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binutils-gdb/gdb/i386-tdep.c
Stan Shebs d4f3574e77 import gdb-1999-09-08 snapshot
1999-09-09 00:02:17 +00:00

1034 lines
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/* Intel 386 target-dependent stuff.
Copyright (C) 1988, 1989, 1991, 1994, 1995, 1996, 1998
Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "gdb_string.h"
#include "frame.h"
#include "inferior.h"
#include "gdbcore.h"
#include "target.h"
#include "floatformat.h"
#include "symtab.h"
#include "gdbcmd.h"
#include "command.h"
static long i386_get_frame_setup PARAMS ((CORE_ADDR));
static void i386_follow_jump PARAMS ((void));
static void codestream_read PARAMS ((unsigned char *, int));
static void codestream_seek PARAMS ((CORE_ADDR));
static unsigned char codestream_fill PARAMS ((int));
CORE_ADDR skip_trampoline_code PARAMS ((CORE_ADDR, char *));
static int gdb_print_insn_i386 (bfd_vma, disassemble_info *);
void _initialize_i386_tdep PARAMS ((void));
/* This is the variable the is set with "set disassembly-flavor",
and its legitimate values. */
static char att_flavor[] = "att";
static char intel_flavor[] = "intel";
static char *valid_flavors[] =
{
att_flavor,
intel_flavor,
NULL
};
static char *disassembly_flavor = att_flavor;
static void i386_print_register PARAMS ((char *, int, int));
/* This is used to keep the bfd arch_info in sync with the disassembly flavor. */
static void set_disassembly_flavor_sfunc PARAMS ((char *, int, struct cmd_list_element *));
static void set_disassembly_flavor PARAMS ((void));
/* Stdio style buffering was used to minimize calls to ptrace, but this
buffering did not take into account that the code section being accessed
may not be an even number of buffers long (even if the buffer is only
sizeof(int) long). In cases where the code section size happened to
be a non-integral number of buffers long, attempting to read the last
buffer would fail. Simply using target_read_memory and ignoring errors,
rather than read_memory, is not the correct solution, since legitimate
access errors would then be totally ignored. To properly handle this
situation and continue to use buffering would require that this code
be able to determine the minimum code section size granularity (not the
alignment of the section itself, since the actual failing case that
pointed out this problem had a section alignment of 4 but was not a
multiple of 4 bytes long), on a target by target basis, and then
adjust it's buffer size accordingly. This is messy, but potentially
feasible. It probably needs the bfd library's help and support. For
now, the buffer size is set to 1. (FIXME -fnf) */
#define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */
static CORE_ADDR codestream_next_addr;
static CORE_ADDR codestream_addr;
static unsigned char codestream_buf[CODESTREAM_BUFSIZ];
static int codestream_off;
static int codestream_cnt;
#define codestream_tell() (codestream_addr + codestream_off)
#define codestream_peek() (codestream_cnt == 0 ? \
codestream_fill(1): codestream_buf[codestream_off])
#define codestream_get() (codestream_cnt-- == 0 ? \
codestream_fill(0) : codestream_buf[codestream_off++])
static unsigned char
codestream_fill (peek_flag)
int peek_flag;
{
codestream_addr = codestream_next_addr;
codestream_next_addr += CODESTREAM_BUFSIZ;
codestream_off = 0;
codestream_cnt = CODESTREAM_BUFSIZ;
read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ);
if (peek_flag)
return (codestream_peek ());
else
return (codestream_get ());
}
static void
codestream_seek (place)
CORE_ADDR place;
{
codestream_next_addr = place / CODESTREAM_BUFSIZ;
codestream_next_addr *= CODESTREAM_BUFSIZ;
codestream_cnt = 0;
codestream_fill (1);
while (codestream_tell () != place)
codestream_get ();
}
static void
codestream_read (buf, count)
unsigned char *buf;
int count;
{
unsigned char *p;
int i;
p = buf;
for (i = 0; i < count; i++)
*p++ = codestream_get ();
}
/* next instruction is a jump, move to target */
static void
i386_follow_jump ()
{
unsigned char buf[4];
