gdb/sparc-sol2-tdep.c

   1 /* Target-dependent code for Solaris SPARC.
   2
   3    Copyright (C) 2003, 2004, 2006 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 "sol2-tdep.h"
  37 #include "sparc-tdep.h"
  38 #include "solib-svr4.h"
  39
  40 /* From <sys/regset.h>.  */
  41 const struct sparc_gregset sparc32_sol2_gregset =
  42 {
  43   32 * 4,                       /* %psr */
  44   33 * 4,                       /* %pc */
  45   34 * 4,                       /* %npc */
  46   35 * 4,                       /* %y */
  47   36 * 4,                       /* %wim */
  48   37 * 4,                       /* %tbr */
  49   1 * 4,                        /* %g1 */
  50   16 * 4,                       /* %l0 */
  51 };
  52 \f
  53
  54 /* The Solaris signal trampolines reside in libc.  For normal signals,
  55    the function `sigacthandler' is used.  This signal trampoline will
  56    call the signal handler using the System V calling convention,
  57    where the third argument is a pointer to an instance of
  58    `ucontext_t', which has a member `uc_mcontext' that contains the
  59    saved registers.  Incidentally, the kernel passes the `ucontext_t'
  60    pointer as the third argument of the signal trampoline too, and
  61    `sigacthandler' simply passes it on. However, if you link your
  62    program with "-L/usr/ucblib -R/usr/ucblib -lucb", the function
  63    `ucbsigvechandler' will be used, which invokes the using the BSD
  64    convention, where the third argument is a pointer to an instance of
  65    `struct sigcontext'.  It is the `ucbsigvechandler' function that
  66    converts the `ucontext_t' to a `sigcontext', and back.  Unless the
  67    signal handler modifies the `struct sigcontext' we can safely
  68    ignore this.  */
  69
  70 int
  71 sparc_sol2_pc_in_sigtramp (CORE_ADDR pc, char *name)
  72 {
  73   return (name && (strcmp (name, "sigacthandler") == 0
  74                    || strcmp (name, "ucbsigvechandler") == 0
  75                    || strcmp (name, "__sighndlr") == 0));
  76 }
  77
  78 static struct sparc_frame_cache *
  79 sparc32_sol2_sigtramp_frame_cache (struct frame_info *next_frame,
  80                                    void **this_cache)
  81 {
  82   struct sparc_frame_cache *cache;
  83   CORE_ADDR mcontext_addr, addr;
  84   int regnum;
  85
  86   if (*this_cache)
  87     return *this_cache;
  88
  89   cache = sparc_frame_cache (next_frame, this_cache);
  90   gdb_assert (cache == *this_cache);
  91
  92   cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);
  93
  94   /* The third argument is a pointer to an instance of `ucontext_t',
  95      which has a member `uc_mcontext' that contains the saved
  96      registers.  */
  97   regnum = (cache->frameless_p ? SPARC_O2_REGNUM : SPARC_I2_REGNUM);
  98   mcontext_addr = frame_unwind_register_unsigned (next_frame, regnum) + 40;
  99
 100   cache->saved_regs[SPARC32_PSR_REGNUM].addr = mcontext_addr + 0 * 4;
 101   cache->saved_regs[SPARC32_PC_REGNUM].addr = mcontext_addr + 1 * 4;
 102   cache->saved_regs[SPARC32_NPC_REGNUM].addr = mcontext_addr + 2 * 4;
 103   cache->saved_regs[SPARC32_Y_REGNUM].addr = mcontext_addr + 3 * 4;
 104
 105   /* Since %g0 is always zero, keep the identity encoding.  */
 106   for (regnum = SPARC_G1_REGNUM, addr = mcontext_addr + 4 * 4;
 107        regnum <= SPARC_O7_REGNUM; regnum++, addr += 4)
 108     cache->saved_regs[regnum].addr = addr;
 109
 110   if (get_frame_memory_unsigned (next_frame, mcontext_addr + 19 * 4, 4))
 111     {
 112       /* The register windows haven't been flushed.  */
 113       for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
 114         trad_frame_set_unknown (cache->saved_regs, regnum);
 115     }
 116   else
 117     {
 118       addr = cache->saved_regs[SPARC_SP_REGNUM].addr;
 119       addr = get_frame_memory_unsigned (next_frame, addr, 4);
 120       for (regnum = SPARC_L0_REGNUM;
 121            regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 122         cache->saved_regs[regnum].addr = addr;
 123     }
 124
 125   return cache;
 126 }
 127
 128 static void
 129 sparc32_sol2_sigtramp_frame_this_id (struct frame_info *next_frame,
 130                                      void **this_cache,
 131                                      struct frame_id *this_id)
 132 {
 133   struct sparc_frame_cache *cache =
 134     sparc32_sol2_sigtramp_frame_cache (next_frame, this_cache);
 135
 136   (*this_id) = frame_id_build (cache->base, cache->pc);
 137 }
 138
 139 static void
 140 sparc32_sol2_sigtramp_frame_prev_register (struct frame_info *next_frame,
 141                                            void **this_cache,
 142                                            int regnum, int *optimizedp,
 143                                            enum lval_type *lvalp,
 144                                            CORE_ADDR *addrp,
 145                                            int *realnump, gdb_byte *valuep)
 146 {
 147   struct sparc_frame_cache *cache =
 148     sparc32_sol2_sigtramp_frame_cache (next_frame, this_cache);
 149
 150   trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
 151                                 optimizedp, lvalp, addrp, realnump, valuep);
 152 }
 153
 154 static const struct frame_unwind sparc32_sol2_sigtramp_frame_unwind =
 155 {
 156   SIGTRAMP_FRAME,
 157   sparc32_sol2_sigtramp_frame_this_id,
 158   sparc32_sol2_sigtramp_frame_prev_register
 159 };
 160
 161 static const struct frame_unwind *
 162 sparc32_sol2_sigtramp_frame_sniffer (struct frame_info *next_frame)
 163 {
 164   CORE_ADDR pc = frame_pc_unwind (next_frame);
 165   char *name;
 166
 167   find_pc_partial_function (pc, &name, NULL, NULL);
 168   if (sparc_sol2_pc_in_sigtramp (pc, name))
 169     return &sparc32_sol2_sigtramp_frame_unwind;
 170
 171   return NULL;
 172 }
 173 \f
 174
 175 void
 176 sparc32_sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 177 {
 178   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 179
 180   /* Solaris has SVR4-style shared libraries...  */
 181   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 182   set_gdbarch_skip_solib_resolver (gdbarch, sol2_skip_solib_resolver);
 183   set_solib_svr4_fetch_link_map_offsets
 184     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 185
 186   /* ...which means that we need some special handling when doing
 187      prologue analysis.  */
 188   tdep->plt_entry_size = 12;
 189
 190   /* Solaris has kernel-assisted single-stepping support.  */
 191   set_gdbarch_software_single_step (gdbarch, NULL);
 192
 193   frame_unwind_append_sniffer (gdbarch, sparc32_sol2_sigtramp_frame_sniffer);
 194 }
 195 \f
 196
 197 /* Provide a prototype to silence -Wmissing-prototypes.  */
 198 void _initialize_sparc_sol2_tdep (void);
 199
 200 void
 201 _initialize_sparc_sol2_tdep (void)
 202 {
 203   gdbarch_register_osabi (bfd_arch_sparc, 0,
 204                           GDB_OSABI_SOLARIS, sparc32_sol2_init_abi);
 205 }