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_byte[i] is the offset into the register file of the
58 start of register number i. We initialize this from
59 i386_register_raw_size. */
60 int i386_register_byte
[MAX_NUM_REGS
];
62 /* i386_register_raw_size[i] is the number of bytes of storage in
63 GDB's register array occupied by register i. */
64 int i386_register_raw_size
[MAX_NUM_REGS
] = {
78 /* i386_register_virtual_size[i] is the size in bytes of the virtual
79 type of register i. */
80 int i386_register_virtual_size
[MAX_NUM_REGS
];
82 /* Return the name of register REG. */
85 i386_register_name (int reg
)
89 if (reg
>= sizeof (i386_register_names
) / sizeof (*i386_register_names
))
92 return i386_register_names
[reg
];
95 /* Convert stabs register number REG to the appropriate register
96 number used by GDB. */
99 i386_stab_reg_to_regnum (int reg
)
101 /* This implements what GCC calls the "default" register map. */
102 if (reg
>= 0 && reg
<= 7)
104 /* General registers. */
107 else if (reg
>= 12 && reg
<= 19)
109 /* Floating-point registers. */
110 return reg
- 12 + FP0_REGNUM
;
112 else if (reg
>= 21 && reg
<= 28)
115 return reg
- 21 + XMM0_REGNUM
;
117 else if (reg
>= 29 && reg
<= 36)
120 /* FIXME: kettenis/2001-07-28: Should we have the MMX registers
121 as pseudo-registers? */
122 return reg
- 29 + FP0_REGNUM
;
125 /* This will hopefully provoke a warning. */
126 return NUM_REGS
+ NUM_PSEUDO_REGS
;
129 /* Convert Dwarf register number REG to the appropriate register
130 number used by GDB. */
133 i386_dwarf_reg_to_regnum (int reg
)
135 /* The DWARF register numbering includes %eip and %eflags, and
136 numbers the floating point registers differently. */
137 if (reg
>= 0 && reg
<= 9)
139 /* General registers. */
142 else if (reg
>= 11 && reg
<= 18)
144 /* Floating-point registers. */
145 return reg
- 11 + FP0_REGNUM
;
149 /* The SSE and MMX registers have identical numbers as in stabs. */
150 return i386_stab_reg_to_regnum (reg
);
153 /* This will hopefully provoke a warning. */
154 return NUM_REGS
+ NUM_PSEUDO_REGS
;
158 /* This is the variable that is set with "set disassembly-flavor", and
159 its legitimate values. */
160 static const char att_flavor
[] = "att";
161 static const char intel_flavor
[] = "intel";
162 static const char *valid_flavors
[] =
168 static const char *disassembly_flavor
= att_flavor
;
170 /* This is used to keep the bfd arch_info in sync with the disassembly
172 static void set_disassembly_flavor_sfunc (char *, int,
173 struct cmd_list_element
*);
174 static void set_disassembly_flavor (void);
177 /* Stdio style buffering was used to minimize calls to ptrace, but
178 this buffering did not take into account that the code section
179 being accessed may not be an even number of buffers long (even if
180 the buffer is only sizeof(int) long). In cases where the code
181 section size happened to be a non-integral number of buffers long,
182 attempting to read the last buffer would fail. Simply using
183 target_read_memory and ignoring errors, rather than read_memory, is
184 not the correct solution, since legitimate access errors would then
185 be totally ignored. To properly handle this situation and continue
186 to use buffering would require that this code be able to determine
187 the minimum code section size granularity (not the alignment of the
188 section itself, since the actual failing case that pointed out this
189 problem had a section alignment of 4 but was not a multiple of 4
190 bytes long), on a target by target basis, and then adjust it's
191 buffer size accordingly. This is messy, but potentially feasible.
