mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-15 04:31:49 +08:00
1903f0e64b
All callers updated. (amd64_get_insn_details): Handle more 3-byte opcode insns. (amd64_breakpoint_p): Delete. (amd64_displaced_step_fixup): When fixing up after stepping an int3, don't back up pc to the start of the int3. * i386-tdep.c: #include opcode/i386.h. (i386_skip_prefixes): New function. (i386_absolute_jmp_p): Constify argument. (i386_absolute_call_p,i386_ret_p,i386_call_p,i386_syscall_p): Ditto. (i386_breakpoint_p): Delete. (i386_displaced_step_fixup): Handle unnecessary or redundant prefixes. When fixing up after stepping an int3, don't back up pc to the start of the int3. * gdb.arch/amd64-disp-step.S (test_int3): New test. * gdb.arch/amd64-disp-step.exp (test_int3): New test. * gdb.arch/i386-disp-step.S (test_prefixed_abs_jump): New test. (test_prefixed_syscall,test_int3): New tests. * gdb.arch/i386-disp-step.exp (test_prefixed_abs_jump): New test. (test_prefixed_syscall,test_int3): New tests.
2921 lines
84 KiB
C
2921 lines
84 KiB
C
/* Intel 386 target-dependent stuff.
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Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
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1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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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 3 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, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "opcode/i386.h"
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#include "arch-utils.h"
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#include "command.h"
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#include "dummy-frame.h"
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#include "dwarf2-frame.h"
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#include "doublest.h"
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#include "frame.h"
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#include "frame-base.h"
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#include "frame-unwind.h"
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#include "inferior.h"
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#include "gdbcmd.h"
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#include "gdbcore.h"
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#include "gdbtypes.h"
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#include "objfiles.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "reggroups.h"
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#include "regset.h"
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#include "symfile.h"
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#include "symtab.h"
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#include "target.h"
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#include "value.h"
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#include "dis-asm.h"
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#include "gdb_assert.h"
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#include "gdb_string.h"
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#include "i386-tdep.h"
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#include "i387-tdep.h"
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/* Register names. */
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static char *i386_register_names[] =
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{
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"eax", "ecx", "edx", "ebx",
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"esp", "ebp", "esi", "edi",
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"eip", "eflags", "cs", "ss",
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"ds", "es", "fs", "gs",
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"st0", "st1", "st2", "st3",
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"st4", "st5", "st6", "st7",
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"fctrl", "fstat", "ftag", "fiseg",
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"fioff", "foseg", "fooff", "fop",
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"xmm0", "xmm1", "xmm2", "xmm3",
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"xmm4", "xmm5", "xmm6", "xmm7",
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"mxcsr"
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};
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static const int i386_num_register_names = ARRAY_SIZE (i386_register_names);
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/* Register names for MMX pseudo-registers. */
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static char *i386_mmx_names[] =
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{
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"mm0", "mm1", "mm2", "mm3",
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"mm4", "mm5", "mm6", "mm7"
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};
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static const int i386_num_mmx_regs = ARRAY_SIZE (i386_mmx_names);
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static int
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i386_mmx_regnum_p (struct gdbarch *gdbarch, int regnum)
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{
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int mm0_regnum = gdbarch_tdep (gdbarch)->mm0_regnum;
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if (mm0_regnum < 0)
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return 0;
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return (regnum >= mm0_regnum && regnum < mm0_regnum + i386_num_mmx_regs);
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}
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/* SSE register? */
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static int
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i386_sse_regnum_p (struct gdbarch *gdbarch, int regnum)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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if (I387_NUM_XMM_REGS (tdep) == 0)
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return 0;
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return (I387_XMM0_REGNUM (tdep) <= regnum
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&& regnum < I387_MXCSR_REGNUM (tdep));
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}
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static int
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i386_mxcsr_regnum_p (struct gdbarch *gdbarch, int regnum)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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if (I387_NUM_XMM_REGS (tdep) == 0)
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return 0;
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return (regnum == I387_MXCSR_REGNUM (tdep));
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}
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/* FP register? */
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int
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i386_fp_regnum_p (struct gdbarch *gdbarch, int regnum)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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if (I387_ST0_REGNUM (tdep) < 0)
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return 0;
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return (I387_ST0_REGNUM (tdep) <= regnum
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&& regnum < I387_FCTRL_REGNUM (tdep));
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}
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int
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i386_fpc_regnum_p (struct gdbarch *gdbarch, int regnum)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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if (I387_ST0_REGNUM (tdep) < 0)
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return 0;
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return (I387_FCTRL_REGNUM (tdep) <= regnum
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&& regnum < I387_XMM0_REGNUM (tdep));
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}
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/* Return the name of register REGNUM. */
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const char *
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i386_register_name (struct gdbarch *gdbarch, int regnum)
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{
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if (i386_mmx_regnum_p (gdbarch, regnum))
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return i386_mmx_names[regnum - I387_MM0_REGNUM (gdbarch_tdep (gdbarch))];
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if (regnum >= 0 && regnum < i386_num_register_names)
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return i386_register_names[regnum];
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return NULL;
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}
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/* Convert a dbx register number REG to the appropriate register
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number used by GDB. */
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static int
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i386_dbx_reg_to_regnum (struct gdbarch *gdbarch, int reg)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* This implements what GCC calls the "default" register map
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(dbx_register_map[]). */
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if (reg >= 0 && reg <= 7)
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{
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/* General-purpose registers. The debug info calls %ebp
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register 4, and %esp register 5. */
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if (reg == 4)
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return 5;
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else if (reg == 5)
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return 4;
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else return reg;
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}
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else if (reg >= 12 && reg <= 19)
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{
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/* Floating-point registers. */
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return reg - 12 + I387_ST0_REGNUM (tdep);
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}
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else if (reg >= 21 && reg <= 28)
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{
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/* SSE registers. */
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return reg - 21 + I387_XMM0_REGNUM (tdep);
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}
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else if (reg >= 29 && reg <= 36)
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{
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/* MMX registers. */
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return reg - 29 + I387_MM0_REGNUM (tdep);
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}
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/* This will hopefully provoke a warning. */
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return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
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}
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/* Convert SVR4 register number REG to the appropriate register number
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used by GDB. */
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static int
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i386_svr4_reg_to_regnum (struct gdbarch *gdbarch, int reg)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* This implements the GCC register map that tries to be compatible
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with the SVR4 C compiler for DWARF (svr4_dbx_register_map[]). */
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/* The SVR4 register numbering includes %eip and %eflags, and
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numbers the floating point registers differently. */
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if (reg >= 0 && reg <= 9)
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{
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/* General-purpose registers. */
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return reg;
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}
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else if (reg >= 11 && reg <= 18)
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{
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/* Floating-point registers. */
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return reg - 11 + I387_ST0_REGNUM (tdep);
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}
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else if (reg >= 21 && reg <= 36)
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{
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/* The SSE and MMX registers have the same numbers as with dbx. */
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return i386_dbx_reg_to_regnum (gdbarch, reg);
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}
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switch (reg)
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{
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case 37: return I387_FCTRL_REGNUM (tdep);
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case 38: return I387_FSTAT_REGNUM (tdep);
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case 39: return I387_MXCSR_REGNUM (tdep);
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case 40: return I386_ES_REGNUM;
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case 41: return I386_CS_REGNUM;
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case 42: return I386_SS_REGNUM;
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case 43: return I386_DS_REGNUM;
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case 44: return I386_FS_REGNUM;
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case 45: return I386_GS_REGNUM;
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}
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/* This will hopefully provoke a warning. */
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return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
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}
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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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/* Use the program counter to determine the contents and size of a
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breakpoint instruction. Return a pointer to a string of bytes that
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encode a breakpoint instruction, store the length of the string in
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*LEN and optionally adjust *PC to point to the correct memory
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location for inserting the breakpoint.
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On the i386 we have a single breakpoint that fits in a single byte
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and can be inserted anywhere.
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This function is 64-bit safe. */
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static const gdb_byte *
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i386_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pc, int *len)
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{
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static gdb_byte break_insn[] = { 0xcc }; /* int 3 */
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*len = sizeof (break_insn);
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return break_insn;
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}
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/* Displaced instruction handling. */
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/* Skip the legacy instruction prefixes in INSN.
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Not all prefixes are valid for any particular insn
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but we needn't care, the insn will fault if it's invalid.
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The result is a pointer to the first opcode byte,
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or NULL if we run off the end of the buffer. */
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static gdb_byte *
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i386_skip_prefixes (gdb_byte *insn, size_t max_len)
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{
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gdb_byte *end = insn + max_len;
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while (insn < end)
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{
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switch (*insn)
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{
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case DATA_PREFIX_OPCODE:
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case ADDR_PREFIX_OPCODE:
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case CS_PREFIX_OPCODE:
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case DS_PREFIX_OPCODE:
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case ES_PREFIX_OPCODE:
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case FS_PREFIX_OPCODE:
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case GS_PREFIX_OPCODE:
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case SS_PREFIX_OPCODE:
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case LOCK_PREFIX_OPCODE:
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case REPE_PREFIX_OPCODE:
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case REPNE_PREFIX_OPCODE:
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++insn;
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continue;
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default:
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return insn;
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}
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}
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return NULL;
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}
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static int
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i386_absolute_jmp_p (const gdb_byte *insn)
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{
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/* jmp far (absolute address in operand) */
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if (insn[0] == 0xea)
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return 1;
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if (insn[0] == 0xff)
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{
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/* jump near, absolute indirect (/4) */
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if ((insn[1] & 0x38) == 0x20)
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return 1;
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/* jump far, absolute indirect (/5) */
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if ((insn[1] & 0x38) == 0x28)
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return 1;
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}
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return 0;
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}
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static int
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i386_absolute_call_p (const gdb_byte *insn)
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{
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/* call far, absolute */
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if (insn[0] == 0x9a)
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return 1;
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if (insn[0] == 0xff)
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{
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/* Call near, absolute indirect (/2) */
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if ((insn[1] & 0x38) == 0x10)
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return 1;
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/* Call far, absolute indirect (/3) */
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if ((insn[1] & 0x38) == 0x18)
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return 1;
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}
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return 0;
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}
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static int
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i386_ret_p (const gdb_byte *insn)
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{
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switch (insn[0])
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{
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case 0xc2: /* ret near, pop N bytes */
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case 0xc3: /* ret near */
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case 0xca: /* ret far, pop N bytes */
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case 0xcb: /* ret far */
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case 0xcf: /* iret */
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return 1;
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default:
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return 0;
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}
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}
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static int
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i386_call_p (const gdb_byte *insn)
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{
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if (i386_absolute_call_p (insn))
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return 1;
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/* call near, relative */
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if (insn[0] == 0xe8)
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return 1;
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return 0;
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}
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/* Return non-zero if INSN is a system call, and set *LENGTHP to its
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length in bytes. Otherwise, return zero. */
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static int
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i386_syscall_p (const gdb_byte *insn, ULONGEST *lengthp)
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{
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if (insn[0] == 0xcd)
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{
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*lengthp = 2;
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return 1;
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}
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return 0;
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||
}
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||
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/* Fix up the state of registers and memory after having single-stepped
|
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a displaced instruction. */
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||
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void
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i386_displaced_step_fixup (struct gdbarch *gdbarch,
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struct displaced_step_closure *closure,
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CORE_ADDR from, CORE_ADDR to,
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struct regcache *regs)
|
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{
|
||
/* The offset we applied to the instruction's address.
|
||
This could well be negative (when viewed as a signed 32-bit
|
||
value), but ULONGEST won't reflect that, so take care when
|
||
applying it. */
|
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ULONGEST insn_offset = to - from;
|
||
|
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/* Since we use simple_displaced_step_copy_insn, our closure is a
|
||
copy of the instruction. */
|
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gdb_byte *insn = (gdb_byte *) closure;
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||
/* The start of the insn, needed in case we see some prefixes. */
|
||
gdb_byte *insn_start = insn;
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced: fixup (0x%s, 0x%s), "
|
||
"insn = 0x%02x 0x%02x ...\n",
|
||
paddr_nz (from), paddr_nz (to), insn[0], insn[1]);
|
||
|
||
/* The list of issues to contend with here is taken from
|
||
resume_execution in arch/i386/kernel/kprobes.c, Linux 2.6.20.
|
||
Yay for Free Software! */
|
||
|
||
/* Relocate the %eip, if necessary. */
|
||
|
||
/* The instruction recognizers we use assume any leading prefixes
|
||
have been skipped. */
|
||
{
|
||
/* This is the size of the buffer in closure. */
|
||
size_t max_insn_len = gdbarch_max_insn_length (gdbarch);
|
||
gdb_byte *opcode = i386_skip_prefixes (insn, max_insn_len);
|
||
/* If there are too many prefixes, just ignore the insn.
|
||
It will fault when run. */
|
||
if (opcode != NULL)
|
||
insn = opcode;
|
||
}
|
||
|
||
/* Except in the case of absolute or indirect jump or call
|
||
instructions, or a return instruction, the new eip is relative to
|
||
the displaced instruction; make it relative. Well, signal
|
||
handler returns don't need relocation either, but we use the
|
||
value of %eip to recognize those; see below. */
|
||
if (! i386_absolute_jmp_p (insn)
|
||
&& ! i386_absolute_call_p (insn)
|
||
&& ! i386_ret_p (insn))
|
||
{
|
||
ULONGEST orig_eip;
|
||
ULONGEST insn_len;
|
||
|
||
regcache_cooked_read_unsigned (regs, I386_EIP_REGNUM, &orig_eip);
|
||
|
||
/* A signal trampoline system call changes the %eip, resuming
|
||
execution of the main program after the signal handler has
|
||
returned. That makes them like 'return' instructions; we
|
||
shouldn't relocate %eip.
