gdb/sparc-sol2-tdep.c

   1 /* Target-dependent code for Solaris SPARC.
   2
   3    Copyright (C) 2003, 2004, 2006, 2007 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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "frame.h"
  22 #include "frame-unwind.h"
  23 #include "gdbcore.h"
  24 #include "symtab.h"
  25 #include "objfiles.h"
  26 #include "osabi.h"
  27 #include "regcache.h"
  28 #include "target.h"
  29 #include "trad-frame.h"
  30
  31 #include "gdb_assert.h"
  32 #include "gdb_string.h"
  33
  34 #include "sol2-tdep.h"
  35 #include "sparc-tdep.h"
  36 #include "solib-svr4.h"
  37
  38 /* From <sys/regset.h>.  */
  39 const struct sparc_gregset sparc32_sol2_gregset =
  40 {
  41   32 * 4,                       /* %psr */
  42   33 * 4,                       /* %pc */
  43   34 * 4,                       /* %npc */
  44   35 * 4,                       /* %y */
  45   36 * 4,                       /* %wim */
  46   37 * 4,                       /* %tbr */
  47   1 * 4,                        /* %g1 */
  48   16 * 4,                       /* %l0 */
  49 };
  50 \f
  51
  52 /* The Solaris signal trampolines reside in libc.  For normal signals,
  53    the function `sigacthandler' is used.  This signal trampoline will
  54    call the signal handler using the System V calling convention,
  55    where the third argument is a pointer to an instance of
  56    `ucontext_t', which has a member `uc_mcontext' that contains the
  57    saved registers.  Incidentally, the kernel passes the `ucontext_t'
  58    pointer as the third argument of the signal trampoline too, and
  59    `sigacthandler' simply passes it on. However, if you link your
  60    program with "-L/usr/ucblib -R/usr/ucblib -lucb", the function
  61    `ucbsigvechandler' will be used, which invokes the using the BSD
  62    convention, where the third argument is a pointer to an instance of
  63    `struct sigcontext'.  It is the `ucbsigvechandler' function that
  64    converts the `ucontext_t' to a `sigcontext', and back.  Unless the
  65    signal handler modifies the `struct sigcontext' we can safely
  66    ignore this.  */
  67
  68 int
  69 sparc_sol2_pc_in_sigtramp (CORE_ADDR pc, char *name)
  70 {
  71   return (name && (strcmp (name, "sigacthandler") == 0
  72                    || strcmp (name, "ucbsigvechandler") == 0
  73                    || strcmp (name, "__sighndlr") == 0));
  74 }
  75
  76 static struct sparc_frame_cache *
  77 sparc32_sol2_sigtramp_frame_cache (struct frame_info *next_frame,
  78                                    void **this_cache)
  79 {
  80   struct sparc_frame_cache *cache;
  81   CORE_ADDR mcontext_addr, addr;
  82   int regnum;
  83
  84   if (*this_cache)
  85     return *this_cache;
  86
  87   cache = sparc_frame_cache (next_frame, this_cache);
  88   gdb_assert (cache == *this_cache);
  89
  90   cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
  91
  92   /* The third argument is a pointer to an instance of `ucontext_t',
  93      which has a member `uc_mcontext' that contains the saved
  94      registers.  */
  95   regnum = (cache->frameless_p ? SPARC_O2_REGNUM : SPARC_I2_REGNUM);
  96   mcontext_addr = frame_unwind_register_unsigned (next_frame, regnum) + 40;
  97
  98   cache->saved_regs[SPARC32_PSR_REGNUM].addr = mcontext_addr + 0 * 4;
  99   cache->saved_regs[SPARC32_PC_REGNUM].addr = mcontext_addr + 1 * 4;
 100   cache->saved_regs[SPARC32_NPC_REGNUM].addr = mcontext_addr + 2 * 4;
 101   cache->saved_regs[SPARC32_Y_REGNUM].addr = mcontext_addr + 3 * 4;
 102
 103   /* Since %g0 is always zero, keep the identity encoding.  */
 104   for (regnum = SPARC_G1_REGNUM, addr = mcontext_addr + 4 * 4;
 105        regnum <= SPARC_O7_REGNUM; regnum++, addr += 4)
 106     cache->saved_regs[regnum].addr = addr;
 107
 108   if (get_frame_memory_unsigned (next_frame, mcontext_addr + 19 * 4, 4))
 109     {
 110       /* The register windows haven't been flushed.  */
 111       for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
 112         trad_frame_set_unknown (cache->saved_regs, regnum);
 113     }
 114   else
 115     {
 116       addr = cache->saved_regs[SPARC_SP_REGNUM].addr;
 117       addr = get_frame_memory_unsigned (next_frame, addr, 4);
 118       for (regnum = SPARC_L0_REGNUM;
 119            regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 120         cache->saved_regs[regnum].addr = addr;
 121     }
 122
 123   return cache;
 124 }
 125
 126 static void
 127 sparc32_sol2_sigtramp_frame_this_id (struct frame_info *next_frame,
 128                                      void **this_cache,
 129                                      struct frame_id *this_id)
 130 {
 131   struct sparc_frame_cache *cache =
 132     sparc32_sol2_sigtramp_frame_cache (next_frame, this_cache);
 133
 134   (*this_id) = frame_id_build (cache->base, cache->pc);
 135 }
 136
 137 static void
 138 sparc32_sol2_sigtramp_frame_prev_register (struct frame_info *next_frame,
 139                                            void **this_cache,
 140                                            int regnum, int *optimizedp,
 141                                            enum lval_type *lvalp,
 142                                            CORE_ADDR *addrp,
 143                                            int *realnump, gdb_byte *valuep)
 144 {
 145   struct sparc_frame_cache *cache =
 146     sparc32_sol2_sigtramp_frame_cache (next_frame, this_cache);
 147
 148   trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
 149                                 optimizedp, lvalp, addrp, realnump, valuep);
 150 }
 151
 152 static const struct frame_unwind sparc32_sol2_sigtramp_frame_unwind =
 153 {
 154   SIGTRAMP_FRAME,
 155   sparc32_sol2_sigtramp_frame_this_id,
 156   sparc32_sol2_sigtramp_frame_prev_register
 157 };
 158
 159 static const struct frame_unwind *
 160 sparc32_sol2_sigtramp_frame_sniffer (struct frame_info *next_frame)
 161 {
 162   CORE_ADDR pc = frame_pc_unwind (next_frame);
 163   char *name;
 164
 165   find_pc_partial_function (pc, &name, NULL, NULL);
 166   if (sparc_sol2_pc_in_sigtramp (pc, name))
 167     return &sparc32_sol2_sigtramp_frame_unwind;
 168
 169   return NULL;
 170 }
 171 \f
 172
 173 void
 174 sparc32_sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 175 {
 176   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 177
 178   /* Solaris has SVR4-style shared libraries...  */
 179   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 180   set_gdbarch_skip_solib_resolver (gdbarch, sol2_skip_solib_resolver);
 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 }