_order);
-}
+struct s390_arg_state
+ {
+ /* Register cache, or NULL, if we are in "preparation mode". */
+ struct regcache *regcache;
+ /* Next available general/floating-point register for argument
+ passing. */
+ int gr, fr;
+ /* Current pointer to copy area (grows downwards). */
+ CORE_ADDR copy;
+ /* Current pointer to parameter area (grows upwards). */
+ CORE_ADDR argp;
+ };
+/* Prepare one argument ARG for a dummy call and update the argument
+ passing state AS accordingly. If the regcache field in AS is set,
+ operate in "write mode" and write ARG into the inferior. Otherwise
+ run "preparation mode" and skip all updates to the inferior. */
-/* Return the alignment required by TYPE. */
-static int
-alignment_of (struct type *type)
+static void
+s390_handle_arg (struct s390_arg_state *as, struct value *arg,
+ struct gdbarch_tdep *tdep, int word_size,
+ enum bfd_endian byte_order)
{
- int alignment;
+ struct type *type = check_typedef (value_type (arg));
+ unsigned int length = TYPE_LENGTH (type);
+ int write_mode = as->regcache != NULL;
- if (is_integer_like (type)
- || is_pointer_like (type)
- || TYPE_CODE (type) == TYPE_CODE_FLT
- || TYPE_CODE (type) == TYPE_CODE_DECFLOAT)
- alignment = TYPE_LENGTH (type);
- else if (TYPE_CODE (type) == TYPE_CODE_STRUCT
- || TYPE_CODE (type) == TYPE_CODE_UNION)
+ if (s390_function_arg_float (type))
+ {
+ /* The GNU/Linux for S/390 ABI uses FPRs 0 and 2 to pass
+ arguments. The GNU/Linux for zSeries ABI uses 0, 2, 4, and
+ 6. */
+ if (as->fr <= (tdep->abi == ABI_LINUX_S390 ? 2 : 6))
+ {
+ /* When we store a single-precision value in an FP register,
+ it occupies the leftmost bits. */
+ if (write_mode)
+ regcache_cooked_write_part (as->regcache,
+ S390_F0_REGNUM + as->fr,
+ 0, length,
+ value_contents (arg));
+ as->fr += 2;
+ }
+ else
+ {
+ /* When we store a single-precision value in a stack slot,
+ it occupies the rightmost bits. */
+ as->argp = align_up (as->argp + length, word_size);
+ if (write_mode)
+ write_memory (as->argp - length, value_contents (arg),
+ length);
+ }
+ }
+ else if (s390_function_arg_integer (type) && length <= word_size)
{
- int i;
+ ULONGEST val;
- alignment = 1;
- for (i = 0; i < TYPE_NFIELDS (type); i++)
+ if (write_mode)
{
- int field_alignment
- = alignment_of (check_typedef (TYPE_FIELD_TYPE (type, i)));
+ /* Place value in least significant bits of the register or
+ memory word and sign- or zero-extend to full word size.
+ This also applies to a struct or union. */
+ val = TYPE_UNSIGNED (type)
+ ? extract_unsigned_integer (value_contents (arg),
+ length, byte_order)
+ : extract_signed_integer (value_contents (arg),
+ length, byte_order);
+ }
- if (field_alignment > alignment)
- alignment = field_alignment;
+ if (as->gr <= 6)
+ {
+ if (write_mode)
+ regcache_cooked_write_unsigned (as->regcache,
+ S390_R0_REGNUM + as->gr,
+ val);
+ as->gr++;
+ }
+ else
+ {
+ if (write_mode)
+ write_memory_unsigned_integer (as->argp, word_size,
+ byte_order, val);
+ as->argp += word_size;
}
}
- else
- alignment = 1;
+ else if (s390_function_arg_integer (type) && length == 8)
+ {
+ if (as->gr <= 5)
+ {
+ if (write_mode)
+ {
+ regcache_cooked_write (as->regcache,
+ S390_R0_REGNUM + as->gr,
+ value_contents (arg));
+ regcache_cooked_write (as->regcache,
+ S390_R0_REGNUM + as->gr + 1,
+ value_contents (arg) + word_size);
+ }
+ as->gr += 2;
+ }
+ else
+ {
+ /* If we skipped r6 because we couldn't fit a DOUBLE_ARG
+ in it, then don't go back and use it again later. */
+ as->gr = 7;
- /* Check that everything we ever return is a power of two. Lots of
- code doesn't want to deal with aligning things to arbitrary
- boundaries. */
- gdb_assert ((alignment & (alignment - 1)) == 0);
+ if (write_mode)