192 It probably needs the bfd library's help and support. For now, the
193 buffer size is set to 1. (FIXME -fnf) */
195 #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */
196 static CORE_ADDR codestream_next_addr
;
197 static CORE_ADDR codestream_addr
;
198 static unsigned char codestream_buf
[CODESTREAM_BUFSIZ
];
199 static int codestream_off
;
200 static int codestream_cnt
;
202 #define codestream_tell() (codestream_addr + codestream_off)
203 #define codestream_peek() \
204 (codestream_cnt == 0 ? \
205 codestream_fill(1) : codestream_buf[codestream_off])
206 #define codestream_get() \
207 (codestream_cnt-- == 0 ? \
208 codestream_fill(0) : codestream_buf[codestream_off++])
211 codestream_fill (int peek_flag
)
213 codestream_addr
= codestream_next_addr
;
214 codestream_next_addr
+= CODESTREAM_BUFSIZ
;
216 codestream_cnt
= CODESTREAM_BUFSIZ
;
217 read_memory (codestream_addr
, (char *) codestream_buf
, CODESTREAM_BUFSIZ
);
220 return (codestream_peek ());
222 return (codestream_get ());
226 codestream_seek (CORE_ADDR place
)
228 codestream_next_addr
= place
/ CODESTREAM_BUFSIZ
;
229 codestream_next_addr
*= CODESTREAM_BUFSIZ
;
232 while (codestream_tell () != place
)
237 codestream_read (unsigned char *buf
, int count
)
242 for (i
= 0; i
< count
; i
++)
243 *p
++ = codestream_get ();
247 /* If the next instruction is a jump, move to its target. */
250 i386_follow_jump (void)
252 unsigned char buf
[4];
258 pos
= codestream_tell ();
261 if (codestream_peek () == 0x66)
267 switch (codestream_get ())
270 /* Relative jump: if data16 == 0, disp32, else disp16. */
273 codestream_read (buf
, 2);
274 delta
= extract_signed_integer (buf
, 2);
276 /* Include the size of the jmp instruction (including the
282 codestream_read (buf
, 4);
283 delta
= extract_signed_integer (buf
, 4);
289 /* Relative jump, disp8 (ignore data16). */
290 codestream_read (buf
, 1);
291 /* Sign-extend it. */
292 delta
= extract_signed_integer (buf
, 1);
297 codestream_seek (pos
);
300 /* Find & return the amount a local space allocated, and advance the
301 codestream to the first register push (if any).
303 If the entry sequence doesn't make sense, return -1, and leave
304 codestream pointer at a random spot. */
307 i386_get_frame_setup (CORE_ADDR pc
)
311 codestream_seek (pc
);
315 op
= codestream_get ();
317 if (op
== 0x58) /* popl %eax */
319 /* This function must start with
322 xchgl %eax, (%esp) 0x87 0x04 0x24
323 or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
325 (the System V compiler puts out the second `xchg'
326 instruction, and the assembler doesn't try to optimize it, so
327 the 'sib' form gets generated). This sequence is used to get
328 the address of the return buffer for a function that returns
331 unsigned char buf
[4];
332 static unsigned char proto1
[3] = { 0x87, 0x04, 0x24 };
333 static unsigned char proto2
[4] = { 0x87, 0x44, 0x24, 0x00 };
335 pos
= codestream_tell ();
336 codestream_read (buf
, 4);
337 if (memcmp (buf
, proto1
, 3) == 0)
339 else if (memcmp (buf
, proto2
, 4) == 0)
342 codestream_seek (pos
);
343 op
= codestream_get (); /* Update next opcode. */
346 if (op
== 0x68 || op
== 0x6a)
348 /* This function may start with
360 unsigned char buf
[8];
362 /* Skip past the `pushl' instruction; it has either a one-byte
363 or a four-byte operand, depending on the opcode. */
364 pos
= codestream_tell ();
369 codestream_seek (pos
);
371 /* Read the following 8 bytes, which should be "call _probe" (6
372 bytes) followed by "addl $4,%esp" (2 bytes). */
373 codestream_read (buf
, sizeof (buf
));
374 if (buf
[0] == 0xe8 && buf
[6] == 0xc4 && buf
[7] == 0x4)
376 codestream_seek (pos
);
377 op
= codestream_get (); /* Update next opcode. */
