1 /* Intel 386 target-dependent stuff.
2 Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
4 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"
38 #include "gdb_assert.h"
40 /* Names of the registers. The first 10 registers match the register
41 numbering scheme used by GCC for stabs and DWARF. */
42 static char *i386_register_names
[] =
44 "eax", "ecx", "edx", "ebx",
45 "esp", "ebp", "esi", "edi",
46 "eip", "eflags", "cs", "ss",
47 "ds", "es", "fs", "gs",
48 "st0", "st1", "st2", "st3",
49 "st4", "st5", "st6", "st7",
50 "fctrl", "fstat", "ftag", "fiseg",
51 "fioff", "foseg", "fooff", "fop",
52 "xmm0", "xmm1", "xmm2", "xmm3",
53 "xmm4", "xmm5", "xmm6", "xmm7",
57 /* i386_register_offset[i] is the offset into the register file of the
58 start of register number i. We initialize this from
59 i386_register_size. */
60 static int i386_register_offset
[MAX_NUM_REGS
];
62 /* i386_register_size[i] is the number of bytes of storage in GDB's
63 register array occupied by register i. */
64 static int i386_register_size
[MAX_NUM_REGS
] = {
78 /* Return the name of register REG. */
81 i386_register_name (int reg
)
85 if (reg
>= sizeof (i386_register_names
) / sizeof (*i386_register_names
))
88 return i386_register_names
[reg
];
91 /* Return the offset into the register array of the start of register
94 i386_register_byte (int reg
)
96 return i386_register_offset
[reg
];
99 /* Return the number of bytes of storage in GDB's register array
100 occupied by register REG. */
103 i386_register_raw_size (int reg
)
105 return i386_register_size
[reg
];
108 /* Return the size in bytes of the virtual type of register REG. */
111 i386_register_virtual_size (int reg
)
113 return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (reg
));
116 /* Convert stabs register number REG to the appropriate register
117 number used by GDB. */
120 i386_stab_reg_to_regnum (int reg
)
122 /* This implements what GCC calls the "default" register map. */
123 if (reg
>= 0 && reg
<= 7)
125 /* General registers. */
128 else if (reg
>= 12 && reg
<= 19)
130 /* Floating-point registers. */
131 return reg
- 12 + FP0_REGNUM
;
133 else if (reg
>= 21 && reg
<= 28)
136 return reg
- 21 + XMM0_REGNUM
;
138 else if (reg
>= 29 && reg
<= 36)
141 /* FIXME: kettenis/2001-07-28: Should we have the MMX registers
142 as pseudo-registers? */
143 return reg
- 29 + FP0_REGNUM
;
146 /* This will hopefully provoke a warning. */
147 return NUM_REGS
+ NUM_PSEUDO_REGS
;
150 /* Convert Dwarf register number REG to the appropriate register
151 number used by GDB. */
154 i386_dwarf_reg_to_regnum (int reg
)
156 /* The DWARF register numbering includes %eip and %eflags, and
157 numbers the floating point registers differently. */
158 if (reg
>= 0 && reg
<= 9)
160 /* General registers. */
163 else if (reg
>= 11 && reg
<= 18)
165 /* Floating-point registers. */
166 return reg
- 11 + FP0_REGNUM
;
170 /* The SSE and MMX registers have identical numbers as in stabs. */
171 return i386_stab_reg_to_regnum (reg
);
174 /* This will hopefully provoke a warning. */
175 return NUM_REGS
+ NUM_PSEUDO_REGS
;
179 /* This is the variable that is set with "set disassembly-flavor", and
180 its legitimate values. */
181 static const char att_flavor
[] = "att";
182 static const char intel_flavor
[] = "intel";
183 static const char *valid_flavors
[] =
189 static const char *disassembly_flavor
= att_flavor
;
191 /* Stdio style buffering was used to minimize calls to ptrace, but
192 this buffering did not take into account that the code section
193 being accessed may not be an even number of buffers long (even if
194 the buffer is only sizeof(int) long). In cases where the code
195 section size happened to be a non-integral number of buffers long,
196 attempting to read the last buffer would fail. Simply using
197 target_read_memory and ignoring errors, rather than read_memory, is
198 not the correct solution, since legitimate access errors would then
199 be totally ignored. To properly handle this situation and continue
200 to use buffering would require that this code be able to determine
201 the minimum code section size granularity (not the alignment of the
202 section itself, since the actual failing case that pointed out this
203 problem had a section alignment of 4 but was not a multiple of 4
204 bytes long), on a target by target basis, and then adjust it's
205 buffer size accordingly. This is messy, but potentially feasible.
