1019 lines
28 KiB
C
1019 lines
28 KiB
C
/* Intel 386 target-dependent stuff.
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Copyright (C) 1988, 1989, 1991, 1994, 1995, 1996, 1998, 2001
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Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "gdb_string.h"
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#include "frame.h"
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#include "inferior.h"
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#include "gdbcore.h"
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#include "target.h"
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#include "floatformat.h"
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#include "symtab.h"
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#include "gdbcmd.h"
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#include "command.h"
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#include "arch-utils.h"
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static long i386_get_frame_setup (CORE_ADDR);
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static void i386_follow_jump (void);
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static void codestream_read (unsigned char *, int);
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static void codestream_seek (CORE_ADDR);
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static unsigned char codestream_fill (int);
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CORE_ADDR skip_trampoline_code (CORE_ADDR, char *);
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static int gdb_print_insn_i386 (bfd_vma, disassemble_info *);
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void _initialize_i386_tdep (void);
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/* i386_register_byte[i] is the offset into the register file of the
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start of register number i. We initialize this from
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i386_register_raw_size. */
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int i386_register_byte[MAX_NUM_REGS];
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/* i386_register_raw_size[i] is the number of bytes of storage in
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GDB's register array occupied by register i. */
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int i386_register_raw_size[MAX_NUM_REGS] = {
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4, 4, 4, 4,
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4, 4, 4, 4,
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4, 4, 4, 4,
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4, 4, 4, 4,
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10, 10, 10, 10,
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10, 10, 10, 10,
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4, 4, 4, 4,
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4, 4, 4, 4,
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16, 16, 16, 16,
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16, 16, 16, 16,
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4
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};
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/* i386_register_virtual_size[i] is the size in bytes of the virtual
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type of register i. */
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int i386_register_virtual_size[MAX_NUM_REGS];
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/* This is the variable the is set with "set disassembly-flavor",
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and its legitimate values. */
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static const char att_flavor[] = "att";
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static const char intel_flavor[] = "intel";
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static const char *valid_flavors[] =
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{
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att_flavor,
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intel_flavor,
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NULL
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};
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static const char *disassembly_flavor = att_flavor;
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static void i386_print_register (char *, int, int);
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/* This is used to keep the bfd arch_info in sync with the disassembly flavor. */
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static void set_disassembly_flavor_sfunc (char *, int,
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struct cmd_list_element *);
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static void set_disassembly_flavor (void);
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/* Stdio style buffering was used to minimize calls to ptrace, but this
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buffering did not take into account that the code section being accessed
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may not be an even number of buffers long (even if the buffer is only
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sizeof(int) long). In cases where the code section size happened to
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be a non-integral number of buffers long, attempting to read the last
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buffer would fail. Simply using target_read_memory and ignoring errors,
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rather than read_memory, is not the correct solution, since legitimate
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access errors would then be totally ignored. To properly handle this
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situation and continue to use buffering would require that this code
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be able to determine the minimum code section size granularity (not the
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alignment of the section itself, since the actual failing case that
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pointed out this problem had a section alignment of 4 but was not a
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multiple of 4 bytes long), on a target by target basis, and then
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adjust it's buffer size accordingly. This is messy, but potentially
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feasible. It probably needs the bfd library's help and support. For
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now, the buffer size is set to 1. (FIXME -fnf) */
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#define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */
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static CORE_ADDR codestream_next_addr;
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static CORE_ADDR codestream_addr;
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static unsigned char codestream_buf[CODESTREAM_BUFSIZ];
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static int codestream_off;
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static int codestream_cnt;
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#define codestream_tell() (codestream_addr + codestream_off)
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#define codestream_peek() (codestream_cnt == 0 ? \
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codestream_fill(1): codestream_buf[codestream_off])
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#define codestream_get() (codestream_cnt-- == 0 ? \
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codestream_fill(0) : codestream_buf[codestream_off++])
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static unsigned char
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codestream_fill (int peek_flag)
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{
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codestream_addr = codestream_next_addr;
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codestream_next_addr += CODESTREAM_BUFSIZ;
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codestream_off = 0;
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codestream_cnt = CODESTREAM_BUFSIZ;
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read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ);
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if (peek_flag)
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return (codestream_peek ());
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else