|
||
|
||
But most system calls don't, and we do need to relocate %eip.
|
||
|
||
Our heuristic for distinguishing these cases: if stepping
|
||
over the system call instruction left control directly after
|
||
the instruction, the we relocate --- control almost certainly
|
||
doesn't belong in the displaced copy. Otherwise, we assume
|
||
the instruction has put control where it belongs, and leave
|
||
it unrelocated. Goodness help us if there are PC-relative
|
||
system calls. */
|
||
if (i386_syscall_p (insn, &insn_len)
|
||
&& orig_eip != to + (insn - insn_start) + insn_len)
|
||
{
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced: syscall changed %%eip; "
|
||
"not relocating\n");
|
||
}
|
||
else
|
||
{
|
||
ULONGEST eip = (orig_eip - insn_offset) & 0xffffffffUL;
|
||
|
||
/* If we just stepped over a breakpoint insn, we don't backup
|
||
the pc on purpose; this is to match behaviour without
|
||
stepping. */
|
||
|
||
regcache_cooked_write_unsigned (regs, I386_EIP_REGNUM, eip);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced: "
|
||
"relocated %%eip from 0x%s to 0x%s\n",
|
||
paddr_nz (orig_eip), paddr_nz (eip));
|
||
}
|
||
}
|
||
|
||
/* If the instruction was PUSHFL, then the TF bit will be set in the
|
||
pushed value, and should be cleared. We'll leave this for later,
|
||
since GDB already messes up the TF flag when stepping over a
|
||
pushfl. */
|
||
|
||
/* If the instruction was a call, the return address now atop the
|
||
stack is the address following the copied instruction. We need
|
||
to make it the address following the original instruction. */
|
||
if (i386_call_p (insn))
|
||
{
|
||
ULONGEST esp;
|
||
ULONGEST retaddr;
|
||
const ULONGEST retaddr_len = 4;
|
||
|
||
regcache_cooked_read_unsigned (regs, I386_ESP_REGNUM, &esp);
|
||
retaddr = read_memory_unsigned_integer (esp, retaddr_len);
|
||
retaddr = (retaddr - insn_offset) & 0xffffffffUL;
|
||
write_memory_unsigned_integer (esp, retaddr_len, retaddr);
|
||
|
||
if (debug_displaced)
|
||
fprintf_unfiltered (gdb_stdlog,
|
||
"displaced: relocated return addr at 0x%s "
|
||
"to 0x%s\n",
|
||
paddr_nz (esp),
|
||
paddr_nz (retaddr));
|
||
}
|
||
}
|
||
|
||
#ifdef I386_REGNO_TO_SYMMETRY
|
||
#error "The Sequent Symmetry is no longer supported."
|
||
#endif
|
||
|
||
/* According to the System V ABI, the registers %ebp, %ebx, %edi, %esi
|
||
and %esp "belong" to the calling function. Therefore these
|
||
registers should be saved if they're going to be modified. */
|
||
|
||
/* The maximum number of saved registers. This should include all
|
||
registers mentioned above, and %eip. */
|
||
#define I386_NUM_SAVED_REGS I386_NUM_GREGS
|
||
|
||
struct i386_frame_cache
|
||
{
|
||
/* Base address. */
|
||
CORE_ADDR base;
|
||
LONGEST sp_offset;
|
||
CORE_ADDR pc;
|
||
|
||
/* Saved registers. */
|
||
CORE_ADDR saved_regs[I386_NUM_SAVED_REGS];
|
||
CORE_ADDR saved_sp;
|
||
int saved_sp_reg;
|
||
int pc_in_eax;
|
||
|
||
/* Stack space reserved for local variables. */
|
||
long locals;
|
||
};
|
||
|
||
/* Allocate and initialize a frame cache. */
|
||
|
||
static struct i386_frame_cache *
|
||
i386_alloc_frame_cache (void)
|
||
{
|
||
struct i386_frame_cache *cache;
|
||
int i;
|
||
|
||
cache = FRAME_OBSTACK_ZALLOC (struct i386_frame_cache);
|
||
|
||
/* Base address. */
|
||
cache->base = 0;
|
||
cache->sp_offset = -4;
|
||
cache->pc = 0;
|
||
|
||
/* Saved registers. We initialize these to -1 since zero is a valid
|
||
offset (that's where %ebp is supposed to be stored). */
|
||
for (i = 0; i < I386_NUM_SAVED_REGS; i++)
|
||
cache->saved_regs[i] = -1;
|
||
cache->saved_sp = 0;
|
||
cache->saved_sp_reg = -1;
|
||
cache->pc_in_eax = 0;
|
||
|
||
/* Frameless until proven otherwise. */
|
||
cache->locals = -1;
|
||
|
||
return cache;
|
||
}
|
||
|
||
/* If the instruction at PC is a jump, return the address of its
|
||
target. Otherwise, return PC. */
|
||
|
||
static CORE_ADDR
|
||
i386_follow_jump (CORE_ADDR pc)
|
||
{
|
||
gdb_byte op;
|
||
long delta = 0;
|
||
int data16 = 0;
|
||
|
||
target_read_memory (pc, &op, 1);
|
||
if (op == 0x66)
|
||
{
|
||
data16 = 1;
|
||
op = read_memory_unsigned_integer (pc + 1, 1);
|
||
}
|
||
|
||
switch (op)
|
||
{
|
||
case 0xe9:
|
||
/* Relative jump: if data16 == 0, disp32, else disp16. */
|
||
if (data16)
|
||
{
|
||
delta = read_memory_integer (pc + 2, 2);
|
||
|
||
/* Include the size of the jmp instruction (including the
|
||
0x66 prefix). */
|
||
delta += 4;
|
||
}
|
||
else
|
||
{
|
||
delta = read_memory_integer (pc + 1, 4);
|
||
|
||
/* Include the size of the jmp instruction. */
|
||
delta += 5;
|
||
}
|
||
break;
|
||
case 0xeb:
|
||
/* Relative jump, disp8 (ignore data16). */
|
||
delta = read_memory_integer (pc + data16 + 1, 1);
|
||
|
||
delta += data16 + 2;
|
||
break;
|
||
}
|
||
|
||
return pc + delta;
|
||
}
|
||
|
||
/* Check whether PC points at a prologue for a function returning a
|
||
structure or union. If so, it updates CACHE and returns the
|
||
address of the first instruction after the code sequence that
|
||
removes the "hidden" argument from the stack or CURRENT_PC,
|
||
whichever is smaller. Otherwise, return PC. */
|
||
|
||
static CORE_ADDR
|
||
i386_analyze_struct_return (CORE_ADDR pc, CORE_ADDR current_pc,
|
||
struct i386_frame_cache *cache)
|
||
{
|
||
/* Functions that return a structure or union start with:
|
||
|
||
popl %eax 0x58
|
||
xchgl %eax, (%esp) 0x87 0x04 0x24
|
||
or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
|
||
|
||
(the System V compiler puts out the second `xchg' instruction,
|
||
and the assembler doesn't try to optimize it, so the 'sib' form
|
||
gets generated). This sequence is used to get the address of the
|
||
return buffer for a function that returns a structure. */
|
||
static gdb_byte proto1[3] = { 0x87, 0x04, 0x24 };
|
||
static gdb_byte proto2[4] = { 0x87, 0x44, 0x24, 0x00 };
|
||
gdb_byte buf[4];
|
||
gdb_byte op;
|
||
|
||
if (current_pc <= pc)
|
||
return pc;
|
||
|
||
target_read_memory (pc, &op, 1);
|
||
|
||
if (op != 0x58) /* popl %eax */
|
||
return pc;
|
||
|
||
target_read_memory (pc + 1, buf, 4);
|
||
if (memcmp (buf, proto1, 3) != 0 && memcmp (buf, proto2, 4) != 0)
|
||
return pc;
|
||
|
||
if (current_pc == pc)
|
||
{
|
||
cache->sp_offset += 4;
|
||
return current_pc;
|
||
}
|
||
|
||
if (current_pc == pc + 1)
|
||
{
|
||
cache->pc_in_eax = 1;
|
||
return current_pc;
|
||
}
|
||
|
||
if (buf[1] == proto1[1])
|
||
return pc + 4;
|
||
else
|
||
return pc + 5;
|
||
}
|
||
|
||
static CORE_ADDR
|
||
i386_skip_probe (CORE_ADDR pc)
|
||
{
|
||
/* A function may start with
|
||
|
||
pushl constant
|
||
call _probe
|
||
addl $4, %esp
|
||
|
||
followed by
|
||
|
||
pushl %ebp
|
||
|
||
etc. */
|
||
gdb_byte buf[8];
|
||
gdb_byte op;
|
||
|
||
target_read_memory (pc, &op, 1);
|
||
|
||
if (op == 0x68 || op == 0x6a)
|
||
{
|
||
int delta;
|
||
|
||
/* Skip past the `pushl' instruction; it has either a one-byte or a
|
||
four-byte operand, depending on the opcode. */
|
||
if (op == 0x68)
|
||
delta = 5;
|
||
else
|
||
delta = 2;
|
||
|
||
/* Read the following 8 bytes, which should be `call _probe' (6
|
||
bytes) followed by `addl $4,%esp' (2 bytes). */
|
||
read_memory (pc + delta, buf, sizeof (buf));
|
||
if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4)
|
||
pc += delta + sizeof (buf);
|
||
}
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* GCC 4.1 and later, can put code in the prologue to realign the
|
||
stack pointer. Check whether PC points to such code, and update
|
||
CACHE accordingly. Return the first instruction after the code
|
||
sequence or CURRENT_PC, whichever is smaller. If we don't
|
||
recognize the code, return PC. */
|
||
|
||
static CORE_ADDR
|
||
i386_analyze_stack_align (CORE_ADDR pc, CORE_ADDR current_pc,
|
||
struct i386_frame_cache *cache)
|
||
{
|
||
/* There are 2 code sequences to re-align stack before the frame
|
||
gets set up:
|
||
|
||
1. Use a caller-saved saved register:
|
||
|
||
leal 4(%esp), %reg
|
||
andl $-XXX, %esp
|
||
pushl -4(%reg)
|
||
|
||
2. Use a callee-saved saved register:
|
||
|
||
pushl %reg
|
||
leal 8(%esp), %reg
|
||
andl $-XXX, %esp
|
||
pushl -4(%reg)
|
||
|
||
"andl $-XXX, %esp" can be either 3 bytes or 6 bytes:
|
||
|
||
0x83 0xe4 0xf0 andl $-16, %esp
|
||
0x81 0xe4 0x00 0xff 0xff 0xff andl $-256, %esp
|
||
*/
|
||
|
||
gdb_byte buf[14];
|
||
int reg;
|
||
int offset, offset_and;
|
||
static int regnums[8] = {
|
||
I386_EAX_REGNUM, /* %eax */
|
||
I386_ECX_REGNUM, /* %ecx */
|
||
I386_EDX_REGNUM, /* %edx */
|
||
I386_EBX_REGNUM, /* %ebx */
|
||
I386_ESP_REGNUM, /* %esp */
|
||
I386_EBP_REGNUM, /* %ebp */
|
||
I386_ESI_REGNUM, /* %esi */
|
||
I386_EDI_REGNUM /* %edi */
|
||
};
|
||
|
||
if (target_read_memory (pc, buf, sizeof buf))
|
||
return pc;
|
||
|
||
/* Check caller-saved saved register. The first instruction has
|
||
to be "leal 4(%esp), %reg". */
|
||
if (buf[0] == 0x8d && buf[2] == 0x24 && buf[3] == 0x4)
|
||
{
|
||
/* MOD must be binary 10 and R/M must be binary 100. */
|
||
if ((buf[1] & 0xc7) != 0x44)
|
||
return pc;
|
||
|
||
/* REG has register number. */
|
||
reg = (buf[1] >> 3) & 7;
|
||
offset = 4;
|
||
}
|
||
else
|
||
{
|
||
/* Check callee-saved saved register. The first instruction
|
||
has to be "pushl %reg". */
|
||
if ((buf[0] & 0xf8) != 0x50)
|
||
return pc;
|
||
|
||
/* Get register. */
|
||
reg = buf[0] & 0x7;
|
||
|
||
/* The next instruction has to be "leal 8(%esp), %reg". */
|
||
if (buf[1] != 0x8d || buf[3] != 0x24 || buf[4] != 0x8)
|
||
return pc;
|
||
|
||
/* MOD must be binary 10 and R/M must be binary 100. */
|
||
if ((buf[2] & 0xc7) != 0x44)
|
||
return pc;
|
||
|
||
/* REG has register number. Registers in pushl and leal have to
|
||
be the same. */
|
||
if (reg != ((buf[2] >> 3) & 7))
|
||
return pc;
|
||
|
||
offset = 5;
|
||
}
|
||
|
||
/* Rigister can't be %esp nor %ebp. */
|
||
if (reg == 4 || reg == 5)
|
||
return pc;
|
||
|
||
/* The next instruction has to be "andl $-XXX, %esp". */
|
||
if (buf[offset + 1] != 0xe4
|
||
|| (buf[offset] != 0x81 && buf[offset] != 0x83))
|
||
return pc;
|
||
|
||
offset_and = offset;
|
||
offset += buf[offset] == 0x81 ? 6 : 3;
|
||
|
||
/* The next instruction has to be "pushl -4(%reg)". 8bit -4 is
|
||
0xfc. REG must be binary 110 and MOD must be binary 01. */
|
||
if (buf[offset] != 0xff
|
||
|| buf[offset + 2] != 0xfc
|
||
|| (buf[offset + 1] & 0xf8) != 0x70)
|
||
return pc;
|
||
|
||
/* R/M has register. Registers in leal and pushl have to be the
|
||
same. */
|
||
if (reg != (buf[offset + 1] & 7))
|
||
return pc;
|
||
|
||
if (current_pc > pc + offset_and)
|
||
cache->saved_sp_reg = regnums[reg];
|
||
|
||
return min (pc + offset + 3, current_pc);
|
||
}
|
||
|
||
/* Maximum instruction length we need to handle. */
|
||
#define I386_MAX_MATCHED_INSN_LEN 6
|
||
|
||
/* Instruction description. */
|
||
struct i386_insn
|
||
{
|
||
size_t len;
|
||
gdb_byte insn[I386_MAX_MATCHED_INSN_LEN];
|
||
gdb_byte mask[I386_MAX_MATCHED_INSN_LEN];
|
||
};
|
||
|
||
/* Search for the instruction at PC in the list SKIP_INSNS. Return
|
||
the first instruction description that matches. Otherwise, return
|
||
NULL. */
|
||
|
||
static struct i386_insn *
|
||
i386_match_insn (CORE_ADDR pc, struct i386_insn *skip_insns)
|
||
{
|
||
struct i386_insn *insn;
|
||
gdb_byte op;
|
||
|
||
target_read_memory (pc, &op, 1);
|
||
|
||
for (insn = skip_insns; insn->len > 0; insn++)
|
||
{
|
||
if ((op & insn->mask[0]) == insn->insn[0])
|
||
{
|
||
gdb_byte buf[I386_MAX_MATCHED_INSN_LEN - 1];
|
||
int insn_matched = 1;
|
||
size_t i;
|
||
|
||
gdb_assert (insn->len > 1);
|
||
gdb_assert (insn->len <= I386_MAX_MATCHED_INSN_LEN);
|
||
|
||
target_read_memory (pc + 1, buf, insn->len - 1);
|
||
for (i = 1; i < insn->len; i++)
|
||
{
|
||
if ((buf[i - 1] & insn->mask[i]) != insn->insn[i])
|
||
insn_matched = 0;
|
||
}
|
||
|
||
if (insn_matched)
|
||
return insn;
|
||
}
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
/* Some special instructions that might be migrated by GCC into the
|
||
part of the prologue that sets up the new stack frame. Because the
|
||
stack frame hasn't been setup yet, no registers have been saved
|
||
yet, and only the scratch registers %eax, %ecx and %edx can be
|
||
touched. */
|
||
|
||
struct i386_insn i386_frame_setup_skip_insns[] =
|
||
{
|
||
/* Check for `movb imm8, r' and `movl imm32, r'.
