binutils-gdb/gdb/symm-tdep.c
1991-04-05 09:01:15 +00:00

495 lines
12 KiB
C

/* Sequent Symmetry target interface, for GDB when running under Unix.
Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
This file is part of GDB.
GDB 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 1, or (at your option)
any later version.
GDB 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 GDB; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/* many 387-specific items of use taken from i386-dep.c */
#include <stdio.h>
#include "defs.h"
#include "param.h"
#include "frame.h"
#include "inferior.h"
#include "symtab.h"
#include <signal.h>
#include <sys/param.h>
#include <sys/user.h>
#include <sys/dir.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include "gdbcore.h"
#include <fcntl.h>
static long i386_get_frame_setup ();
static i386_follow_jump ();
#include <sgtty.h>
#define TERMINAL struct sgttyb
exec_file_command (filename, from_tty)
char *filename;
int from_tty;
{
int val;
/* Eliminate all traces of old exec file.
Mark text segment as empty. */
if (execfile)
free (execfile);
execfile = 0;
data_start = 0;
data_end -= exec_data_start;
text_start = 0;
text_end = 0;
exec_data_start = 0;
exec_data_end = 0;
if (execchan >= 0)
close (execchan);
execchan = -1;
/* Now open and digest the file the user requested, if any. */
if (filename)
{
filename = tilde_expand (filename);
make_cleanup (free, filename);
execchan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0,
&execfile);
if (execchan < 0)
perror_with_name (filename);
#ifdef COFF_FORMAT
{
int aout_hdrsize;
int num_sections;
if (read_file_hdr (execchan, &file_hdr) < 0)
error ("\"%s\": not in executable format.", execfile);
aout_hdrsize = file_hdr.f_opthdr;
num_sections = file_hdr.f_nscns;
if (read_aout_hdr (execchan, &exec_aouthdr, aout_hdrsize) < 0)
error ("\"%s\": can't read optional aouthdr", execfile);
if (read_section_hdr (execchan, _TEXT, &text_hdr, num_sections,
aout_hdrsize) < 0)
error ("\"%s\": can't read text section header", execfile);
if (read_section_hdr (execchan, _DATA, &data_hdr, num_sections,
aout_hdrsize) < 0)
error ("\"%s\": can't read data section header", execfile);
text_start = exec_aouthdr.text_start;
text_end = text_start + exec_aouthdr.tsize;
text_offset = text_hdr.s_scnptr;
exec_data_start = exec_aouthdr.data_start;
exec_data_end = exec_data_start + exec_aouthdr.dsize;
exec_data_offset = data_hdr.s_scnptr;
data_start = exec_data_start;
data_end += exec_data_start;
exec_mtime = file_hdr.f_timdat;
}
#else /* not COFF_FORMAT */
{
struct stat st_exec;
val = myread (execchan, &exec_aouthdr, sizeof (AOUTHDR));
if (val < 0)
perror_with_name (filename);
text_start = N_ADDRADJ(exec_aouthdr);
exec_data_start = round(exec_aouthdr.a_text, NBPG*CLSIZE);
text_offset = N_TXTOFF (exec_aouthdr);
exec_data_offset = N_TXTOFF (exec_aouthdr) + exec_aouthdr.a_text;
text_end = exec_aouthdr.a_text;
exec_data_end = exec_data_start + exec_aouthdr.a_data;
data_start = exec_data_start;
data_end = data_start + exec_aouthdr.a_data;
exec_data_offset = N_TXTOFF(exec_aouthdr);
fstat (execchan, &st_exec);
exec_mtime = st_exec.st_mtime;
}
#endif /* not COFF_FORMAT */
validate_files ();
}
else if (from_tty)
printf ("No exec file now.\n");
/* Tell display code (if any) about the changed file name. */
if (exec_file_display_hook)
(*exec_file_display_hook) (filename);
}
/* rounds 'one' up to divide evenly by 'two' */
int
round(one,two)
register int one, two;
{
register int temp;
temp = (one/two)*two;
if (one != temp) {
temp += two;
}
return temp;
}
static CORE_ADDR codestream_next_addr;
static CORE_ADDR codestream_addr;
static unsigned char codestream_buf[sizeof (int)];
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)
{
codestream_addr = codestream_next_addr;
codestream_next_addr += sizeof (int);
codestream_off = 0;
codestream_cnt = sizeof (int);
read_memory (codestream_addr,
(unsigned char *)codestream_buf,
sizeof (int));
if (peek_flag)
return (codestream_peek());
else
return (codestream_get());
}
static void
codestream_seek (place)
{
codestream_next_addr = place & -sizeof (int);
codestream_cnt = 0;
codestream_fill (1);
while (codestream_tell() != place)
codestream_get ();
}
static void
codestream_read (buf, count)
unsigned char *buf;
{
unsigned char *p;
int i;
p = buf;
for (i = 0; i < count; i++)
*p++ = codestream_get ();
}
/*
* Following macro translates i386 opcode register numbers to Symmetry
* register numbers. This is used by FRAME_FIND_SAVED_REGS.
