1 /* Darwin support for GDB, the GNU debugger.
2 Copyright (C) 1997-2014 Free Software Foundation, Inc.
4 Contributed by Apple Computer, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
26 #include "floatformat.h"
32 #include "i387-tdep.h"
33 #include "i386-tdep.h"
38 #include "gdb_assert.h"
39 #include "i386-darwin-tdep.h"
41 #include "solib-darwin.h"
42 #include "dwarf2-frame.h"
44 /* Offsets into the struct i386_thread_state where we'll find the saved regs.
45 From <mach/i386/thread_status.h> and i386-tdep.h. */
46 int i386_darwin_thread_state_reg_offset[] =
66 const int i386_darwin_thread_state_num_regs =
67 ARRAY_SIZE (i386_darwin_thread_state_reg_offset);
69 /* Assuming THIS_FRAME is a Darwin sigtramp routine, return the
70 address of the associated sigcontext structure. */
73 i386_darwin_sigcontext_addr (struct frame_info *this_frame)
75 struct gdbarch *gdbarch = get_frame_arch (this_frame);
76 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
81 get_frame_register (this_frame, I386_EBP_REGNUM, buf);
82 bp = extract_unsigned_integer (buf, 4, byte_order);
84 /* A pointer to the ucontext is passed as the fourth argument
85 to the signal handler. */
86 read_memory (bp + 24, buf, 4);
87 si = extract_unsigned_integer (buf, 4, byte_order);
89 /* The pointer to mcontext is at offset 28. */
90 read_memory (si + 28, buf, 4);
92 /* First register (eax) is at offset 12. */
93 return extract_unsigned_integer (buf, 4, byte_order) + 12;
96 /* Return true if the PC of THIS_FRAME is in a signal trampoline which
99 On Darwin, signal trampolines have DWARF-2 CFI but it has only one FDE
100 that covers only the indirect call to the user handler.
101 Without this function, the frame is recognized as a normal frame which is
105 darwin_dwarf_signal_frame_p (struct gdbarch *gdbarch,
106 struct frame_info *this_frame)
108 return i386_sigtramp_p (this_frame);
111 /* Check wether TYPE is a 128-bit vector (__m128, __m128d or __m128i). */
114 i386_m128_p (struct type *type)
116 return (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type)
117 && TYPE_LENGTH (type) == 16);
120 /* Return the alignment for TYPE when passed as an argument. */
123 i386_darwin_arg_type_alignment (struct type *type)
125 type = check_typedef (type);
126 /* According to Mac OS X ABI document (passing arguments):
127 6. The caller places 64-bit vectors (__m64) on the parameter area,
128 aligned to 8-byte boundaries.
129 7. [...] The caller aligns 128-bit vectors in the parameter area to
130 16-byte boundaries. */
131 if (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type))
132 return TYPE_LENGTH (type);
133 /* 4. The caller places all the fields of structures (or unions) with no
134 vector elements in the parameter area. These structures are 4-byte
136 5. The caller places structures with vector elements on the stack,
138 if (TYPE_CODE (type) == TYPE_CODE_STRUCT
139 || TYPE_CODE (type) == TYPE_CODE_UNION)
143 for (i = 0; i < TYPE_NFIELDS (type); i++)
145 i386_darwin_arg_type_alignment (TYPE_FIELD_TYPE (type, i)));
148 /* 2. The caller aligns nonvector arguments to 4-byte boundaries. */
153 i386_darwin_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
154 struct regcache *regcache, CORE_ADDR bp_addr,
155 int nargs, struct value **args, CORE_ADDR sp,
156 int struct_return, CORE_ADDR struct_addr)
158 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
159 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
164 /* Determine the total space required for arguments and struct
165 return address in a first pass, then push arguments in a second pass. */
167 for (write_pass = 0; write_pass < 2; write_pass++)
176 /* Push value address. */
177 store_unsigned_integer (buf, 4, byte_order, struct_addr);
178 write_memory (sp, buf, 4);
183 for (i = 0; i < nargs; i++)
185 struct type *arg_type = value_enclosing_type (args[i]);
187 if (i386_m128_p (arg_type) && num_m128 < 4)
191 const gdb_byte *val = value_contents_all (args[i]);
193 (regcache, I387_MM0_REGNUM(tdep) + num_m128, val);
199 args_space = align_up (args_space,
200 i386_darwin_arg_type_alignment (arg_type));
202 write_memory (sp + args_space,
203 value_contents_all (args[i]),
204 TYPE_LENGTH (arg_type));
206 /* The System V ABI says that:
208 "An argument's size is increased, if necessary, to make it a
209 multiple of [32-bit] words. This may require tail padding,
210 depending on the size of the argument."
