1 /* Intel 386 target-dependent stuff.
3 Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, 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 2 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, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 #include "gdb_string.h"
29 #include "floatformat.h"
33 #include "arch-utils.h"
37 #include "gdb_assert.h"
39 #include "i386-tdep.h"
41 /* Names of the registers. The first 10 registers match the register
42 numbering scheme used by GCC for stabs and DWARF. */
43 static char *i386_register_names
[] =
45 "eax", "ecx", "edx", "ebx",
46 "esp", "ebp", "esi", "edi",
47 "eip", "eflags", "cs", "ss",
48 "ds", "es", "fs", "gs",
49 "st0", "st1", "st2", "st3",
50 "st4", "st5", "st6", "st7",
51 "fctrl", "fstat", "ftag", "fiseg",
52 "fioff", "foseg", "fooff", "fop",
53 "xmm0", "xmm1", "xmm2", "xmm3",
54 "xmm4", "xmm5", "xmm6", "xmm7",
58 /* i386_register_offset[i] is the offset into the register file of the
59 start of register number i. We initialize this from
60 i386_register_size. */
61 static int i386_register_offset
[I386_SSE_NUM_REGS
];
63 /* i386_register_size[i] is the number of bytes of storage in GDB's
64 register array occupied by register i. */
65 static int i386_register_size
[I386_SSE_NUM_REGS
] = {
79 /* Return the name of register REG. */
82 i386_register_name (int reg
)
86 if (reg
>= sizeof (i386_register_names
) / sizeof (*i386_register_names
))
89 return i386_register_names
[reg
];
92 /* Return the offset into the register array of the start of register
95 i386_register_byte (int reg
)
97 return i386_register_offset
[reg
];
100 /* Return the number of bytes of storage in GDB's register array
101 occupied by register REG. */
104 i386_register_raw_size (int reg
)
106 return i386_register_size
[reg
];
109 /* Convert stabs register number REG to the appropriate register
110 number used by GDB. */
113 i386_stab_reg_to_regnum (int reg
)
115 /* This implements what GCC calls the "default" register map. */
116 if (reg
>= 0 && reg
<= 7)
118 /* General registers. */
121 else if (reg
>= 12 && reg
<= 19)
123 /* Floating-point registers. */
124 return reg
- 12 + FP0_REGNUM
;
126 else if (reg
>= 21 && reg
<= 28)
129 return reg
- 21 + XMM0_REGNUM
;
131 else if (reg
>= 29 && reg
<= 36)
134 /* FIXME: kettenis/2001-07-28: Should we have the MMX registers
135 as pseudo-registers? */
136 return reg
- 29 + FP0_REGNUM
;
139 /* This will hopefully provoke a warning. */
140 return NUM_REGS
+ NUM_PSEUDO_REGS
;
143 /* Convert DWARF register number REG to the appropriate register
144 number used by GDB. */
147 i386_dwarf_reg_to_regnum (int reg
)
149 /* The DWARF register numbering includes %eip and %eflags, and
150 numbers the floating point registers differently. */
151 if (reg
>= 0 && reg
<= 9)
153 /* General registers. */
156 else if (reg
>= 11 && reg
<= 18)
158 /* Floating-point registers. */
159 return reg
- 11 + FP0_REGNUM
;
163 /* The SSE and MMX registers have identical numbers as in stabs. */
164 return i386_stab_reg_to_regnum (reg
);
167 /* This will hopefully provoke a warning. */
168 return NUM_REGS
+ NUM_PSEUDO_REGS
;
172 /* This is the variable that is set with "set disassembly-flavor", and
173 its legitimate values. */
174 static const char att_flavor
[] = "att";
175 static const char intel_flavor
[] = "intel";
176 static const char *valid_flavors
[] =
182 static const char *disassembly_flavor
= att_flavor
;
184 /* Stdio style buffering was used to minimize calls to ptrace, but
185 this buffering did not take into account that the code section
186 being accessed may not be an even number of buffers long (even if
187 the buffer is only sizeof(int) long). In cases where the code
188 section size happened to be a non-integral number of buffers long,
189 attempting to read the last buffer would fail. Simply using
190 target_read_memory and ignoring errors, rather than read_memory, is
191 not the correct solution, since legitimate access errors would then
192 be totally ignored. To properly handle this situation and continue
193 to use buffering would require that this code be able to determine
194 the minimum code section size granularity (not the alignment of the
195 section itself, since the actual failing case that pointed out this
196 problem had a section alignment of 4 but was not a multiple of 4
197 bytes long), on a target by target basis, and then adjust it's
198 buffer size accordingly. This is messy, but potentially feasible.
199 It probably needs the bfd library's help and support. For now, the
200 buffer size is set to 1. (FIXME -fnf) */
202 #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */
203 static CORE_ADDR codestream_next_addr
;
204 static CORE_ADDR codestream_addr
;
205 static unsigned char codestream_buf
[CODESTREAM_BUFSIZ
];
206 static int codestream_off
;
207 static int codestream_cnt
;
209 #define codestream_tell() (codestream_addr + codestream_off)
210 #define codestream_peek() \
211 (codestream_cnt == 0 ? \
212 codestream_fill(1) : codestream_buf[codestream_off])
213 #define codestream_get() \
214 (codestream_cnt-- == 0 ? \
215 codestream_fill(0) : codestream_buf[codestream_off++])
218 codestream_fill (int peek_flag
)
220 codestream_addr
= codestream_next_addr
;
221 codestream_next_addr
+= CODESTREAM_BUFSIZ
;
223 codestream_cnt
= CODESTREAM_BUFSIZ
;
224 read_memory (codestream_addr
, (char *) codestream_buf
, CODESTREAM_BUFSIZ
);
227 return (codestream_peek ());
229 return (codestream_get ());
233 codestream_seek (CORE_ADDR place
)
235 codestream_next_addr
= place
/ CODESTREAM_BUFSIZ
;
236 codestream_next_addr
*= CODESTREAM_BUFSIZ
;
239 while (codestream_tell () != place
)
244 codestream_read (unsigned char *buf
, int count
)
249 for (i
= 0; i
< count
; i
++)
250 *p
++ = codestream_get ();
254 /* If the next instruction is a jump, move to its target. */
257 i386_follow_jump (void)
259 unsigned char buf
[4];
265 pos
= codestream_tell ();
268 if (codestream_peek () == 0x66)
274 switch (codestream_get ())
277 /* Relative jump: if data16 == 0, disp32, else disp16. */
280 codestream_read (buf
, 2);
281 delta
= extract_signed_integer (buf
, 2);
283 /* Include the size of the jmp instruction (including the
289 codestream_read (buf
, 4);
290 delta
= extract_signed_integer (buf
, 4);
296 /* Relative jump, disp8 (ignore data16). */
297 codestream_read (buf
, 1);
298 /* Sign-extend it. */
299 delta
= extract_signed_integer (buf
, 1);
304 codestream_seek (pos
);
307 /* Find & return the amount a local space allocated, and advance the
308 codestream to the first register push (if any).