*
* %eax %ecx %edx %ebx %esp %ebp %esi %edi
* i386 0 1 2 3 4 5 6 7
* Symmetry 0 2 1 5 14 15 6 7
*
*/
#define I386_REGNO_TO_SYMMETRY(n) \
((n)==0?0 :(n)==1?2 :(n)==2?1 :(n)==3?5 :(n)==4?14 :(n)==5?15 :(n))
/* from i386-dep.c */
i386_frame_find_saved_regs (fip, fsrp)
struct frame_info *fip;
struct frame_saved_regs *fsrp;
{
unsigned long locals;
unsigned char *p;
unsigned char op;
CORE_ADDR dummy_bottom;
CORE_ADDR adr;
int i;
bzero (fsrp, sizeof *fsrp);
/* if frame is the end of a dummy, compute where the
* beginning would be
*/
dummy_bottom = fip->frame - 4 - NUM_REGS*4 - 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 - 4;
for (i = 0; i < NUM_REGS; i++)
{
fsrp->regs[i] = adr;
adr -= 4;
}
return;
}
locals = i386_get_frame_setup (get_pc_function_start (fip->pc));
if (locals >= 0)
{
adr = fip->frame - 4 - locals;
for (i = 0; i < 8; i++)
{
op = codestream_get ();
if (op < 0x50 || op > 0x57)
break;
fsrp->regs[I386_REGNO_TO_SYMMETRY(op - 0x50)] = adr;
adr -= 4;
}
}
fsrp->regs[PC_REGNUM] = fip->frame + 4;
fsrp->regs[FP_REGNUM] = fip->frame;
}
static long
i386_get_frame_setup (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 (bcmp (buf, proto1, 3) == 0)
pos += 3;
else if (bcmp (buf, proto2, 4) == 0)
pos += 4;
codestream_seek (pos);
op = codestream_get (); /* update next opcode */
}
if (op == 0x55) /* pushl %esp */
{
if (codestream_get () != 0x8b) /* movl %esp, %ebp (2bytes) */
return (-1);
if (codestream_get () != 0xec)
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)
return (-1);
/* subl with signed byte immediate
* (though it wouldn't make sense to be negative)
*/
return (codestream_get());
}
else if (op == 0x81) /* subl with 32 bit immed */
{
int locals;
if (codestream_get () != 0xec)
return (-1);
/* subl with 32 bit immediate */
codestream_read ((unsigned char *)&locals, 4);
return (locals);
}
else
{
return (0);
}
}
else if (op == 0xc8)
{
/* enter instruction: arg is 16 unsigned immed */
unsigned short slocals;
codestream_read ((unsigned char *)&slocals, 2);
codestream_get (); /* flush final byte of enter instruction */
return (slocals);
}
return (-1);
}
/* next instruction is a jump, move to target */
static
i386_follow_jump ()
{
int long_delta;
short short_delta;
char byte_delta;
int data16;
int 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 ((unsigned char *)&short_delta, 2);
pos += short_delta + 3; /* include size of jmp inst */
}
else
{
codestream_read ((unsigned char *)&long_delta, 4);
pos += long_delta + 5;
}
break;
case 0xeb:
/* relative jump, disp8 (ignore data16) */
codestream_read ((unsigned char *)&byte_delta, 1);
pos += byte_delta + 2;
break;
}
codestream_seek (pos + data16);
}
/* return pc of first real instruction */
/* from i386-dep.c */
i386_skip_prologue (pc)
{
unsigned char op;
int i;
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 ();
}
i386_follow_jump ();
return (codestream_tell ());
}
symmetry_extract_return_value(type, regbuf, valbuf)
struct type *type;
char *regbuf;
char *valbuf;
{
union {
double d;
int l[2];
} xd;
int i;
float f;
if (TYPE_CODE_FLT == TYPE_CODE(type)) {
for (i = 0; i < misc_function_count; i++) {
if (!strcmp(misc_function_vector[i].name, "1167_flt"))
break;
}
if (i < misc_function_count) {
/* found "1167_flt" means 1167, %fp2-%fp3 */
/* float & double; 19= %fp2, 20= %fp3 */
/* no single precision on 1167 */
xd.l[1] = *((int *)&regbuf[REGISTER_BYTE(19)]);
xd.l[0] = *((int *)&regbuf[REGISTER_BYTE(20)]);
switch (TYPE_LENGTH(type)) {
case 4:
f = (float) xd.d;
bcopy(&f, valbuf, TYPE_LENGTH(type));
break;
case 8:
bcopy(&xd.d, valbuf, TYPE_LENGTH(type));
break;
default:
error("Unknown floating point size");
break;
}
} else {
/* 387 %st(0), gcc uses this */
i387_to_double(((int *)&regbuf[REGISTER_BYTE(3)]),
&xd.d);
switch (TYPE_LENGTH(type)) {
case 4: /* float */
f = (float) xd.d;
bcopy(&f, valbuf, 4);
break;
case 8: /* double */
bcopy(&xd.d, valbuf, 8);
break;
default:
error("Unknown floating point size");
break;
}
}
} else {
bcopy (regbuf, valbuf, TYPE_LENGTH (type));
}
}