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return (codestream_get ());
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}
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static void
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codestream_seek (CORE_ADDR place)
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{
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codestream_next_addr = place / CODESTREAM_BUFSIZ;
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codestream_next_addr *= CODESTREAM_BUFSIZ;
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codestream_cnt = 0;
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codestream_fill (1);
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while (codestream_tell () != place)
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codestream_get ();
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}
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static void
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codestream_read (unsigned char *buf, int count)
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{
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unsigned char *p;
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int i;
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p = buf;
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for (i = 0; i < count; i++)
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*p++ = codestream_get ();
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}
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/* next instruction is a jump, move to target */
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static void
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i386_follow_jump (void)
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{
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unsigned char buf[4];
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long delta;
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int data16;
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CORE_ADDR pos;
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pos = codestream_tell ();
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data16 = 0;
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if (codestream_peek () == 0x66)
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{
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codestream_get ();
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data16 = 1;
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}
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switch (codestream_get ())
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{
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case 0xe9:
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/* relative jump: if data16 == 0, disp32, else disp16 */
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if (data16)
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{
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codestream_read (buf, 2);
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delta = extract_signed_integer (buf, 2);
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/* include size of jmp inst (including the 0x66 prefix). */
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pos += delta + 4;
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}
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else
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{
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codestream_read (buf, 4);
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delta = extract_signed_integer (buf, 4);
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pos += delta + 5;
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}
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break;
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case 0xeb:
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/* relative jump, disp8 (ignore data16) */
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codestream_read (buf, 1);
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/* Sign-extend it. */
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delta = extract_signed_integer (buf, 1);
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pos += delta + 2;
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break;
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}
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codestream_seek (pos);
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}
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/*
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* find & return amound a local space allocated, and advance codestream to
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* first register push (if any)
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*
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* if entry sequence doesn't make sense, return -1, and leave
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* codestream pointer random
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*/
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static long
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i386_get_frame_setup (CORE_ADDR pc)
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{
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unsigned char op;
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codestream_seek (pc);
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i386_follow_jump ();
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op = codestream_get ();
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if (op == 0x58) /* popl %eax */
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{
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/*
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* this function must start with
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*
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* popl %eax 0x58
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* xchgl %eax, (%esp) 0x87 0x04 0x24
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* or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
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*
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* (the system 5 compiler puts out the second xchg
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* inst, and the assembler doesn't try to optimize it,
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* so the 'sib' form gets generated)
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*
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* this sequence is used to get the address of the return
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* buffer for a function that returns a structure
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*/
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int pos;
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unsigned char buf[4];
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static unsigned char proto1[3] =
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{0x87, 0x04, 0x24};
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static unsigned char proto2[4] =
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{0x87, 0x44, 0x24, 0x00};
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pos = codestream_tell ();
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codestream_read (buf, 4);
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if (memcmp (buf, proto1, 3) == 0)
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pos += 3;
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else if (memcmp (buf, proto2, 4) == 0)
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pos += 4;
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codestream_seek (pos);
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op = codestream_get (); /* update next opcode */
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}
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if (op == 0x68 || op == 0x6a)
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{
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/*
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* this function may start with
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*
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* pushl constant
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* call _probe
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* addl $4, %esp
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* followed by
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* pushl %ebp
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* etc.
