/* Intel 386 target-dependent stuff.
- Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc.
+ Copyright (C) 1988, 1989, 1991, 1994, 1995, 1996 Free Software Foundation, Inc.
This file is part of GDB.
-GDB is free software; you can redistribute it and/or modify
+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 1, or (at your option)
-any later version.
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
-GDB is distributed in the hope that it will be useful,
+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 GDB; see the file COPYING. If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
-#include <stdio.h>
#include "defs.h"
-#include "param.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"
-#ifdef USG
-#include <sys/types.h>
-#endif
+static long i386_get_frame_setup PARAMS ((CORE_ADDR));
-#include <sys/param.h>
-#include <sys/dir.h>
-#include <signal.h>
-#include <sys/user.h>
-#include <sys/ioctl.h>
-#include <fcntl.h>
+static void i386_follow_jump PARAMS ((void));
-#ifndef N_SET_MAGIC
-#ifdef COFF_FORMAT
-#define N_SET_MAGIC(exec, val) ((exec).magic = (val))
-#else
-#define N_SET_MAGIC(exec, val) ((exec).a_magic = (val))
-#endif
-#endif
+static void codestream_read PARAMS ((unsigned char *, int));
-#include <sys/file.h>
-#include <sys/stat.h>
+static void codestream_seek PARAMS ((CORE_ADDR));
-/* helper functions for tm-i386.h */
+static unsigned char codestream_fill PARAMS ((int));
-/* stdio style buffering to minimize calls to ptrace */
+/* 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[sizeof (int)];
+static unsigned char codestream_buf[CODESTREAM_BUFSIZ];
static int codestream_off;
static int codestream_cnt;
static unsigned char
codestream_fill (peek_flag)
+ int peek_flag;
{
codestream_addr = codestream_next_addr;
- codestream_next_addr += sizeof (int);
+ codestream_next_addr += CODESTREAM_BUFSIZ;
codestream_off = 0;
- codestream_cnt = sizeof (int);
- read_memory (codestream_addr,
- (unsigned char *)codestream_buf,
- sizeof (int));
+ codestream_cnt = CODESTREAM_BUFSIZ;
+ read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ);
if (peek_flag)
return (codestream_peek());
static void
codestream_seek (place)
+ CORE_ADDR place;
{
- codestream_next_addr = place & -sizeof (int);
+ codestream_next_addr = place / CODESTREAM_BUFSIZ;
+ codestream_next_addr *= CODESTREAM_BUFSIZ;
codestream_cnt = 0;
codestream_fill (1);
while (codestream_tell() != place)
static void
codestream_read (buf, count)
unsigned char *buf;
+ int count;
{
unsigned char *p;
int i;
}
/* next instruction is a jump, move to target */
-static
+
+static void
i386_follow_jump ()
{
- int long_delta;
- short short_delta;
- char byte_delta;
+ unsigned char buf[4];
+ long delta;
+
int data16;
- int pos;
-
+ 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 ((unsigned char *)&short_delta, 2);
+ codestream_read (buf, 2);
+ delta = extract_signed_integer (buf, 2);
/* include size of jmp inst (including the 0x66 prefix). */
- pos += short_delta + 4;
+ pos += delta + 4;
}
else
{
- codestream_read ((unsigned char *)&long_delta, 4);
- pos += long_delta + 5;
+ codestream_read (buf, 4);
+ delta = extract_signed_integer (buf, 4);
+
+ pos += delta + 5;
}
break;
case 0xeb:
/* relative jump, disp8 (ignore data16) */
- codestream_read ((unsigned char *)&byte_delta, 1);
- pos += byte_delta + 2;
+ codestream_read (buf, 1);
+ /* Sign-extend it. */
+ delta = extract_signed_integer (buf, 1);
+
+ pos += delta + 2;
break;
}
codestream_seek (pos);
* 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 */
{
/*
static unsigned char proto2[4] = { 0x87,0x44,0x24,0x00 };
pos = codestream_tell ();
codestream_read (buf, 4);
- if (bcmp (buf, proto1, 3) == 0)
+ if (memcmp (buf, proto1, 3) == 0)
pos += 3;
- else if (bcmp (buf, proto2, 4) == 0)
+ else if (memcmp (buf, proto2, 4) == 0)
pos += 4;
-
+
codestream_seek (pos);
op = codestream_get (); /* update next opcode */
}
-
+
if (op == 0x55) /* pushl %ebp */
{
/* check for movl %esp, %ebp - can be written two ways */
}
else if (op == 0x81)
{
- /* subl with 32 bit immed */
- int locals;
+ 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;
}
- /* subl with 32 bit immediate */
- codestream_read ((unsigned char *)&locals, 4);
- SWAP_TARGET_AND_HOST (&locals, 4);
- return (locals);
+ /* It is subl with 32 bit immediate. */
+ codestream_read ((unsigned char *)buf, 4);
+ return extract_signed_integer (buf, 4);
}
else
{
}
else if (op == 0xc8)
{
+ char buf[2];
/* enter instruction: arg is 16 bit unsigned immed */
- unsigned short slocals;
- codestream_read ((unsigned char *)&slocals, 2);
- SWAP_TARGET_AND_HOST (&slocals, 2);
+ codestream_read ((unsigned char *)buf, 2);
codestream_get (); /* flush final byte of enter instruction */
- return (slocals);
+ return extract_unsigned_integer (buf, 2);
}
return (-1);
}
/* Return number of args passed to a frame.
