gdb/sparc-sol2-tdep.c

   1 /* Target-dependent code for Solaris SPARC.
   2
   3    Copyright (C) 2003-2014 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 "sol2-tdep.h"
  32 #include "sparc-tdep.h"
  33 #include "solib-svr4.h"
  34
  35 /* From <sys/regset.h>.  */
  36 const struct sparc_gregmap sparc32_sol2_gregmap =
  37 {
  38   32 * 4,                       /* %psr */
  39   33 * 4,                       /* %pc */
  40   34 * 4,                       /* %npc */
  41   35 * 4,                       /* %y */
  42   36 * 4,                       /* %wim */
  43   37 * 4,                       /* %tbr */
  44   1 * 4,                        /* %g1 */
  45   16 * 4,                       /* %l0 */
  46 };
  47
  48 const struct sparc_fpregmap sparc32_sol2_fpregmap =
  49 {
  50   0 * 4,                        /* %f0 */
  51   33 * 4,                       /* %fsr */
  52 };
  53 \f
  54
  55 /* The Solaris signal trampolines reside in libc.  For normal signals,
  56    the function `sigacthandler' is used.  This signal trampoline will
  57    call the signal handler using the System V calling convention,
  58    where the third argument is a pointer to an instance of
  59    `ucontext_t', which has a member `uc_mcontext' that contains the
  60    saved registers.  Incidentally, the kernel passes the `ucontext_t'
  61    pointer as the third argument of the signal trampoline too, and
  62    `sigacthandler' simply passes it on.  However, if you link your
  63    program with "-L/usr/ucblib -R/usr/ucblib -lucb", the function
  64    `ucbsigvechandler' will be used, which invokes the using the BSD
  65    convention, where the third argument is a pointer to an instance of
  66    `struct sigcontext'.  It is the `ucbsigvechandler' function that
  67    converts the `ucontext_t' to a `sigcontext', and back.  Unless the
  68    signal handler modifies the `struct sigcontext' we can safely
  69    ignore this.  */
  70
  71 int
  72 sparc_sol2_pc_in_sigtramp (CORE_ADDR pc, const char *name)
  73 {
  74   return (name && (strcmp (name, "sigacthandler") == 0
  75                    || strcmp (name, "ucbsigvechandler") == 0
  76                    || strcmp (name, "__sighndlr") == 0));
  77 }
  78
  79 static struct sparc_frame_cache *
  80 sparc32_sol2_sigtramp_frame_cache (struct frame_info *this_frame,
  81                                    void **this_cache)
  82 {
  83   struct sparc_frame_cache *cache;
  84   CORE_ADDR mcontext_addr, addr;
  85   int regnum;
  86
  87   if (*this_cache)
  88     return *this_cache;
  89
  90   cache = sparc_frame_cache (this_frame, this_cache);
  91   gdb_assert (cache == *this_cache);
  92
  93   cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
  94
  95   /* The third argument is a pointer to an instance of `ucontext_t',
  96      which has a member `uc_mcontext' that contains the saved
  97      registers.  */
  98   regnum =
  99     (cache->copied_regs_mask & 0x04) ? SPARC_I2_REGNUM : SPARC_O2_REGNUM;
 100   mcontext_addr = get_frame_register_unsigned (this_frame, regnum) + 40;
 101
 102   cache->saved_regs[SPARC32_PSR_REGNUM].addr = mcontext_addr + 0 * 4;
 103   cache->saved_regs[SPARC32_PC_REGNUM].addr = mcontext_addr + 1 * 4;
 104   cache->saved_regs[SPARC32_NPC_REGNUM].addr = mcontext_addr + 2 * 4;
 105   cache->saved_regs[SPARC32_Y_REGNUM].addr = mcontext_addr + 3 * 4;
 106
 107   /* Since %g0 is always zero, keep the identity encoding.  */
 108   for (regnum = SPARC_G1_REGNUM, addr = mcontext_addr + 4 * 4;
 109        regnum <= SPARC_O7_REGNUM; regnum++, addr += 4)
 110     cache->saved_regs[regnum].addr = addr;
 111
 112   if (get_frame_memory_unsigned (this_frame, mcontext_addr + 19 * 4, 4))
 113     {
 114       /* The register windows haven't been flushed.  */
 115       for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
 116         trad_frame_set_unknown (cache->saved_regs, regnum);
 117     }
 118   else
 119     {
 120       addr = cache->saved_regs[SPARC_SP_REGNUM].addr;
 121       addr = get_frame_memory_unsigned (this_frame, addr, 4);
 122       for (regnum = SPARC_L0_REGNUM;
 123            regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 124         cache->saved_regs[regnum].addr = addr;
 125     }
 126
 127   return cache;
 128 }
 129
 130 static void
 131 sparc32_sol2_sigtramp_frame_this_id (struct frame_info *this_frame,
 132                                      void **this_cache,
 133                                      struct frame_id *this_id)
 134 {