|
||
|
||
??? Should we handle 16-bit operand-sizes here? */
|
||
|
||
/* `movb imm8, %al' and `movb imm8, %ah' */
|
||
/* `movb imm8, %cl' and `movb imm8, %ch' */
|
||
{ 2, { 0xb0, 0x00 }, { 0xfa, 0x00 } },
|
||
/* `movb imm8, %dl' and `movb imm8, %dh' */
|
||
{ 2, { 0xb2, 0x00 }, { 0xfb, 0x00 } },
|
||
/* `movl imm32, %eax' and `movl imm32, %ecx' */
|
||
{ 5, { 0xb8 }, { 0xfe } },
|
||
/* `movl imm32, %edx' */
|
||
{ 5, { 0xba }, { 0xff } },
|
||
|
||
/* Check for `mov imm32, r32'. Note that there is an alternative
|
||
encoding for `mov m32, %eax'.
|
||
|
||
??? Should we handle SIB adressing here?
|
||
??? Should we handle 16-bit operand-sizes here? */
|
||
|
||
/* `movl m32, %eax' */
|
||
{ 5, { 0xa1 }, { 0xff } },
|
||
/* `movl m32, %eax' and `mov; m32, %ecx' */
|
||
{ 6, { 0x89, 0x05 }, {0xff, 0xf7 } },
|
||
/* `movl m32, %edx' */
|
||
{ 6, { 0x89, 0x15 }, {0xff, 0xff } },
|
||
|
||
/* Check for `xorl r32, r32' and the equivalent `subl r32, r32'.
|
||
Because of the symmetry, there are actually two ways to encode
|
||
these instructions; opcode bytes 0x29 and 0x2b for `subl' and
|
||
opcode bytes 0x31 and 0x33 for `xorl'. */
|
||
|
||
/* `subl %eax, %eax' */
|
||
{ 2, { 0x29, 0xc0 }, { 0xfd, 0xff } },
|
||
/* `subl %ecx, %ecx' */
|
||
{ 2, { 0x29, 0xc9 }, { 0xfd, 0xff } },
|
||
/* `subl %edx, %edx' */
|
||
{ 2, { 0x29, 0xd2 }, { 0xfd, 0xff } },
|
||
/* `xorl %eax, %eax' */
|
||
{ 2, { 0x31, 0xc0 }, { 0xfd, 0xff } },
|
||
/* `xorl %ecx, %ecx' */
|
||
{ 2, { 0x31, 0xc9 }, { 0xfd, 0xff } },
|
||
/* `xorl %edx, %edx' */
|
||
{ 2, { 0x31, 0xd2 }, { 0xfd, 0xff } },
|
||
{ 0 }
|
||
};
|
||
|
||
|
||
/* Check whether PC points to a no-op instruction. */
|
||
static CORE_ADDR
|
||
i386_skip_noop (CORE_ADDR pc)
|
||
{
|
||
gdb_byte op;
|
||
int check = 1;
|
||
|
||
target_read_memory (pc, &op, 1);
|
||
|
||
while (check)
|
||
{
|
||
check = 0;
|
||
/* Ignore `nop' instruction. */
|
||
if (op == 0x90)
|
||
{
|
||
pc += 1;
|
||
target_read_memory (pc, &op, 1);
|
||
check = 1;
|
||
}
|
||
/* Ignore no-op instruction `mov %edi, %edi'.
|
||
Microsoft system dlls often start with
|
||
a `mov %edi,%edi' instruction.
|
||
The 5 bytes before the function start are
|
||
filled with `nop' instructions.
|
||
This pattern can be used for hot-patching:
|
||
The `mov %edi, %edi' instruction can be replaced by a
|
||
near jump to the location of the 5 `nop' instructions
|
||
which can be replaced by a 32-bit jump to anywhere
|
||
in the 32-bit address space. */
|
||
|
||
else if (op == 0x8b)
|
||
{
|
||
target_read_memory (pc + 1, &op, 1);
|
||
if (op == 0xff)
|
||
{
|
||
pc += 2;
|
||
target_read_memory (pc, &op, 1);
|
||
check = 1;
|
||
}
|
||
}
|
||
}
|
||
return pc;
|
||
}
|
||
|
||
/* Check whether PC points at a code that sets up a new stack frame.
|
||
If so, it updates CACHE and returns the address of the first
|
||
instruction after the sequence that sets up the frame or LIMIT,
|
||
whichever is smaller. If we don't recognize the code, return PC. */
|
||
|
||
static CORE_ADDR
|
||
i386_analyze_frame_setup (CORE_ADDR pc, CORE_ADDR limit,
|
||
struct i386_frame_cache *cache)
|
||
{
|
||
struct i386_insn *insn;
|
||
gdb_byte op;
|
||
int skip = 0;
|
||
|
||
if (limit <= pc)
|
||
return limit;
|
||
|
||
target_read_memory (pc, &op, 1);
|
||
|
||
if (op == 0x55) /* pushl %ebp */
|
||
{
|
||
/* Take into account that we've executed the `pushl %ebp' that
|
||
starts this instruction sequence. */
|
||
cache->saved_regs[I386_EBP_REGNUM] = 0;
|
||
cache->sp_offset += 4;
|
||
pc++;
|
||
|
||
/* If that's all, return now. */
|
||
if (limit <= pc)
|
||
return limit;
|
||
|
||
/* Check for some special instructions that might be migrated by
|
||
GCC into the prologue and skip them. At this point in the
|
||
prologue, code should only touch the scratch registers %eax,
|
||
%ecx and %edx, so while the number of posibilities is sheer,
|
||
it is limited.
|
||
|
||
Make sure we only skip these instructions if we later see the
|
||
`movl %esp, %ebp' that actually sets up the frame. */
|
||
while (pc + skip < limit)
|
||
{
|
||
insn = i386_match_insn (pc + skip, i386_frame_setup_skip_insns);
|
||
if (insn == NULL)
|
||
break;
|
||
|
||
skip += insn->len;
|
||
}
|
||
|
||
/* If that's all, return now. */
|
||
if (limit <= pc + skip)
|
||
return limit;
|
||
|
||
target_read_memory (pc + skip, &op, 1);
|
||
|
||
/* Check for `movl %esp, %ebp' -- can be written in two ways. */
|
||
switch (op)
|
||
{
|
||
case 0x8b:
|
||
if (read_memory_unsigned_integer (pc + skip + 1, 1) != 0xec)
|
||
return pc;
|
||
break;
|
||
case 0x89:
|
||
if (read_memory_unsigned_integer (pc + skip + 1, 1) != 0xe5)
|
||
return pc;
|
||
break;
|
||
default:
|
||
return pc;
|
||
}
|
||
|
||
/* OK, we actually have a frame. We just don't know how large
|
||
it is yet. Set its size to zero. We'll adjust it if
|
||
necessary. We also now commit to skipping the special
|
||
instructions mentioned before. */
|
||
cache->locals = 0;
|
||
pc += (skip + 2);
|
||
|
||
/* If that's all, return now. */
|
||
if (limit <= pc)
|
||
return limit;
|
||
|
||
/* Check for stack adjustment
|
||
|
||
subl $XXX, %esp
|
||
|
||
NOTE: You can't subtract a 16-bit immediate from a 32-bit
|
||
reg, so we don't have to worry about a data16 prefix. */
|
||
target_read_memory (pc, &op, 1);
|
||
if (op == 0x83)
|
||
{
|
||
/* `subl' with 8-bit immediate. */
|
||
if (read_memory_unsigned_integer (pc + 1, 1) != 0xec)
|
||
/* Some instruction starting with 0x83 other than `subl'. */
|
||
return pc;
|
||
|
||
/* `subl' with signed 8-bit immediate (though it wouldn't
|
||
make sense to be negative). */
|
||
cache->locals = read_memory_integer (pc + 2, 1);
|
||
return pc + 3;
|
||
}
|
||
else if (op == 0x81)
|
||
{
|
||
/* Maybe it is `subl' with a 32-bit immediate. */
|
||
if (read_memory_unsigned_integer (pc + 1, 1) != 0xec)
|
||
/* Some instruction starting with 0x81 other than `subl'. */
|
||
return pc;
|
||
|
||
/* It is `subl' with a 32-bit immediate. */
|
||
cache->locals = read_memory_integer (pc + 2, 4);
|
||
return pc + 6;
|
||
}
|
||
else
|
||
{
|
||
/* Some instruction other than `subl'. */
|
||
return pc;
|
||
}
|
||
}
|
||
else if (op == 0xc8) /* enter */
|
||
{
|
||
cache->locals = read_memory_unsigned_integer (pc + 1, 2);
|
||
return pc + 4;
|
||
}
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* Check whether PC points at code that saves registers on the stack.
|
||
If so, it updates CACHE and returns the address of the first
|
||
instruction after the register saves or CURRENT_PC, whichever is
|
||
smaller. Otherwise, return PC. */
|
||
|
||
static CORE_ADDR
|
||
i386_analyze_register_saves (CORE_ADDR pc, CORE_ADDR current_pc,
|
||
struct i386_frame_cache *cache)
|
||
{
|
||
CORE_ADDR offset = 0;
|
||
gdb_byte op;
|
||
int i;
|
||
|
||
if (cache->locals > 0)
|
||
offset -= cache->locals;
|
||
for (i = 0; i < 8 && pc < current_pc; i++)
|
||
{
|
||
target_read_memory (pc, &op, 1);
|
||
if (op < 0x50 || op > 0x57)
|
||
break;
|
||
|
||
offset -= 4;
|
||
cache->saved_regs[op - 0x50] = offset;
|
||
cache->sp_offset += 4;
|
||
pc++;
|
||
}
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* Do a full analysis of the prologue at PC and update CACHE
|
||
accordingly. Bail out early if CURRENT_PC is reached. Return the
|
||
address where the analysis stopped.
