[deliverable/binutils-gdb.git] / gdb / config / i386 / tm-linux.h

/* Definitions to target GDB to GNU/Linux on 386.
   Copyright 1992, 1993, 2000 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef TM_LINUX_H
#define TM_LINUX_H

#define I386_GNULINUX_TARGET
#define HAVE_I387_REGS
#ifdef HAVE_PTRACE_GETFPXREGS
#define HAVE_SSE_REGS
#endif

#include "i386/tm-i386.h"
#include "tm-linux.h"

/* FIXME: kettenis/2000-03-26: We should get rid of this last piece of
   Linux-specific `long double'-support code, probably by adding code
   to valprint.c:print_floating() to recognize various extended
   floating-point formats.  */

#if defined(HAVE_LONG_DOUBLE) && defined(HOST_I386)
/* The host and target are i386 machines and the compiler supports
   long doubles. Long doubles on the host therefore have the same
   layout as a 387 FPU stack register. */

#define TARGET_ANALYZE_FLOATING					\
  do								\
    {								\
      unsigned expon;						\
								\
      low = extract_unsigned_integer (valaddr, 4);		\
      high = extract_unsigned_integer (valaddr + 4, 4);		\
      expon = extract_unsigned_integer (valaddr + 8, 2);	\
								\
      nonnegative = ((expon & 0x8000) == 0);			\
      is_nan = ((expon & 0x7fff) == 0x7fff)			\
	&& ((high & 0x80000000) == 0x80000000)			\
	&& (((high & 0x7fffffff) | low) != 0);			\
    }								\
  while (0)

#endif

/* The following works around a problem with /usr/include/sys/procfs.h  */
#define sys_quotactl 1

/* When the i386 Linux kernel calls a signal handler, the return
   address points to a bit of code on the stack.  These definitions
   are used to identify this bit of code as a signal trampoline in
   order to support backtracing through calls to signal handlers.  */

#define IN_SIGTRAMP(pc, name) i386_linux_in_sigtramp (pc, name)
extern int i386_linux_in_sigtramp (CORE_ADDR, char *);

/* We need our own version of sigtramp_saved_pc to get the saved PC in
   a sigtramp routine.  */

#define sigtramp_saved_pc i386_linux_sigtramp_saved_pc
extern CORE_ADDR i386_linux_sigtramp_saved_pc (struct frame_info *);

/* Signal trampolines don't have a meaningful frame.  As in tm-i386.h,
   the frame pointer value we use is actually the frame pointer of the
   calling frame--that is, the frame which was in progress when the
   signal trampoline was entered.  gdb mostly treats this frame
   pointer value as a magic cookie.  We detect the case of a signal
   trampoline by looking at the SIGNAL_HANDLER_CALLER field, which is
   set based on IN_SIGTRAMP.

   When a signal trampoline is invoked from a frameless function, we
   essentially have two frameless functions in a row.  In this case,
   we use the same magic cookie for three frames in a row.  We detect
   this case by seeing whether the next frame has
   SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the
   current frame is actually frameless.  In this case, we need to get
   the PC by looking at the SP register value stored in the signal
   context.

   This should work in most cases except in horrible situations where
   a signal occurs just as we enter a function but before the frame
   has been set up.  */

#define FRAMELESS_SIGNAL(FRAME)					\
  ((FRAME)->next != NULL					\
   && (FRAME)->next->signal_handler_caller			\
   && frameless_look_for_prologue (FRAME))

#undef FRAME_CHAIN
#define FRAME_CHAIN(FRAME)					\
  ((FRAME)->signal_handler_caller				\
   ? (FRAME)->frame						\
    : (FRAMELESS_SIGNAL (FRAME)					\
       ? (FRAME)->frame						\
       : (!inside_entry_file ((FRAME)->pc)			\
	  ? read_memory_integer ((FRAME)->frame, 4)		\
	  : 0)))

#undef FRAME_SAVED_PC
#define FRAME_SAVED_PC(FRAME)					\
  ((FRAME)->signal_handler_caller				\
   ? sigtramp_saved_pc (FRAME)					\
   : (FRAMELESS_SIGNAL (FRAME)					\
      ? read_memory_integer (i386_linux_sigtramp_saved_sp ((FRAME)->next), 4) \
      : read_memory_integer ((FRAME)->frame + 4, 4)))

extern CORE_ADDR i386_linux_sigtramp_saved_sp (struct frame_info *);

#undef SAVED_PC_AFTER_CALL
#define SAVED_PC_AFTER_CALL(frame) i386_linux_saved_pc_after_call (frame)
extern CORE_ADDR i386_linux_saved_pc_after_call (struct frame_info *);