206 It probably needs the bfd library's help and support. For now, the
207 buffer size is set to 1. (FIXME -fnf) */
209 #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */
210 static CORE_ADDR codestream_next_addr
;
211 static CORE_ADDR codestream_addr
;
212 static unsigned char codestream_buf
[CODESTREAM_BUFSIZ
];
213 static int codestream_off
;
214 static int codestream_cnt
;
216 #define codestream_tell() (codestream_addr + codestream_off)
217 #define codestream_peek() \
218 (codestream_cnt == 0 ? \
219 codestream_fill(1) : codestream_buf[codestream_off])
220 #define codestream_get() \
221 (codestream_cnt-- == 0 ? \
222 codestream_fill(0) : codestream_buf[codestream_off++])
225 codestream_fill (int peek_flag
)
227 codestream_addr
= codestream_next_addr
;
228 codestream_next_addr
+= CODESTREAM_BUFSIZ
;
230 codestream_cnt
= CODESTREAM_BUFSIZ
;
231 read_memory (codestream_addr
, (char *) codestream_buf
, CODESTREAM_BUFSIZ
);
234 return (codestream_peek ());
236 return (codestream_get ());
240 codestream_seek (CORE_ADDR place
)
242 codestream_next_addr
= place
/ CODESTREAM_BUFSIZ
;
243 codestream_next_addr
*= CODESTREAM_BUFSIZ
;
246 while (codestream_tell () != place
)
251 codestream_read (unsigned char *buf
, int count
)
256 for (i
= 0; i
< count
; i
++)
257 *p
++ = codestream_get ();
261 /* If the next instruction is a jump, move to its target. */
264 i386_follow_jump (void)
266 unsigned char buf
[4];
272 pos
= codestream_tell ();
275 if (codestream_peek () == 0x66)
281 switch (codestream_get ())
284 /* Relative jump: if data16 == 0, disp32, else disp16. */
287 codestream_read (buf
, 2);
288 delta
= extract_signed_integer (buf
, 2);
290 /* Include the size of the jmp instruction (including the
296 codestream_read (buf
, 4);
297 delta
= extract_signed_integer (buf
, 4);
303 /* Relative jump, disp8 (ignore data16). */
304 codestream_read (buf
, 1);
305 /* Sign-extend it. */
306 delta
= extract_signed_integer (buf
, 1);
311 codestream_seek (pos
);
314 /* Find & return the amount a local space allocated, and advance the
315 codestream to the first register push (if any).