|
||
|
||
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. */
|
||
|
||
static CORE_ADDR
|
||
i386_analyze_prologue (CORE_ADDR pc, CORE_ADDR current_pc,
|
||
struct i386_frame_cache *cache)
|
||
{
|
||
pc = i386_skip_noop (pc);
|
||
pc = i386_follow_jump (pc);
|
||
pc = i386_analyze_struct_return (pc, current_pc, cache);
|
||
pc = i386_skip_probe (pc);
|
||
pc = i386_analyze_stack_align (pc, current_pc, cache);
|
||
pc = i386_analyze_frame_setup (pc, current_pc, cache);
|
||
return i386_analyze_register_saves (pc, current_pc, cache);
|
||
}
|
||
|
||
/* Return PC of first real instruction. */
|
||
|
||
static CORE_ADDR
|
||
i386_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc)
|
||
{
|
||
static gdb_byte pic_pat[6] =
|
||
{
|
||
0xe8, 0, 0, 0, 0, /* call 0x0 */
|
||
0x5b, /* popl %ebx */
|
||
};
|
||
struct i386_frame_cache cache;
|
||
CORE_ADDR pc;
|
||
gdb_byte op;
|
||
int i;
|
||
|
||
cache.locals = -1;
|
||
pc = i386_analyze_prologue (start_pc, 0xffffffff, &cache);
|
||
if (cache.locals < 0)
|
||
return start_pc;
|
||
|
||
/* Found valid frame setup. */
|
||
|
||
/* 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. */
|
||
|
||
for (i = 0; i < 6; i++)
|
||
{
|
||
target_read_memory (pc + i, &op, 1);
|
||
if (pic_pat[i] != op)
|
||
break;
|
||
}
|
||
if (i == 6)
|
||
{
|
||
int delta = 6;
|
||
|
||
target_read_memory (pc + delta, &op, 1);
|
||
|
||
if (op == 0x89) /* movl %ebx, x(%ebp) */
|
||
{
|
||
op = read_memory_unsigned_integer (pc + delta + 1, 1);
|
||
|
||
if (op == 0x5d) /* One byte offset from %ebp. */
|
||
delta += 3;
|
||
else if (op == 0x9d) /* Four byte offset from %ebp. */
|
||
delta += 6;
|
||
else /* Unexpected instruction. */
|
||
delta = 0;
|
||
|
||
target_read_memory (pc + delta, &op, 1);
|
||
}
|
||
|
||
/* addl y,%ebx */
|
||
if (delta > 0 && op == 0x81
|
||
&& read_memory_unsigned_integer (pc + delta + 1, 1) == 0xc3)
|
||
{
|
||
pc += delta + 6;
|
||
}
|
||
}
|
||
|
||
/* If the function starts with a branch (to startup code at the end)
|
||
the last instruction should bring us back to the first
|
||
instruction of the real code. */
|
||
if (i386_follow_jump (start_pc) != start_pc)
|
||
pc = i386_follow_jump (pc);
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* Check that the code pointed to by PC corresponds to a call to
|
||
__main, skip it if so. Return PC otherwise. */
|
||
|
||
CORE_ADDR
|
||
i386_skip_main_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
|
||
{
|
||
gdb_byte op;
|
||
|
||
target_read_memory (pc, &op, 1);
|
||
if (op == 0xe8)
|
||
{
|
||
gdb_byte buf[4];
|
||
|
||
if (target_read_memory (pc + 1, buf, sizeof buf) == 0)
|
||
{
|
||
/* Make sure address is computed correctly as a 32bit
|
||
integer even if CORE_ADDR is 64 bit wide. */
|
||
struct minimal_symbol *s;
|
||
CORE_ADDR call_dest = pc + 5 + extract_signed_integer (buf, 4);
|
||
|
||
call_dest = call_dest & 0xffffffffU;
|
||
s = lookup_minimal_symbol_by_pc (call_dest);
|
||
if (s != NULL
|
||
&& SYMBOL_LINKAGE_NAME (s) != NULL
|
||
&& strcmp (SYMBOL_LINKAGE_NAME (s), "__main") == 0)
|
||
pc += 5;
|
||
}
|
||
}
|
||
|
||
return pc;
|
||
}
|
||
|
||
/* This function is 64-bit safe. */
|
||
|
||
static CORE_ADDR
|
||
i386_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
|
||
{
|
||
gdb_byte buf[8];
|
||
|
||
frame_unwind_register (next_frame, gdbarch_pc_regnum (gdbarch), buf);
|
||
return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr);
|
||
}
|
||
|
||
|
||
/* Normal frames. */
|
||
|
||
static struct i386_frame_cache *
|
||
i386_frame_cache (struct frame_info *this_frame, void **this_cache)
|
||
{
|
||
struct i386_frame_cache *cache;
|
||
gdb_byte buf[4];
|
||
int i;
|
||
|
||
if (*this_cache)
|
||
return *this_cache;
|
||
|
||
cache = i386_alloc_frame_cache ();
|
||
*this_cache = cache;
|
||
|
||
/* In principle, for normal frames, %ebp holds the frame pointer,
|
||
which holds the base address for the current stack frame.
|
||
However, for functions that don't need it, the frame pointer is
|
||
optional. For these "frameless" functions the frame pointer is
|
||
actually the frame pointer of the calling frame. Signal
|
||
trampolines are just a special case of a "frameless" function.
|
||
They (usually) share their frame pointer with the frame that was
|
||
in progress when the signal occurred. */
|
||
|
||
get_frame_register (this_frame, I386_EBP_REGNUM, buf);
|
||
cache->base = extract_unsigned_integer (buf, 4);
|
||
if (cache->base == 0)
|
||
return cache;
|
||
|
||
/* For normal frames, %eip is stored at 4(%ebp). */
|
||
cache->saved_regs[I386_EIP_REGNUM] = 4;
|
||
|
||
cache->pc = get_frame_func (this_frame);
|
||
if (cache->pc != 0)
|
||
i386_analyze_prologue (cache->pc, get_frame_pc (this_frame), cache);
|
||
|
||
if (cache->saved_sp_reg != -1)
|
||
{
|
||
/* Saved stack pointer has been saved. */
|
||
get_frame_register (this_frame, cache->saved_sp_reg, buf);
|
||
cache->saved_sp = extract_unsigned_integer(buf, 4);
|
||
}
|
||
|
||
if (cache->locals < 0)
|
||
{
|
||
/* We didn't find a valid frame, which means that CACHE->base
|
||
currently holds the frame pointer for our calling frame. If
|
||
we're at the start of a function, or somewhere half-way its
|
||
prologue, the function's frame probably hasn't been fully
|
||
setup yet. Try to reconstruct the base address for the stack
|
||
frame by looking at the stack pointer. For truly "frameless"
|
||
functions this might work too. */
|
||
|
||
if (cache->saved_sp_reg != -1)
|
||
{
|
||
/* We're halfway aligning the stack. */
|
||
cache->base = ((cache->saved_sp - 4) & 0xfffffff0) - 4;
|
||
cache->saved_regs[I386_EIP_REGNUM] = cache->saved_sp - 4;
|
||
|
||
/* This will be added back below. */
|
||
cache->saved_regs[I386_EIP_REGNUM] -= cache->base;
|
||
}
|
||
else
|
||
{
|
||
get_frame_register (this_frame, I386_ESP_REGNUM, buf);
|
||
cache->base = extract_unsigned_integer (buf, 4) + cache->sp_offset;
|
||
}
|
||
}
|
||
|
||
/* Now that we have the base address for the stack frame we can
|
||
calculate the value of %esp in the calling frame. */
|
||
if (cache->saved_sp == 0)
|
||
cache->saved_sp = cache->base + 8;
|
||
|
||
/* Adjust all the saved registers such that they contain addresses
|
||
instead of offsets. */
|
||
for (i = 0; i < I386_NUM_SAVED_REGS; i++)
|
||
if (cache->saved_regs[i] != -1)
|
||
cache->saved_regs[i] += cache->base;
|
||
|
||
return cache;
|
||
}
|
||
|
||
static void
|
||
i386_frame_this_id (struct frame_info *this_frame, void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache);
|
||
|
||
/* This marks the outermost frame. */
|
||
if (cache->base == 0)
|
||
return;
|
||
|
||
/* See the end of i386_push_dummy_call. */
|
||
(*this_id) = frame_id_build (cache->base + 8, cache->pc);
|
||
}
|
||
|
||
static struct value *
|
||
i386_frame_prev_register (struct frame_info *this_frame, void **this_cache,
|
||
int regnum)
|
||
{
|
||
struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache);
|
||
|
||
gdb_assert (regnum >= 0);
|
||
|
||
/* The System V ABI says that:
|
||
|
||
"The flags register contains the system flags, such as the
|
||
direction flag and the carry flag. The direction flag must be
|
||
set to the forward (that is, zero) direction before entry and
|
||
upon exit from a function. Other user flags have no specified
|
||
role in the standard calling sequence and are not preserved."
|
||
|
||
To guarantee the "upon exit" part of that statement we fake a
|
||
saved flags register that has its direction flag cleared.
|
||
|
||
Note that GCC doesn't seem to rely on the fact that the direction
|
||
flag is cleared after a function return; it always explicitly
|
||
clears the flag before operations where it matters.
|
||
|
||
FIXME: kettenis/20030316: I'm not quite sure whether this is the
|
||
right thing to do. The way we fake the flags register here makes
|
||
it impossible to change it. */
|
||
|
||
if (regnum == I386_EFLAGS_REGNUM)
|
||
{
|
||
ULONGEST val;
|
||
|
||
val = get_frame_register_unsigned (this_frame, regnum);
|
||
val &= ~(1 << 10);
|
||
return frame_unwind_got_constant (this_frame, regnum, val);
|
||
}
|
||
|
||
if (regnum == I386_EIP_REGNUM && cache->pc_in_eax)
|
||
return frame_unwind_got_register (this_frame, regnum, I386_EAX_REGNUM);
|
||
|
||
if (regnum == I386_ESP_REGNUM && cache->saved_sp)
|
||
return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp);
|
||
|
||
if (regnum < I386_NUM_SAVED_REGS && cache->saved_regs[regnum] != -1)
|
||
return frame_unwind_got_memory (this_frame, regnum,
|
||
cache->saved_regs[regnum]);
|
||
|
||
return frame_unwind_got_register (this_frame, regnum, regnum);
|
||
}
|
||
|
||
static const struct frame_unwind i386_frame_unwind =
|
||
{
|
||
NORMAL_FRAME,
|
||
i386_frame_this_id,
|
||
i386_frame_prev_register,
|
||
NULL,
|
||
default_frame_sniffer
|
||
};
|
||
|
||
|
||
/* Signal trampolines. */
|
||
|
||
static struct i386_frame_cache *
|
||
i386_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
|
||
{
|
||
struct i386_frame_cache *cache;
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame));
|
||
CORE_ADDR addr;
|
||
gdb_byte buf[4];
|
||
|
||
if (*this_cache)
|
||
return *this_cache;
|
||
|
||
cache = i386_alloc_frame_cache ();
|
||
|
||
get_frame_register (this_frame, I386_ESP_REGNUM, buf);
|
||
cache->base = extract_unsigned_integer (buf, 4) - 4;
|
||
|
||
addr = tdep->sigcontext_addr (this_frame);
|
||
if (tdep->sc_reg_offset)
|
||
{
|
||
int i;
|
||
|
||
gdb_assert (tdep->sc_num_regs <= I386_NUM_SAVED_REGS);
|
||
|
||
for (i = 0; i < tdep->sc_num_regs; i++)
|
||
if (tdep->sc_reg_offset[i] != -1)
|
||
cache->saved_regs[i] = addr + tdep->sc_reg_offset[i];
|
||
}
|
||
else
|
||
{
|
||
cache->saved_regs[I386_EIP_REGNUM] = addr + tdep->sc_pc_offset;
|
||
cache->saved_regs[I386_ESP_REGNUM] = addr + tdep->sc_sp_offset;
|
||
}
|
||
|
||
*this_cache = cache;
|
||
return cache;
|
||
}
|
||
|
||
static void
|
||
i386_sigtramp_frame_this_id (struct frame_info *this_frame, void **this_cache,
|
||
struct frame_id *this_id)
|
||
{
|
||
struct i386_frame_cache *cache =
|
||
i386_sigtramp_frame_cache (this_frame, this_cache);
|
||
|
||
/* See the end of i386_push_dummy_call. */
|
||
(*this_id) = frame_id_build (cache->base + 8, get_frame_pc (this_frame));
|
||
}
|
||
|
||
static struct value *
|
||
i386_sigtramp_frame_prev_register (struct frame_info *this_frame,
|
||
void **this_cache, int regnum)
|
||
{
|
||
/* Make sure we've initialized the cache. */
|
||
i386_sigtramp_frame_cache (this_frame, this_cache);
|
||
|
||
return i386_frame_prev_register (this_frame, this_cache, regnum);
|
||
}
|
||
|
||
static int
|
||
i386_sigtramp_frame_sniffer (const struct frame_unwind *self,
|
||
struct frame_info *this_frame,
|
||
void **this_prologue_cache)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame));
|
||
|
||
/* We shouldn't even bother if we don't have a sigcontext_addr
|
||
handler. */
|
||
if (tdep->sigcontext_addr == NULL)
|
||
return 0;
|
||
|
||
if (tdep->sigtramp_p != NULL)
|
||
{
|
||
if (tdep->sigtramp_p (this_frame))
|
||
return 1;
|
||
}
|
||
|
||
if (tdep->sigtramp_start != 0)
|
||
{
|
||
CORE_ADDR pc = get_frame_pc (this_frame);
|
||
|
||
gdb_assert (tdep->sigtramp_end != 0);
|
||
if (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end)
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
static const struct frame_unwind i386_sigtramp_frame_unwind =
|
||
{
|
||
SIGTRAMP_FRAME,
|
||
i386_sigtramp_frame_this_id,
|
||
i386_sigtramp_frame_prev_register,
|
||
NULL,
|
||
i386_sigtramp_frame_sniffer
|
||
};
|
||
|
||
|
||
static CORE_ADDR
|
||
i386_frame_base_address (struct frame_info *this_frame, void **this_cache)
|
||
{
|
||
struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache);
|
||
|
||
return cache->base;
|
||
}
|
||
|
||
static const struct frame_base i386_frame_base =
|
||
{
|
||
&i386_frame_unwind,
|
||
i386_frame_base_address,
|
||
i386_frame_base_address,
|
||
i386_frame_base_address
|
||
};
|
||
|
||
static struct frame_id
|
||
i386_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
|
||
{
|
||
CORE_ADDR fp;
|
||
|
||
fp = get_frame_register_unsigned (this_frame, I386_EBP_REGNUM);
|
||
|
||
/* See the end of i386_push_dummy_call. */
|
||
return frame_id_build (fp + 8, get_frame_pc (this_frame));
|
||
}
|
||
|
||
|
||
/* 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 address that we will land at.