 135   struct sparc_frame_cache *cache =
 136     sparc32_sol2_sigtramp_frame_cache (this_frame, this_cache);
 137
 138   (*this_id) = frame_id_build (cache->base, cache->pc);
 139 }
 140
 141 static struct value *
 142 sparc32_sol2_sigtramp_frame_prev_register (struct frame_info *this_frame,
 143                                            void **this_cache,
 144                                            int regnum)
 145 {
 146   struct sparc_frame_cache *cache =
 147     sparc32_sol2_sigtramp_frame_cache (this_frame, this_cache);
 148
 149   return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
 150 }
 151
 152 static int
 153 sparc32_sol2_sigtramp_frame_sniffer (const struct frame_unwind *self,
 154                                      struct frame_info *this_frame,
 155                                      void **this_cache)
 156 {
 157   CORE_ADDR pc = get_frame_pc (this_frame);
 158   const char *name;
 159
 160   find_pc_partial_function (pc, &name, NULL, NULL);
 161   if (sparc_sol2_pc_in_sigtramp (pc, name))
 162     return 1;
 163
 164   return 0;
 165 }
 166
 167 static const struct frame_unwind sparc32_sol2_sigtramp_frame_unwind =
 168 {
 169   SIGTRAMP_FRAME,
 170   default_frame_unwind_stop_reason,
 171   sparc32_sol2_sigtramp_frame_this_id,
 172   sparc32_sol2_sigtramp_frame_prev_register,
 173   NULL,
 174   sparc32_sol2_sigtramp_frame_sniffer
 175 };
 176
 177 /* Unglobalize NAME.  */
 178
 179 const const char *
 180 sparc_sol2_static_transform_name (const char *name)
 181 {
 182   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop,
 183      SunPRO) convert file static variables into global values, a
 184      process known as globalization.  In order to do this, the
 185      compiler will create a unique prefix and prepend it to each file
 186      static variable.  For static variables within a function, this
 187      globalization prefix is followed by the function name (nested
 188      static variables within a function are supposed to generate a
 189      warning message, and are left alone).  The procedure is
 190      documented in the Stabs Interface Manual, which is distrubuted
 191      with the compilers, although version 4.0 of the manual seems to
 192      be incorrect in some places, at least for SPARC.  The
 193      globalization prefix is encoded into an N_OPT stab, with the form
 194      "G=<prefix>".  The globalization prefix always seems to start
 195      with a dollar sign '$'; a dot '.' is used as a seperator.  So we
 196      simply strip everything up until the last dot.  */
 197
 198   if (name[0] == '$')
 199     {
 200       char *p = strrchr (name, '.');
 201       if (p)
 202         return p + 1;
 203     }
 204
 205   return name;
 206 }
 207 \f
 208
 209 void
 210 sparc32_sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 211 {
 212   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 213
 214   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop, SunPRO)
 215      compiler puts out 0 instead of the address in N_SO stabs.  Starting with
 216      SunPRO 3.0, the compiler does this for N_FUN stabs too.  */
 217   set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
 218
 219   /* The Sun compilers also do "globalization"; see the comment in
 220      sparc_sol2_static_transform_name for more information.  */
 221   set_gdbarch_static_transform_name
 222     (gdbarch, sparc_sol2_static_transform_name);
 223
 224   /* Solaris has SVR4-style shared libraries...  */
 225   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 226   set_gdbarch_skip_solib_resolver (gdbarch, sol2_skip_solib_resolver);
 227   set_solib_svr4_fetch_link_map_offsets
 228     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 229
 230   /* ...which means that we need some special handling when doing
 231      prologue analysis.  */
 232   tdep->plt_entry_size = 12;
 233
 234   /* Solaris has kernel-assisted single-stepping support.  */
 235   set_gdbarch_software_single_step (gdbarch, NULL);
 236
 237   frame_unwind_append_unwinder (gdbarch, &sparc32_sol2_sigtramp_frame_unwind);
 238
 239   /* How to print LWP PTIDs from core files.  */
 240   set_gdbarch_core_pid_to_str (gdbarch, sol2_core_pid_to_str);
 241 }
 242 \f
 243
 244 /* Provide a prototype to silence -Wmissing-prototypes.  */
 245 void _initialize_sparc_sol2_tdep (void);
 246
 247 void
 248 _initialize_sparc_sol2_tdep (void)
 249 {
 250   gdbarch_register_osabi (bfd_arch_sparc, 0,
 251                           GDB_OSABI_SOLARIS, sparc32_sol2_init_abi);
 252 }