310 If the entry sequence doesn't make sense, return -1, and leave
311 codestream pointer at a random spot. */
314 i386_get_frame_setup (CORE_ADDR pc
)
318 codestream_seek (pc
);
322 op
= codestream_get ();
324 if (op
== 0x58) /* popl %eax */
326 /* This function must start with
329 xchgl %eax, (%esp) 0x87 0x04 0x24
330 or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
332 (the System V compiler puts out the second `xchg'
333 instruction, and the assembler doesn't try to optimize it, so
334 the 'sib' form gets generated). This sequence is used to get
335 the address of the return buffer for a function that returns
338 unsigned char buf
[4];
339 static unsigned char proto1
[3] = { 0x87, 0x04, 0x24 };
340 static unsigned char proto2
[4] = { 0x87, 0x44, 0x24, 0x00 };
342 pos
= codestream_tell ();
343 codestream_read (buf
, 4);
344 if (memcmp (buf
, proto1
, 3) == 0)
346 else if (memcmp (buf
, proto2
, 4) == 0)
349 codestream_seek (pos
);
350 op
= codestream_get (); /* Update next opcode. */
353 if (op
== 0x68 || op
== 0x6a)
355 /* This function may start with
367 unsigned char buf
[8];
369 /* Skip past the `pushl' instruction; it has either a one-byte
370 or a four-byte operand, depending on the opcode. */
371 pos
= codestream_tell ();
376 codestream_seek (pos
);
378 /* Read the following 8 bytes, which should be "call _probe" (6
379 bytes) followed by "addl $4,%esp" (2 bytes). */
380 codestream_read (buf
, sizeof (buf
));
381 if (buf
[0] == 0xe8 && buf
[6] == 0xc4 && buf
[7] == 0x4)
383 codestream_seek (pos
);
384 op
= codestream_get (); /* Update next opcode. */
387 if (op
== 0x55) /* pushl %ebp */
389 /* Check for "movl %esp, %ebp" -- can be written in two ways. */
390 switch (codestream_get ())
393 if (codestream_get () != 0xec)
397 if (codestream_get () != 0xe5)
403 /* Check for stack adjustment
407 NOTE: You can't subtract a 16 bit immediate from a 32 bit
408 reg, so we don't have to worry about a data16 prefix. */
409 op
= codestream_peek ();
412 /* `subl' with 8 bit immediate. */
414 if (codestream_get () != 0xec)
415 /* Some instruction starting with 0x83 other than `subl'. */
417 codestream_seek (codestream_tell () - 2);
420 /* `subl' with signed byte immediate (though it wouldn't
421 make sense to be negative). */
422 return (codestream_get ());
427 /* Maybe it is `subl' with a 32 bit immedediate. */
429 if (codestream_get () != 0xec)
430 /* Some instruction starting with 0x81 other than `subl'. */
432 codestream_seek (codestream_tell () - 2);
435 /* It is `subl' with a 32 bit immediate. */
436 codestream_read ((unsigned char *) buf
, 4);
437 return extract_signed_integer (buf
, 4);
447 /* `enter' with 16 bit unsigned immediate. */
448 codestream_read ((unsigned char *) buf
, 2);
449 codestream_get (); /* Flush final byte of enter instruction. */
450 return extract_unsigned_integer (buf
, 2);
455 /* Return the chain-pointer for FRAME. In the case of the i386, the
456 frame's nominal address is the address of a 4-byte word containing
457 the calling frame's address. */
460 i386_frame_chain (struct frame_info
*frame
)
462 if (frame
->signal_handler_caller
)
465 if (! inside_entry_file (frame
->pc
))
466 return read_memory_unsigned_integer (frame
->frame
, 4);
471 /* Determine whether the function invocation represented by FRAME does
472 not have a from on the stack associated with it. If it does not,
473 return non-zero, otherwise return zero. */
476 i386_frameless_function_invocation (struct frame_info
*frame
)
478 if (frame
->signal_handler_caller
)
481 return frameless_look_for_prologue (frame
);
484 /* Return the saved program counter for FRAME. */
487 i386_frame_saved_pc (struct frame_info
*frame
)
489 if (frame
->signal_handler_caller
)
491 CORE_ADDR (*sigtramp_saved_pc
) (struct frame_info
*);
492 sigtramp_saved_pc
= gdbarch_tdep (current_gdbarch
)->sigtramp_saved_pc
;
494 gdb_assert (sigtramp_saved_pc
!= NULL
);
495 return sigtramp_saved_pc (frame
);
498 return read_memory_unsigned_integer (frame
->frame
+ 4, 4);
501 /* Immediately after a function call, return the saved pc. */
504 i386_saved_pc_after_call (struct frame_info
*frame
)
506 return read_memory_unsigned_integer (read_register (SP_REGNUM
), 4);
509 /* Return number of args passed to a frame.