|
||
This address is copied into PC. This routine returns non-zero on
|
||
success. */
|
||
|
||
static int
|
||
i386_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
|
||
{
|
||
gdb_byte buf[4];
|
||
CORE_ADDR sp, jb_addr;
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
int jb_pc_offset = gdbarch_tdep (gdbarch)->jb_pc_offset;
|
||
|
||
/* If JB_PC_OFFSET is -1, we have no way to find out where the
|
||
longjmp will land. */
|
||
if (jb_pc_offset == -1)
|
||
return 0;
|
||
|
||
get_frame_register (frame, I386_ESP_REGNUM, buf);
|
||
sp = extract_unsigned_integer (buf, 4);
|
||
if (target_read_memory (sp + 4, buf, 4))
|
||
return 0;
|
||
|
||
jb_addr = extract_unsigned_integer (buf, 4);
|
||
if (target_read_memory (jb_addr + jb_pc_offset, buf, 4))
|
||
return 0;
|
||
|
||
*pc = extract_unsigned_integer (buf, 4);
|
||
return 1;
|
||
}
|
||
|
||
|
||
/* Check whether TYPE must be 16-byte-aligned when passed as a
|
||
function argument. 16-byte vectors, _Decimal128 and structures or
|
||
unions containing such types must be 16-byte-aligned; other
|
||
arguments are 4-byte-aligned. */
|
||
|
||
static int
|
||
i386_16_byte_align_p (struct type *type)
|
||
{
|
||
type = check_typedef (type);
|
||
if ((TYPE_CODE (type) == TYPE_CODE_DECFLOAT
|
||
|| (TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type)))
|
||
&& TYPE_LENGTH (type) == 16)
|
||
return 1;
|
||
if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
|
||
return i386_16_byte_align_p (TYPE_TARGET_TYPE (type));
|
||
if (TYPE_CODE (type) == TYPE_CODE_STRUCT
|
||
|| TYPE_CODE (type) == TYPE_CODE_UNION)
|
||
{
|
||
int i;
|
||
for (i = 0; i < TYPE_NFIELDS (type); i++)
|
||
{
|
||
if (i386_16_byte_align_p (TYPE_FIELD_TYPE (type, i)))
|
||
return 1;
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
static CORE_ADDR
|
||
i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
|
||
struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
|
||
struct value **args, CORE_ADDR sp, int struct_return,
|
||
CORE_ADDR struct_addr)
|
||
{
|
||
gdb_byte buf[4];
|
||
int i;
|
||
int write_pass;
|
||
int args_space = 0;
|
||
|
||
/* Determine the total space required for arguments and struct
|
||
return address in a first pass (allowing for 16-byte-aligned
|
||
arguments), then push arguments in a second pass. */
|
||
|
||
for (write_pass = 0; write_pass < 2; write_pass++)
|
||
{
|
||
int args_space_used = 0;
|
||
int have_16_byte_aligned_arg = 0;
|
||
|
||
if (struct_return)
|
||
{
|
||
if (write_pass)
|
||
{
|
||
/* Push value address. */
|
||
store_unsigned_integer (buf, 4, struct_addr);
|
||
write_memory (sp, buf, 4);
|
||
args_space_used += 4;
|
||
}
|
||
else
|
||
args_space += 4;
|
||
}
|
||
|
||
for (i = 0; i < nargs; i++)
|
||
{
|
||
int len = TYPE_LENGTH (value_enclosing_type (args[i]));
|
||
|
||
if (write_pass)
|
||
{
|
||
if (i386_16_byte_align_p (value_enclosing_type (args[i])))
|
||
args_space_used = align_up (args_space_used, 16);
|
||
|
||
write_memory (sp + args_space_used,
|
||
value_contents_all (args[i]), len);
|
||
/* The System V ABI says that:
|
||
|
||
"An argument's size is increased, if necessary, to make it a
|
||
multiple of [32-bit] words. This may require tail padding,
|
||
depending on the size of the argument."
|
||
|
||
This makes sure the stack stays word-aligned. */
|
||
args_space_used += align_up (len, 4);
|
||
}
|
||
else
|
||
{
|
||
if (i386_16_byte_align_p (value_enclosing_type (args[i])))
|
||
{
|
||
args_space = align_up (args_space, 16);
|
||
have_16_byte_aligned_arg = 1;
|
||
}
|
||
args_space += align_up (len, 4);
|
||
}
|
||
}
|
||
|
||
if (!write_pass)
|
||
{
|
||
if (have_16_byte_aligned_arg)
|
||
args_space = align_up (args_space, 16);
|
||
sp -= args_space;
|
||
}
|
||
}
|
||
|
||
/* Store return address. */
|
||
sp -= 4;
|
||
store_unsigned_integer (buf, 4, bp_addr);
|
||
write_memory (sp, buf, 4);
|
||
|
||
/* Finally, update the stack pointer... */
|
||
store_unsigned_integer (buf, 4, sp);
|
||
regcache_cooked_write (regcache, I386_ESP_REGNUM, buf);
|
||
|
||
/* ...and fake a frame pointer. */
|
||
regcache_cooked_write (regcache, I386_EBP_REGNUM, buf);
|
||
|
||
/* MarkK wrote: This "+ 8" is all over the place:
|
||
(i386_frame_this_id, i386_sigtramp_frame_this_id,
|
||
i386_dummy_id). It's there, since all frame unwinders for
|
||
a given target have to agree (within a certain margin) on the
|
||
definition of the stack address of a frame. Otherwise frame id
|
||
comparison might not work correctly. Since DWARF2/GCC uses the
|
||
stack address *before* the function call as a frame's CFA. On
|
||
the i386, when %ebp is used as a frame pointer, the offset
|
||
between the contents %ebp and the CFA as defined by GCC. */
|
||
return sp + 8;
|
||
}
|
||
|
||
/* 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 I386_EAX_REGNUM /* %eax */
|
||
#define HIGH_RETURN_REGNUM I386_EDX_REGNUM /* %edx */
|
||
|
||
/* Read, for architecture GDBARCH, a function return value of TYPE
|
||
from REGCACHE, and copy that into VALBUF. */
|
||
|
||
static void
|
||
i386_extract_return_value (struct gdbarch *gdbarch, struct type *type,
|
||
struct regcache *regcache, gdb_byte *valbuf)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
int len = TYPE_LENGTH (type);
|
||
gdb_byte buf[I386_MAX_REGISTER_SIZE];
|
||
|
||
if (TYPE_CODE (type) == TYPE_CODE_FLT)
|
||
{
|
||
if (tdep->st0_regnum < 0)
|
||
{
|
||
warning (_("Cannot find floating-point return value."));
|
||
memset (valbuf, 0, len);
|
||
return;
|
||
}
|
||
|
||
/* Floating-point return values can be found in %st(0). Convert
|
||
its contents 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. */
|
||
regcache_raw_read (regcache, I386_ST0_REGNUM, buf);
|
||
convert_typed_floating (buf, builtin_type_i387_ext, valbuf, type);
|
||
}
|
||
else
|
||
{
|
||
int low_size = register_size (gdbarch, LOW_RETURN_REGNUM);
|
||
int high_size = register_size (gdbarch, HIGH_RETURN_REGNUM);
|
||
|
||
if (len <= low_size)
|
||
{
|
||
regcache_raw_read (regcache, LOW_RETURN_REGNUM, buf);
|
||
memcpy (valbuf, buf, len);
|
||
}
|
||
else if (len <= (low_size + high_size))
|
||
{
|
||
regcache_raw_read (regcache, LOW_RETURN_REGNUM, buf);
|
||
memcpy (valbuf, buf, low_size);
|
||
regcache_raw_read (regcache, HIGH_RETURN_REGNUM, buf);
|
||
memcpy (valbuf + low_size, buf, len - low_size);
|
||
}
|
||
else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("Cannot extract return value of %d bytes long."), len);
|
||
}
|
||
}
|
||
|
||
/* Write, for architecture GDBARCH, a function return value of TYPE
|
||
from VALBUF into REGCACHE. */
|
||
|
||
static void
|
||
i386_store_return_value (struct gdbarch *gdbarch, struct type *type,
|
||
struct regcache *regcache, const gdb_byte *valbuf)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
int len = TYPE_LENGTH (type);
|
||
|
||
if (TYPE_CODE (type) == TYPE_CODE_FLT)
|
||
{
|
||
ULONGEST fstat;
|
||
gdb_byte buf[I386_MAX_REGISTER_SIZE];
|
||
|
||
if (tdep->st0_regnum < 0)
|
||
{
|
||
warning (_("Cannot set floating-point return value."));
|
||
return;
|
||
}
|
||
|
||
/* Returning floating-point values is a bit tricky. Apart from
|
||
storing the return value in %st(0), we have to simulate the
|
||
state of the FPU at function return point. */
|
||
|
||
/* 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. */
|
||
convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext);
|
||
regcache_raw_write (regcache, I386_ST0_REGNUM, buf);
|
||
|
||
/* Set the top of the floating-point register stack to 7. The
|
||
actual value doesn't really matter, but 7 is what a normal
|
||
function return would end up with if the program started out
|
||
with a freshly initialized FPU. */
|
||
regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM (tdep), &fstat);
|
||
fstat |= (7 << 11);
|
||
regcache_raw_write_unsigned (regcache, I387_FSTAT_REGNUM (tdep), fstat);
|
||
|
||
/* Mark %st(1) through %st(7) as empty. Since we set the top of
|
||
the floating-point register stack to 7, the appropriate value
|
||
for the tag word is 0x3fff. */
|
||
regcache_raw_write_unsigned (regcache, I387_FTAG_REGNUM (tdep), 0x3fff);
|
||
}
|
||
else
|
||
{
|
||
int low_size = register_size (gdbarch, LOW_RETURN_REGNUM);
|
||
int high_size = register_size (gdbarch, HIGH_RETURN_REGNUM);
|
||
|
||
if (len <= low_size)
|
||
regcache_raw_write_part (regcache, LOW_RETURN_REGNUM, 0, len, valbuf);
|
||
else if (len <= (low_size + high_size))
|
||
{
|
||
regcache_raw_write (regcache, LOW_RETURN_REGNUM, valbuf);
|
||
regcache_raw_write_part (regcache, HIGH_RETURN_REGNUM, 0,
|
||
len - low_size, valbuf + low_size);
|
||
}
|
||
else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("Cannot store return value of %d bytes long."), len);
|
||
}
|
||
}
|
||
|
||
|
||
/* This is the variable that is set with "set struct-convention", and
|
||
its legitimate values. */
|
||
static const char default_struct_convention[] = "default";
|
||
static const char pcc_struct_convention[] = "pcc";
|
||
static const char reg_struct_convention[] = "reg";
|
||
static const char *valid_conventions[] =
|
||
{
|
||
default_struct_convention,
|
||
pcc_struct_convention,
|
||
reg_struct_convention,
|
||
NULL
|
||
};
|
||
static const char *struct_convention = default_struct_convention;
|
||
|
||
/* Return non-zero if TYPE, which is assumed to be a structure,
|
||
a union type, or an array type, should be returned in registers
|
||
for architecture GDBARCH. */
|
||
|
||
static int
|
||
i386_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
enum type_code code = TYPE_CODE (type);
|
||
int len = TYPE_LENGTH (type);
|
||
|
||
gdb_assert (code == TYPE_CODE_STRUCT
|
||
|| code == TYPE_CODE_UNION
|
||
|| code == TYPE_CODE_ARRAY);
|
||
|
||
if (struct_convention == pcc_struct_convention
|
||
|| (struct_convention == default_struct_convention
|
||
&& tdep->struct_return == pcc_struct_return))
|
||
return 0;
|
||
|
||
/* Structures consisting of a single `float', `double' or 'long
|
||
double' member are returned in %st(0). */
|
||
if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1)
|
||
{
|
||
type = check_typedef (TYPE_FIELD_TYPE (type, 0));
|
||
if (TYPE_CODE (type) == TYPE_CODE_FLT)
|
||
return (len == 4 || len == 8 || len == 12);
|
||
}
|
||
|
||
return (len == 1 || len == 2 || len == 4 || len == 8);
|
||
}
|
||
|
||
/* Determine, for architecture GDBARCH, how a return value of TYPE
|
||
should be returned. If it is supposed to be returned in registers,
|
||
and READBUF is non-zero, read the appropriate value from REGCACHE,
|
||
and copy it into READBUF. If WRITEBUF is non-zero, write the value
|
||
from WRITEBUF into REGCACHE. */
|
||
|
||
static enum return_value_convention
|
||
i386_return_value (struct gdbarch *gdbarch, struct type *func_type,
|
||
struct type *type, struct regcache *regcache,
|
||
gdb_byte *readbuf, const gdb_byte *writebuf)
|
||
{
|
||
enum type_code code = TYPE_CODE (type);
|
||
|
||
if (((code == TYPE_CODE_STRUCT
|
||
|| code == TYPE_CODE_UNION
|
||
|| code == TYPE_CODE_ARRAY)
|
||
&& !i386_reg_struct_return_p (gdbarch, type))
|
||
/* 128-bit decimal float uses the struct return convention. */
|
||
|| (code == TYPE_CODE_DECFLOAT && TYPE_LENGTH (type) == 16))
|
||
{
|
||
/* The System V ABI says that:
|
||
|
||
"A function that returns a structure or union also sets %eax
|
||
to the value of the original address of the caller's area
|
||
before it returns. Thus when the caller receives control
|
||
again, the address of the returned object resides in register
|
||
%eax and can be used to access the object."