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*/
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int pos;
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unsigned char buf[8];
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/* Skip past the pushl instruction; it has either a one-byte
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or a four-byte operand, depending on the opcode. */
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pos = codestream_tell ();
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if (op == 0x68)
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pos += 4;
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else
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pos += 1;
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codestream_seek (pos);
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/* Read the following 8 bytes, which should be "call _probe" (6 bytes)
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followed by "addl $4,%esp" (2 bytes). */
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codestream_read (buf, sizeof (buf));
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if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4)
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pos += sizeof (buf);
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codestream_seek (pos);
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op = codestream_get (); /* update next opcode */
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}
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if (op == 0x55) /* pushl %ebp */
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{
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/* check for movl %esp, %ebp - can be written two ways */
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switch (codestream_get ())
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{
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case 0x8b:
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if (codestream_get () != 0xec)
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return (-1);
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break;
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case 0x89:
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if (codestream_get () != 0xe5)
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return (-1);
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break;
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default:
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return (-1);
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}
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/* check for stack adjustment
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* subl $XXX, %esp
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*
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* note: you can't subtract a 16 bit immediate
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* from a 32 bit reg, so we don't have to worry
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* about a data16 prefix
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*/
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op = codestream_peek ();
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if (op == 0x83)
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{
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/* subl with 8 bit immed */
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codestream_get ();
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if (codestream_get () != 0xec)
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/* Some instruction starting with 0x83 other than subl. */
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{
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codestream_seek (codestream_tell () - 2);
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return 0;
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}
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/* subl with signed byte immediate
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* (though it wouldn't make sense to be negative)
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*/
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return (codestream_get ());
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}
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else if (op == 0x81)
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{
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char buf[4];
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/* Maybe it is subl with 32 bit immedediate. */
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codestream_get ();
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if (codestream_get () != 0xec)
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/* Some instruction starting with 0x81 other than subl. */
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{
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codestream_seek (codestream_tell () - 2);
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return 0;
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}
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/* It is subl with 32 bit immediate. */
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codestream_read ((unsigned char *) buf, 4);
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return extract_signed_integer (buf, 4);
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}
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else
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{
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return (0);
