1 /* Target-dependent code for FreeBSD/Alpha.
2    Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
3 
4    This file is part of GDB.
5 
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.
10 
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.
15 
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.  */
20 
21 #include "defs.h"
22 #include "value.h"
23 #include "osabi.h"
24 
25 #include "alpha-tdep.h"
26 
27 static int
28 alphafbsd_use_struct_convention (int gcc_p, struct type *type)
29 {
30   enum type_code code;
31   int i;
32 
33   /* All aggregate types that won't fit in a register must be returned
34      in memory.  */
35   if (TYPE_LENGTH (type) > ALPHA_REGISTER_SIZE)
36     return 1;
37 
38   /* The only aggregate types that can be returned in a register are
39      structs and unions.  Arrays must be returned in memory.  */
40   code = TYPE_CODE (type);
41   if (code != TYPE_CODE_STRUCT && code != TYPE_CODE_UNION)
42     return 1;
43 
44   /* We need to check if this struct/union is "integer" like.  For
45      this to be true, the offset of each adressable subfield must be
46      zero.  Note that bit fields are not addressable.  */
47   for (i = 0; i < TYPE_NFIELDS (type); i++)
48     {
49       /* If the field bitsize is non-zero, it isn't adressable.  */
50       if (TYPE_FIELD_BITPOS (type, i) != 0
51 	  && TYPE_FIELD_BITSIZE (type, i) == 0)
52 	return 1;
53     }
54 
55   return 0;
56 }
57 
58 
59 /* Support for signal handlers.  */
60 
61 /* Return whether PC is in a BSD sigtramp routine.  */
62 
63 CORE_ADDR alphafbsd_sigtramp_start = 0x11ffff68;
64 CORE_ADDR alphafbsd_sigtramp_end = 0x11ffffe0;
65 
66 static int
67 alphafbsd_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
68 {
69   return (pc >= alphafbsd_sigtramp_start && pc < alphafbsd_sigtramp_end);
70 }
71 
72 static LONGEST
73 alphafbsd_sigtramp_offset (CORE_ADDR pc)
74 {
75   return pc - alphafbsd_sigtramp_start;
76 }
77 
78 /* Assuming NEXT_FRAME is for a frame following a BSD sigtramp
79    routine, return the address of the associated sigcontext structure.  */
80 
81 static CORE_ADDR
82 alphafbsd_sigcontext_addr (struct frame_info *next_frame)
83 {
84   return frame_unwind_register_unsigned (next_frame, ALPHA_SP_REGNUM) + 24;
85 }
86 
87 /* FreeBSD 5.0-RELEASE or later.  */
88 
89 static void
90 alphafbsd_init_abi (struct gdbarch_info info,
91                     struct gdbarch *gdbarch)
92 {
93   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
94 
95   /* Hook into the DWARF CFI frame unwinder.  */
96   alpha_dwarf2_init_abi (info, gdbarch);
97 
98   /* Hook into the MDEBUG frame unwinder.  */
99   alpha_mdebug_init_abi (info, gdbarch);
100 
101   set_gdbarch_deprecated_use_struct_convention (gdbarch, alphafbsd_use_struct_convention);
102 
103   tdep->dynamic_sigtramp_offset = alphafbsd_sigtramp_offset;
104   tdep->sigcontext_addr = alphafbsd_sigcontext_addr;
105   tdep->pc_in_sigtramp = alphafbsd_pc_in_sigtramp;
106   tdep->sc_pc_offset = 288;
107   tdep->sc_regs_offset = 24;
108   tdep->sc_fpregs_offset = 320;
109 
110   tdep->jb_pc = 2;
111   tdep->jb_elt_size = 8;
112 }
113 
114 
115 /* Provide a prototype to silence -Wmissing-prototypes.  */
116 void _initialize_alphafbsd_tdep (void);
117 
118 void
119 _initialize_alphafbsd_tdep (void)
120 {
121   gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_FREEBSD_ELF,
122                           alphafbsd_init_abi);
123 }
124