510 Can return -1, meaning no way to tell. */
513 i386_frame_num_args (struct frame_info
*fi
)
518 /* This loses because not only might the compiler not be popping the
519 args right after the function call, it might be popping args from
520 both this call and a previous one, and we would say there are
521 more args than there really are. */
525 struct frame_info
*pfi
;
527 /* On the i386, the instruction following the call could be:
529 addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
530 anything else - zero args. */
534 frameless
= FRAMELESS_FUNCTION_INVOCATION (fi
);
536 /* In the absence of a frame pointer, GDB doesn't get correct
537 values for nameless arguments. Return -1, so it doesn't print
538 any nameless arguments. */
541 pfi
= get_prev_frame (fi
);
544 /* NOTE: This can happen if we are looking at the frame for
545 main, because FRAME_CHAIN_VALID won't let us go into start.
546 If we have debugging symbols, that's not really a big deal;
547 it just means it will only show as many arguments to main as
554 op
= read_memory_integer (retpc
, 1);
555 if (op
== 0x59) /* pop %ecx */
559 op
= read_memory_integer (retpc
+ 1, 1);
561 /* addl $<signed imm 8 bits>, %esp */
562 return (read_memory_integer (retpc
+ 2, 1) & 0xff) / 4;
566 else if (op
== 0x81) /* `add' with 32 bit immediate. */
568 op
= read_memory_integer (retpc
+ 1, 1);
570 /* addl $<imm 32>, %esp */
571 return read_memory_integer (retpc
+ 2, 4) / 4;
583 /* Parse the first few instructions the function to see what registers
586 We handle these cases:
588 The startup sequence can be at the start of the function, or the
589 function can start with a branch to startup code at the end.
591 %ebp can be set up with either the 'enter' instruction, or "pushl
592 %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was
593 once used in the System V compiler).
595 Local space is allocated just below the saved %ebp by either the
596 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a 16
597 bit unsigned argument for space to allocate, and the 'addl'
598 instruction could have either a signed byte, or 32 bit immediate.
600 Next, the registers used by this function are pushed. With the
601 System V compiler they will always be in the order: %edi, %esi,
602 %ebx (and sometimes a harmless bug causes it to also save but not
603 restore %eax); however, the code below is willing to see the pushes
604 in any order, and will handle up to 8 of them.
606 If the setup sequence is at the end of the function, then the next
607 instruction will be a branch back to the start. */
610 i386_frame_init_saved_regs (struct frame_info
*fip
)
614 CORE_ADDR dummy_bottom
;
622 frame_saved_regs_zalloc (fip
);
624 /* If the frame is the end of a dummy, compute where the beginning
626 dummy_bottom
= fip
->frame
- 4 - REGISTER_BYTES
- CALL_DUMMY_LENGTH
;
628 /* Check if the PC points in the stack, in a dummy frame. */
629 if (dummy_bottom
<= fip
->pc
&& fip
->pc
<= fip
->frame
)
631 /* All registers were saved by push_call_dummy. */
633 for (i
= 0; i
< NUM_REGS
; i
++)
635 addr
-= REGISTER_RAW_SIZE (i
);
636 fip
->saved_regs
[i
] = addr
;
641 pc
= get_pc_function_start (fip
->pc
);
643 locals
= i386_get_frame_setup (pc
);
647 addr
= fip
->frame
- 4 - locals
;
648 for (i
= 0; i
< 8; i
++)
650 op
= codestream_get ();
651 if (op
< 0x50 || op
> 0x57)
653 #ifdef I386_REGNO_TO_SYMMETRY
654 /* Dynix uses different internal numbering. Ick. */
655 fip
->saved_regs
[I386_REGNO_TO_SYMMETRY (op
- 0x50)] = addr
;
657 fip
->saved_regs
[op
- 0x50] = addr
;
663 fip
->saved_regs
[PC_REGNUM
] = fip
->frame
+ 4;
664 fip
->saved_regs
[FP_REGNUM
] = fip
->frame
;
667 /* Return PC of first real instruction. */
670 i386_skip_prologue (CORE_ADDR pc
)
674 static unsigned char pic_pat
[6] =
675 { 0xe8, 0, 0, 0, 0, /* call 0x0 */
676 0x5b, /* popl %ebx */
680 if (i386_get_frame_setup (pc
) < 0)
683 /* Found valid frame setup -- codestream now points to start of push
684 instructions for saving registers. */
686 /* Skip over register saves. */
687 for (i
= 0; i
< 8; i
++)
689 op
= codestream_peek ();
690 /* Break if not `pushl' instrunction. */
691 if (op
< 0x50 || op
> 0x57)
696 /* The native cc on SVR4 in -K PIC mode inserts the following code
697 to get the address of the global offset table (GOT) into register
702 movl %ebx,x(%ebp) (optional)
705 This code is with the rest of the prologue (at the end of the
706 function), so we have to skip it to get to the first real
707 instruction at the start of the function. */
709 pos
= codestream_tell ();
710 for (i
= 0; i
< 6; i
++)
712 op
= codestream_get ();
713 if (pic_pat
[i
] != op
)
718 unsigned char buf
[4];
721 op
= codestream_get ();
722 if (op
== 0x89) /* movl %ebx, x(%ebp) */
724 op
= codestream_get ();
725 if (op
== 0x5d) /* One byte offset from %ebp. */
728 codestream_read (buf
, 1);
730 else if (op
== 0x9d) /* Four byte offset from %ebp. */
733 codestream_read (buf
, 4);
735 else /* Unexpected instruction. */
737 op
= codestream_get ();
740 if (delta
> 0 && op
== 0x81 && codestream_get () == 0xc3)
745 codestream_seek (pos
);
749 return (codestream_tell ());
752 /* Use the program counter to determine the contents and size of a
753 breakpoint instruction. Return a pointer to a string of bytes that
754 encode a breakpoint instruction, store the length of the string in
755 *LEN and optionally adjust *PC to point to the correct memory
756 location for inserting the breakpoint.