/* When we call a function in a shared library, and the PLT sends us
   into the dynamic linker to find the function's real address, we
   need to skip over the dynamic linker call.  This function decides
   when to skip, and where to skip to.  See the comments for
   SKIP_SOLIB_RESOLVER at the top of infrun.c.  */
#define SKIP_SOLIB_RESOLVER i386_linux_skip_solib_resolver
extern CORE_ADDR i386_linux_skip_solib_resolver (CORE_ADDR pc);

/* N_FUN symbols in shared libaries have 0 for their values and need
   to be relocated. */
#define SOFUN_ADDRESS_MAYBE_MISSING
\f

/* Support for longjmp.  */

/* Details about jmp_buf.  It's supposed to be an array of integers.  */

#define JB_ELEMENT_SIZE 4	/* Size of elements in jmp_buf.  */
#define JB_PC		5	/* Array index of saved PC.  */

/* Figure out where the longjmp will land.  Slurp the args out of the
   stack.  We expect the first arg to be a pointer to the jmp_buf
   structure from which we extract the pc (JB_PC) that we will land
   at.  The pc is copied into ADDR.  This routine returns true on
   success.  */

#define GET_LONGJMP_TARGET(addr) get_longjmp_target (addr)
extern int get_longjmp_target (CORE_ADDR *addr);