long delta;
int data16;
CORE_ADDR pos;
pos = codestream_tell ();
data16 = 0;
if (codestream_peek () == 0x66)
{
codestream_get ();
data16 = 1;
}
switch (codestream_get ())
{
case 0xe9:
/* relative jump: if data16 == 0, disp32, else disp16 */
if (data16)
{
codestream_read (buf, 2);
delta = extract_signed_integer (buf, 2);
/* include size of jmp inst (including the 0x66 prefix). */
pos += delta + 4;
}
else
{
codestream_read (buf, 4);
delta = extract_signed_integer (buf, 4);
pos += delta + 5;
}
break;
case 0xeb:
/* relative jump, disp8 (ignore data16) */
codestream_read (buf, 1);
/* Sign-extend it. */
delta = extract_signed_integer (buf, 1);
pos += delta + 2;
break;
}
codestream_seek (pos);
}
/*
* find & return amound a local space allocated, and advance codestream to
* first register push (if any)
*
* if entry sequence doesn't make sense, return -1, and leave
* codestream pointer random
*/
static long
i386_get_frame_setup (pc)
CORE_ADDR pc;
{
unsigned char op;
codestream_seek (pc);
i386_follow_jump ();
op = codestream_get ();
if (op == 0x58) /* popl %eax */
{
/*
* this function must start with
*
* popl %eax 0x58
* xchgl %eax, (%esp) 0x87 0x04 0x24
* or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
*
* (the system 5 compiler puts out the second xchg
* inst, and the assembler doesn't try to optimize it,
* so the 'sib' form gets generated)
*
* this sequence is used to get the address of the return
* buffer for a function that returns a structure
*/
int pos;
unsigned char buf[4];
static unsigned char proto1[3] =
{0x87, 0x04, 0x24};
static unsigned char proto2[4] =
{0x87, 0x44, 0x24, 0x00};
pos = codestream_tell ();
codestream_read (buf, 4);
if (memcmp (buf, proto1, 3) == 0)
pos += 3;
else if (memcmp (buf, proto2, 4) == 0)
pos += 4;
codestream_seek (pos);
op = codestream_get (); /* update next opcode */
}
if (op == 0x68 || op == 0x6a)
{
/*
* this function may start with
*
* pushl constant
* call _probe
* addl $4, %esp
* followed by
* pushl %ebp
* etc.
*/
int pos;
unsigned char buf[8];
/* Skip past the pushl instruction; it has either a one-byte
or a four-byte operand, depending on the opcode. */
pos = codestream_tell ();
if (op == 0x68)
pos += 4;
else
pos += 1;
codestream_seek (pos);
/* Read the following 8 bytes, which should be "call _probe" (6 bytes)
followed by "addl $4,%esp" (2 bytes). */
codestream_read (buf, sizeof (buf));
if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4)
pos += sizeof (buf);
codestream_seek (pos);
op = codestream_get (); /* update next opcode */
}
if (op == 0x55) /* pushl %ebp */
{
/* check for movl %esp, %ebp - can be written two ways */
switch (codestream_get ())
{
case 0x8b:
if (codestream_get () != 0xec)
return (-1);
break;
case 0x89:
if (codestream_get () != 0xe5)
return (-1);
break;
default:
return (-1);
}
/* check for stack adjustment
* subl $XXX, %esp
*
* note: you can't subtract a 16 bit immediate
* from a 32 bit reg, so we don't have to worry
* about a data16 prefix
*/
op = codestream_peek ();
if (op == 0x83)
{
/* subl with 8 bit immed */
codestream_get ();
if (codestream_get () != 0xec)
/* Some instruction starting with 0x83 other than subl. */
{
codestream_seek (codestream_tell () - 2);
return 0;
}
/* subl with signed byte immediate
* (though it wouldn't make sense to be negative)
*/
return (codestream_get ());
}
else if (op == 0x81)
{
char buf[4];
/* Maybe it is subl with 32 bit immedediate. */
codestream_get ();
if (codestream_get () != 0xec)
/* Some instruction starting with 0x81 other than subl. */
{
codestream_seek (codestream_tell () - 2);
return 0;
}
/* It is subl with 32 bit immediate. */
codestream_read ((unsigned char *) buf, 4);
return extract_signed_integer (buf, 4);
}
else
{
return (0);
}
}
else if (op == 0xc8)
{
char buf[2];
/* enter instruction: arg is 16 bit unsigned immed */
codestream_read ((unsigned char *) buf, 2);
codestream_get (); /* flush final byte of enter instruction */
return extract_unsigned_integer (buf, 2);
}
return (-1);
}
/* Return number of args passed to a frame.