380 if (op
== 0x55) /* pushl %ebp */
382 /* Check for "movl %esp, %ebp" -- can be written in two ways. */
383 switch (codestream_get ())
386 if (codestream_get () != 0xec)
390 if (codestream_get () != 0xe5)
396 /* Check for stack adjustment
400 NOTE: You can't subtract a 16 bit immediate from a 32 bit
401 reg, so we don't have to worry about a data16 prefix. */
402 op
= codestream_peek ();
405 /* `subl' with 8 bit immediate. */
407 if (codestream_get () != 0xec)
408 /* Some instruction starting with 0x83 other than `subl'. */
410 codestream_seek (codestream_tell () - 2);
413 /* `subl' with signed byte immediate (though it wouldn't
414 make sense to be negative). */
415 return (codestream_get ());
420 /* Maybe it is `subl' with a 32 bit immedediate. */
422 if (codestream_get () != 0xec)
423 /* Some instruction starting with 0x81 other than `subl'. */
425 codestream_seek (codestream_tell () - 2);
428 /* It is `subl' with a 32 bit immediate. */
429 codestream_read ((unsigned char *) buf
, 4);
430 return extract_signed_integer (buf
, 4);
440 /* `enter' with 16 bit unsigned immediate. */
441 codestream_read ((unsigned char *) buf
, 2);
442 codestream_get (); /* Flush final byte of enter instruction. */
443 return extract_unsigned_integer (buf
, 2);
448 /* Return the chain-pointer for FRAME. In the case of the i386, the
449 frame's nominal address is the address of a 4-byte word containing
450 the calling frame's address. */
453 i386_frame_chain (struct frame_info
*frame
)
455 if (frame
->signal_handler_caller
)
458 if (! inside_entry_file (frame
->pc
))
459 return read_memory_unsigned_integer (frame
->frame
, 4);
464 /* Determine whether the function invocation represented by FRAME does
465 not have a from on the stack associated with it. If it does not,
466 return non-zero, otherwise return zero. */
469 i386_frameless_function_invocation (struct frame_info
*frame
)
471 if (frame
->signal_handler_caller
)
474 return frameless_look_for_prologue (frame
);
477 /* Return the saved program counter for FRAME. */
480 i386_frame_saved_pc (struct frame_info
*frame
)
482 /* FIXME: kettenis/2001-05-09: Conditionalizing the next bit of code
483 on SIGCONTEXT_PC_OFFSET and I386V4_SIGTRAMP_SAVED_PC should be
484 considered a temporary hack. I plan to come up with something
485 better when we go multi-arch. */
486 #if defined (SIGCONTEXT_PC_OFFSET) || defined (I386V4_SIGTRAMP_SAVED_PC)
487 if (frame
->signal_handler_caller
)
488 return sigtramp_saved_pc (frame
);
491 return read_memory_unsigned_integer (frame
->frame
+ 4, 4);
494 /* Immediately after a function call, return the saved pc. */
497 i386_saved_pc_after_call (struct frame_info
*frame
)
499 return read_memory_unsigned_integer (read_register (SP_REGNUM
), 4);
502 /* Return number of args passed to a frame.
503 Can return -1, meaning no way to tell. */
506 i386_frame_num_args (struct frame_info
*fi
)
511 /* This loses because not only might the compiler not be popping the
512 args right after the function call, it might be popping args from
513 both this call and a previous one, and we would say there are
514 more args than there really are. */
518 struct frame_info
*pfi
;
520 /* On the i386, the instruction following the call could be:
522 addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
523 anything else - zero args. */
527 frameless
= FRAMELESS_FUNCTION_INVOCATION (fi
);
529 /* In the absence of a frame pointer, GDB doesn't get correct
530 values for nameless arguments. Return -1, so it doesn't print
531 any nameless arguments. */
534 pfi
= get_prev_frame (fi
);
537 /* NOTE: This can happen if we are looking at the frame for
538 main, because FRAME_CHAIN_VALID won't let us go into start.
