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
 172 /* Unglobalize NAME.  */
 173
 174 char *
 175 sparc_sol2_static_transform_name (char *name)
 176 {
 177   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop,
 178      SunPRO) convert file static variables into global values, a
 179      process known as globalization.  In order to do this, the
 180      compiler will create a unique prefix and prepend it to each file
 181      static variable.  For static variables within a function, this
 182      globalization prefix is followed by the function name (nested
 183      static variables within a function are supposed to generate a
 184      warning message, and are left alone).  The procedure is
 185      documented in the Stabs Interface Manual, which is distrubuted
 186      with the compilers, although version 4.0 of the manual seems to
 187      be incorrect in some places, at least for SPARC.  The
 188      globalization prefix is encoded into an N_OPT stab, with the form
 189      "G=<prefix>".  The globalization prefix always seems to start
 190      with a dollar sign '$'; a dot '.' is used as a seperator.  So we
 191      simply strip everything up until the last dot.  */
 192
 193   if (name[0] == '$')
 194     {
 195       char *p = strrchr (name, '.');
 196       if (p)
 197         return p + 1;
 198     }
 199
 200   return name;
 201 }
 202 \f
 203
 204 void
 205 sparc32_sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 206 {
 207   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 208
 209   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop, SunPRO)
 210      compiler puts out 0 instead of the address in N_SO stabs.  Starting with
 211      SunPRO 3.0, the compiler does this for N_FUN stabs too.  */
 212   set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
 213
 214   /* The Sun compilers also do "globalization"; see the comment in
 215      sparc_sol2_static_transform_name for more information.  */
 216   set_gdbarch_static_transform_name
 217     (gdbarch, sparc_sol2_static_transform_name);
 218
 219   /* Solaris has SVR4-style shared libraries...  */
 220   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 221   set_gdbarch_skip_solib_resolver (gdbarch, sol2_skip_solib_resolver);
 222   set_solib_svr4_fetch_link_map_offsets
 223     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 224
 225   /* ...which means that we need some special handling when doing
 226      prologue analysis.  */
 227   tdep->plt_entry_size = 12;
 228
 229   /* Solaris has kernel-assisted single-stepping support.  */
 230   set_gdbarch_software_single_step (gdbarch, NULL);
 231
 232   frame_unwind_append_sniffer (gdbarch, sparc32_sol2_sigtramp_frame_sniffer);
 233 }
 234 \f
 235
 236 /* Provide a prototype to silence -Wmissing-prototypes.  */
 237 void _initialize_sparc_sol2_tdep (void);
 238
 239 void
 240 _initialize_sparc_sol2_tdep (void)
 241 {
 242   gdbarch_register_osabi (bfd_arch_sparc, 0,
 243                           GDB_OSABI_SOLARIS, sparc32_sol2_init_abi);
 244 }