Can return -1, meaning no way to tell. */
int
i386_frame_num_args (fi)
struct frame_info *fi;
{
#if 1
return -1;
#else
/* This loses because not only might the compiler not be popping the
args right after the function call, it might be popping args from both
this call and a previous one, and we would say there are more args
than there really are. */
int retpc;
unsigned char op;
struct frame_info *pfi;
/* on the 386, the instruction following the call could be:
popl %ecx - one arg
addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
anything else - zero args */
int frameless;
frameless = FRAMELESS_FUNCTION_INVOCATION (fi);
if (frameless)
/* In the absence of a frame pointer, GDB doesn't get correct values
for nameless arguments. Return -1, so it doesn't print any
nameless arguments. */
return -1;
pfi = get_prev_frame (fi);
if (pfi == 0)
{
/* Note: this can happen if we are looking at the frame for
main, because FRAME_CHAIN_VALID won't let us go into
start. If we have debugging symbols, that's not really
a big deal; it just means it will only show as many arguments
to main as are declared. */
return -1;
}
else
{
retpc = pfi->pc;
op = read_memory_integer (retpc, 1);
if (op == 0x59)
/* pop %ecx */
return 1;
else if (op == 0x83)
{
op = read_memory_integer (retpc + 1, 1);
if (op == 0xc4)
/* addl $<signed imm 8 bits>, %esp */
return (read_memory_integer (retpc + 2, 1) & 0xff) / 4;
else
return 0;
}
else if (op == 0x81)
{ /* add with 32 bit immediate */
op = read_memory_integer (retpc + 1, 1);
if (op == 0xc4)
/* addl $<imm 32>, %esp */
return read_memory_integer (retpc + 2, 4) / 4;
else
return 0;
}
else
{
return 0;
}
}
#endif
}
/*
* parse the first few instructions of the function to see
* what registers were stored.
*
* We handle these cases:
*
* The startup sequence can be at the start of the function,
* or the function can start with a branch to startup code at the end.
*
* %ebp can be set up with either the 'enter' instruction, or
* 'pushl %ebp, movl %esp, %ebp' (enter is too slow to be useful,
* but was once used in the sys5 compiler)
*
* Local space is allocated just below the saved %ebp by either the
* 'enter' instruction, or by 'subl $<size>, %esp'. 'enter' has
* a 16 bit unsigned argument for space to allocate, and the
* 'addl' instruction could have either a signed byte, or
* 32 bit immediate.
*
* Next, the registers used by this function are pushed. In
* the sys5 compiler they will always be in the order: %edi, %esi, %ebx
* (and sometimes a harmless bug causes it to also save but not restore %eax);
* however, the code below is willing to see the pushes in any order,
* and will handle up to 8 of them.
*
* If the setup sequence is at the end of the function, then the
* next instruction will be a branch back to the start.