539 If we have debugging symbols, that's not really a big deal;
540 it just means it will only show as many arguments to main as
547 op
= read_memory_integer (retpc
, 1);
548 if (op
== 0x59) /* pop %ecx */
552 op
= read_memory_integer (retpc
+ 1, 1);
554 /* addl $<signed imm 8 bits>, %esp */
555 return (read_memory_integer (retpc
+ 2, 1) & 0xff) / 4;
559 else if (op
== 0x81) /* `add' with 32 bit immediate. */
561 op
= read_memory_integer (retpc
+ 1, 1);
563 /* addl $<imm 32>, %esp */
564 return read_memory_integer (retpc
+ 2, 4) / 4;
576 /* Parse the first few instructions the function to see what registers
579 We handle these cases:
581 The startup sequence can be at the start of the function, or the
582 function can start with a branch to startup code at the end.
584 %ebp can be set up with either the 'enter' instruction, or "pushl
585 %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was
586 once used in the System V compiler).
588 Local space is allocated just below the saved %ebp by either the
589 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a 16
590 bit unsigned argument for space to allocate, and the 'addl'
591 instruction could have either a signed byte, or 32 bit immediate.
593 Next, the registers used by this function are pushed. With the
594 System V compiler they will always be in the order: %edi, %esi,
595 %ebx (and sometimes a harmless bug causes it to also save but not
596 restore %eax); however, the code below is willing to see the pushes
597 in any order, and will handle up to 8 of them.
599 If the setup sequence is at the end of the function, then the next
600 instruction will be a branch back to the start. */
603 i386_frame_init_saved_regs (struct frame_info
*fip
)
607 CORE_ADDR dummy_bottom
;
615 frame_saved_regs_zalloc (fip
);
617 /* If the frame is the end of a dummy, compute where the beginning
619 dummy_bottom
= fip
->frame
- 4 - REGISTER_BYTES
- CALL_DUMMY_LENGTH
;
621 /* Check if the PC points in the stack, in a dummy frame. */
622 if (dummy_bottom
<= fip
->pc
&& fip
->pc
<= fip
->frame
)
624 /* All registers were saved by push_call_dummy. */
626 for (i
= 0; i
< NUM_REGS
; i
++)
628 addr
-= REGISTER_RAW_SIZE (i
);
629 fip
->saved_regs
[i
] = addr
;
634 pc
= get_pc_function_start (fip
->pc
);
636 locals
= i386_get_frame_setup (pc
);
640 addr
= fip
->frame
- 4 - locals
;
641 for (i
= 0; i
< 8; i
++)
643 op
= codestream_get ();
644 if (op
< 0x50 || op
> 0x57)
646 #ifdef I386_REGNO_TO_SYMMETRY
647 /* Dynix uses different internal numbering. Ick. */
648 fip
->saved_regs
[I386_REGNO_TO_SYMMETRY (op
- 0x50)] = addr
;
650 fip
->saved_regs
[op
- 0x50] = addr
;
656 fip
->saved_regs
[PC_REGNUM
] = fip
->frame
+ 4;
657 fip
->saved_regs
[FP_REGNUM
] = fip
->frame
;
660 /* Return PC of first real instruction. */
663 i386_skip_prologue (int pc
)
667 static unsigned char pic_pat
[6] =
668 { 0xe8, 0, 0, 0, 0, /* call 0x0 */
669 0x5b, /* popl %ebx */
673 if (i386_get_frame_setup (pc
) < 0)
676 /* Found valid frame setup -- codestream now points to start of push
677 instructions for saving registers. */
679 /* Skip over register saves. */
680 for (i
= 0; i
< 8; i
++)
682 op
= codestream_peek ();
683 /* Break if not `pushl' instrunction. */
684 if (op
< 0x50 || op
> 0x57)
689 /* The native cc on SVR4 in -K PIC mode inserts the following code
690 to get the address of the global offset table (GOT) into register
695 movl %ebx,x(%ebp) (optional)
698 This code is with the rest of the prologue (at the end of the
699 function), so we have to skip it to get to the first real
700 instruction at the start of the function. */
702 pos
= codestream_tell ();