Can return -1, meaning no way to tell. */
-/* 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
i386_frame_num_args (fi)
- struct frame_info 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_FUNCTION_INVOCATION (fi, frameless);
nameless arguments. */
return -1;
- pfi = get_prev_frame_info ((fi));
+ pfi = get_prev_frame_info (fi);
if (pfi == 0)
{
/* Note: this can happen if we are looking at the frame for
return 0;
}
}
+#endif
}
/*
* 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;
- unsigned char *p;
unsigned char op;
CORE_ADDR dummy_bottom;
CORE_ADDR adr;
int i;
- bzero (fsrp, sizeof *fsrp);
+ memset (fsrp, 0, sizeof *fsrp);
/* if frame is the end of a dummy, compute where the
* beginning would be
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;
}
}
}
/* 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);
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);
write_register (SP_REGNUM, sp);
}
+void
i386_pop_frame ()
{
- FRAME frame = get_current_frame ();
+ struct frame_info *frame = get_current_frame ();
CORE_ADDR fp;
int regnum;
struct frame_saved_regs fsr;
- struct frame_info *fi;
char regbuf[MAX_REGISTER_RAW_SIZE];
- fi = get_frame_info (frame);
- fp = fi->frame;
- get_frame_saved_regs (fi, &fsr);
+ fp = FRAME_FP (frame);
+ get_frame_saved_regs (frame, &fsr);
for (regnum = 0; regnum < NUM_REGS; regnum++)
{
CORE_ADDR adr;
write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
write_register (SP_REGNUM, fp + 8);
flush_cached_frames ();
- set_current_frame ( create_new_frame (read_register (FP_REGNUM),
- read_pc ()));
+}
+
+#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, floating point values are returned in floating point registers. */
+#ifdef I386_AIX_TARGET
+ if (TYPE_CODE_FLT == TYPE_CODE(type))
+ {
+ double d;
+ /* 387 %st(0), gcc uses this */
+ floatformat_to_double (&floatformat_i387_ext,
+ ®buf[REGISTER_BYTE(FP0_REGNUM)],
+ &d);
+ store_floating (valbuf, TYPE_LENGTH (type), d);
+ }
+ else
+#endif /* I386_AIX_TARGET */
+ {
+ memcpy (valbuf, regbuf, TYPE_LENGTH (type));
+ }
+}
+
+#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 */
+
+
+
+/* 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 char *x86_assembly_types[] = {"i386", "i8086", NULL};
+static char *x86_assembly_result = "i386";
+
+static void
+set_assembly_language_command (ignore, from_tty, c)
+ char *ignore;
+ int from_tty;
+ struct cmd_list_element *c;
+{
+ if (strcmp (x86_assembly_result, "i386") == 0)
+ tm_print_insn = print_insn_i386;
+ else
+ tm_print_insn = print_insn_i8086;
+}
+
+void
+_initialize_i386_tdep ()
+{
+ struct cmd_list_element *cmd;
+
+ tm_print_insn = print_insn_i386;
+
+ cmd = add_set_enum_cmd ("assembly-language", class_obscure,
+ x86_assembly_types, (char *)&x86_assembly_result,
+ "Set x86 instruction set to use for disassembly.\n\
+This value can be set to either i386 or i8086 to change how instructions are disassembled.",
+ &setlist);
+ add_show_from_set (cmd, &showlist);
+
+ cmd->function.sfunc = set_assembly_language_command;
}
projects / deliverable / binutils-gdb.git / blobdiff