*/
void
i386_frame_find_saved_regs (fip, fsrp)
struct frame_info *fip;
struct frame_saved_regs *fsrp;
{
long locals = -1;
unsigned char op;
CORE_ADDR dummy_bottom;
CORE_ADDR adr;
CORE_ADDR pc;
int i;
memset (fsrp, 0, sizeof *fsrp);
/* if frame is the end of a dummy, compute where the
* beginning would be
*/
dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH;
/* check if the PC is in the stack, in a dummy frame */
if (dummy_bottom <= fip->pc && fip->pc <= fip->frame)
{
/* all regs were saved by push_call_dummy () */
adr = fip->frame;
for (i = 0; i < NUM_REGS; i++)
{
adr -= REGISTER_RAW_SIZE (i);
fsrp->regs[i] = adr;
}
return;
}
pc = get_pc_function_start (fip->pc);
if (pc != 0)
locals = i386_get_frame_setup (pc);
if (locals >= 0)
{
adr = fip->frame - 4 - locals;
for (i = 0; i < 8; i++)
{
op = codestream_get ();
if (op < 0x50 || op > 0x57)
break;
#ifdef I386_REGNO_TO_SYMMETRY
/* Dynix uses different internal numbering. Ick. */
fsrp->regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = adr;
#else
fsrp->regs[op - 0x50] = adr;
#endif
adr -= 4;
}
}
fsrp->regs[PC_REGNUM] = fip->frame + 4;
fsrp->regs[FP_REGNUM] = fip->frame;
}
/* return pc of first real instruction */
int
i386_skip_prologue (pc)
int pc;
{
unsigned char op;
int i;
static unsigned char pic_pat[6] =
{0xe8, 0, 0, 0, 0, /* call 0x0 */
0x5b, /* popl %ebx */
};
CORE_ADDR pos;
if (i386_get_frame_setup (pc) < 0)
return (pc);
/* found valid frame setup - codestream now points to
* start of push instructions for saving registers
*/
/* skip over register saves */
for (i = 0; i < 8; i++)
{
op = codestream_peek ();
/* break if not pushl inst */
if (op < 0x50 || op > 0x57)
break;
codestream_get ();
}
/* The native cc on SVR4 in -K PIC mode inserts the following code to get
the address of the global offset table (GOT) into register %ebx.
call 0x0
popl %ebx
movl %ebx,x(%ebp) (optional)
addl y,%ebx
This code is with the rest of the prologue (at the end of the
function), so we have to skip it to get to the first real
instruction at the start of the function. */
pos = codestream_tell ();
for (i = 0; i < 6; i++)
{
op = codestream_get ();
if (pic_pat[i] != op)
break;
}
if (i == 6)
{
unsigned char buf[4];
long delta = 6;
op = codestream_get ();
if (op == 0x89) /* movl %ebx, x(%ebp) */
{
op = codestream_get ();
if (op == 0x5d) /* one byte offset from %ebp */
{
delta += 3;
codestream_read (buf, 1);
}
else if (op == 0x9d) /* four byte offset from %ebp */
{
delta += 6;
codestream_read (buf, 4);
}
else /* unexpected instruction */
delta = -1;
op = codestream_get ();
}
/* addl y,%ebx */
if (delta > 0 && op == 0x81 && codestream_get () == 0xc3)
{
pos += delta + 6;
}
}
codestream_seek (pos);
i386_follow_jump ();
return (codestream_tell ());
}
void
i386_push_dummy_frame ()
{
CORE_ADDR sp = read_register (SP_REGNUM);
int regnum;
char regbuf[MAX_REGISTER_RAW_SIZE];
sp = push_word (sp, read_register (PC_REGNUM));
sp = push_word (sp, read_register (FP_REGNUM));
write_register (FP_REGNUM, sp);
for (regnum = 0; regnum < NUM_REGS; regnum++)
{
read_register_gen (regnum, regbuf);
sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum));
}
write_register (SP_REGNUM, sp);
}
void
i386_pop_frame ()
{
struct frame_info *frame = get_current_frame ();
CORE_ADDR fp;
int regnum;
struct frame_saved_regs fsr;
char regbuf[MAX_REGISTER_RAW_SIZE];
fp = FRAME_FP (frame);
get_frame_saved_regs (frame, &fsr);
for (regnum = 0; regnum < NUM_REGS; regnum++)
{
CORE_ADDR adr;
adr = fsr.regs[regnum];
if (adr)
{
read_memory (adr, regbuf, REGISTER_RAW_SIZE (regnum));
write_register_bytes (REGISTER_BYTE (regnum), regbuf,
REGISTER_RAW_SIZE (regnum));
}
}
write_register (FP_REGNUM, read_memory_integer (fp, 4));
write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
write_register (SP_REGNUM, fp + 8);
flush_cached_frames ();
}
#ifdef GET_LONGJMP_TARGET
/* Figure out where the longjmp will land. Slurp the args out of the stack.