317 If the entry sequence doesn't make sense, return -1, and leave
318 codestream pointer at a random spot. */
321 i386_get_frame_setup (CORE_ADDR pc
)
325 codestream_seek (pc
);
329 op
= codestream_get ();
331 if (op
== 0x58) /* popl %eax */
333 /* This function must start with
336 xchgl %eax, (%esp) 0x87 0x04 0x24
337 or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
339 (the System V compiler puts out the second `xchg'
340 instruction, and the assembler doesn't try to optimize it, so
341 the 'sib' form gets generated). This sequence is used to get
342 the address of the return buffer for a function that returns
345 unsigned char buf
[4];
346 static unsigned char proto1
[3] = { 0x87, 0x04, 0x24 };
347 static unsigned char proto2
[4] = { 0x87, 0x44, 0x24, 0x00 };
349 pos
= codestream_tell ();
350 codestream_read (buf
, 4);
351 if (memcmp (buf
, proto1
, 3) == 0)
353 else if (memcmp (buf
, proto2
, 4) == 0)
356 codestream_seek (pos
);
357 op
= codestream_get (); /* Update next opcode. */
360 if (op
== 0x68 || op
== 0x6a)
362 /* This function may start with
374 unsigned char buf
[8];
376 /* Skip past the `pushl' instruction; it has either a one-byte
377 or a four-byte operand, depending on the opcode. */
378 pos
= codestream_tell ();
383 codestream_seek (pos
);
385 /* Read the following 8 bytes, which should be "call _probe" (6
386 bytes) followed by "addl $4,%esp" (2 bytes). */
387 codestream_read (buf
, sizeof (buf
));
388 if (buf
[0] == 0xe8 && buf
[6] == 0xc4 && buf
[7] == 0x4)
390 codestream_seek (pos
);
391 op
= codestream_get (); /* Update next opcode. */
394 if (op
== 0x55) /* pushl %ebp */
396 /* Check for "movl %esp, %ebp" -- can be written in two ways. */
397 switch (codestream_get ())
400 if (codestream_get () != 0xec)
404 if (codestream_get () != 0xe5)
410 /* Check for stack adjustment
414 NOTE: You can't subtract a 16 bit immediate from a 32 bit
415 reg, so we don't have to worry about a data16 prefix. */
416 op
= codestream_peek ();
419 /* `subl' with 8 bit immediate. */
421 if (codestream_get () != 0xec)
422 /* Some instruction starting with 0x83 other than `subl'. */
424 codestream_seek (codestream_tell () - 2);
427 /* `subl' with signed byte immediate (though it wouldn't
428 make sense to be negative). */
429 return (codestream_get ());
434 /* Maybe it is `subl' with a 32 bit immedediate. */
436 if (codestream_get () != 0xec)
437 /* Some instruction starting with 0x81 other than `subl'. */
439 codestream_seek (codestream_tell () - 2);
442 /* It is `subl' with a 32 bit immediate. */
443 codestream_read ((unsigned char *) buf
, 4);
444 return extract_signed_integer (buf
, 4);
454 /* `enter' with 16 bit unsigned immediate. */
455 codestream_read ((unsigned char *) buf
, 2);
456 codestream_get (); /* Flush final byte of enter instruction. */
457 return extract_unsigned_integer (buf
, 2);
462 /* Return the chain-pointer for FRAME. In the case of the i386, the
463 frame's nominal address is the address of a 4-byte word containing
464 the calling frame's address. */
467 i386_frame_chain (struct frame_info
*frame
)
469 if (frame
->signal_handler_caller
)
472 if (! inside_entry_file (frame
->pc
))
473 return read_memory_unsigned_integer (frame
->frame
, 4);
478 /* Determine whether the function invocation represented by FRAME does
479 not have a from on the stack associated with it. If it does not,
480 return non-zero, otherwise return zero. */
483 i386_frameless_function_invocation (struct frame_info
*frame
)
485 if (frame
->signal_handler_caller
)
488 return frameless_look_for_prologue (frame
);
491 /* Return the saved program counter for FRAME. */
494 i386_frame_saved_pc (struct frame_info
*frame
)
496 /* FIXME: kettenis/2001-05-09: Conditionalizing the next bit of code
497 on SIGCONTEXT_PC_OFFSET and I386V4_SIGTRAMP_SAVED_PC should be
498 considered a temporary hack. I plan to come up with something
499 better when we go multi-arch. */
500 #if defined (SIGCONTEXT_PC_OFFSET) || defined (I386V4_SIGTRAMP_SAVED_PC)
501 if (frame
->signal_handler_caller
)
502 return sigtramp_saved_pc (frame
);
505 return read_memory_unsigned_integer (frame
->frame
+ 4, 4);
508 /* Immediately after a function call, return the saved pc. */
511 i386_saved_pc_after_call (struct frame_info
*frame
)
513 return read_memory_unsigned_integer (read_register (SP_REGNUM
), 4);
516 /* Return number of args passed to a frame.
