gdb/sparc-sol2-tdep.c

   1 /* Target-dependent code for Solaris SPARC.
   2
   3    Copyright (C) 2003, 2004 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "frame.h"
  24 #include "frame-unwind.h"
  25 #include "gdbcore.h"
  26 #include "symtab.h"
  27 #include "objfiles.h"
  28 #include "osabi.h"
  29 #include "regcache.h"
  30 #include "target.h"
  31 #include "trad-frame.h"
  32
  33 #include "gdb_assert.h"
  34 #include "gdb_string.h"
  35
  36 #include "sparc-tdep.h"
  37 #include "solib-svr4.h"
  38
  39 /* From <sys/regset.h>.  */
  40 const struct sparc_gregset sparc32_sol2_gregset =
  41 {
  42   32 * 4,                       /* %psr */
  43   33 * 4,                       /* %pc */
  44   34 * 4,                       /* %npc */
  45   35 * 4,                       /* %y */
  46   36 * 4,                       /* %wim */
  47   37 * 4,                       /* %tbr */
  48   1 * 4,                        /* %g1 */
  49   16 * 4,                       /* %l0 */
  50 };
  51 \f
  52
  53 /* The Solaris signal trampolines reside in libc.  For normal signals,
  54    the function `sigacthandler' is used.  This signal trampoline will
  55    call the signal handler using the System V calling convention,
  56    where the third argument is a pointer to an instance of
  57    `ucontext_t', which has a member `uc_mcontext' that contains the
  58    saved registers.  Incidentally, the kernel passes the `ucontext_t'
  59    pointer as the third argument of the signal trampoline too, and
  60    `sigacthandler' simply passes it on. However, if you link your
  61    program with "-L/usr/ucblib -R/usr/ucblib -lucb", the function
  62    `ucbsigvechandler' will be used, which invokes the using the BSD
  63    convention, where the third argument is a pointer to an instance of
  64    `struct sigcontext'.  It is the `ucbsigvechandler' function that
  65    converts the `ucontext_t' to a `sigcontext', and back.  Unless the
  66    signal handler modifies the `struct sigcontext' we can safely
  67    ignore this.  */
  68
  69 int
  70 sparc_sol2_pc_in_sigtramp (CORE_ADDR pc, char *name)
  71 {
  72   return (name && (strcmp (name, "sigacthandler") == 0
  73                    || strcmp (name, "ucbsigvechandler") == 0
  74                    || strcmp (name, "__sighndlr") == 0));
  75 }
  76
  77 static struct sparc_frame_cache *
  78 sparc32_sol2_sigtramp_frame_cache (struct frame_info *next_frame,
  79                                    void **this_cache)
  80 {
  81   struct sparc_frame_cache *cache;
  82   CORE_ADDR mcontext_addr, addr;
  83   int regnum;
  84
  85   if (*this_cache)
  86     return *this_cache;
  87
  88   cache = sparc_frame_cache (next_frame, this_cache);
  89   gdb_assert (cache == *this_cache);
  90
  91   cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
  92
  93   /* The third argument is a pointer to an instance of `ucontext_t',
  94      which has a member `uc_mcontext' that contains the saved
  95      registers.  */
  96   regnum = (cache->frameless_p ? SPARC_O2_REGNUM : SPARC_I2_REGNUM);
  97   mcontext_addr = frame_unwind_register_unsigned (next_frame, regnum) + 40;
  98
  99   cache->saved_regs[SPARC32_PSR_REGNUM].addr = mcontext_addr + 0 * 4;
 100   cache->saved_regs[SPARC32_PC_REGNUM].addr = mcontext_addr + 1 * 4;
 101   cache->saved_regs[SPARC32_NPC_REGNUM].addr = mcontext_addr + 2 * 4;
 102   cache->saved_regs[SPARC32_Y_REGNUM].addr = mcontext_addr + 3 * 4;
 103
 104   /* Since %g0 is always zero, keep the identity encoding.  */
 105   for (regnum = SPARC_G1_REGNUM, addr = mcontext_addr + 4 * 4;