We expect the first arg to be a pointer to the jmp_buf structure from which
we extract the pc (JB_PC) that we will land at. The pc is copied into PC.
This routine returns true on success. */
int
get_longjmp_target (pc)
CORE_ADDR *pc;
{
char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
CORE_ADDR sp, jb_addr;
sp = read_register (SP_REGNUM);
if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */
buf,
TARGET_PTR_BIT / TARGET_CHAR_BIT))
return 0;
jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
TARGET_PTR_BIT / TARGET_CHAR_BIT))
return 0;
*pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
return 1;
}
#endif /* GET_LONGJMP_TARGET */
void
i386_extract_return_value (type, regbuf, valbuf)
struct type *type;
char regbuf[REGISTER_BYTES];
char *valbuf;
{
/* On AIX and i386 GNU/Linux, floating point values are returned in
floating point registers. */
#if defined(I386_AIX_TARGET) || defined(I386_GNULINUX_TARGET)
if (TYPE_CODE_FLT == TYPE_CODE (type))
{
double d;
/* 387 %st(0), gcc uses this */
floatformat_to_double (&floatformat_i387_ext,
&regbuf[REGISTER_BYTE(FPDATA_REGNUM)],
&d);
store_floating (valbuf, TYPE_LENGTH (type), d);
}
else
#endif /* I386_AIX_TARGET || I386_GNULINUX_TARGET*/
{
int len = TYPE_LENGTH (type);
int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
if (len <= low_size)
memcpy (valbuf, regbuf + REGISTER_BYTE (LOW_RETURN_REGNUM), len);
else if (len <= (low_size + high_size))
{
memcpy (valbuf,
regbuf + REGISTER_BYTE (LOW_RETURN_REGNUM),
low_size);
memcpy (valbuf + low_size,
regbuf + REGISTER_BYTE (HIGH_RETURN_REGNUM),
len - low_size);
}
else
error ("GDB bug: i386-tdep.c (i386_extract_return_value): Don't know how to find a return value %d bytes long", len);
}
}
#ifdef I386V4_SIGTRAMP_SAVED_PC
/* Get saved user PC for sigtramp from the pushed ucontext on the stack
for all three variants of SVR4 sigtramps. */
CORE_ADDR
i386v4_sigtramp_saved_pc (frame)
struct frame_info *frame;
{
CORE_ADDR saved_pc_offset = 4;
char *name = NULL;
find_pc_partial_function (frame->pc, &name, NULL, NULL);
if (name)
{
if (STREQ (name, "_sigreturn"))
saved_pc_offset = 132 + 14 * 4;
else if (STREQ (name, "_sigacthandler"))
saved_pc_offset = 80 + 14 * 4;
else if (STREQ (name, "sigvechandler"))
saved_pc_offset = 120 + 14 * 4;
}
if (frame->next)
return read_memory_integer (frame->next->frame + saved_pc_offset, 4);
return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4);
}
#endif /* I386V4_SIGTRAMP_SAVED_PC */
#ifdef I386_LINUX_SIGTRAMP
/* When the i386 Linux kernel calls a signal handler, the return
address points to a bit of code on the stack. This function
returns whether the PC appears to be within this bit of code.