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}
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}
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else if (op == 0xc8)
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{
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||
char buf[2];
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/* enter instruction: arg is 16 bit unsigned immed */
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codestream_read ((unsigned char *) buf, 2);
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codestream_get (); /* flush final byte of enter instruction */
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return extract_unsigned_integer (buf, 2);
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||
}
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return (-1);
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||
}
|
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/* Return number of args passed to a frame.
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Can return -1, meaning no way to tell. */
|
||
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||
int
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i386_frame_num_args (struct frame_info *fi)
|
||
{
|
||
#if 1
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return -1;
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||
#else
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/* This loses because not only might the compiler not be popping the
|
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args right after the function call, it might be popping args from both
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this call and a previous one, and we would say there are more args
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||
than there really are. */
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int retpc;
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unsigned char op;
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struct frame_info *pfi;
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||
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/* on the 386, the instruction following the call could be:
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popl %ecx - one arg
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addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
|
||
anything else - zero args */
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||
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int frameless;
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||
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||
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. */
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return -1;
|
||
|
||
pfi = get_prev_frame (fi);
|
||
if (pfi == 0)
|
||
{
|
||
/* Note: this can happen if we are looking at the frame for
|
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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;
|
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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_init_saved_regs (struct frame_info *fip)
|
||
{
|
||
long locals = -1;
|
||
unsigned char op;
|
||
CORE_ADDR dummy_bottom;
|
||
CORE_ADDR adr;
|
||
CORE_ADDR pc;
|
||
int i;
|
||
|
||
if (fip->saved_regs)
|
||
return;
|
||
|
||
frame_saved_regs_zalloc (fip);
|
||
|
||
/* 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);
|
||
fip->saved_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. */
|
||
fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = adr;
|
||
#else
|
||
fip->saved_regs[op - 0x50] = adr;
|
||
#endif
|
||
adr -= 4;
|
||
}
|
||
}
|
||
|
||
fip->saved_regs[PC_REGNUM] = fip->frame + 4;
|
||
fip->saved_regs[FP_REGNUM] = fip->frame;
|
||
}
|
||
|
||
/* return pc of first real instruction */
|
||
|
||
int
|
||
i386_skip_prologue (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 (void)
|
||
{
|
||
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);
|
||
}
|
||
|
||
/* Insert the (relative) function address into the call sequence
|
||
stored at DYMMY. */
|
||
|
||
void
|
||
i386_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
|
||
value_ptr *args, struct type *type, int gcc_p)
|
||
{
|
||
int from, to, delta, loc;
|
||
|
||
loc = (int)(read_register (SP_REGNUM) - CALL_DUMMY_LENGTH);
|
||
from = loc + 5;
|
||
to = (int)(fun);
|
||
delta = to - from;
|
||
|
||
*((char *)(dummy) + 1) = (delta & 0xff);
|
||
*((char *)(dummy) + 2) = ((delta >> 8) & 0xff);
|
||
*((char *)(dummy) + 3) = ((delta >> 16) & 0xff);
|
||
*((char *)(dummy) + 4) = ((delta >> 24) & 0xff);
|
||
}
|
||
|
||
void
|
||
i386_pop_frame (void)
|
||
{
|
||
struct frame_info *frame = get_current_frame ();
|
||
CORE_ADDR fp;
|
||
int regnum;
|
||
char regbuf[MAX_REGISTER_RAW_SIZE];
|
||
|
||
fp = FRAME_FP (frame);
|
||
i386_frame_init_saved_regs (frame);
|
||
|
||
for (regnum = 0; regnum < NUM_REGS; regnum++)
|
||
{
|
||
CORE_ADDR adr;
|
||
adr = frame->saved_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 (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 */
|
||
|
||
/* These registers are used for returning integers (and on some
|
||
targets also for returning `struct' and `union' values when their
|
||
size and alignment match an integer type). */
|
||
#define LOW_RETURN_REGNUM 0 /* %eax */
|
||
#define HIGH_RETURN_REGNUM 2 /* %edx */
|
||
|
||
/* Extract from an array REGBUF containing the (raw) register state, a
|
||
function return value of TYPE, and copy that, in virtual format,
|
||
into VALBUF. */
|
||
|
||
void
|
||
i386_extract_return_value (struct type *type, char *regbuf, char *valbuf)
|
||
{
|
||
int len = TYPE_LENGTH (type);
|
||
|
||
if (TYPE_CODE_FLT == TYPE_CODE (type))
