1076 lines
29 KiB
C
1076 lines
29 KiB
C
/* Intel 386 target-dependent stuff.
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Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
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1998, 1999, 2000, 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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#include "regcache.h"
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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 that is set with "set disassembly-flavor", and
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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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/* This is used to keep the bfd arch_info in sync with the disassembly
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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
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this buffering did not take into account that the code section
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being accessed may not be an even number of buffers long (even if
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the buffer is only sizeof(int) long). In cases where the code
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section size happened to be a non-integral number of buffers long,
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attempting to read the last buffer would fail. Simply using
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target_read_memory and ignoring errors, rather than read_memory, is
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not the correct solution, since legitimate access errors would then
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be totally ignored. To properly handle this situation and continue
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to use buffering would require that this code be able to determine
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the minimum code section size granularity (not the alignment of the
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section itself, since the actual failing case that pointed out this
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problem had a section alignment of 4 but was not a multiple of 4
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bytes long), on a target by target basis, and then adjust it's
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buffer size accordingly. This is messy, but potentially feasible.
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It probably needs the bfd library's help and support. For now, the
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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() \
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(codestream_cnt == 0 ? \
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codestream_fill(1) : codestream_buf[codestream_off])
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#define codestream_get() \
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(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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/* If the next instruction is a jump, move to its 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 the size of the jmp instruction (including the
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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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/* Find & return the amount a local space allocated, and advance the
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codestream to the first register push (if any).
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If the entry sequence doesn't make sense, return -1, and leave
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codestream pointer at a random spot. */
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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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/* This function must start with
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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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(the System V compiler puts out the second `xchg'
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instruction, and the assembler doesn't try to optimize it, so
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the 'sib' form gets generated). This sequence is used to get
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the address of the return buffer for a function that returns
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a structure. */
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int pos;
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unsigned char buf[4];
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static unsigned char proto1[3] = { 0x87, 0x04, 0x24 };
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static unsigned char proto2[4] = { 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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/* This function may start with
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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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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
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bytes) 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 in 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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NOTE: You can't subtract a 16 bit immediate from a 32 bit
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reg, so we don't have to worry about a data16 prefix. */
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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 immediate. */
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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 (though it wouldn't
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make sense to be negative). */
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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 a 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 a 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' with 16 bit unsigned immediate. */
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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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|
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/* Return the chain-pointer for FRAME. In the case of the i386, the
|
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frame's nominal address is the address of a 4-byte word containing
|
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the calling frame's address. */
|
||
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CORE_ADDR
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i386_frame_chain (struct frame_info *frame)
|
||
{
|
||
if (frame->signal_handler_caller)
|
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return frame->frame;
|
||
|
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if (! inside_entry_file (frame->pc))
|
||
return read_memory_unsigned_integer (frame->frame, 4);
|
||
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||
return 0;
|
||
}
|
||
|
||
/* Return number of args passed to a frame.
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||
Can return -1, meaning no way to tell. */
|
||
|
||
int
|
||
i386_frame_num_args (struct frame_info *fi)
|
||
{
|
||
#if 1
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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. */
|
||
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||
int retpc;
|
||
unsigned char op;
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||
struct frame_info *pfi;
|
||
|
||
/* On the i386, 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. */
|
||
|
||
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 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 System V 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. With the
|
||
System V 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 addr;
|
||
CORE_ADDR pc;
|
||
int i;
|
||
|
||
if (fip->saved_regs)
|
||
return;
|
||
|
||
frame_saved_regs_zalloc (fip);
|
||
|
||
/* If the 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 points in the stack, in a dummy frame. */
|
||
if (dummy_bottom <= fip->pc && fip->pc <= fip->frame)
|
||
{
|
||
/* All registers were saved by push_call_dummy. */
|
||
addr = fip->frame;
|
||
for (i = 0; i < NUM_REGS; i++)
|
||
{
|
||
addr -= REGISTER_RAW_SIZE (i);
|
||
fip->saved_regs[i] = addr;
|
||
}
|
||
return;
|
||
}
|
||
|
||
pc = get_pc_function_start (fip->pc);
|
||
if (pc != 0)
|
||
locals = i386_get_frame_setup (pc);
|
||
|
||
if (locals >= 0)
|
||
{
|
||
addr = 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)] = addr;
|
||
#else
|
||
fip->saved_regs[op - 0x50] = addr;
|
||
#endif
|
||
addr -= 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' instrunction. */
|
||
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 addr;
|
||
addr = frame->saved_regs[regnum];
|
||
if (addr)
|
||
{
|
||
read_memory (addr, 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 */
|
||
|
||
|
||
CORE_ADDR
|
||
i386_push_arguments (int nargs, value_ptr *args, CORE_ADDR sp,
|
||
int struct_return, CORE_ADDR struct_addr)
|
||
{
|
||
sp = default_push_arguments (nargs, args, sp, struct_return, struct_addr);
|
||
|
||
if (struct_return)
|
||
{
|
||
char buf[4];
|
||
|
||
sp -= 4;
|
||
store_address (buf, 4, struct_addr);
|
||
write_memory (sp, buf, 4);
|
||
}
|
||
|
||
return sp;
|
||
}
|
||
|
||
void
|
||
i386_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
|
||
{
|
||
/* Do nothing. Everything was already done by i386_push_arguments. */
|
||
}
|
||
|
||
/* 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 (type) == TYPE_CODE_STRUCT
|
||
&& TYPE_NFIELDS (type) == 1)
|
||
{
|
||
i386_extract_return_value (TYPE_FIELD_TYPE (type, 0), regbuf, valbuf);
|
||
return;
|
||
}
|
||
|
||
if (TYPE_CODE (type) == TYPE_CODE_FLT)
|
||
{
|
||
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 (type) == TYPE_CODE_STRUCT
|
||
&& TYPE_NFIELDS (type) == 1)
|
||
{
|
||
i386_store_return_value (TYPE_FIELD_TYPE (type, 0), valbuf);
|
||
return;
|
||
}
|
||
|
||
if (TYPE_CODE (type) == TYPE_CODE_FLT)
|
||
{
|
||
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);
|
||
}
|
||
}
|
||
|
||
/* Extract from an array REGBUF containing the (raw) register state
|
||
the address in which a function should return its structure value,
|
||
as a CORE_ADDR. */
|
||
|
||
CORE_ADDR
|
||
i386_extract_struct_value_address (char *regbuf)
|
||
{
|
||
return extract_address (®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)],
|
||
REGISTER_RAW_SIZE (LOW_RETURN_REGNUM));
|
||
}
|
||
|
||
|
||
/* 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. */
|
||
}
|
||
|
||
|
||
/* We have two flavours of disassembly. The machinery on this page
|
||
deals with switching between those. */
|
||
|
||
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. */
|
||
internal_error (__FILE__, __LINE__, "failed internal consistency check");
|
||
}
|
||
|
||
/* 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);
|
||
}
|
||
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
void _initialize_i386_tdep (void);
|
||
|
||
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 ();
|
||
}
|