 106        regnum <= SPARC_O7_REGNUM; regnum++, addr += 4)
 107     cache->saved_regs[regnum].addr = addr;
 108
 109   if (get_frame_memory_unsigned (next_frame, mcontext_addr + 19 * 4, 4))
 110     {
 111       /* The register windows haven't been flushed.  */
 112       for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
 113         trad_frame_set_unknown (cache->saved_regs, regnum);
 114     }
 115   else
 116     {
 117       addr = cache->saved_regs[SPARC_SP_REGNUM].addr;
 118       addr = get_frame_memory_unsigned (next_frame, addr, 4);
 119       for (regnum = SPARC_L0_REGNUM;
 120            regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 121         cache->saved_regs[regnum].addr = addr;
 122     }
 123
 124   return cache;
 125 }
 126
 127 static void
 128 sparc32_sol2_sigtramp_frame_this_id (struct frame_info *next_frame,
 129                                      void **this_cache,
 130                                      struct frame_id *this_id)
 131 {
 132   struct sparc_frame_cache *cache =
 133     sparc32_sol2_sigtramp_frame_cache (next_frame, this_cache);
 134
 135   (*this_id) = frame_id_build (cache->base, cache->pc);
 136 }
 137
 138 static void
 139 sparc32_sol2_sigtramp_frame_prev_register (struct frame_info *next_frame,
 140                                            void **this_cache,
 141                                            int regnum, int *optimizedp,
 142                                            enum lval_type *lvalp,
 143                                            CORE_ADDR *addrp,
 144                                            int *realnump, gdb_byte *valuep)
 145 {
 146   struct sparc_frame_cache *cache =
 147     sparc32_sol2_sigtramp_frame_cache (next_frame, this_cache);
 148
 149   trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
 150                                 optimizedp, lvalp, addrp, realnump, valuep);
 151 }
 152
 153 static const struct frame_unwind sparc32_sol2_sigtramp_frame_unwind =
 154 {
 155   SIGTRAMP_FRAME,
 156   sparc32_sol2_sigtramp_frame_this_id,
 157   sparc32_sol2_sigtramp_frame_prev_register
 158 };
 159
 160 static const struct frame_unwind *
 161 sparc32_sol2_sigtramp_frame_sniffer (struct frame_info *next_frame)
 162 {
 163   CORE_ADDR pc = frame_pc_unwind (next_frame);
 164   char *name;
 165
 166   find_pc_partial_function (pc, &name, NULL, NULL);
 167   if (sparc_sol2_pc_in_sigtramp (pc, name))
 168     return &sparc32_sol2_sigtramp_frame_unwind;
 169
 170   return NULL;
 171 }
 172 \f
 173
 174 void
 175 sparc32_sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 176 {
 177   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 178
 179   /* Solaris has SVR4-style shared libraries...  */
 180   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 181   set_solib_svr4_fetch_link_map_offsets
 182     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 183
 184   /* ...which means that we need some special handling when doing
 185      prologue analysis.  */
 186   tdep->plt_entry_size = 12;
 187
 188   /* Solaris has kernel-assisted single-stepping support.  */
 189   set_gdbarch_software_single_step (gdbarch, NULL);
 190
 191   frame_unwind_append_sniffer (gdbarch, sparc32_sol2_sigtramp_frame_sniffer);
 192 }
 193 \f
 194
 195 /* Provide a prototype to silence -Wmissing-prototypes.  */
 196 void _initialize_sparc_sol2_tdep (void);
 197
 198 void
 199 _initialize_sparc_sol2_tdep (void)
 200 {
 201   gdbarch_register_osabi (bfd_arch_sparc, 0,
 202                           GDB_OSABI_SOLARIS, sparc32_sol2_init_abi);
 203 }