|
||
|
||
So the ABI guarantees that we can always find the return
|
||
value just after the function has returned. */
|
||
|
||
/* Note that the ABI doesn't mention functions returning arrays,
|
||
which is something possible in certain languages such as Ada.
|
||
In this case, the value is returned as if it was wrapped in
|
||
a record, so the convention applied to records also applies
|
||
to arrays. */
|
||
|
||
if (readbuf)
|
||
{
|
||
ULONGEST addr;
|
||
|
||
regcache_raw_read_unsigned (regcache, I386_EAX_REGNUM, &addr);
|
||
read_memory (addr, readbuf, TYPE_LENGTH (type));
|
||
}
|
||
|
||
return RETURN_VALUE_ABI_RETURNS_ADDRESS;
|
||
}
|
||
|
||
/* This special case is for structures consisting of a single
|
||
`float', `double' or 'long double' member. These structures are
|
||
returned in %st(0). For these structures, we call ourselves
|
||
recursively, changing TYPE into the type of the first member of
|
||
the structure. Since that should work for all structures that
|
||
have only one member, we don't bother to check the member's type
|
||
here. */
|
||
if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1)
|
||
{
|
||
type = check_typedef (TYPE_FIELD_TYPE (type, 0));
|
||
return i386_return_value (gdbarch, func_type, type, regcache,
|
||
readbuf, writebuf);
|
||
}
|
||
|
||
if (readbuf)
|
||
i386_extract_return_value (gdbarch, type, regcache, readbuf);
|
||
if (writebuf)
|
||
i386_store_return_value (gdbarch, type, regcache, writebuf);
|
||
|
||
return RETURN_VALUE_REGISTER_CONVENTION;
|
||
}
|
||
|
||
|
||
/* Type for %eflags. */
|
||
struct type *i386_eflags_type;
|
||
|
||
/* Type for %mxcsr. */
|
||
struct type *i386_mxcsr_type;
|
||
|
||
/* Construct types for ISA-specific registers. */
|
||
static void
|
||
i386_init_types (void)
|
||
{
|
||
struct type *type;
|
||
|
||
type = init_flags_type ("builtin_type_i386_eflags", 4);
|
||
append_flags_type_flag (type, 0, "CF");
|
||
append_flags_type_flag (type, 1, NULL);
|
||
append_flags_type_flag (type, 2, "PF");
|
||
append_flags_type_flag (type, 4, "AF");
|
||
append_flags_type_flag (type, 6, "ZF");
|
||
append_flags_type_flag (type, 7, "SF");
|
||
append_flags_type_flag (type, 8, "TF");
|
||
append_flags_type_flag (type, 9, "IF");
|
||
append_flags_type_flag (type, 10, "DF");
|
||
append_flags_type_flag (type, 11, "OF");
|
||
append_flags_type_flag (type, 14, "NT");
|
||
append_flags_type_flag (type, 16, "RF");
|
||
append_flags_type_flag (type, 17, "VM");
|
||
append_flags_type_flag (type, 18, "AC");
|
||
append_flags_type_flag (type, 19, "VIF");
|
||
append_flags_type_flag (type, 20, "VIP");
|
||
append_flags_type_flag (type, 21, "ID");
|
||
i386_eflags_type = type;
|
||
|
||
type = init_flags_type ("builtin_type_i386_mxcsr", 4);
|
||
append_flags_type_flag (type, 0, "IE");
|
||
append_flags_type_flag (type, 1, "DE");
|
||
append_flags_type_flag (type, 2, "ZE");
|
||
append_flags_type_flag (type, 3, "OE");
|
||
append_flags_type_flag (type, 4, "UE");
|
||
append_flags_type_flag (type, 5, "PE");
|
||
append_flags_type_flag (type, 6, "DAZ");
|
||
append_flags_type_flag (type, 7, "IM");
|
||
append_flags_type_flag (type, 8, "DM");
|
||
append_flags_type_flag (type, 9, "ZM");
|
||
append_flags_type_flag (type, 10, "OM");
|
||
append_flags_type_flag (type, 11, "UM");
|
||
append_flags_type_flag (type, 12, "PM");
|
||
append_flags_type_flag (type, 15, "FZ");
|
||
i386_mxcsr_type = type;
|
||
}
|
||
|
||
/* Construct vector type for MMX registers. */
|
||
struct type *
|
||
i386_mmx_type (struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
if (!tdep->i386_mmx_type)
|
||
{
|
||
/* The type we're building is this: */
|
||
#if 0
|
||
union __gdb_builtin_type_vec64i
|
||
{
|
||
int64_t uint64;
|
||
int32_t v2_int32[2];
|
||
int16_t v4_int16[4];
|
||
int8_t v8_int8[8];
|
||
};
|
||
#endif
|
||
|
||
struct type *t;
|
||
|
||
t = init_composite_type ("__gdb_builtin_type_vec64i", TYPE_CODE_UNION);
|
||
append_composite_type_field (t, "uint64", builtin_type_int64);
|
||
append_composite_type_field (t, "v2_int32",
|
||
init_vector_type (builtin_type_int32, 2));
|
||
append_composite_type_field (t, "v4_int16",
|
||
init_vector_type (builtin_type_int16, 4));
|
||
append_composite_type_field (t, "v8_int8",
|
||
init_vector_type (builtin_type_int8, 8));
|
||
|
||
TYPE_VECTOR (t) = 1;
|
||
TYPE_NAME (t) = "builtin_type_vec64i";
|
||
tdep->i386_mmx_type = t;
|
||
}
|
||
|
||
return tdep->i386_mmx_type;
|
||
}
|
||
|
||
struct type *
|
||
i386_sse_type (struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
if (!tdep->i386_sse_type)
|
||
{
|
||
/* The type we're building is this: */
|
||
#if 0
|
||
union __gdb_builtin_type_vec128i
|
||
{
|
||
int128_t uint128;
|
||
int64_t v2_int64[2];
|
||
int32_t v4_int32[4];
|
||
int16_t v8_int16[8];
|
||
int8_t v16_int8[16];
|
||
double v2_double[2];
|
||
float v4_float[4];
|
||
};
|
||
#endif
|
||
|
||
struct type *t;
|
||
|
||
t = init_composite_type ("__gdb_builtin_type_vec128i", TYPE_CODE_UNION);
|
||
append_composite_type_field (t, "v4_float",
|
||
init_vector_type (builtin_type (gdbarch)
|
||
->builtin_float, 4));
|
||
append_composite_type_field (t, "v2_double",
|
||
init_vector_type (builtin_type (gdbarch)
|
||
->builtin_double, 2));
|
||
append_composite_type_field (t, "v16_int8",
|
||
init_vector_type (builtin_type_int8, 16));
|
||
append_composite_type_field (t, "v8_int16",
|
||
init_vector_type (builtin_type_int16, 8));
|
||
append_composite_type_field (t, "v4_int32",
|
||
init_vector_type (builtin_type_int32, 4));
|
||
append_composite_type_field (t, "v2_int64",
|
||
init_vector_type (builtin_type_int64, 2));
|
||
append_composite_type_field (t, "uint128", builtin_type_int128);
|
||
|
||
TYPE_VECTOR (t) = 1;
|
||
TYPE_NAME (t) = "builtin_type_vec128i";
|
||
tdep->i386_sse_type = t;
|
||
}
|
||
|
||
return tdep->i386_sse_type;
|
||
}
|
||
|
||
/* Return the GDB type object for the "standard" data type of data in
|
||
register REGNUM. Perhaps %esi and %edi should go here, but
|
||
potentially they could be used for things other than address. */
|
||
|
||
static struct type *
|
||
i386_register_type (struct gdbarch *gdbarch, int regnum)
|
||
{
|
||
if (regnum == I386_EIP_REGNUM)
|
||
return builtin_type (gdbarch)->builtin_func_ptr;
|
||
|
||
if (regnum == I386_EFLAGS_REGNUM)
|
||
return i386_eflags_type;
|
||
|
||
if (regnum == I386_EBP_REGNUM || regnum == I386_ESP_REGNUM)
|
||
return builtin_type (gdbarch)->builtin_data_ptr;
|
||
|
||
if (i386_fp_regnum_p (gdbarch, regnum))
|
||
return builtin_type_i387_ext;
|
||
|
||
if (i386_mmx_regnum_p (gdbarch, regnum))
|
||
return i386_mmx_type (gdbarch);
|
||
|
||
if (i386_sse_regnum_p (gdbarch, regnum))
|
||
return i386_sse_type (gdbarch);
|
||
|
||
if (regnum == I387_MXCSR_REGNUM (gdbarch_tdep (gdbarch)))
|
||
return i386_mxcsr_type;
|
||
|
||
return builtin_type (gdbarch)->builtin_int;
|
||
}
|
||
|
||
/* Map a cooked register onto a raw register or memory. For the i386,
|
||
the MMX registers need to be mapped onto floating point registers. */
|
||
|
||
static int
|
||
i386_mmx_regnum_to_fp_regnum (struct regcache *regcache, int regnum)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
|
||
int mmxreg, fpreg;
|
||
ULONGEST fstat;
|
||
int tos;
|
||
|
||
mmxreg = regnum - tdep->mm0_regnum;
|
||
regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM (tdep), &fstat);
|
||
tos = (fstat >> 11) & 0x7;
|
||
fpreg = (mmxreg + tos) % 8;
|
||
|
||
return (I387_ST0_REGNUM (tdep) + fpreg);
|
||
}
|
||
|
||
static void
|
||
i386_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
|
||
int regnum, gdb_byte *buf)
|
||
{
|
||
if (i386_mmx_regnum_p (gdbarch, regnum))
|
||
{
|
||
gdb_byte mmx_buf[MAX_REGISTER_SIZE];
|
||
int fpnum = i386_mmx_regnum_to_fp_regnum (regcache, regnum);
|
||
|
||
/* Extract (always little endian). */
|
||
regcache_raw_read (regcache, fpnum, mmx_buf);
|
||
memcpy (buf, mmx_buf, register_size (gdbarch, regnum));
|
||
}
|
||
else
|
||
regcache_raw_read (regcache, regnum, buf);
|
||
}
|
||
|
||
static void
|
||
i386_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
|
||
int regnum, const gdb_byte *buf)
|
||
{
|
||
if (i386_mmx_regnum_p (gdbarch, regnum))
|
||
{
|
||
gdb_byte mmx_buf[MAX_REGISTER_SIZE];
|
||
int fpnum = i386_mmx_regnum_to_fp_regnum (regcache, regnum);
|
||
|
||
/* Read ... */
|
||
regcache_raw_read (regcache, fpnum, mmx_buf);
|
||
/* ... Modify ... (always little endian). */
|
||
memcpy (mmx_buf, buf, register_size (gdbarch, regnum));
|
||
/* ... Write. */
|
||
regcache_raw_write (regcache, fpnum, mmx_buf);
|
||
}
|
||
else
|
||
regcache_raw_write (regcache, regnum, buf);
|
||
}
|
||
|
||
|
||
/* Return the register number of the register allocated by GCC after
|
||
REGNUM, or -1 if there is no such register. */
|
||
|
||
static int
|
||
i386_next_regnum (int regnum)
|
||
{
|
||
/* GCC allocates the registers in the order:
|
||
|
||
%eax, %edx, %ecx, %ebx, %esi, %edi, %ebp, %esp, ...