+ write_memory (as->argp, value_contents (arg), length);
+ as->argp += length;
+ }
+ }
+ else
+ {
+ /* This argument type is never passed in registers. Place the
+ value in the copy area and pass a pointer to it. Use 8-byte
+ alignment as a conservative assumption. */
+ as->copy = align_down (as->copy - length, 8);
+ if (write_mode)
+ write_memory (as->copy, value_contents (arg), length);
- return alignment;
+ if (as->gr <= 6)
+ {
+ if (write_mode)
+ regcache_cooked_write_unsigned (as->regcache,
+ S390_R0_REGNUM + as->gr,
+ as->copy);
+ as->gr++;
+ }
+ else
+ {
+ if (write_mode)
+ write_memory_unsigned_integer (as->argp, word_size,
+ byte_order, as->copy);
+ as->argp += word_size;
+ }
+ }
}
-
/* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in
place to be passed to a function, as specified by the "GNU/Linux
for S/390 ELF Application Binary Interface Supplement".
Our caller has taken care of any type promotions needed to satisfy
prototypes or the old K&R argument-passing rules. */
+
static CORE_ADDR
s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
struct regcache *regcache, CORE_ADDR bp_addr,
int word_size = gdbarch_ptr_bit (gdbarch) / 8;
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
int i;
+ struct s390_arg_state arg_state, arg_prep;
+ CORE_ADDR param_area_start, new_sp;
- /* If the i'th argument is passed as a reference to a copy, then
- copy_addr[i] is the address of the copy we made. */
- CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR));
+ arg_prep.copy = sp;
+ arg_prep.gr = struct_return ? 3 : 2;
+ arg_prep.fr = 0;
+ arg_prep.argp = 0;
+ arg_prep.regcache = NULL;
- /* Reserve space for the reference-to-copy area. */
- for (i = 0; i < nargs; i++)
- {
- struct value *arg = args[i];
- struct type *type = check_typedef (value_type (arg));
+ /* Initialize arg_state for "preparation mode". */
+ arg_state = arg_prep;
- if (s390_function_arg_pass_by_reference (type))
- {
- sp -= TYPE_LENGTH (type);
- sp = align_down (sp, alignment_of (type));
- copy_addr[i] = sp;
- }
- }
-
- /* Reserve space for the parameter area. As a conservative
- simplification, we assume that everything will be passed on the
- stack. Since every argument larger than 8 bytes will be
- passed by reference, we use this simple upper bound. */
- sp -= nargs * 8;
+ /* Update arg_state.copy with the start of the reference-to-copy area
+ and arg_state.argp with the size of the parameter area. */
+ for (i = 0; i < nargs; i++)
+ s390_handle_arg (&arg_state, args[i], tdep, word_size, byte_order);
- /* After all that, make sure it's still aligned on an eight-byte
- boundary. */
- sp = align_down (sp, 8);
+ param_area_start = align_down (arg_state.copy - arg_state.argp, 8);
/* Allocate the standard frame areas: the register save area, the
- word reserved for the compiler (which seems kind of meaningless),
- and the back chain pointer. */
- sp -= 16*word_size + 32;
-
- /* Now we have the final SP value. Make sure we didn't underflow;
- on 31-bit, this would result in addresses with the high bit set,
- which causes confusion elsewhere. Note that if we error out
- here, stack and registers remain untouched. */
- if (gdbarch_addr_bits_remove (gdbarch, sp) != sp)
+ word reserved for the compiler, and the back chain pointer. */
+ new_sp = param_area_start - (16 * word_size + 32);
+
+ /* Now we have the final stack pointer. Make sure we didn't
+ underflow; on 31-bit, this would result in addresses with the
+ high bit set, which causes confusion elsewhere. Note that if we
+ error out here, stack and registers remain untouched. */
+ if (gdbarch_addr_bits_remove (gdbarch, new_sp) != new_sp)
error (_("Stack overflow"));
+ /* Pass the structure return address in general register 2. */