517 Can return -1, meaning no way to tell. */
520 i386_frame_num_args (struct frame_info
*fi
)
525 /* This loses because not only might the compiler not be popping the
526 args right after the function call, it might be popping args from
527 both this call and a previous one, and we would say there are
528 more args than there really are. */
532 struct frame_info
*pfi
;
534 /* On the i386, the instruction following the call could be:
536 addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
537 anything else - zero args. */
541 frameless
= FRAMELESS_FUNCTION_INVOCATION (fi
);
543 /* In the absence of a frame pointer, GDB doesn't get correct
544 values for nameless arguments. Return -1, so it doesn't print
545 any nameless arguments. */
548 pfi
= get_prev_frame (fi
);
551 /* NOTE: This can happen if we are looking at the frame for
552 main, because FRAME_CHAIN_VALID won't let us go into start.
553 If we have debugging symbols, that's not really a big deal;
554 it just means it will only show as many arguments to main as
561 op
= read_memory_integer (retpc
, 1);
562 if (op
== 0x59) /* pop %ecx */
566 op
= read_memory_integer (retpc
+ 1, 1);
568 /* addl $<signed imm 8 bits>, %esp */
569 return (read_memory_integer (retpc
+ 2, 1) & 0xff) / 4;
573 else if (op
== 0x81) /* `add' with 32 bit immediate. */
575 op
= read_memory_integer (retpc
+ 1, 1);
577 /* addl $<imm 32>, %esp */
578 return read_memory_integer (retpc
+ 2, 4) / 4;
590 /* Parse the first few instructions the function to see what registers
593 We handle these cases:
595 The startup sequence can be at the start of the function, or the
596 function can start with a branch to startup code at the end.
598 %ebp can be set up with either the 'enter' instruction, or "pushl
599 %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was
600 once used in the System V compiler).
602 Local space is allocated just below the saved %ebp by either the
603 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a 16
604 bit unsigned argument for space to allocate, and the 'addl'
605 instruction could have either a signed byte, or 32 bit immediate.
607 Next, the registers used by this function are pushed. With the
608 System V compiler they will always be in the order: %edi, %esi,
609 %ebx (and sometimes a harmless bug causes it to also save but not
610 restore %eax); however, the code below is willing to see the pushes
611 in any order, and will handle up to 8 of them.
613 If the setup sequence is at the end of the function, then the next
614 instruction will be a branch back to the start. */
617 i386_frame_init_saved_regs (struct frame_info
*fip
)
621 CORE_ADDR dummy_bottom
;
629 frame_saved_regs_zalloc (fip
);
631 /* If the frame is the end of a dummy, compute where the beginning
633 dummy_bottom
= fip
->frame
- 4 - REGISTER_BYTES
- CALL_DUMMY_LENGTH
;
635 /* Check if the PC points in the stack, in a dummy frame. */
636 if (dummy_bottom
<= fip
->pc
&& fip
->pc
<= fip
->frame
)
638 /* All registers were saved by push_call_dummy. */
640 for (i
= 0; i
< NUM_REGS
; i
++)
642 addr
-= REGISTER_RAW_SIZE (i
);
643 fip
->saved_regs
[i
] = addr
;
648 pc
= get_pc_function_start (fip
->pc
);
650 locals
= i386_get_frame_setup (pc
);
654 addr
= fip
->frame
- 4 - locals
;
655 for (i
= 0; i
< 8; i
++)
657 op
= codestream_get ();
658 if (op
< 0x50 || op
> 0x57)
660 #ifdef I386_REGNO_TO_SYMMETRY
661 /* Dynix uses different internal numbering. Ick. */
662 fip
->saved_regs
[I386_REGNO_TO_SYMMETRY (op
- 0x50)] = addr
;
664 fip
->saved_regs
[op
- 0x50] = addr
;
670 fip
->saved_regs
[PC_REGNUM
] = fip
->frame
+ 4;
671 fip
->saved_regs