758 On the i386 we have a single breakpoint that fits in a single byte
759 and can be inserted anywhere. */
761 static const unsigned char *
762 i386_breakpoint_from_pc (CORE_ADDR
*pc
, int *len
)
764 static unsigned char break_insn
[] = { 0xcc }; /* int 3 */
766 *len
= sizeof (break_insn
);
771 i386_push_dummy_frame (void)
773 CORE_ADDR sp
= read_register (SP_REGNUM
);
776 char regbuf
[MAX_REGISTER_RAW_SIZE
];
778 sp
= push_word (sp
, read_register (PC_REGNUM
));
779 sp
= push_word (sp
, read_register (FP_REGNUM
));
781 for (regnum
= 0; regnum
< NUM_REGS
; regnum
++)
783 read_register_gen (regnum
, regbuf
);
784 sp
= push_bytes (sp
, regbuf
, REGISTER_RAW_SIZE (regnum
));
786 write_register (SP_REGNUM
, sp
);
787 write_register (FP_REGNUM
, fp
);
790 /* The i386 call dummy sequence:
792 call 11223344 (32-bit relative)
795 It is 8 bytes long. */
797 static LONGEST i386_call_dummy_words
[] =
803 /* Insert the (relative) function address into the call sequence
807 i386_fix_call_dummy (char *dummy
, CORE_ADDR pc
, CORE_ADDR fun
, int nargs
,
808 struct value
**args
, struct type
*type
, int gcc_p
)
810 int from
, to
, delta
, loc
;
812 loc
= (int)(read_register (SP_REGNUM
) - CALL_DUMMY_LENGTH
);
817 *((char *)(dummy
) + 1) = (delta
& 0xff);
818 *((char *)(dummy
) + 2) = ((delta
>> 8) & 0xff);
819 *((char *)(dummy
) + 3) = ((delta
>> 16) & 0xff);
820 *((char *)(dummy
) + 4) = ((delta
>> 24) & 0xff);
824 i386_pop_frame (void)
826 struct frame_info
*frame
= get_current_frame ();
829 char regbuf
[MAX_REGISTER_RAW_SIZE
];
831 fp
= FRAME_FP (frame
);
832 i386_frame_init_saved_regs (frame
);
834 for (regnum
= 0; regnum
< NUM_REGS
; regnum
++)
837 addr
= frame
->saved_regs
[regnum
];
840 read_memory (addr
, regbuf
, REGISTER_RAW_SIZE (regnum
));
841 write_register_bytes (REGISTER_BYTE (regnum
), regbuf
,
842 REGISTER_RAW_SIZE (regnum
));
845 write_register (FP_REGNUM
, read_memory_integer (fp
, 4));
846 write_register (PC_REGNUM
, read_memory_integer (fp
+ 4, 4));
847 write_register (SP_REGNUM
, fp
+ 8);
848 flush_cached_frames ();
852 /* Figure out where the longjmp will land. Slurp the args out of the
853 stack. We expect the first arg to be a pointer to the jmp_buf
854 structure from which we extract the address that we will land at.
855 This address is copied into PC. This routine returns true on
859 i386_get_longjmp_target (CORE_ADDR
*pc
)
862 CORE_ADDR sp
, jb_addr
;
863 int jb_pc_offset
= gdbarch_tdep (current_gdbarch
)->jb_pc_offset
;
865 /* If JB_PC_OFFSET is -1, we have no way to find out where the
866 longjmp will land. */
867 if (jb_pc_offset
== -1)
870 sp
= read_register (SP_REGNUM
);
871 if (target_read_memory (sp
+ 4, buf
, 4))
874 jb_addr
= extract_address (buf
, 4);
875 if (target_read_memory (jb_addr
+ jb_pc_offset
, buf
, 4))
878 *pc
= extract_address (buf
, 4);
884 i386_push_arguments (int nargs
, struct value
**args
, CORE_ADDR sp
,
885 int struct_return
, CORE_ADDR struct_addr
)
887 sp
= default_push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
);
894 store_address (buf
, 4, struct_addr
);
895 write_memory (sp
, buf
, 4);
902 i386_store_struct_return (CORE_ADDR addr
, CORE_ADDR sp
)
904 /* Do nothing. Everything was already done by i386_push_arguments. */
907 /* These registers are used for returning integers (and on some
908 targets also for returning `struct' and `union' values when their
909 size and alignment match an integer type). */
910 #define LOW_RETURN_REGNUM 0 /* %eax */
911 #define HIGH_RETURN_REGNUM 2 /* %edx */
913 /* Extract from an array REGBUF containing the (raw) register state, a
914 function return value of TYPE, and copy that, in virtual format,
918 i386_extract_return_value (struct type
*type
, char *regbuf
, char *valbuf
)
920 int len
= TYPE_LENGTH (type
);
922 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
923 && TYPE_NFIELDS (type
) == 1)
925 i386_extract_return_value (TYPE_FIELD_TYPE (type
, 0), regbuf
, valbuf
);
929 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
933 warning ("Cannot find floating-point return value.");
934 memset (valbuf
, 0, len
);
938 /* Floating-point return values can be found in %st(0). Convert
939 its contents to the desired type. This is probably not
940 exactly how it would happen on the target itself, but it is
941 the best we can do. */
942 convert_typed_floating (®buf
[REGISTER_BYTE (FP0_REGNUM
)],
943 builtin_type_i387_ext
, valbuf
, type
);
947 int low_size
= REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
);
948 int high_size
= REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM
);
951 memcpy (valbuf
, ®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)], len
);
952 else if (len
<= (low_size
+ high_size
))
955 ®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)], low_size
);
956 memcpy (valbuf
+ low_size
,
957 ®buf
[REGISTER_BYTE (HIGH_RETURN_REGNUM
)], len
- low_size
);
960 internal_error (__FILE__
, __LINE__
,
961 "Cannot extract return value of %d bytes long.", len
);
965 /* Write into the appropriate registers a function return value stored
966 in VALBUF of type TYPE, given in virtual format. */
969 i386_store_return_value (struct type
*type
, char *valbuf
)
971 int len
= TYPE_LENGTH (type
);
973 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
974 && TYPE_NFIELDS (type
) == 1)
976 i386_store_return_value (TYPE_FIELD_TYPE (type
, 0), valbuf
);
980 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
983 char buf
[FPU_REG_RAW_SIZE
];
987 warning ("Cannot set floating-point return value.");