#endif /* #ifndef TM_LINUX_H */
Commit	Line	Data
c906108c	1	/* Definitions to target GDB to GNU/Linux on 386.
6ce2ac0b	2	Copyright 1992, 1993, 2000 Free Software Foundation, Inc.
c906108c	3
c5aa993b	4	This file is part of GDB.
c906108c	5
c5aa993b JM	6	This program is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2 of the License, or
	9	(at your option) any later version.
c906108c	10
c5aa993b JM	11	This program is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
c906108c	15
c5aa993b JM	16	You should have received a copy of the GNU General Public License
	17	along with this program; if not, write to the Free Software
	18	Foundation, Inc., 59 Temple Place - Suite 330,
	19	Boston, MA 02111-1307, USA. */
c906108c SS	20
	21	#ifndef TM_LINUX_H
	22	#define TM_LINUX_H
	23
d4f3574e	24	#define I386_GNULINUX_TARGET
917317f4	25	#define HAVE_I387_REGS
6ce2ac0b	26	#ifdef HAVE_PTRACE_GETFPXREGS
5c44784c JM	27	#define HAVE_SSE_REGS
5c44784c JM	28	#endif
c906108c SS	29
c906108c SS	30	#include "i386/tm-i386.h"
c2d11a7d	31	#include "tm-linux.h"
c906108c	32
ac27f131 MK	33	/* FIXME: kettenis/2000-03-26: We should get rid of this last piece of
	34	Linux-specific `long double'-support code, probably by adding code
	35	to valprint.c:print_floating() to recognize various extended
	36	floating-point formats. */
d4f3574e SS	37
	38	#if defined(HAVE_LONG_DOUBLE) && defined(HOST_I386)
	39	/* The host and target are i386 machines and the compiler supports
	40	long doubles. Long doubles on the host therefore have the same
	41	layout as a 387 FPU stack register. */
d4f3574e SS	42
	43	#define TARGET_ANALYZE_FLOATING \
	44	do \
	45	{ \
	46	unsigned expon; \
	47	\
	48	low = extract_unsigned_integer (valaddr, 4); \
	49	high = extract_unsigned_integer (valaddr + 4, 4); \
	50	expon = extract_unsigned_integer (valaddr + 8, 2); \
	51	\
	52	nonnegative = ((expon & 0x8000) == 0); \
	53	is_nan = ((expon & 0x7fff) == 0x7fff) \
	54	&& ((high & 0x80000000) == 0x80000000) \
	55	&& (((high & 0x7fffffff) \| low) != 0); \
	56	} \
	57	while (0)
d4f3574e	58
d4f3574e SS	59	#endif
d4f3574e SS	60
c906108c SS	61	/* The following works around a problem with /usr/include/sys/procfs.h */
	62	#define sys_quotactl 1
	63
a0b3c4fd JM	64	/* When the i386 Linux kernel calls a signal handler, the return
	65	address points to a bit of code on the stack. These definitions
	66	are used to identify this bit of code as a signal trampoline in
	67	order to support backtracing through calls to signal handlers. */
	68
45a816d9 MK	69	#define IN_SIGTRAMP(pc, name) i386_linux_in_sigtramp (pc, name)
45a816d9 MK	70	extern int i386_linux_in_sigtramp (CORE_ADDR, char *);
a0b3c4fd JM	71
	72	/* We need our own version of sigtramp_saved_pc to get the saved PC in
	73	a sigtramp routine. */
	74
	75	#define sigtramp_saved_pc i386_linux_sigtramp_saved_pc
45a816d9	76	extern CORE_ADDR i386_linux_sigtramp_saved_pc (struct frame_info *);
a0b3c4fd JM	77
	78	/* Signal trampolines don't have a meaningful frame. As in tm-i386.h,
	79	the frame pointer value we use is actually the frame pointer of the
	80	calling frame--that is, the frame which was in progress when the
	81	signal trampoline was entered. gdb mostly treats this frame
	82	pointer value as a magic cookie. We detect the case of a signal
	83	trampoline by looking at the SIGNAL_HANDLER_CALLER field, which is
	84	set based on IN_SIGTRAMP.
	85
	86	When a signal trampoline is invoked from a frameless function, we
	87	essentially have two frameless functions in a row. In this case,
	88	we use the same magic cookie for three frames in a row. We detect
	89	this case by seeing whether the next frame has
	90	SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the
	91	current frame is actually frameless. In this case, we need to get
	92	the PC by looking at the SP register value stored in the signal
	93	context.
	94
	95	This should work in most cases except in horrible situations where
	96	a signal occurs just as we enter a function but before the frame
	97	has been set up. */
	98
	99	#define FRAMELESS_SIGNAL(FRAME) \
	100	((FRAME)->next != NULL \
	101	&& (FRAME)->next->signal_handler_caller \
	102	&& frameless_look_for_prologue (FRAME))
	103
	104	#undef FRAME_CHAIN
	105	#define FRAME_CHAIN(FRAME) \
	106	((FRAME)->signal_handler_caller \
	107	? (FRAME)->frame \
	108	: (FRAMELESS_SIGNAL (FRAME) \
	109	? (FRAME)->frame \
	110	: (!inside_entry_file ((FRAME)->pc) \
	111	? read_memory_integer ((FRAME)->frame, 4) \
	112	: 0)))
	113
	114	#undef FRAME_SAVED_PC
	115	#define FRAME_SAVED_PC(FRAME) \
	116	((FRAME)->signal_handler_caller \
	117	? sigtramp_saved_pc (FRAME) \
	118	: (FRAMELESS_SIGNAL (FRAME) \
	119	? read_memory_integer (i386_linux_sigtramp_saved_sp ((FRAME)->next), 4) \
	120	: read_memory_integer ((FRAME)->frame + 4, 4)))
	121
45a816d9	122	extern CORE_ADDR i386_linux_sigtramp_saved_sp (struct frame_info *);
a0b3c4fd	123
4cc24188 MK	124	#undef SAVED_PC_AFTER_CALL
	125	#define SAVED_PC_AFTER_CALL(frame) i386_linux_saved_pc_after_call (frame)
	126	extern CORE_ADDR i386_linux_saved_pc_after_call (struct frame_info *);
	127
d4f3574e SS	128	/* When we call a function in a shared library, and the PLT sends us
	129	into the dynamic linker to find the function's real address, we
	130	need to skip over the dynamic linker call. This function decides
	131	when to skip, and where to skip to. See the comments for
	132	SKIP_SOLIB_RESOLVER at the top of infrun.c. */
	133	#define SKIP_SOLIB_RESOLVER i386_linux_skip_solib_resolver
	134	extern CORE_ADDR i386_linux_skip_solib_resolver (CORE_ADDR pc);
	135
	136	/* N_FUN symbols in shared libaries have 0 for their values and need
	137	to be relocated. */
	138	#define SOFUN_ADDRESS_MAYBE_MISSING
f19ebbbc MK	139	\f
	140
	141	/* Support for longjmp. */
	142
	143	/* Details about jmp_buf. It's supposed to be an array of integers. */
	144
	145	#define JB_ELEMENT_SIZE 4 /* Size of elements in jmp_buf. */
	146	#define JB_PC 5 /* Array index of saved PC. */
	147
	148	/* Figure out where the longjmp will land. Slurp the args out of the
	149	stack. We expect the first arg to be a pointer to the jmp_buf
	150	structure from which we extract the pc (JB_PC) that we will land
	151	at. The pc is copied into ADDR. This routine returns true on
	152	success. */
	153
	154	#define GET_LONGJMP_TARGET(addr) get_longjmp_target (addr)
	155	extern int get_longjmp_target (CORE_ADDR *addr);
d4f3574e	156
c5aa993b	157	#endif /* #ifndef TM_LINUX_H */