703 for (i
= 0; i
< 6; i
++)
705 op
= codestream_get ();
706 if (pic_pat
[i
] != op
)
711 unsigned char buf
[4];
714 op
= codestream_get ();
715 if (op
== 0x89) /* movl %ebx, x(%ebp) */
717 op
= codestream_get ();
718 if (op
== 0x5d) /* One byte offset from %ebp. */
721 codestream_read (buf
, 1);
723 else if (op
== 0x9d) /* Four byte offset from %ebp. */
726 codestream_read (buf
, 4);
728 else /* Unexpected instruction. */
730 op
= codestream_get ();
733 if (delta
> 0 && op
== 0x81 && codestream_get () == 0xc3)
738 codestream_seek (pos
);
742 return (codestream_tell ());
746 i386_push_dummy_frame (void)
748 CORE_ADDR sp
= read_register (SP_REGNUM
);
750 char regbuf
[MAX_REGISTER_RAW_SIZE
];
752 sp
= push_word (sp
, read_register (PC_REGNUM
));
753 sp
= push_word (sp
, read_register (FP_REGNUM
));
754 write_register (FP_REGNUM
, sp
);
755 for (regnum
= 0; regnum
< NUM_REGS
; regnum
++)
757 read_register_gen (regnum
, regbuf
);
758 sp
= push_bytes (sp
, regbuf
, REGISTER_RAW_SIZE (regnum
));
760 write_register (SP_REGNUM
, sp
);
763 /* Insert the (relative) function address into the call sequence
767 i386_fix_call_dummy (char *dummy
, CORE_ADDR pc
, CORE_ADDR fun
, int nargs
,
768 struct value
**args
, struct type
*type
, int gcc_p
)
770 int from
, to
, delta
, loc
;
772 loc
= (int)(read_register (SP_REGNUM
) - CALL_DUMMY_LENGTH
);
777 *((char *)(dummy
) + 1) = (delta
& 0xff);
778 *((char *)(dummy
) + 2) = ((delta
>> 8) & 0xff);
779 *((char *)(dummy
) + 3) = ((delta
>> 16) & 0xff);
780 *((char *)(dummy
) + 4) = ((delta
>> 24) & 0xff);
784 i386_pop_frame (void)
786 struct frame_info
*frame
= get_current_frame ();
789 char regbuf
[MAX_REGISTER_RAW_SIZE
];
791 fp
= FRAME_FP (frame
);
792 i386_frame_init_saved_regs (frame
);
794 for (regnum
= 0; regnum
< NUM_REGS
; regnum
++)
797 addr
= frame
->saved_regs
[regnum
];
800 read_memory (addr
, regbuf
, REGISTER_RAW_SIZE (regnum
));
801 write_register_bytes (REGISTER_BYTE (regnum
), regbuf
,
802 REGISTER_RAW_SIZE (regnum
));
805 write_register (FP_REGNUM
, read_memory_integer (fp
, 4));
806 write_register (PC_REGNUM
, read_memory_integer (fp
+ 4, 4));
807 write_register (SP_REGNUM
, fp
+ 8);
808 flush_cached_frames ();
812 #ifdef GET_LONGJMP_TARGET
814 /* Figure out where the longjmp will land. Slurp the args out of the
815 stack. We expect the first arg to be a pointer to the jmp_buf
816 structure from which we extract the pc (JB_PC) that we will land
817 at. The pc is copied into PC. This routine returns true on
821 get_longjmp_target (CORE_ADDR
*pc
)
823 char buf
[TARGET_PTR_BIT
/ TARGET_CHAR_BIT
];
824 CORE_ADDR sp
, jb_addr
;
826 sp
= read_register (SP_REGNUM
);
828 if (target_read_memory (sp
+ SP_ARG0
, /* Offset of first arg on stack. */
830 TARGET_PTR_BIT
/ TARGET_CHAR_BIT
))
833 jb_addr
= extract_address (buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
835 if (target_read_memory (jb_addr
+ JB_PC
* JB_ELEMENT_SIZE
, buf
,
836 TARGET_PTR_BIT
/ TARGET_CHAR_BIT
))
839 *pc
= extract_address (buf
, TARGET_PTR_BIT
/ TARGET_CHAR_BIT
);
844 #endif /* GET_LONGJMP_TARGET */
848 i386_push_arguments (int nargs
, struct value
**args
, CORE_ADDR sp
,
849 int struct_return
, CORE_ADDR struct_addr
)
851 sp
= default_push_arguments (nargs
, args
, sp
, struct_return
, struct_addr
);
858 store_address (buf
, 4, struct_addr
);
859 write_memory (sp
, buf
, 4);
866 i386_store_struct_return (CORE_ADDR addr
, CORE_ADDR sp
)
868 /* Do nothing. Everything was already done by i386_push_arguments. */
871 /* These registers are used for returning integers (and on some
872 targets also for returning `struct' and `union' values when their