|
||
{
|
||
if (NUM_FREGS == 0)
|
||
{
|
||
warning ("Cannot find floating-point return value.");
|
||
memset (valbuf, 0, len);
|
||
return;
|
||
}
|
||
|
||
/* Floating-point return values can be found in %st(0). */
|
||
if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT
|
||
&& TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext)
|
||
{
|
||
/* Copy straight over, but take care of the padding. */
|
||
memcpy (valbuf, ®buf[REGISTER_BYTE (FP0_REGNUM)],
|
||
FPU_REG_RAW_SIZE);
|
||
memset (valbuf + FPU_REG_RAW_SIZE, 0, len - FPU_REG_RAW_SIZE);
|
||
}
|
||
else
|
||
{
|
||
/* Convert the extended floating-point number found in
|
||
%st(0) to the desired type. This is probably not exactly
|
||
how it would happen on the target itself, but it is the
|
||
best we can do. */
|
||
DOUBLEST val;
|
||
floatformat_to_doublest (&floatformat_i387_ext,
|
||
®buf[REGISTER_BYTE (FP0_REGNUM)], &val);
|
||
store_floating (valbuf, TYPE_LENGTH (type), val);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
|
||
int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
|
||
|
||
if (len <= low_size)
|
||
memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len);
|
||
else if (len <= (low_size + high_size))
|
||
{
|
||
memcpy (valbuf,
|
||
®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size);
|
||
memcpy (valbuf + low_size,
|
||
®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size);
|
||
}
|
||
else
|
||
internal_error (__FILE__, __LINE__,
|
||
"Cannot extract return value of %d bytes long.", len);
|
||
}
|
||
}
|
||
|
||
/* Write into the appropriate registers a function return value stored
|
||
in VALBUF of type TYPE, given in virtual format. */
|
||
|
||
void
|
||
i386_store_return_value (struct type *type, char *valbuf)
|
||
{
|
||
int len = TYPE_LENGTH (type);
|
||
|
||
if (TYPE_CODE_FLT == TYPE_CODE (type))
|
||
{
|
||
if (NUM_FREGS == 0)
|
||
{
|
||
warning ("Cannot set floating-point return value.");
|
||
return;
|
||
}
|
||
|
||
/* Floating-point return values can be found in %st(0). */
|
||
if (len == TARGET_LONG_DOUBLE_BIT / TARGET_CHAR_BIT
|
||
&& TARGET_LONG_DOUBLE_FORMAT == &floatformat_i387_ext)
|
||
{
|
||
/* Copy straight over. */
|
||
write_register_bytes (REGISTER_BYTE (FP0_REGNUM), valbuf,
|
||
FPU_REG_RAW_SIZE);
|
||
}
|
||
else
|
||
{
|
||
char buf[FPU_REG_RAW_SIZE];
|
||
DOUBLEST val;
|
||
|
||
/* Convert the value found in VALBUF to the extended
|
||
floating point format used by the FPU. This is probably
|
||
not exactly how it would happen on the target itself, but
|
||
it is the best we can do. */
|
||
val = extract_floating (valbuf, TYPE_LENGTH (type));
|
||
floatformat_from_doublest (&floatformat_i387_ext, &val, buf);
|
||
write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf,
|
||
FPU_REG_RAW_SIZE);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
|
||
int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
|
||
|
||
if (len <= low_size)
|
||
write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), valbuf, len);
|
||
else if (len <= (low_size + high_size))
|
||
{
|
||
write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM),
|
||
valbuf, low_size);
|
||
write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM),
|
||
valbuf + low_size, len - low_size);
|
||
}
|
||
else
|
||
internal_error (__FILE__, __LINE__,
|
||
"Cannot store return value of %d bytes long.", len);
|
||
}
|
||
}
|
||
|
||
/* Convert data from raw format for register REGNUM in buffer FROM to
|
||
virtual format with type TYPE in buffer TO. In principle both
|
||
formats are identical except that the virtual format has two extra
|
||
bytes appended that aren't used. We set these to zero. */
|
||
|
||
void
|
||
i386_register_convert_to_virtual (int regnum, struct type *type,
|
||
char *from, char *to)
|
||
{
|
||
/* Copy straight over, but take care of the padding. */
|
||
memcpy (to, from, FPU_REG_RAW_SIZE);
|
||
memset (to + FPU_REG_RAW_SIZE, 0, TYPE_LENGTH (type) - FPU_REG_RAW_SIZE);
|
||
}
|
||
|
||
/* Convert data from virtual format with type TYPE in buffer FROM to
|
||
raw format for register REGNUM in buffer TO. Simply omit the two
|
||
unused bytes. */
|
||
|
||
void
|
||
i386_register_convert_to_raw (struct type *type, int regnum,
|
||
char *from, char *to)
|
||
{
|
||
memcpy (to, from, FPU_REG_RAW_SIZE);
|
||
}
|
||
|
||
|
||
#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 (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 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 (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 (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 (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 (char *args, int from_tty,
|
||
struct cmd_list_element *c)
|
||
{
|
||
set_disassembly_flavor ();
|
||
}
|
||
|
||
static void
|
||
set_disassembly_flavor (void)
|
||
{
|
||
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);
|
||
}
|
||
|
||
|
||
void
|
||
_initialize_i386_tdep (void)
|
||
{
|
||
/* Initialize the table saying where each register starts in the
|
||
register file. */
|
||
{
|
||
int i, offset;
|
||
|
||
offset = 0;
|
||
for (i = 0; i < MAX_NUM_REGS; i++)
|
||
{
|
||
i386_register_byte[i] = offset;
|
||
offset += i386_register_raw_size[i];
|
||
}
|
||
}
|
||
|
||
/* Initialize the table of virtual register sizes. */
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < MAX_NUM_REGS; i++)
|
||
i386_register_virtual_size[i] = TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (i));
|
||
}
|
||
|
||
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 */
|
||
{
|
||
struct cmd_list_element *new_cmd;
|
||
|
||
new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
|
||
valid_flavors,
|
||
&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 ();
|
||
}
|