The instruction sequence is
pop %eax
mov $0x77,%eax
int $0x80
or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
Checking for the code sequence should be somewhat reliable, because
the effect is to call the system call sigreturn. This is unlikely
to occur anywhere other than a signal trampoline.
It kind of sucks that we have to read memory from the process in
order to identify a signal trampoline, but there doesn't seem to be
any other way. The IN_SIGTRAMP macro in tm-linux.h arranges to
only call us if no function name could be identified, which should
be the case since the code is on the stack. */
#define LINUX_SIGTRAMP_INSN0 (0x58) /* pop %eax */
#define LINUX_SIGTRAMP_OFFSET0 (0)
#define LINUX_SIGTRAMP_INSN1 (0xb8) /* mov $NNNN,%eax */
#define LINUX_SIGTRAMP_OFFSET1 (1)
#define LINUX_SIGTRAMP_INSN2 (0xcd) /* int */
#define LINUX_SIGTRAMP_OFFSET2 (6)
static const unsigned char linux_sigtramp_code[] =
{
LINUX_SIGTRAMP_INSN0, /* pop %eax */
LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
};
#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
/* If PC is in a sigtramp routine, return the address of the start of
the routine. Otherwise, return 0. */
static CORE_ADDR
i386_linux_sigtramp_start (pc)
CORE_ADDR pc;
{
unsigned char buf[LINUX_SIGTRAMP_LEN];
/* We only recognize a signal trampoline if PC is at the start of
one of the three instructions. We optimize for finding the PC at
the start, as will be the case when the trampoline is not the
first frame on the stack. We assume that in the case where the
PC is not at the start of the instruction sequence, there will be
a few trailing readable bytes on the stack. */
if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
return 0;
if (buf[0] != LINUX_SIGTRAMP_INSN0)
{
int adjust;
switch (buf[0])
{
case LINUX_SIGTRAMP_INSN1:
adjust = LINUX_SIGTRAMP_OFFSET1;
break;
case LINUX_SIGTRAMP_INSN2:
adjust = LINUX_SIGTRAMP_OFFSET2;
break;
default:
return 0;
}
pc -= adjust;
if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
return 0;
}
if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
return 0;
return pc;
}
/* Return whether PC is in a Linux sigtramp routine. */
int
i386_linux_sigtramp (pc)
CORE_ADDR pc;
{
return i386_linux_sigtramp_start (pc) != 0;
}
/* Assuming FRAME is for a Linux sigtramp routine, return the saved
program counter. The Linux kernel will set up a sigcontext
structure immediately before the sigtramp routine on the stack. */
CORE_ADDR
i386_linux_sigtramp_saved_pc (frame)
struct frame_info *frame;
{
CORE_ADDR pc;
pc = i386_linux_sigtramp_start (frame->pc);
if (pc == 0)
error ("i386_linux_sigtramp_saved_pc called when no sigtramp");
return read_memory_integer ((pc
- LINUX_SIGCONTEXT_SIZE
+ LINUX_SIGCONTEXT_PC_OFFSET),
4);
}
/* Assuming FRAME is for a Linux sigtramp routine, return the saved
stack pointer. The Linux kernel will set up a sigcontext structure
immediately before the sigtramp routine on the stack. */
CORE_ADDR
i386_linux_sigtramp_saved_sp (frame)
struct frame_info *frame;
{
CORE_ADDR pc;
pc = i386_linux_sigtramp_start (frame->pc);
if (pc == 0)
error ("i386_linux_sigtramp_saved_sp called when no sigtramp");
return read_memory_integer ((pc
- LINUX_SIGCONTEXT_SIZE
+ LINUX_SIGCONTEXT_SP_OFFSET),
4);
}
#endif /* I386_LINUX_SIGTRAMP */
#ifdef STATIC_TRANSFORM_NAME
/* SunPRO encodes the static variables. This is not related to C++ mangling,
it is done for C too. */
char *
sunpro_static_transform_name (name)
char *name;
{
char *p;
if (IS_STATIC_TRANSFORM_NAME (name))
{
/* For file-local statics there will be a period, a bunch