873 size and alignment match an integer type). */
874 #define LOW_RETURN_REGNUM 0 /* %eax */
875 #define HIGH_RETURN_REGNUM 2 /* %edx */
877 /* Extract from an array REGBUF containing the (raw) register state, a
878 function return value of TYPE, and copy that, in virtual format,
882 i386_extract_return_value (struct type
*type
, char *regbuf
, char *valbuf
)
884 int len
= TYPE_LENGTH (type
);
886 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
887 && TYPE_NFIELDS (type
) == 1)
889 i386_extract_return_value (TYPE_FIELD_TYPE (type
, 0), regbuf
, valbuf
);
893 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
897 warning ("Cannot find floating-point return value.");
898 memset (valbuf
, 0, len
);
902 /* Floating-point return values can be found in %st(0). Convert
903 its contents to the desired type. This is probably not
904 exactly how it would happen on the target itself, but it is
905 the best we can do. */
906 convert_typed_floating (®buf
[REGISTER_BYTE (FP0_REGNUM
)],
907 builtin_type_i387_ext
, valbuf
, type
);
911 int low_size
= REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
);
912 int high_size
= REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM
);
915 memcpy (valbuf
, ®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)], len
);
916 else if (len
<= (low_size
+ high_size
))
919 ®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)], low_size
);
920 memcpy (valbuf
+ low_size
,
921 ®buf
[REGISTER_BYTE (HIGH_RETURN_REGNUM
)], len
- low_size
);
924 internal_error (__FILE__
, __LINE__
,
925 "Cannot extract return value of %d bytes long.", len
);
929 /* Write into the appropriate registers a function return value stored
930 in VALBUF of type TYPE, given in virtual format. */
933 i386_store_return_value (struct type
*type
, char *valbuf
)
935 int len
= TYPE_LENGTH (type
);
937 if (TYPE_CODE (type
) == TYPE_CODE_STRUCT
938 && TYPE_NFIELDS (type
) == 1)
940 i386_store_return_value (TYPE_FIELD_TYPE (type
, 0), valbuf
);
944 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
947 char buf
[FPU_REG_RAW_SIZE
];
951 warning ("Cannot set floating-point return value.");
955 /* Returning floating-point values is a bit tricky. Apart from
956 storing the return value in %st(0), we have to simulate the
957 state of the FPU at function return point. */
959 /* Convert the value found in VALBUF to the extended
960 floating-point format used by the FPU. This is probably
961 not exactly how it would happen on the target itself, but
962 it is the best we can do. */
963 convert_typed_floating (valbuf
, type
, buf
, builtin_type_i387_ext
);
964 write_register_bytes (REGISTER_BYTE (FP0_REGNUM
), buf
,
967 /* Set the top of the floating-point register stack to 7. The
968 actual value doesn't really matter, but 7 is what a normal
969 function return would end up with if the program started out
970 with a freshly initialized FPU. */
971 fstat
= read_register (FSTAT_REGNUM
);
973 write_register (FSTAT_REGNUM
, fstat
);
975 /* Mark %st(1) through %st(7) as empty. Since we set the top of
976 the floating-point register stack to 7, the appropriate value
977 for the tag word is 0x3fff. */
978 write_register (FTAG_REGNUM
, 0x3fff);
982 int low_size
= REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
);
983 int high_size
= REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM
);
986 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM
), valbuf
, len
);
987 else if (len
<= (low_size
+ high_size
))
989 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM
),
991 write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM
),
992 valbuf
+ low_size
, len
- low_size