[FP_REGNUM
] = fip
->frame
;
674 /* Return PC of first real instruction. */
677 i386_skip_prologue (int pc
)
681 static unsigned char pic_pat
[6] =
682 { 0xe8, 0, 0, 0, 0, /* call 0x0 */
683 0x5b, /* popl %ebx */
687 if (i386_get_frame_setup (pc
) < 0)
690 /* Found valid frame setup -- codestream now points to start of push
691 instructions for saving registers. */
693 /* Skip over register saves. */
694 for (i
= 0; i
< 8; i
++)
696 op
= codestream_peek ();
697 /* Break if not `pushl' instrunction. */
698 if (op
< 0x50 || op
> 0x57)
703 /* The native cc on SVR4 in -K PIC mode inserts the following code
704 to get the address of the global offset table (GOT) into register
709 movl %ebx,x(%ebp) (optional)
712 This code is with the rest of the prologue (at the end of the
713 function), so we have to skip it to get to the first real
714 instruction at the start of the function. */
716 pos
= codestream_tell ();
717 for (i
= 0; i
< 6; i
++)
719 op
= codestream_get ();
720 if (pic_pat
[i
] != op
)
725 unsigned char buf
[4];
728 op
= codestream_get ();
729 if (op
== 0x89) /* movl %ebx, x(%ebp) */
731 op
= codestream_get ();
732 if (op
== 0x5d) /* One byte offset from %ebp. */
735 codestream_read (buf
, 1);
737 else if (op
== 0x9d) /* Four byte offset from %ebp. */
740 codestream_read (buf
, 4);
742 else /* Unexpected instruction. */
744 op
= codestream_get ();
747 if (delta
> 0 && op
== 0x81 && codestream_get () == 0xc3)
752 codestream_seek (pos
);
756 return (codestream_tell ());
760 i386_push_dummy_frame (void)
762 CORE_ADDR sp
= read_register (SP_REGNUM
);
764 char regbuf
[MAX_REGISTER_RAW_SIZE
];
766 sp
= push_word (sp
, read_register (PC_REGNUM
));
767 sp
= push_word (sp
, read_register (FP_REGNUM
));
768 write_register (FP_REGNUM
, sp
);
769 for (regnum
= 0; regnum
< NUM_REGS
; regnum
++)
771 read_register_gen (regnum
, regbuf
);
772 sp
= push_bytes (sp
, regbuf
, REGISTER_RAW_SIZE (regnum
));
774 write_register (SP_REGNUM
, sp
);
777 /* Insert the (relative) function address into the call sequence
781 i386_fix_call_dummy (char *dummy
, CORE_ADDR pc
, CORE_ADDR fun
, int nargs
,
782 struct value
**args
, struct type
*type
, int gcc_p
)
784 int from
, to
, delta
, loc
;
786 loc
= (int)(read_register (SP_REGNUM
) - CALL_DUMMY_LENGTH
);
791 *((char *)(dummy
) + 1) = (delta
& 0xff);
792 *((char *)(dummy
) + 2) = ((delta
>> 8) & 0xff);
793 *((char *)(dummy
) + 3) = ((delta
>> 16) & 0xff);
794 *((char *)(dummy
) + 4) = ((delta
>> 24) & 0xff);
798 i386_pop_frame (void)
800 struct frame_info
*frame
= get_current_frame ();
803 char regbuf
[MAX_REGISTER_RAW_SIZE
];
805 fp
= FRAME_FP (frame
);
806 i386_frame_init_saved_regs (frame
);
808 for (regnum
= 0; regnum
< NUM_REGS
; regnum
++)
811 addr
= frame
->saved_regs
[regnum
];
814 read_memory (addr
, regbuf
, REGISTER_RAW_SIZE (regnum
));
815 write_register_bytes (REGISTER_BYTE (regnum
), regbuf
,
816 REGISTER_RAW_SIZE (regnum
));
819 write_register (FP_REGNUM
, read_memory_integer (fp
, 4));
820 write_register (PC_REGNUM
, read_memory_integer (fp
+ 4, 4));
821 write_register (SP_REGNUM
, fp
+ 8);
822 flush_cached_frames ();
826 #ifdef GET_LONGJMP_TARGET
828 /* Figure out where the longjmp will land. Slurp the args out of the
829 stack. We expect the first arg to be a pointer to the jmp_buf
830 structure from which we extract the pc (JB_PC) that we will land
831 at. The pc is copied into PC. This routine returns true on
835 get_longjmp_target (CORE_ADDR
*pc
)
837 char buf
[TARGET_PTR_BIT
/ TARGET_CHAR_BIT
];
838 CORE_ADDR sp
, jb_addr
;
840 sp
= read_register (SP_REGNUM
);
842 if (target_read_memory (sp
+ SP_ARG0
