diff options
| -rw-r--r-- | gdb/ChangeLog | 20 | ||||
| -rw-r--r-- | gdb/s390-linux-tdep.c | 490 |
2 files changed, 220 insertions, 290 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f922735bb1..57a431f5bf 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,25 @@ 2015-04-27 Andreas Arnez <arnez@linux.vnet.ibm.com> + * s390-linux-tdep.c + (is_float_singleton): Remove function. Move the "singleton" part + of the logic... + (s390_effective_inner_type): ...here. New function. + (is_float_like): Remove function. Inline its logic... + (s390_function_arg_float): ...here. + (is_pointer_like, is_integer_like, is_struct_like): Remove + functions. Inline their logic... + (s390_function_arg_integer): ...here. + (s390_function_arg_pass_by_reference): Remove function. + (extend_simple_arg): Remove function. + (alignment_of): Remove function. + (struct s390_arg_state): New structure. + (s390_handle_arg): New function. + (s390_push_dummy_call): Move parameter placement logic to the new + function s390_handle_arg. Call it for calculating the stack area + sizes first, and again for actually writing the parameters. + +2015-04-27 Andreas Arnez <arnez@linux.vnet.ibm.com> + * s390-linux-tdep.c (is_power_of_two): Add comment. Return false if the argument is zero. diff --git a/gdb/s390-linux-tdep.c b/gdb/s390-linux-tdep.c index 44feee7bbe..3b7e4b6ecb 100644 --- a/gdb/s390-linux-tdep.c +++ b/gdb/s390-linux-tdep.c @@ -2389,99 +2389,40 @@ s390_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, /* 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. */ @@ -2492,101 +2433,172 @@ is_power_of_two (unsigned int n) 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". @@ -2601,6 +2613,7 @@ alignment_of (struct type *type) 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, @@ -2611,151 +2624,48 @@ s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function, 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) @@ -2767,11 +2677,11 @@ s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function, 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 |