);
995 internal_error (__FILE__
, __LINE__
,
996 "Cannot store return value of %d bytes long.", len
);
1000 /* Extract from an array REGBUF containing the (raw) register state
1001 the address in which a function should return its structure value,
1005 i386_extract_struct_value_address (char *regbuf
)
1007 return extract_address (®buf
[REGISTER_BYTE (LOW_RETURN_REGNUM
)],
1008 REGISTER_RAW_SIZE (LOW_RETURN_REGNUM
));
1012 /* Return the GDB type object for the "standard" data type of data in
1013 register REGNUM. Perhaps %esi and %edi should go here, but
1014 potentially they could be used for things other than address. */
1017 i386_register_virtual_type (int regnum
)
1019 if (regnum
== PC_REGNUM
|| regnum
== FP_REGNUM
|| regnum
== SP_REGNUM
)
1020 return lookup_pointer_type (builtin_type_void
);
1022 if (IS_FP_REGNUM (regnum
))
1023 return builtin_type_i387_ext
;
1025 if (IS_SSE_REGNUM (regnum
))
1026 return builtin_type_v4sf
;
1028 return builtin_type_int
;
1031 /* Return true iff register REGNUM's virtual format is different from
1032 its raw format. Note that this definition assumes that the host
1033 supports IEEE 32-bit floats, since it doesn't say that SSE
1034 registers need conversion. Even if we can't find a counterexample,
1035 this is still sloppy. */
1038 i386_register_convertible (int regnum
)
1040 return IS_FP_REGNUM (regnum
);
1043 /* Convert data from raw format for register REGNUM in buffer FROM to
1044 virtual format with type TYPE in buffer TO. */
1047 i386_register_convert_to_virtual (int regnum
, struct type
*type
,
1048 char *from
, char *to
)
1050 gdb_assert (IS_FP_REGNUM (regnum
));
1052 /* We only support floating-point values. */
1053 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
1055 warning ("Cannot convert floating-point register value "
1056 "to non-floating-point type.");
1057 memset (to
, 0, TYPE_LENGTH (type
));
1061 /* Convert to TYPE. This should be a no-op if TYPE is equivalent to
1062 the extended floating-point format used by the FPU. */
1063 convert_typed_floating (from
, builtin_type_i387_ext
, to
, type
);
1066 /* Convert data from virtual format with type TYPE in buffer FROM to
1067 raw format for register REGNUM in buffer TO. */
1070 i386_register_convert_to_raw (struct type
*type
, int regnum
,
1071 char *from
, char *to
)
1073 gdb_assert (IS_FP_REGNUM (regnum
));
1075 /* We only support floating-point values. */
1076 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
1078 warning ("Cannot convert non-floating-point type "
1079 "to floating-point register value.");
1080 memset (to
, 0, TYPE_LENGTH (type
));
1084 /* Convert from TYPE. This should be a no-op if TYPE is equivalent
1085 to the extended floating-point format used by the FPU. */
1086 convert_typed_floating (from
, type
, to
, builtin_type_i387_ext
);
1090 #ifdef I386V4_SIGTRAMP_SAVED_PC
1091 /* Get saved user PC for sigtramp from the pushed ucontext on the
1092 stack for all three variants of SVR4 sigtramps. */
1095 i386v4_sigtramp_saved_pc (struct frame_info
*frame
)
1097 CORE_ADDR saved_pc_offset
= 4;
1100 find_pc_partial_function (frame
->pc
, &name
, NULL
, NULL
);
1103 if (STREQ (name
, "_sigreturn"))
1104 saved_pc_offset
= 132 + 14 * 4;
1105 else if (STREQ (name
, "_sigacthandler"))
1106 saved_pc_offset
= 80 + 14 * 4;
1107 else if (STREQ (name
, "sigvechandler"))
1108 saved_pc_offset
= 120 + 14 * 4;
1112 return read_memory_integer (frame
->next
->frame
+ saved_pc_offset
, 4);
1113 return read_memory_integer (read_register (SP_REGNUM
) + saved_pc_offset
, 4);
1115 #endif /* I386V4_SIGTRAMP_SAVED_PC */
1118 #ifdef STATIC_TRANSFORM_NAME