991 /* Returning floating-point values is a bit tricky. Apart from
992 storing the return value in %st(0), we have to simulate the
993 state of the FPU at function return point. */
995 /* Convert the value found in VALBUF to the extended
996 floating-point format used by the FPU. This is probably
997 not exactly how it would happen on the target itself, but
998 it is the best we can do. */
999 convert_typed_floating (valbuf
, type
, buf
, builtin_type_i387_ext
);
1000 write_register_bytes (REGISTER_BYTE (FP0_REGNUM
), buf
,
1003 /* Set the top of the floating-point register stack to 7. The
1004 actual value doesn't really matter, but 7 is what a normal
1005 function return would end up with if the program started out
1006 with a freshly initialized FPU. */
1007 fstat
= read_register (FSTAT_REGNUM
);
1009 write_register (FSTAT_REGNUM
, fstat
);
1011 /* Mark %st(1) through %st(7) as empty. Since we set the top of
1012 the floating-point register stack to 7, the appropriate value
1013 for the tag word is 0x3fff. */
1014 write_register (FTAG_REGNUM
, 0x3fff);
1018 int low_size
= REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
);
1019 int high_size
= REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM
);
1021 if (len
<= low_size
)
1022 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM
), valbuf
, len
);
1023 else if (len
<= (low_size
+ high_size
))
1025 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM
),
1027 write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM
),
1028 valbuf
+ low_size
, len
- low_size
);
1031 internal_error (__FILE__
, __LINE__
,
1032 "Cannot store return value of %d bytes long.", len
);
1036 /* Extract from an array REGBUF containing the (raw) register state
1037 the address in which a function should return its structure value,
1041 i386_extract_struct_value_address (char *regbuf
)
1043 return extract_address (®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)],
1044 REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
));
1048 /* This is the variable that is set with "set struct-convention", and
1049 its legitimate values. */
1050 static const char default_struct_convention
[] = "default";
1051 static const char pcc_struct_convention
[] = "pcc";
1052 static const char reg_struct_convention
[] = "reg";
1053 static const char *valid_conventions
[] =
1055 default_struct_convention
,
1056 pcc_struct_convention
,
1057 reg_struct_convention
,
1060 static const char *struct_convention
= default_struct_convention
;
1063 i386_use_struct_convention (int gcc_p
, struct type
*type
)
1065 enum struct_return struct_return
;
1067 if (struct_convention
== default_struct_convention
)
1068 struct_return
= gdbarch_tdep (current_gdbarch
)->struct_return
;
1069 else if (struct_convention
== pcc_struct_convention
)
1070 struct_return
= pcc_struct_return
;
1072 struct_return
= reg_struct_return
;
1074 return generic_use_struct_convention (struct_return
== reg_struct_return
,
1079 /* Return the GDB type object for the "standard" data type of data in
1080 register REGNUM. Perhaps %esi and %edi should go here, but
1081 potentially they could be used for things other than address. */
1084 i386_register_virtual_type (int regnum
)
1086 if (regnum
== PC_REGNUM
|| regnum
== FP_REGNUM
|| regnum
== SP_REGNUM
)
1087 return lookup_pointer_type (builtin_type_void
);
1089 if (IS_FP_REGNUM (regnum
))
1090 return builtin_type_i387_ext
;
1092 if (IS_SSE_REGNUM (regnum
))
1093 return builtin_type_vec128i
;
1095 return builtin_type_int
;
1098 /* Return true iff register REGNUM's virtual format is different from
1099 its raw format. Note that this definition assumes that the host
1100 supports IEEE 32-bit floats, since it doesn't say that SSE
1101 registers need conversion. Even if we can't find a counterexample,
1102 this is still sloppy. */
1105 i386_register_convertible (int regnum
)
1107 return IS_FP_REGNUM (regnum
);
1110 /* Convert data from raw format for register REGNUM in buffer FROM to
1111 virtual format with type TYPE in buffer TO. */
1114 i386_register_convert_to_virtual (int regnum
, struct type
*type
,
1115 char *from
, char *to
)
1117 gdb_assert (IS_FP_REGNUM (regnum
));
1119 /* We only support floating-point values. */
1120 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
1122 warning ("Cannot convert floating-point register value "
1123 "to non-floating-point type.");
1124 memset (to
, 0, TYPE_LENGTH (type
));
1128 /* Convert to TYPE. This should be a no-op if TYPE is equivalent to
1129 the extended floating-point format used by the FPU. */
1130 convert_typed_floating (from
, builtin_type_i387_ext
, to
, type
);
1133 /* Convert data from virtual format with type TYPE in buffer FROM to
1134 raw format for register REGNUM in buffer TO. */
1137 i386_register_convert_to_raw (struct type
*type
, int regnum
,
1138 char *from
, char *to
)
1140 gdb_assert (IS_FP_REGNUM (regnum
));
1142 /* We only support floating-point values. */
1143 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
1145 warning ("Cannot convert non-floating-point type "
1146 "to floating-point register value.");
1147 memset (to
, 0, TYPE_LENGTH (type
));
1151 /* Convert from TYPE. This should be a no-op if TYPE is equivalent
1152 to the extended floating-point format used by the FPU. */
1153 convert_typed_floating (from
, type
, to
, builtin_type_i387_ext
);
1157 #ifdef STATIC_TRANSFORM_NAME
1158 /* SunPRO encodes the static variables. This is not related to C++
1159 mangling, it is done for C too. */