+ if (struct_return)
+ regcache_cooked_write_unsigned (regcache, S390_R2_REGNUM, struct_addr);
- /* Finally, place the actual parameters, working from SP towards
- higher addresses. The code above is supposed to reserve enough
- space for this. */
- {
- int fr = 0;
- int gr = 2;
- CORE_ADDR starg = sp + 16*word_size + 32;
+ /* Initialize arg_state for "write mode". */
+ arg_state = arg_prep;
+ arg_state.argp = param_area_start;
+ arg_state.regcache = regcache;
- /* A struct is returned using general register 2. */
- if (struct_return)
- {
- regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr,
- struct_addr);
- gr++;
- }
-
- for (i = 0; i < nargs; i++)
- {
- struct value *arg = args[i];
- struct type *type = check_typedef (value_type (arg));
- unsigned length = TYPE_LENGTH (type);
-
- if (s390_function_arg_pass_by_reference (type))
- {
- /* Actually copy the argument contents to the stack slot
- that was reserved above. */
- write_memory (copy_addr[i], value_contents (arg), length);
-
- if (gr <= 6)
- {
- regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr,
- copy_addr[i]);
- gr++;
- }
- else
- {
- write_memory_unsigned_integer (starg, word_size, byte_order,
- copy_addr[i]);
- starg += word_size;
- }
- }
- else if (s390_function_arg_float (type))
- {
- /* The GNU/Linux for S/390 ABI uses FPRs 0 and 2 to pass arguments,
- the GNU/Linux for zSeries ABI uses 0, 2, 4, and 6. */
- if (fr <= (tdep->abi == ABI_LINUX_S390 ? 2 : 6))
- {
- /* When we store a single-precision value in an FP register,
- it occupies the leftmost bits. */
- regcache_cooked_write_part (regcache, S390_F0_REGNUM + fr,
- 0, length, value_contents (arg));
- fr += 2;
- }
- else
- {
- /* When we store a single-precision value in a stack slot,
- it occupies the rightmost bits. */
- starg = align_up (starg + length, word_size);
- write_memory (starg - length, value_contents (arg), length);
- }
- }
- else if (s390_function_arg_integer (type) && length <= word_size)
- {
- if (gr <= 6)
- {
- /* Integer arguments are always extended to word size. */
- regcache_cooked_write_signed (regcache, S390_R0_REGNUM + gr,
- extend_simple_arg (gdbarch,
- arg));
- gr++;
- }
- else
- {
- /* Integer arguments are always extended to word size. */
- write_memory_signed_integer (starg, word_size, byte_order,
- extend_simple_arg (gdbarch, arg));
- starg += word_size;
- }
- }
- else if (s390_function_arg_integer (type) && length == 2*word_size)
- {
- if (gr <= 5)
- {
- regcache_cooked_write (regcache, S390_R0_REGNUM + gr,
- value_contents (arg));
- regcache_cooked_write (regcache, S390_R0_REGNUM + gr + 1,
- value_contents (arg) + word_size);
- gr += 2;
- }
- else
- {
- /* If we skipped r6 because we couldn't fit a DOUBLE_ARG
- in it, then don't go back and use it again later. */
- gr = 7;
-
- write_memory (starg, value_contents (arg), length);
- starg += length;
- }
- }
- else
- internal_error (__FILE__, __LINE__, _("unknown argument type"));
- }
- }
+ /* Write all parameters. */
+ for (i = 0; i < nargs; i++)
+ s390_handle_arg (&arg_state, args[i], tdep, word_size, byte_order);
/* Store return PSWA. In 31-bit mode, keep addressing mode bit. */
if (word_size == 4)
regcache_cooked_write_unsigned (regcache, S390_RETADDR_REGNUM, bp_addr);
/* Store updated stack pointer. */
- regcache_cooked_write_unsigned (regcache, S390_SP_REGNUM, sp);
+ regcache_cooked_write_unsigned (regcache, S390_SP_REGNUM, new_sp);
/* We need to return the 'stack part' of the frame ID,
which is actually the top of the register save area. */
- return sp + 16*word_size + 32;
+ return param_area_start;
}
/* Assuming THIS_FRAME is a dummy, return the frame ID of that
projects / binutils-gdb.git / commitdiff