1119 /* SunPRO encodes the static variables. This is not related to C++
1120 mangling, it is done for C too. */
1123 sunpro_static_transform_name (char *name
)
1126 if (IS_STATIC_TRANSFORM_NAME (name
))
1128 /* For file-local statics there will be a period, a bunch of
1129 junk (the contents of which match a string given in the
1130 N_OPT), a period and the name. For function-local statics
1131 there will be a bunch of junk (which seems to change the
1132 second character from 'A' to 'B'), a period, the name of the
1133 function, and the name. So just skip everything before the
1135 p
= strrchr (name
, '.');
1141 #endif /* STATIC_TRANSFORM_NAME */
1144 /* Stuff for WIN32 PE style DLL's but is pretty generic really. */
1147 skip_trampoline_code (CORE_ADDR pc
, char *name
)
1149 if (pc
&& read_memory_unsigned_integer (pc
, 2) == 0x25ff) /* jmp *(dest) */
1151 unsigned long indirect
= read_memory_unsigned_integer (pc
+ 2, 4);
1152 struct minimal_symbol
*indsym
=
1153 indirect
? lookup_minimal_symbol_by_pc (indirect
) : 0;
1154 char *symname
= indsym
? SYMBOL_NAME (indsym
) : 0;
1158 if (strncmp (symname
, "__imp_", 6) == 0
1159 || strncmp (symname
, "_imp_", 5) == 0)
1160 return name
? 1 : read_memory_unsigned_integer (indirect
, 4);
1163 return 0; /* Not a trampoline. */
1167 /* We have two flavours of disassembly. The machinery on this page
1168 deals with switching between those. */
1171 gdb_print_insn_i386 (bfd_vma memaddr
, disassemble_info
*info
)
1173 if (disassembly_flavor
== att_flavor
)
1174 return print_insn_i386_att (memaddr
, info
);
1175 else if (disassembly_flavor
== intel_flavor
)
1176 return print_insn_i386_intel (memaddr
, info
);
1177 /* Never reached -- disassembly_flavour is always either att_flavor
1179 internal_error (__FILE__
, __LINE__
, "failed internal consistency check");
1182 /* If the disassembly mode is intel, we have to also switch the bfd
1183 mach_type. This function is run in the set disassembly_flavor
1184 command, and does that. */
1187 set_disassembly_flavor_sfunc (char *args
, int from_tty
,
1188 struct cmd_list_element
*c
)
1190 set_disassembly_flavor ();
1194 set_disassembly_flavor (void)
1196 if (disassembly_flavor
== att_flavor
)
1197 set_architecture_from_arch_mach (bfd_arch_i386
, bfd_mach_i386_i386
);
1198 else if (disassembly_flavor
== intel_flavor
)
1199 set_architecture_from_arch_mach (bfd_arch_i386
,
1200 bfd_mach_i386_i386_intel_syntax
);
1204 /* Provide a prototype to silence -Wmissing-prototypes. */
1205 void _initialize_i386_tdep (void);
1208 _initialize_i386_tdep (void)
1210 /* Initialize the table saying where each register starts in the
1216 for (i
= 0; i
< MAX_NUM_REGS
; i
++)
1218 i386_register_byte
[i
] = offset
;
1219 offset
+= i386_register_raw_size
[i
];
1223 /* Initialize the table of virtual register sizes. */
1227 for (i
= 0; i
< MAX_NUM_REGS
; i
++)
1228 i386_register_virtual_size
[i
] = TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (i
));
1231 tm_print_insn
= gdb_print_insn_i386
;
1232 tm_print_insn_info
.mach
= bfd_lookup_arch (bfd_arch_i386
, 0)->mach
;
1234 /* Add the variable that controls the disassembly flavor. */
1236 struct cmd_list_element
*new_cmd
;
1238 new_cmd
= add_set_enum_cmd ("disassembly-flavor", no_class
,
1240 &disassembly_flavor
,
1242 Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
1243 and the default value is \"att\".",
1245 new_cmd
->function
.sfunc
= set_disassembly_flavor_sfunc
;
1246 add_show_from_set (new_cmd
, &showlist
);
1249 /* Finally, initialize the disassembly flavor to the default given
1250 in the disassembly_flavor variable. */
1251 set_disassembly_flavor ();