|
||
|
||
Since storing a variable in %esp doesn't make any sense we return
|
||
-1 for %ebp and for %esp itself. */
|
||
static int next_regnum[] =
|
||
{
|
||
I386_EDX_REGNUM, /* Slot for %eax. */
|
||
I386_EBX_REGNUM, /* Slot for %ecx. */
|
||
I386_ECX_REGNUM, /* Slot for %edx. */
|
||
I386_ESI_REGNUM, /* Slot for %ebx. */
|
||
-1, -1, /* Slots for %esp and %ebp. */
|
||
I386_EDI_REGNUM, /* Slot for %esi. */
|
||
I386_EBP_REGNUM /* Slot for %edi. */
|
||
};
|
||
|
||
if (regnum >= 0 && regnum < sizeof (next_regnum) / sizeof (next_regnum[0]))
|
||
return next_regnum[regnum];
|
||
|
||
return -1;
|
||
}
|
||
|
||
/* Return nonzero if a value of type TYPE stored in register REGNUM
|
||
needs any special handling. */
|
||
|
||
static int
|
||
i386_convert_register_p (struct gdbarch *gdbarch, int regnum, struct type *type)
|
||
{
|
||
int len = TYPE_LENGTH (type);
|
||
|
||
/* Values may be spread across multiple registers. Most debugging
|
||
formats aren't expressive enough to specify the locations, so
|
||
some heuristics is involved. Right now we only handle types that
|
||
have a length that is a multiple of the word size, since GCC
|
||
doesn't seem to put any other types into registers. */
|
||
if (len > 4 && len % 4 == 0)
|
||
{
|
||
int last_regnum = regnum;
|
||
|
||
while (len > 4)
|
||
{
|
||
last_regnum = i386_next_regnum (last_regnum);
|
||
len -= 4;
|
||
}
|
||
|
||
if (last_regnum != -1)
|
||
return 1;
|
||
}
|
||
|
||
return i387_convert_register_p (gdbarch, regnum, type);
|
||
}
|
||
|
||
/* Read a value of type TYPE from register REGNUM in frame FRAME, and
|
||
return its contents in TO. */
|
||
|
||
static void
|
||
i386_register_to_value (struct frame_info *frame, int regnum,
|
||
struct type *type, gdb_byte *to)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
int len = TYPE_LENGTH (type);
|
||
|
||
/* FIXME: kettenis/20030609: What should we do if REGNUM isn't
|
||
available in FRAME (i.e. if it wasn't saved)? */
|
||
|
||
if (i386_fp_regnum_p (gdbarch, regnum))
|
||
{
|
||
i387_register_to_value (frame, regnum, type, to);
|
||
return;
|
||
}
|
||
|
||
/* Read a value spread across multiple registers. */
|
||
|
||
gdb_assert (len > 4 && len % 4 == 0);
|
||
|
||
while (len > 0)
|
||
{
|
||
gdb_assert (regnum != -1);
|
||
gdb_assert (register_size (gdbarch, regnum) == 4);
|
||
|
||
get_frame_register (frame, regnum, to);
|
||
regnum = i386_next_regnum (regnum);
|
||
len -= 4;
|
||
to += 4;
|
||
}
|
||
}
|
||
|
||
/* Write the contents FROM of a value of type TYPE into register
|
||
REGNUM in frame FRAME. */
|
||
|
||
static void
|
||
i386_value_to_register (struct frame_info *frame, int regnum,
|
||
struct type *type, const gdb_byte *from)
|
||
{
|
||
int len = TYPE_LENGTH (type);
|
||
|
||
if (i386_fp_regnum_p (get_frame_arch (frame), regnum))
|
||
{
|
||
i387_value_to_register (frame, regnum, type, from);
|
||
return;
|
||
}
|
||
|
||
/* Write a value spread across multiple registers. */
|
||
|
||
gdb_assert (len > 4 && len % 4 == 0);
|
||
|
||
while (len > 0)
|
||
{
|
||
gdb_assert (regnum != -1);
|
||
gdb_assert (register_size (get_frame_arch (frame), regnum) == 4);
|
||
|
||
put_frame_register (frame, regnum, from);
|
||
regnum = i386_next_regnum (regnum);
|
||
len -= 4;
|
||
from += 4;
|
||
}
|
||
}
|
||
|
||
/* Supply register REGNUM from the buffer specified by GREGS and LEN
|
||
in the general-purpose register set REGSET to register cache
|
||
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
|
||
|
||
void
|
||
i386_supply_gregset (const struct regset *regset, struct regcache *regcache,
|
||
int regnum, const void *gregs, size_t len)
|
||
{
|
||
const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
|
||
const gdb_byte *regs = gregs;
|
||
int i;
|
||
|
||
gdb_assert (len == tdep->sizeof_gregset);
|
||
|
||
for (i = 0; i < tdep->gregset_num_regs; i++)
|
||
{
|
||
if ((regnum == i || regnum == -1)
|
||
&& tdep->gregset_reg_offset[i] != -1)
|
||
regcache_raw_supply (regcache, i, regs + tdep->gregset_reg_offset[i]);
|
||
}
|
||
}
|
||
|
||
/* Collect register REGNUM from the register cache REGCACHE and store
|
||
it in the buffer specified by GREGS and LEN as described by the
|
||
general-purpose register set REGSET. If REGNUM is -1, do this for
|
||
all registers in REGSET. */
|
||
|
||
void
|
||
i386_collect_gregset (const struct regset *regset,
|
||
const struct regcache *regcache,
|
||
int regnum, void *gregs, size_t len)
|
||
{
|
||
const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
|
||
gdb_byte *regs = gregs;
|
||
int i;
|
||
|
||
gdb_assert (len == tdep->sizeof_gregset);
|
||
|
||
for (i = 0; i < tdep->gregset_num_regs; i++)
|
||
{
|
||
if ((regnum == i || regnum == -1)
|
||
&& tdep->gregset_reg_offset[i] != -1)
|
||
regcache_raw_collect (regcache, i, regs + tdep->gregset_reg_offset[i]);
|
||
}
|
||
}
|
||
|
||
/* Supply register REGNUM from the buffer specified by FPREGS and LEN
|
||
in the floating-point register set REGSET to register cache
|
||
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
|
||
|
||
static void
|
||
i386_supply_fpregset (const struct regset *regset, struct regcache *regcache,
|
||
int regnum, const void *fpregs, size_t len)
|
||
{
|
||
const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
|
||
|
||
if (len == I387_SIZEOF_FXSAVE)
|
||
{
|
||
i387_supply_fxsave (regcache, regnum, fpregs);
|
||
return;
|
||
}
|
||
|
||
gdb_assert (len == tdep->sizeof_fpregset);
|
||
i387_supply_fsave (regcache, regnum, fpregs);
|
||
}
|
||
|
||
/* Collect register REGNUM from the register cache REGCACHE and store
|
||
it in the buffer specified by FPREGS and LEN as described by the
|
||
floating-point register set REGSET. If REGNUM is -1, do this for
|
||
all registers in REGSET. */
|
||
|
||
static void
|
||
i386_collect_fpregset (const struct regset *regset,
|
||
const struct regcache *regcache,
|
||
int regnum, void *fpregs, size_t len)
|
||
{
|
||
const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
|
||
|
||
if (len == I387_SIZEOF_FXSAVE)
|
||
{
|
||
i387_collect_fxsave (regcache, regnum, fpregs);
|
||
return;
|
||
}
|
||
|
||
gdb_assert (len == tdep->sizeof_fpregset);
|
||
i387_collect_fsave (regcache, regnum, fpregs);
|
||
}
|
||
|
||
/* Return the appropriate register set for the core section identified
|
||
by SECT_NAME and SECT_SIZE. */
|
||
|
||
const struct regset *
|
||
i386_regset_from_core_section (struct gdbarch *gdbarch,
|
||
const char *sect_name, size_t sect_size)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
if (strcmp (sect_name, ".reg") == 0 && sect_size == tdep->sizeof_gregset)
|
||
{
|
||
if (tdep->gregset == NULL)
|
||
tdep->gregset = regset_alloc (gdbarch, i386_supply_gregset,
|
||
i386_collect_gregset);
|
||
return tdep->gregset;
|
||
}
|
||
|
||
if ((strcmp (sect_name, ".reg2") == 0 && sect_size == tdep->sizeof_fpregset)
|
||
|| (strcmp (sect_name, ".reg-xfp") == 0
|
||
&& sect_size == I387_SIZEOF_FXSAVE))
|
||
{
|
||
if (tdep->fpregset == NULL)
|
||
tdep->fpregset = regset_alloc (gdbarch, i386_supply_fpregset,
|
||
i386_collect_fpregset);
|
||
return tdep->fpregset;
|
||
}
|
||
|
||
return NULL;
|
||
}
|
||
|
||
|
||
/* Stuff for WIN32 PE style DLL's but is pretty generic really. */
|
||
|
||
CORE_ADDR
|
||
i386_pe_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_LINKAGE_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. */
|
||
}
|
||
|
||
|
||
/* Return whether the THIS_FRAME corresponds to a sigtramp
|
||
routine. */
|
||
|
||
int
|
||
i386_sigtramp_p (struct frame_info *this_frame)
|
||
{
|
||
CORE_ADDR pc = get_frame_pc (this_frame);
|
||
char *name;
|
||
|
||
find_pc_partial_function (pc, &name, NULL, NULL);
|
||
return (name && strcmp ("_sigtramp", name) == 0);
|
||
}
|
||
|
||
|
||
/* We have two flavours of disassembly. The machinery on this page
|
||
deals with switching between those. */
|
||
|
||
static int
|
||
i386_print_insn (bfd_vma pc, struct disassemble_info *info)
|
||
{
|
||
gdb_assert (disassembly_flavor == att_flavor
|
||
|| disassembly_flavor == intel_flavor);
|
||
|
||
/* FIXME: kettenis/20020915: Until disassembler_options is properly
|
||
constified, cast to prevent a compiler warning. */
|
||
info->disassembler_options = (char *) disassembly_flavor;
|
||
|
||
return print_insn_i386 (pc, info);
|
||
}
|
||
|
||
|
||
/* There are a few i386 architecture variants that differ only
|
||
slightly from the generic i386 target. For now, we don't give them
|
||
their own source file, but include them here. As a consequence,
|
||
they'll always be included. */
|
||
|
||
/* System V Release 4 (SVR4). */
|
||
|
||
/* Return whether THIS_FRAME corresponds to a SVR4 sigtramp
|
||
routine. */
|
||
|
||
static int
|
||
i386_svr4_sigtramp_p (struct frame_info *this_frame)
|
||
{
|
||
CORE_ADDR pc = get_frame_pc (this_frame);
|
||
char *name;
|
||
|
||
/* UnixWare uses _sigacthandler. The origin of the other symbols is
|
||
currently unknown. */
|
||
find_pc_partial_function (pc, &name, NULL, NULL);
|
||
return (name && (strcmp ("_sigreturn", name) == 0
|
||
|| strcmp ("_sigacthandler", name) == 0
|
||
|| strcmp ("sigvechandler", name) == 0));
|
||
}
|
||
|
||
/* Assuming THIS_FRAME is for a SVR4 sigtramp routine, return the
|
||
address of the associated sigcontext (ucontext) structure. */
|
||
|
||
static CORE_ADDR
|
||
i386_svr4_sigcontext_addr (struct frame_info *this_frame)
|
||
{
|
||
gdb_byte buf[4];
|
||
CORE_ADDR sp;
|
||
|
||
get_frame_register (this_frame, I386_ESP_REGNUM, buf);
|
||
sp = extract_unsigned_integer (buf, 4);
|
||
|
||
return read_memory_unsigned_integer (sp + 8, 4);
|
||
}
|
||
|
||
|
||
/* Generic ELF. */
|
||
|
||
void
|
||
i386_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
/* We typically use stabs-in-ELF with the SVR4 register numbering. */
|
||
set_gdbarch_stab_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum);
|
||
}
|
||
|
||
/* System V Release 4 (SVR4). */
|
||
|
||
void
|
||
i386_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
/* System V Release 4 uses ELF. */
|
||
i386_elf_init_abi (info, gdbarch);
|
||
|
||
/* System V Release 4 has shared libraries. */
|
||
set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
|
||
|
||
tdep->sigtramp_p = i386_svr4_sigtramp_p;
|
||
tdep->sigcontext_addr = i386_svr4_sigcontext_addr;
|
||
tdep->sc_pc_offset = 36 + 14 * 4;
|
||
tdep->sc_sp_offset = 36 + 17 * 4;
|
||
|
||
tdep->jb_pc_offset = 20;
|
||
}
|
||
|
||
/* DJGPP. */
|
||
|
||
static void
|
||
i386_go32_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
|
||
/* DJGPP doesn't have any special frames for signal handlers. */
|
||
tdep->sigtramp_p = NULL;
|
||
|
||
tdep->jb_pc_offset = 36;
|
||
}
|
||
|
||
|
||
/* i386 register groups. In addition to the normal groups, add "mmx"
|
||
and "sse". */
|
||
|
||
static struct reggroup *i386_sse_reggroup;
|
||
static struct reggroup *i386_mmx_reggroup;
|
||
|
||
static void
|
||
i386_init_reggroups (void)
|
||
{
|
||
i386_sse_reggroup = reggroup_new ("sse", USER_REGGROUP);
|
||
i386_mmx_reggroup = reggroup_new ("mmx", USER_REGGROUP);
|
||
}
|
||
|
||
static void
|
||
i386_add_reggroups (struct gdbarch *gdbarch)
|
||
{
|
||
reggroup_add (gdbarch, i386_sse_reggroup);
|
||
reggroup_add (gdbarch, i386_mmx_reggroup);
|
||
reggroup_add (gdbarch, general_reggroup);
|
||
reggroup_add (gdbarch, float_reggroup);
|
||
reggroup_add (gdbarch, all_reggroup);
|
||
reggroup_add (gdbarch, save_reggroup);
|
||
reggroup_add (gdbarch, restore_reggroup);
|
||
reggroup_add (gdbarch, vector_reggroup);
|
||
reggroup_add (gdbarch, system_reggroup);
|
||
}
|
||
|
||
int
|
||
i386_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
|
||
struct reggroup *group)
|
||
{
|
||
int sse_regnum_p = (i386_sse_regnum_p (gdbarch, regnum)
|
||
|| i386_mxcsr_regnum_p (gdbarch, regnum));
|
||
int fp_regnum_p = (i386_fp_regnum_p (gdbarch, regnum)
|
||
|| i386_fpc_regnum_p (gdbarch, regnum));
|
||
int mmx_regnum_p = (i386_mmx_regnum_p (gdbarch, regnum));
|
||
|
||
if (group == i386_mmx_reggroup)
|
||
return mmx_regnum_p;
|
||
if (group == i386_sse_reggroup)
|
||
return sse_regnum_p;
|
||
if (group == vector_reggroup)
|
||
return (mmx_regnum_p || sse_regnum_p);
|
||
if (group == float_reggroup)
|
||
return fp_regnum_p;
|
||
if (group == general_reggroup)
|
||
return (!fp_regnum_p && !mmx_regnum_p && !sse_regnum_p);
|
||
|
||
return default_register_reggroup_p (gdbarch, regnum, group);
|
||
}
|
||
|
||
|
||
/* Get the ARGIth function argument for the current function. */
|
||
|
||
static CORE_ADDR
|
||
i386_fetch_pointer_argument (struct frame_info *frame, int argi,
|
||
struct type *type)
|
||
{
|
||
CORE_ADDR sp = get_frame_register_unsigned (frame, I386_ESP_REGNUM);
|
||
return read_memory_unsigned_integer (sp + (4 * (argi + 1)), 4);
|
||
}
|
||
|
||
static void
|
||
i386_skip_permanent_breakpoint (struct regcache *regcache)
|
||
{
|
||
CORE_ADDR current_pc = regcache_read_pc (regcache);
|
||
|
||
/* On i386, breakpoint is exactly 1 byte long, so we just
|
||
adjust the PC in the regcache. */
|
||
current_pc += 1;
|
||
regcache_write_pc (regcache, current_pc);
|
||
}
|
||
|
||
|
||
|
||
static struct gdbarch *
|
||
i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
|
||
{
|
||
struct gdbarch_tdep *tdep;
|
||
struct gdbarch *gdbarch;
|
||
|
||
/* If there is already a candidate, use it. */
|
||
arches = gdbarch_list_lookup_by_info (arches, &info);
|
||
if (arches != NULL)
|
||
return arches->gdbarch;
|
||
|
||
/* Allocate space for the new architecture. */
|
||
tdep = XCALLOC (1, struct gdbarch_tdep);
|
||
gdbarch = gdbarch_alloc (&info, tdep);
|
||
|
||
/* General-purpose registers. */
|
||
tdep->gregset = NULL;
|
||
tdep->gregset_reg_offset = NULL;
|
||
tdep->gregset_num_regs = I386_NUM_GREGS;
|
||
tdep->sizeof_gregset = 0;
|
||
|
||
/* Floating-point registers. */
|
||
tdep->fpregset = NULL;
|
||
tdep->sizeof_fpregset = I387_SIZEOF_FSAVE;
|
||
|
||
/* The default settings include the FPU registers, the MMX registers
|
||
and the SSE registers. This can be overridden for a specific ABI
|
||
by adjusting the members `st0_regnum', `mm0_regnum' and
|
||
`num_xmm_regs' of `struct gdbarch_tdep', otherwise the registers
|
||
will show up in the output of "info all-registers". Ideally we
|
||
should try to autodetect whether they are available, such that we
|
||
can prevent "info all-registers" from displaying registers that
|
||
aren't available.
