1 /* Definitions to target GDB to GNU/Linux on 386.
2 Copyright 1992, 1993, 2000 Free Software Foundation, Inc.
4 This file is part of GDB.
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.
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.
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. */
24 #define I386_GNULINUX_TARGET
25 #define HAVE_I387_REGS
26 #ifdef HAVE_PTRACE_GETFPXREGS
30 #include "i386/tm-i386.h"
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. */
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. */
43 #define TARGET_ANALYZE_FLOATING \
48 low = extract_unsigned_integer (valaddr, 4); \
49 high = extract_unsigned_integer (valaddr + 4, 4); \
50 expon = extract_unsigned_integer (valaddr + 8, 2); \
52 nonnegative = ((expon & 0x8000) == 0); \
53 is_nan = ((expon & 0x7fff) == 0x7fff) \
54 && ((high & 0x80000000) == 0x80000000) \
55 && (((high & 0x7fffffff) | low) != 0); \
61 /* The following works around a problem with /usr/include/sys/procfs.h */
62 #define sys_quotactl 1
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. */
69 #define IN_SIGTRAMP(pc, name) i386_linux_in_sigtramp (pc, name)
70 extern int i386_linux_in_sigtramp (CORE_ADDR
, char *);
72 /* We need our own version of sigtramp_saved_pc to get the saved PC in
73 a sigtramp routine. */
75 #define sigtramp_saved_pc i386_linux_sigtramp_saved_pc
76 extern CORE_ADDR
i386_linux_sigtramp_saved_pc (struct frame_info
*);
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.
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
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
99 #define FRAMELESS_SIGNAL(FRAME) \
100 ((FRAME)->next != NULL \
101 && (FRAME)->next->signal_handler_caller \
102 && frameless_look_for_prologue (FRAME))
105 #define FRAME_CHAIN(FRAME) \
106 ((FRAME)->signal_handler_caller \
108 : (FRAMELESS_SIGNAL (FRAME) \
110 : (!inside_entry_file ((FRAME)->pc) \
111 ? read_memory_integer ((FRAME)->frame, 4) \
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)))
122 extern CORE_ADDR
i386_linux_sigtramp_saved_sp (struct frame_info
*);
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
*);
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
);
136 /* N_FUN symbols in shared libaries have 0 for their values and need
138 #define SOFUN_ADDRESS_MAYBE_MISSING
141 /* Support for longjmp. */
143 /* Details about jmp_buf. It's supposed to be an array of integers. */
145 #define JB_ELEMENT_SIZE 4 /* Size of elements in jmp_buf. */
146 #define JB_PC 5 /* Array index of saved PC. */
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
154 #define GET_LONGJMP_TARGET(addr) get_longjmp_target (addr)
155 extern int get_longjmp_target (CORE_ADDR
*addr
);
157 #endif /* #ifndef TM_LINUX_H */