, /* Offset of first arg on stack. */
844 TARGET_PTR_BIT
/ TARGET_CHAR_BIT
))
847 jb_addr
= extract_address (buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
849 if (target_read_memory (jb_addr
+ JB_PC
* JB_ELEMENT_SIZE
, buf
,
850 TARGET_PTR_BIT
/ TARGET_CHAR_BIT
))
853 *pc
= extract_address (buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
858 #endif /* GET_LONGJMP_TARGET */
862 i386_push_arguments (int nargs
, struct value
**args
, CORE_ADDR sp
,
863 int struct_return
, CORE_ADDR struct_addr
)
865 sp
= default_push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
);
872 store_address (buf
, 4, struct_addr
);
873 write_memory (sp
, buf
, 4);
880 i386_store_struct_return (CORE_ADDR addr
, CORE_ADDR sp
)
882 /* Do nothing. Everything was already done by i386_push_arguments. */
885 /* These registers are used for returning integers (and on some
886 targets also for returning `struct' and `union' values when their
887 size and alignment match an integer type). */
888 #define LOW_RETURN_REGNUM 0 /* %eax */
889 #define HIGH_RETURN_REGNUM 2 /* %edx */
891 /* Extract from an array REGBUF containing the (raw) register state, a
892 function return value of TYPE, and copy that, in virtual format,
896 i386_extract_return_value (struct type
*type
, char *regbuf
, char *valbuf
)
898 int len
= TYPE_LENGTH (type
);
900 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
901 && TYPE_NFIELDS (type
) == 1)
903 i386_extract_return_value (TYPE_FIELD_TYPE (type
, 0), regbuf
, valbuf
);
907 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
911 warning ("Cannot find floating-point return value.");
912 memset (valbuf
, 0, len
);
916 /* Floating-point return values can be found in %st(0). Convert
917 its contents to the desired type. This is probably not
918 exactly how it would happen on the target itself, but it is
919 the best we can do. */
920 convert_typed_floating (®buf
[REGISTER_BYTE (FP0_REGNUM
)],
921 builtin_type_i387_ext
, valbuf
, type
);
925 int low_size
= REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
);
926 int high_size
= REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM
);
929 memcpy (valbuf
, ®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)], len
);
930 else if (len
<= (low_size
+ high_size
))
933 ®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)], low_size
);
934 memcpy (valbuf
+ low_size
,
935 ®buf
[REGISTER_BYTE (HIGH_RETURN_REGNUM
)], len
- low_size
);
938 internal_error (__FILE__
, __LINE__
,
939 "Cannot extract return value of %d bytes long.", len
);
943 /* Write into the appropriate registers a function return value stored
944 in VALBUF of type TYPE, given in virtual format. */
947 i386_store_return_value (struct type
*type
, char *valbuf
)
949 int len
= TYPE_LENGTH (type
);
951 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
952 && TYPE_NFIELDS (type
) == 1)
954 i386_store_return_value (TYPE_FIELD_TYPE (type
, 0), valbuf
);
958 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
961 char buf
[FPU_REG_RAW_SIZE
];
965 warning ("Cannot set floating-point return value.");
969 /* Returning floating-point values is a bit tricky. Apart from
970 storing the return value in %st(0), we have to simulate the
971 state of the FPU at function return point. */
973 /* Convert the value found in VALBUF to the extended
974 floating-point format used by the FPU. This is probably
975 not exactly how it would happen on the target itself, but
976 it is the best we can do. */
977 convert_typed_floating (valbuf
, type
, buf
, builtin_type_i387_ext
);
978 write_register_bytes (REGISTER_BYTE (FP0_REGNUM
), buf
,