of junk (the contents of which match a string given in the
N_OPT), a period and the name. For function-local statics
there will be a bunch of junk (which seems to change the
second character from 'A' to 'B'), a period, the name of the
function, and the name. So just skip everything before the
last period. */
p = strrchr (name, '.');
if (p != NULL)
name = p + 1;
}
return name;
}
#endif /* STATIC_TRANSFORM_NAME */
/* Stuff for WIN32 PE style DLL's but is pretty generic really. */
CORE_ADDR
skip_trampoline_code (pc, name)
CORE_ADDR pc;
char *name;
{
if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */
{
unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4);
struct minimal_symbol *indsym =
indirect ? lookup_minimal_symbol_by_pc (indirect) : 0;
char *symname = indsym ? SYMBOL_NAME (indsym) : 0;
if (symname)
{
if (strncmp (symname, "__imp_", 6) == 0
|| strncmp (symname, "_imp_", 5) == 0)
return name ? 1 : read_memory_unsigned_integer (indirect, 4);
}
}
return 0; /* not a trampoline */
}
static int
gdb_print_insn_i386 (memaddr, info)
bfd_vma memaddr;
disassemble_info *info;
{
if (disassembly_flavor == att_flavor)
return print_insn_i386_att (memaddr, info);
else if (disassembly_flavor == intel_flavor)
return print_insn_i386_intel (memaddr, info);
/* Never reached - disassembly_flavour is always either att_flavor
or intel_flavor */
abort ();
}
/* If the disassembly mode is intel, we have to also switch the
bfd mach_type. This function is run in the set disassembly_flavor
command, and does that. */
static void
set_disassembly_flavor_sfunc (args, from_tty, c)
char *args;
int from_tty;
struct cmd_list_element *c;
{
set_disassembly_flavor ();
}
static void
set_disassembly_flavor ()
{
if (disassembly_flavor == att_flavor)
set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386);
else if (disassembly_flavor == intel_flavor)
set_architecture_from_arch_mach (bfd_arch_i386, bfd_mach_i386_i386_intel_syntax);
}
/* Print the register regnum, or all registers if regnum is -1 */
void
i386_do_registers_info (regnum, fpregs)
int regnum;
int fpregs;
{
char raw_regs [REGISTER_BYTES];
int i;
for (i = 0; i < NUM_REGS; i++)
read_relative_register_raw_bytes (i, raw_regs + REGISTER_BYTE (i));
if (regnum < FPSTART_REGNUM)
i386_print_register (raw_regs, regnum, fpregs);
else
i387_print_register (raw_regs, regnum);
}
static void
i386_print_register (raw_regs, regnum, fpregs)
char *raw_regs;
int regnum;
int fpregs;
{
int i;
long val;
char string[12];
for (i = 0; i < FPSTART_REGNUM; i++)
{
if ((regnum != -1) && (i != regnum))
continue;
val = extract_signed_integer (raw_regs + REGISTER_BYTE (i), 4);
sprintf(string, "0x%x", val);
printf_filtered ("%8.8s: %10.10s %11d\n", REGISTER_NAME(i), string, val);
}
if ((regnum == -1) && fpregs)
for (i = FPSTART_REGNUM; i < FPEND_REGNUM; i++)
i387_print_register (raw_regs, i);
}
void
_initialize_i386_tdep ()
{
struct cmd_list_element *new_cmd;
tm_print_insn = gdb_print_insn_i386;
tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach;
/* Add the variable that controls the disassembly flavor */
new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
valid_flavors,
(char *) &disassembly_flavor,
"Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
and the default value is \"att\".",
&setlist);
new_cmd->function.sfunc = set_disassembly_flavor_sfunc;
add_show_from_set (new_cmd, &showlist);
/* Finally, initialize the disassembly flavor to the default given
in the disassembly_flavor variable */
set_disassembly_flavor ();
}
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