1162 sunpro_static_transform_name (char *name
)
1165 if (IS_STATIC_TRANSFORM_NAME (name
))
1167 /* For file-local statics there will be a period, a bunch of
1168 junk (the contents of which match a string given in the
1169 N_OPT), a period and the name. For function-local statics
1170 there will be a bunch of junk (which seems to change the
1171 second character from 'A' to 'B'), a period, the name of the
1172 function, and the name. So just skip everything before the
1174 p
= strrchr (name
, '.');
1180 #endif /* STATIC_TRANSFORM_NAME */
1183 /* Stuff for WIN32 PE style DLL's but is pretty generic really. */
1186 skip_trampoline_code (CORE_ADDR pc
, char *name
)
1188 if (pc
&& read_memory_unsigned_integer (pc
, 2) == 0x25ff) /* jmp *(dest) */
1190 unsigned long indirect
= read_memory_unsigned_integer (pc
+ 2, 4);
1191 struct minimal_symbol
*indsym
=
1192 indirect
? lookup_minimal_symbol_by_pc (indirect
) : 0;
1193 char *symname
= indsym
? SYMBOL_NAME (indsym
) : 0;
1197 if (strncmp (symname
, "__imp_", 6) == 0
1198 || strncmp (symname
, "_imp_", 5) == 0)
1199 return name
? 1 : read_memory_unsigned_integer (indirect
, 4);
1202 return 0; /* Not a trampoline. */
1206 /* Return non-zero if PC and NAME show that we are in a signal
1210 i386_pc_in_sigtramp (CORE_ADDR pc
, char *name
)
1212 return (name
&& strcmp ("_sigtramp", name
) == 0);
1216 /* We have two flavours of disassembly. The machinery on this page
1217 deals with switching between those. */
1220 gdb_print_insn_i386 (bfd_vma memaddr
, disassemble_info
*info
)
1222 if (disassembly_flavor
== att_flavor
)
1223 return print_insn_i386_att (memaddr
, info
);
1224 else if (disassembly_flavor
== intel_flavor
)
1225 return print_insn_i386_intel (memaddr
, info
);
1226 /* Never reached -- disassembly_flavour is always either att_flavor
1228 internal_error (__FILE__
, __LINE__
, "failed internal consistency check");
1232 /* There are a few i386 architecture variants that differ only
1233 slightly from the generic i386 target. For now, we don't give them
1234 their own source file, but include them here. As a consequence,
1235 they'll always be included. */
1237 /* System V Release 4 (SVR4). */
1240 i386_svr4_pc_in_sigtramp (CORE_ADDR pc
, char *name
)
1242 return (name
&& (strcmp ("_sigreturn", name
) == 0
1243 || strcmp ("_sigacthandler", name
) == 0
1244 || strcmp ("sigvechandler", name
) == 0));
1247 /* Get saved user PC for sigtramp from the pushed ucontext on the
1248 stack for all three variants of SVR4 sigtramps. */
1251 i386_svr4_sigtramp_saved_pc (struct frame_info
*frame
)
1253 CORE_ADDR saved_pc_offset
= 4;
1256 find_pc_partial_function (frame
->pc
, &name
, NULL
, NULL
);
1259 if (strcmp (name
, "_sigreturn") == 0)
1260 saved_pc_offset
= 132 + 14 * 4;
1261 else if (strcmp (name
, "_sigacthandler") == 0)
1262 saved_pc_offset
= 80 + 14 * 4;
1263 else if (strcmp (name
, "sigvechandler") == 0)
1264 saved_pc_offset
= 120 + 14 * 4;
1268 return read_memory_integer (frame
->next
->frame
+ saved_pc_offset
, 4);
1269 return read_memory_integer (read_register (SP_REGNUM
) + saved_pc_offset
, 4);
1276 i386_go32_pc_in_sigtramp (CORE_ADDR pc
, char *name
)
1278 /* DJGPP doesn't have any special frames for signal handlers. */
1286 i386_elf_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
1288 /* We typically use stabs-in-ELF with the DWARF register numbering. */
1289 set_gdbarch_stab_reg_to_regnum (gdbarch
, i386_dwarf_reg_to_regnum
);
1292 /* System V Release 4 (SVR4). */
1295 i386_svr4_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
1297 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
1299 /* System V Release 4 uses ELF. */
1300 i386_elf_init_abi (info
, gdbarch
);
1302 /* FIXME: kettenis/20020511: Why do we override this function here? */
1303 set_gdbarch_frame_chain_valid (gdbarch
, func_frame_chain_valid
);
1305 set_gdbarch_pc_in_sigtramp (gdbarch
, i386_svr4_pc_in_sigtramp
);
1306 tdep
->sigtramp_saved_pc
= i386_svr4_sigtramp_saved_pc
;
1308 tdep
->jb_pc_offset
= 20;
1314 i386_go32_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
1316 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
1318 set_gdbarch_pc_in_sigtramp (gdbarch
, i386_go32_pc_in_sigtramp
);
1320 tdep
->jb_pc_offset
= 36;
1326 i386_nw_init_abi (struct gdbarch_info info
, struct gdbarch
*gdbarch
)
1328 struct gdbarch_tdep
*tdep
= gdbarch_tdep (gdbarch
);
1330 /* FIXME: kettenis/20020511: Why do we override this function here? */
1331 set_gdbarch_frame_chain_valid (gdbarch
, func_frame_chain_valid
);
1333 tdep
->jb_pc_offset
= 24;
1338 i386_gdbarch_init (struct gdbarch_info info
, struct gdbarch_list
*arches
)
1340 struct gdbarch_tdep
*tdep
;
1341 struct gdbarch
*gdbarch
;
1342 enum gdb_osabi osabi
= GDB_OSABI_UNKNOWN
;
1344 /* Try to determine the OS ABI of the object we're loading. */
1345 if (info
.abfd
!= NULL
)
1346 osabi
= gdbarch_lookup_osabi (info
.abfd
);
1348 /* Find a candidate among extant architectures. */
1349 for (arches
= gdbarch_list_lookup_by_info (arches
, &info
);
1351 arches
= gdbarch_list_lookup_by_info (arches
->next
, &info
))
1353 /* Make sure the OS ABI selection matches. */
1354 tdep
= gdbarch_tdep (arches
->gdbarch
);
1355 if (tdep
&& tdep
->osabi
== osabi
)
1356 return arches
->gdbarch
;
1359 /* Allocate space for the new architecture. */
1360 tdep
= XMALLOC (struct gdbarch_tdep
);
1361 gdbarch
= gdbarch_alloc (&info
, tdep
);
1363 tdep
->osabi
= osabi
;
1365 /* The i386 default settings don't include the SSE registers.