981 /* Set the top of the floating-point register stack to 7. The
982 actual value doesn't really matter, but 7 is what a normal
983 function return would end up with if the program started out
984 with a freshly initialized FPU. */
985 fstat
= read_register (FSTAT_REGNUM
);
987 write_register (FSTAT_REGNUM
, fstat
);
989 /* Mark %st(1) through %st(7) as empty. Since we set the top of
990 the floating-point register stack to 7, the appropriate value
991 for the tag word is 0x3fff. */
992 write_register (FTAG_REGNUM
, 0x3fff);
996 int low_size
= REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
);
997 int high_size
= REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM
);
1000 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM
), valbuf
, len
);
1001 else if (len
<= (low_size
+ high_size
))
1003 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM
),
1005 write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM
),
1006 valbuf
+ low_size
, len
- low_size
);
1009 internal_error (__FILE__
, __LINE__
,
1010 "Cannot store return value of %d bytes long.", len
);
1014 /* Extract from an array REGBUF containing the (raw) register state
1015 the address in which a function should return its structure value,
1019 i386_extract_struct_value_address (char *regbuf
)
1021 return extract_address (®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)],
1022 REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
));
1026 /* Return the GDB type object for the "standard" data type of data in
1027 register REGNUM. Perhaps %esi and %edi should go here, but
1028 potentially they could be used for things other than address. */
1031 i386_register_virtual_type (int regnum
)
1033 if (regnum
== PC_REGNUM
|| regnum
== FP_REGNUM
|| regnum
== SP_REGNUM
)
1034 return lookup_pointer_type (builtin_type_void
);
1036 if (IS_FP_REGNUM (regnum
))
1037 return builtin_type_i387_ext
;
1039 if (IS_SSE_REGNUM (regnum
))
1040 return builtin_type_v4sf
;
1042 return builtin_type_int
;
1045 /* Return true iff register REGNUM's virtual format is different from
1046 its raw format. Note that this definition assumes that the host
1047 supports IEEE 32-bit floats, since it doesn't say that SSE
1048 registers need conversion. Even if we can't find a counterexample,
1049 this is still sloppy. */
1052 i386_register_convertible (int regnum
)
1054 return IS_FP_REGNUM (regnum
);
1057 /* Convert data from raw format for register REGNUM in buffer FROM to
1058 virtual format with type TYPE in buffer TO. */
1061 i386_register_convert_to_virtual (int regnum
, struct type
*type
,
1062 char *from
, char *to
)
1064 gdb_assert (IS_FP_REGNUM (regnum
));
1066 /* We only support floating-point values. */
1067 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
1069 warning ("Cannot convert floating-point register value "
1070 "to non-floating-point type.");
1071 memset (to
, 0, TYPE_LENGTH (type
));
1075 /* Convert to TYPE. This should be a no-op if TYPE is equivalent to
1076 the extended floating-point format used by the FPU. */
1077 convert_typed_floating (from
, builtin_type_i387_ext
, to
, type
);
1080 /* Convert data from virtual format with type TYPE in buffer FROM to
1081 raw format for register REGNUM in buffer TO. */
1084 i386_register_convert_to_raw (struct type
*type
, int regnum
,
1085 char *from
, char *to
)
1087 gdb_assert (IS_FP_REGNUM (regnum
));
1089 /* We only support floating-point values. */
1090 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
1092 warning ("Cannot convert non-floating-point type "
1093 "to floating-point register value.");
1094 memset (to
, 0, TYPE_LENGTH (type
));