212 This makes sure the stack stays word-aligned. */
213 args_space += align_up (TYPE_LENGTH (arg_type), 4);
218 1. The caller ensures that the stack is 16-byte aligned at the point
219 of the function call. */
221 sp = align_down (sp - args_space, 16);
224 /* Store return address. */
226 store_unsigned_integer (buf, 4, byte_order, bp_addr);
227 write_memory (sp, buf, 4);
229 /* Finally, update the stack pointer... */
230 store_unsigned_integer (buf, 4, byte_order, sp);
231 regcache_cooked_write (regcache, I386_ESP_REGNUM, buf);
233 /* ...and fake a frame pointer. */
234 regcache_cooked_write (regcache, I386_EBP_REGNUM, buf);
236 /* MarkK wrote: This "+ 8" is all over the place:
237 (i386_frame_this_id, i386_sigtramp_frame_this_id,
238 i386_dummy_id). It's there, since all frame unwinders for
239 a given target have to agree (within a certain margin) on the
240 definition of the stack address of a frame. Otherwise frame id
241 comparison might not work correctly. Since DWARF2/GCC uses the
242 stack address *before* the function call as a frame's CFA. On
243 the i386, when %ebp is used as a frame pointer, the offset
244 between the contents %ebp and the CFA as defined by GCC. */
249 i386_darwin_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
251 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
253 /* We support the SSE registers. */
254 tdep->num_xmm_regs = I386_NUM_XREGS - 1;
255 set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS);
257 dwarf2_frame_set_signal_frame_p (gdbarch, darwin_dwarf_signal_frame_p);
258 set_gdbarch_push_dummy_call (gdbarch, i386_darwin_push_dummy_call);
260 tdep->struct_return = reg_struct_return;
262 tdep->sigtramp_p = i386_sigtramp_p;
263 tdep->sigcontext_addr = i386_darwin_sigcontext_addr;
264 tdep->sc_reg_offset = i386_darwin_thread_state_reg_offset;
265 tdep->sc_num_regs = i386_darwin_thread_state_num_regs;
267 tdep->jb_pc_offset = 48;
269 /* Although the i387 extended floating-point has only 80 significant
270 bits, a `long double' actually takes up 128, probably to enforce
272 set_gdbarch_long_double_bit (gdbarch, 128);
274 set_solib_ops (gdbarch, &darwin_so_ops);
277 static enum gdb_osabi
278 i386_mach_o_osabi_sniffer (bfd *abfd)
280 if (!bfd_check_format (abfd, bfd_object))
281 return GDB_OSABI_UNKNOWN;
283 if (bfd_get_arch (abfd) == bfd_arch_i386)
284 return GDB_OSABI_DARWIN;
286 return GDB_OSABI_UNKNOWN;
289 /* -Wmissing-prototypes */
290 extern initialize_file_ftype _initialize_i386_darwin_tdep;
293 _initialize_i386_darwin_tdep (void)
295 gdbarch_register_osabi_sniffer (bfd_arch_unknown, bfd_target_mach_o_flavour,
296 i386_mach_o_osabi_sniffer);
298 gdbarch_register_osabi (bfd_arch_i386, bfd_mach_i386_i386,
299 GDB_OSABI_DARWIN, i386_darwin_init_abi);