1366 FIXME: kettenis/20020614: They do include the FPU registers for
1367 now, which probably is not quite right. */
1368 tdep
->num_xmm_regs
= 0;
1370 tdep
->jb_pc_offset
= -1;
1371 tdep
->struct_return
= pcc_struct_return
;
1372 tdep
->sigtramp_saved_pc
= NULL
;
1373 tdep
->sigtramp_start
= 0;
1374 tdep
->sigtramp_end
= 0;
1375 tdep
->sc_pc_offset
= -1;
1377 /* The format used for `long double' on almost all i386 targets is
1378 the i387 extended floating-point format. In fact, of all targets
1379 in the GCC 2.95 tree, only OSF/1 does it different, and insists
1380 on having a `long double' that's not `long' at all. */
1381 set_gdbarch_long_double_format (gdbarch
, &floatformat_i387_ext
);
1383 /* Although the i386 extended floating-point has only 80 significant
1384 bits, a `long double' actually takes up 96, probably to enforce
1386 set_gdbarch_long_double_bit (gdbarch
, 96);
1388 /* NOTE: tm-i386aix.h, tm-i386bsd.h, tm-i386os9k.h, tm-ptx.h,
1389 tm-symmetry.h currently override this. Sigh. */
1390 set_gdbarch_num_regs (gdbarch
, I386_NUM_GREGS
+ I386_NUM_FREGS
);
1392 set_gdbarch_sp_regnum (gdbarch
, 4);
1393 set_gdbarch_fp_regnum (gdbarch
, 5);
1394 set_gdbarch_pc_regnum (gdbarch
, 8);
1395 set_gdbarch_ps_regnum (gdbarch
, 9);
1396 set_gdbarch_fp0_regnum (gdbarch
, 16);
1398 /* Use the "default" register numbering scheme for stabs and COFF. */
1399 set_gdbarch_stab_reg_to_regnum (gdbarch
, i386_stab_reg_to_regnum
);
1400 set_gdbarch_sdb_reg_to_regnum (gdbarch
, i386_stab_reg_to_regnum
);
1402 /* Use the DWARF register numbering scheme for DWARF and DWARF 2. */
1403 set_gdbarch_dwarf_reg_to_regnum (gdbarch
, i386_dwarf_reg_to_regnum
);
1404 set_gdbarch_dwarf2_reg_to_regnum (gdbarch
, i386_dwarf_reg_to_regnum
);
1406 /* We don't define ECOFF_REG_TO_REGNUM, since ECOFF doesn't seem to
1407 be in use on any of the supported i386 targets. */
1409 set_gdbarch_register_name (gdbarch
, i386_register_name
);
1410 set_gdbarch_register_size (gdbarch
, 4);
1411 set_gdbarch_register_bytes (gdbarch
, I386_SIZEOF_GREGS
+ I386_SIZEOF_FREGS
);
1412 set_gdbarch_register_byte (gdbarch
, i386_register_byte
);
1413 set_gdbarch_register_raw_size (gdbarch
, i386_register_raw_size
);
1414 set_gdbarch_max_register_raw_size (gdbarch
, 16);
1415 set_gdbarch_max_register_virtual_size (gdbarch
, 16);
1416 set_gdbarch_register_virtual_type (gdbarch
, i386_register_virtual_type
);
1418 set_gdbarch_get_longjmp_target (gdbarch
, i386_get_longjmp_target
);
1420 set_gdbarch_use_generic_dummy_frames (gdbarch
, 0);
1422 /* Call dummy code. */
1423 set_gdbarch_call_dummy_location (gdbarch
, ON_STACK
);
1424 set_gdbarch_call_dummy_start_offset (gdbarch
, 0);
1425 set_gdbarch_call_dummy_breakpoint_offset (gdbarch
, 5);
1426 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch
, 1);
1427 set_gdbarch_call_dummy_length (gdbarch
, 8);
1428 set_gdbarch_call_dummy_p (gdbarch
, 1);
1429 set_gdbarch_call_dummy_words (gdbarch
, i386_call_dummy_words
);
1430 set_gdbarch_sizeof_call_dummy_words (gdbarch
,
1431 sizeof (i386_call_dummy_words
));
1432 set_gdbarch_call_dummy_stack_adjust_p (gdbarch
, 0);
1433 set_gdbarch_fix_call_dummy (gdbarch
, i386_fix_call_dummy
);
1435 set_gdbarch_register_convertible (gdbarch
, i386_register_convertible
);
1436 set_gdbarch_register_convert_to_virtual (gdbarch
,
1437 i386_register_convert_to_virtual
);
1438 set_gdbarch_register_convert_to_raw (gdbarch
, i386_register_convert_to_raw
);
1440 set_gdbarch_get_saved_register (gdbarch
, generic_get_saved_register
);
1441 set_gdbarch_push_arguments (gdbarch
, i386_push_arguments
);
1443 set_gdbarch_pc_in_call_dummy (gdbarch
, pc_in_call_dummy_on_stack
);
1445 /* "An argument's size is increased, if necessary, to make it a
1446 multiple of [32-bit] words. This may require tail padding,
1447 depending on the size of the argument" -- from the x86 ABI. */
1448 set_gdbarch_parm_boundary (gdbarch
, 32);
1450 set_gdbarch_deprecated_extract_return_value (gdbarch
,
1451 i386_extract_return_value
);
1452 set_gdbarch_push_arguments (gdbarch
, i386_push_arguments