1098 /* Convert from TYPE. This should be a no-op if TYPE is equivalent
1099 to the extended floating-point format used by the FPU. */
1100 convert_typed_floating (from
, type
, to
, builtin_type_i387_ext
);
1104 #ifdef I386V4_SIGTRAMP_SAVED_PC
1105 /* Get saved user PC for sigtramp from the pushed ucontext on the
1106 stack for all three variants of SVR4 sigtramps. */
1109 i386v4_sigtramp_saved_pc (struct frame_info
*frame
)
1111 CORE_ADDR saved_pc_offset
= 4;
1114 find_pc_partial_function (frame
->pc
, &name
, NULL
, NULL
);
1117 if (STREQ (name
, "_sigreturn"))
1118 saved_pc_offset
= 132 + 14 * 4;
1119 else if (STREQ (name
, "_sigacthandler"))
1120 saved_pc_offset
= 80 + 14 * 4;
1121 else if (STREQ (name
, "sigvechandler"))
1122 saved_pc_offset
= 120 + 14 * 4;
1126 return read_memory_integer (frame
->next
->frame
+ saved_pc_offset
, 4);
1127 return read_memory_integer (read_register (SP_REGNUM
) + saved_pc_offset
, 4);
1129 #endif /* I386V4_SIGTRAMP_SAVED_PC */
1132 #ifdef STATIC_TRANSFORM_NAME
1133 /* SunPRO encodes the static variables. This is not related to C++
1134 mangling, it is done for C too. */
1137 sunpro_static_transform_name (char *name
)
1140 if (IS_STATIC_TRANSFORM_NAME (name
))
1142 /* For file-local statics there will be a period, a bunch of
1143 junk (the contents of which match a string given in the
1144 N_OPT), a period and the name. For function-local statics
1145 there will be a bunch of junk (which seems to change the
1146 second character from 'A' to 'B'), a period, the name of the
1147 function, and the name. So just skip everything before the
1149 p
= strrchr (name
, '.');
1155 #endif /* STATIC_TRANSFORM_NAME */
1158 /* Stuff for WIN32 PE style DLL's but is pretty generic really. */
1161 skip_trampoline_code (CORE_ADDR pc
, char *name
)
1163 if (pc
&& read_memory_unsigned_integer (pc
, 2) == 0x25ff) /* jmp *(dest) */
1165 unsigned long indirect
= read_memory_unsigned_integer (pc
+ 2, 4);
1166 struct minimal_symbol
*indsym
=
1167 indirect
? lookup_minimal_symbol_by_pc (indirect
) : 0;
1168 char *symname
= indsym
? SYMBOL_NAME (indsym
) : 0;
1172 if (strncmp (symname
, "__imp_", 6) == 0
1173 || strncmp (symname
, "_imp_", 5) == 0)
1174 return name
? 1 : read_memory_unsigned_integer (indirect
, 4);
1177 return 0; /* Not a trampoline. */
1181 /* We have two flavours of disassembly. The machinery on this page
1182 deals with switching between those. */
1185 gdb_print_insn_i386 (bfd_vma memaddr
, disassemble_info
*info
)
1187 if (disassembly_flavor
== att_flavor
)
1188 return print_insn_i386_att (memaddr
, info
);
1189 else if (disassembly_flavor
== intel_flavor
)
1190 return print_insn_i386_intel (memaddr
, info
);
1191 /* Never reached -- disassembly_flavour is always either att_flavor
1193 internal_error (__FILE__
, __LINE__
, "failed internal consistency check");
1198 /* Provide a prototype to silence -Wmissing-prototypes. */
1199 void _initialize_i386_tdep (void);
1202 _initialize_i386_tdep (void)
1204 /* Initialize the table saying where each register starts in the
1210 for (i
= 0; i
< MAX_NUM_REGS
; i
++)
1212 i386_register_offset
[i
] = offset
;
1213 offset
+= i386_register_size
[i
];
1217 tm_print_insn
= gdb_print_insn_i386
;
1218 tm_print_insn_info
.mach
= bfd_lookup_arch (bfd_arch_i386
, 0)->mach
;
1220 /* Add the variable that controls the disassembly flavor. */
1222 struct cmd_list_element
*new_cmd
;
1224 new_cmd
= add_set_enum_cmd ("disassembly-flavor", no_class
,
1226 &disassembly_flavor
,
1228 Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
1229 and the default value is \"att\".",
1231 add_show_from_set (new_cmd
, &showlist
);