|
||
|
||
NOTE: kevinb/2003-07-13: ... if it's a choice between printing
|
||
[the SSE registers] always (even when they don't exist) or never
|
||
showing them to the user (even when they do exist), I prefer the
|
||
former over the latter. */
|
||
|
||
tdep->st0_regnum = I386_ST0_REGNUM;
|
||
|
||
/* The MMX registers are implemented as pseudo-registers. Put off
|
||
calculating the register number for %mm0 until we know the number
|
||
of raw registers. */
|
||
tdep->mm0_regnum = 0;
|
||
|
||
/* I386_NUM_XREGS includes %mxcsr, so substract one. */
|
||
tdep->num_xmm_regs = I386_NUM_XREGS - 1;
|
||
|
||
tdep->jb_pc_offset = -1;
|
||
tdep->struct_return = pcc_struct_return;
|
||
tdep->sigtramp_start = 0;
|
||
tdep->sigtramp_end = 0;
|
||
tdep->sigtramp_p = i386_sigtramp_p;
|
||
tdep->sigcontext_addr = NULL;
|
||
tdep->sc_reg_offset = NULL;
|
||
tdep->sc_pc_offset = -1;
|
||
tdep->sc_sp_offset = -1;
|
||
|
||
/* The format used for `long double' on almost all i386 targets is
|
||
the i387 extended floating-point format. In fact, of all targets
|
||
in the GCC 2.95 tree, only OSF/1 does it different, and insists
|
||
on having a `long double' that's not `long' at all. */
|
||
set_gdbarch_long_double_format (gdbarch, floatformats_i387_ext);
|
||
|
||
/* Although the i387 extended floating-point has only 80 significant
|
||
bits, a `long double' actually takes up 96, probably to enforce
|
||
alignment. */
|
||
set_gdbarch_long_double_bit (gdbarch, 96);
|
||
|
||
/* The default ABI includes general-purpose registers,
|
||
floating-point registers, and the SSE registers. */
|
||
set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS);
|
||
set_gdbarch_register_name (gdbarch, i386_register_name);
|
||
set_gdbarch_register_type (gdbarch, i386_register_type);
|
||
|
||
/* Register numbers of various important registers. */
|
||
set_gdbarch_sp_regnum (gdbarch, I386_ESP_REGNUM); /* %esp */
|
||
set_gdbarch_pc_regnum (gdbarch, I386_EIP_REGNUM); /* %eip */
|
||
set_gdbarch_ps_regnum (gdbarch, I386_EFLAGS_REGNUM); /* %eflags */
|
||
set_gdbarch_fp0_regnum (gdbarch, I386_ST0_REGNUM); /* %st(0) */
|
||
|
||
/* NOTE: kettenis/20040418: GCC does have two possible register
|
||
numbering schemes on the i386: dbx and SVR4. These schemes
|
||
differ in how they number %ebp, %esp, %eflags, and the
|
||
floating-point registers, and are implemented by the arrays
|
||
dbx_register_map[] and svr4_dbx_register_map in
|
||
gcc/config/i386.c. GCC also defines a third numbering scheme in
|
||
gcc/config/i386.c, which it designates as the "default" register
|
||
map used in 64bit mode. This last register numbering scheme is
|
||
implemented in dbx64_register_map, and is used for AMD64; see
|
||
amd64-tdep.c.
|
||
|
||
Currently, each GCC i386 target always uses the same register
|
||
numbering scheme across all its supported debugging formats
|
||
i.e. SDB (COFF), stabs and DWARF 2. This is because
|
||
gcc/sdbout.c, gcc/dbxout.c and gcc/dwarf2out.c all use the
|
||
DBX_REGISTER_NUMBER macro which is defined by each target's
|
||
respective config header in a manner independent of the requested
|
||
output debugging format.
|
||
|
||
This does not match the arrangement below, which presumes that
|
||
the SDB and stabs numbering schemes differ from the DWARF and
|
||
DWARF 2 ones. The reason for this arrangement is that it is
|
||
likely to get the numbering scheme for the target's
|
||
default/native debug format right. For targets where GCC is the
|
||
native compiler (FreeBSD, NetBSD, OpenBSD, GNU/Linux) or for
|
||
targets where the native toolchain uses a different numbering
|
||
scheme for a particular debug format (stabs-in-ELF on Solaris)
|
||
the defaults below will have to be overridden, like
|
||
i386_elf_init_abi() does. */
|
||
|
||
/* Use the dbx register numbering scheme for stabs and COFF. */
|
||
set_gdbarch_stab_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum);
|
||
set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum);
|
||
|
||
/* Use the SVR4 register numbering scheme for DWARF 2. */
|
||
set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum);
|
||
|
||
/* We don't set gdbarch_stab_reg_to_regnum, since ECOFF doesn't seem to
|
||
be in use on any of the supported i386 targets. */
|
||
|
||
set_gdbarch_print_float_info (gdbarch, i387_print_float_info);
|
||
|
||
set_gdbarch_get_longjmp_target (gdbarch, i386_get_longjmp_target);
|
||
|
||
/* Call dummy code. */
|
||
set_gdbarch_push_dummy_call (gdbarch, i386_push_dummy_call);
|
||
|
||
set_gdbarch_convert_register_p (gdbarch, i386_convert_register_p);
|
||
set_gdbarch_register_to_value (gdbarch, i386_register_to_value);
|
||
set_gdbarch_value_to_register (gdbarch, i386_value_to_register);
|
||
|
||
set_gdbarch_return_value (gdbarch, i386_return_value);
|
||
|
||
set_gdbarch_skip_prologue (gdbarch, i386_skip_prologue);
|
||
|
||
/* Stack grows downward. */
|
||
set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
|
||
|
||
set_gdbarch_breakpoint_from_pc (gdbarch, i386_breakpoint_from_pc);
|
||
set_gdbarch_decr_pc_after_break (gdbarch, 1);
|
||
set_gdbarch_max_insn_length (gdbarch, I386_MAX_INSN_LEN);
|
||
|
||
set_gdbarch_frame_args_skip (gdbarch, 8);
|
||
|
||
/* Wire in the MMX registers. */
|
||
set_gdbarch_num_pseudo_regs (gdbarch, i386_num_mmx_regs);
|
||
set_gdbarch_pseudo_register_read (gdbarch, i386_pseudo_register_read);
|
||
set_gdbarch_pseudo_register_write (gdbarch, i386_pseudo_register_write);
|
||
|
||
set_gdbarch_print_insn (gdbarch, i386_print_insn);
|
||
|
||
set_gdbarch_dummy_id (gdbarch, i386_dummy_id);
|
||
|
||
set_gdbarch_unwind_pc (gdbarch, i386_unwind_pc);
|
||
|
||
/* Add the i386 register groups. */
|
||
i386_add_reggroups (gdbarch);
|
||
set_gdbarch_register_reggroup_p (gdbarch, i386_register_reggroup_p);
|
||
|
||
/* Helper for function argument information. */
|
||
set_gdbarch_fetch_pointer_argument (gdbarch, i386_fetch_pointer_argument);
|
||
|
||
/* Hook in the DWARF CFI frame unwinder. */
|
||
dwarf2_append_unwinders (gdbarch);
|
||
|
||
frame_base_set_default (gdbarch, &i386_frame_base);
|
||
|
||
/* Hook in ABI-specific overrides, if they have been registered. */
|
||
gdbarch_init_osabi (info, gdbarch);
|
||
|
||
frame_unwind_append_unwinder (gdbarch, &i386_sigtramp_frame_unwind);
|
||
frame_unwind_append_unwinder (gdbarch, &i386_frame_unwind);
|
||
|
||
/* If we have a register mapping, enable the generic core file
|
||
support, unless it has already been enabled. */
|
||
if (tdep->gregset_reg_offset
|
||
&& !gdbarch_regset_from_core_section_p (gdbarch))
|
||
set_gdbarch_regset_from_core_section (gdbarch,
|
||
i386_regset_from_core_section);
|
||
|
||
/* Unless support for MMX has been disabled, make %mm0 the first
|
||
pseudo-register. */
|
||
if (tdep->mm0_regnum == 0)
|
||
tdep->mm0_regnum = gdbarch_num_regs (gdbarch);
|
||
|
||
set_gdbarch_skip_permanent_breakpoint (gdbarch,
|
||
i386_skip_permanent_breakpoint);
|
||
|
||
return gdbarch;
|
||
}
|
||
|
||
static enum gdb_osabi
|
||
i386_coff_osabi_sniffer (bfd *abfd)
|
||
{
|
||
if (strcmp (bfd_get_target (abfd), "coff-go32-exe") == 0
|
||
|| strcmp (bfd_get_target (abfd), "coff-go32") == 0)
|
||
return GDB_OSABI_GO32;
|
||
|
||
return GDB_OSABI_UNKNOWN;
|
||
}
|
||
|
||
|
||
/* Provide a prototype to silence -Wmissing-prototypes. */
|
||
void _initialize_i386_tdep (void);
|
||
|
||
void
|
||
_initialize_i386_tdep (void)
|
||
{
|
||
register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init);
|
||
|
||
/* Add the variable that controls the disassembly flavor. */
|
||
add_setshow_enum_cmd ("disassembly-flavor", no_class, valid_flavors,
|
||
&disassembly_flavor, _("\
|
||
Set the disassembly flavor."), _("\
|
||
Show the disassembly flavor."), _("\
|
||
The valid values are \"att\" and \"intel\", and the default value is \"att\"."),
|
||
NULL,
|
||
NULL, /* FIXME: i18n: */
|
||
&setlist, &showlist);
|
||
|
||
/* Add the variable that controls the convention for returning
|
||
structs. */
|
||
add_setshow_enum_cmd ("struct-convention", no_class, valid_conventions,
|
||
&struct_convention, _("\
|
||
Set the convention for returning small structs."), _("\
|
||
Show the convention for returning small structs."), _("\
|
||
Valid values are \"default\", \"pcc\" and \"reg\", and the default value\n\
|
||
is \"default\"."),
|
||
NULL,
|
||
NULL, /* FIXME: i18n: */
|
||
&setlist, &showlist);
|
||
|
||
gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour,
|
||
i386_coff_osabi_sniffer);
|
||
|
||
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_SVR4,
|
||
i386_svr4_init_abi);
|
||
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_GO32,
|
||
i386_go32_init_abi);
|
||
|
||
/* Initialize the i386-specific register groups & types. */
|
||
i386_init_reggroups ();
|
||
i386_init_types();
|
||
}
|