);
1453 set_gdbarch_push_dummy_frame (gdbarch
, i386_push_dummy_frame
);
1454 set_gdbarch_pop_frame (gdbarch
, i386_pop_frame
);
1455 set_gdbarch_store_struct_return (gdbarch
, i386_store_struct_return
);
1456 set_gdbarch_store_return_value (gdbarch
, i386_store_return_value
);
1457 set_gdbarch_deprecated_extract_struct_value_address (gdbarch
,
1458 i386_extract_struct_value_address
);
1459 set_gdbarch_use_struct_convention (gdbarch
, i386_use_struct_convention
);
1461 set_gdbarch_frame_init_saved_regs (gdbarch
, i386_frame_init_saved_regs
);
1462 set_gdbarch_skip_prologue (gdbarch
, i386_skip_prologue
);
1464 /* Stack grows downward. */
1465 set_gdbarch_inner_than (gdbarch
, core_addr_lessthan
);
1467 set_gdbarch_breakpoint_from_pc (gdbarch
, i386_breakpoint_from_pc
);
1468 set_gdbarch_decr_pc_after_break (gdbarch
, 1);
1469 set_gdbarch_function_start_offset (gdbarch
, 0);
1471 /* The following redefines make backtracing through sigtramp work.
1472 They manufacture a fake sigtramp frame and obtain the saved pc in
1473 sigtramp from the sigcontext structure which is pushed by the
1474 kernel on the user stack, along with a pointer to it. */
1476 set_gdbarch_frame_args_skip (gdbarch
, 8);
1477 set_gdbarch_frameless_function_invocation (gdbarch
,
1478 i386_frameless_function_invocation
);
1479 set_gdbarch_frame_chain (gdbarch
, i386_frame_chain
);
1480 set_gdbarch_frame_chain_valid (gdbarch
, file_frame_chain_valid
);
1481 set_gdbarch_frame_saved_pc (gdbarch
, i386_frame_saved_pc
);
1482 set_gdbarch_frame_args_address (gdbarch
, default_frame_address
);
1483 set_gdbarch_frame_locals_address (gdbarch
, default_frame_address
);
1484 set_gdbarch_saved_pc_after_call (gdbarch
, i386_saved_pc_after_call
);
1485 set_gdbarch_frame_num_args (gdbarch
, i386_frame_num_args
);
1486 set_gdbarch_pc_in_sigtramp (gdbarch
, i386_pc_in_sigtramp
);
1488 /* Hook in ABI-specific overrides, if they have been registered. */
1489 gdbarch_init_osabi (info
, gdbarch
, osabi
);
1494 static enum gdb_osabi
1495 i386_coff_osabi_sniffer (bfd
*abfd
)
1497 if (strcmp (bfd_get_target (abfd
), "coff-go32-exe") == 0
1498 || strcmp (bfd_get_target (abfd
), "coff-go32") == 0)
1499 return GDB_OSABI_GO32
;
1501 return GDB_OSABI_UNKNOWN
;
1504 static enum gdb_osabi
1505 i386_nlm_osabi_sniffer (bfd
*abfd
)
1507 return GDB_OSABI_NETWARE
;
1511 /* Provide a prototype to silence -Wmissing-prototypes. */
1512 void _initialize_i386_tdep (void);
1515 _initialize_i386_tdep (void)
1517 register_gdbarch_init (bfd_arch_i386
, i386_gdbarch_init
);
1519 /* Initialize the table saying where each register starts in the
1525 for (i
= 0; i
< I386_SSE_NUM_REGS
; i
++)
1527 i386_register_offset
[i
] = offset
;
1528 offset
+= i386_register_size
[i
];
1532 tm_print_insn
= gdb_print_insn_i386
;
1533 tm_print_insn_info
.mach
= bfd_lookup_arch (bfd_arch_i386
, 0)->mach
;
1535 /* Add the variable that controls the disassembly flavor. */
1537 struct cmd_list_element
*new_cmd
;
1539 new_cmd
= add_set_enum_cmd ("disassembly-flavor", no_class
,
1541 &disassembly_flavor
,
1543 Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
1544 and the default value is \"att\".",
1546 add_show_from_set (new_cmd
, &showlist
);
1549 /* Add the variable that controls the convention for returning
1552 struct cmd_list_element
*new_cmd
;
1554 new_cmd
= add_set_enum_cmd ("struct-convention", no_class
,
1556 &struct_convention
, "\
1557 Set the convention for returning small structs, valid values \
1558 are \"default\", \"pcc\" and \"reg\", and the default value is \"default\".",
1560 add_show_from_set (new_cmd
, &showlist
);
1563 gdbarch_register_osabi_sniffer (bfd_arch_i386
, bfd_target_coff_flavour
,
1564 i386_coff_osabi_sniffer
);
1565 gdbarch_register_osabi_sniffer (bfd_arch_i386
, bfd_target_nlm_flavour
,
1566 i386_nlm_osabi_sniffer
);
1568 gdbarch_register_osabi (bfd_arch_i386
, GDB_OSABI_SVR4
,
1569 i386_svr4_init_abi
);
1570 gdbarch_register_osabi (bfd_arch_i386
, GDB_OSABI_GO32
,
1571 i386_go32_init_abi
);
1572 gdbarch_register_osabi (bfd_arch_i386
, GDB_OSABI_NETWARE
,