gdb/sparc-sol2-tdep.c

   1 /* Target-dependent code for Solaris SPARC.
   2
   3    Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "frame.h"
  23 #include "frame-unwind.h"
  24 #include "gdbcore.h"
  25 #include "symtab.h"
  26 #include "objfiles.h"
  27 #include "osabi.h"
  28 #include "regcache.h"
  29 #include "target.h"
  30 #include "trad-frame.h"
  31
  32 #include "gdb_assert.h"
  33 #include "gdb_string.h"
  34
  35 #include "sol2-tdep.h"
  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 *this_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 (this_frame, this_cache);
  89   gdb_assert (cache == *this_cache);
  90
  91   cache->saved_regs = trad_frame_alloc_saved_regs (this_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 = get_frame_register_unsigned (this_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 (this_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 (this_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 *this_frame,
 129                                      void **this_cache,
 130                                      struct frame_id *this_id)
 131 {
 132   struct sparc_frame_cache *cache =
 133     sparc32_sol2_sigtramp_frame_cache (this_frame, this_cache);
 134
 135   (*this_id) = frame_id_build (cache->base, cache->pc);
 136 }
 137
 138 static struct value *
 139 sparc32_sol2_sigtramp_frame_prev_register (struct frame_info *this_frame,
 140                                            void **this_cache,
 141                                            int regnum)
 142 {
 143   struct sparc_frame_cache *cache =
 144     sparc32_sol2_sigtramp_frame_cache (this_frame, this_cache);
 145
 146   return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
 147 }
 148
 149 static int
 150 sparc32_sol2_sigtramp_frame_sniffer (const struct frame_unwind *self,
 151                                      struct frame_info *this_frame,
 152                                      void **this_cache)
 153 {
 154   CORE_ADDR pc = get_frame_pc (this_frame);
 155   char *name;
 156
 157   find_pc_partial_function (pc, &name, NULL, NULL);
 158   if (sparc_sol2_pc_in_sigtramp (pc, name))
 159     return 1;
 160
 161   return 0;
 162 }
 163
 164 static const struct frame_unwind sparc32_sol2_sigtramp_frame_unwind =
 165 {
 166   SIGTRAMP_FRAME,
 167   sparc32_sol2_sigtramp_frame_this_id,
 168   sparc32_sol2_sigtramp_frame_prev_register,
 169   NULL,
 170   sparc32_sol2_sigtramp_frame_sniffer
 171 };
 172
 173 /* Unglobalize NAME.  */
 174
 175 char *
 176 sparc_sol2_static_transform_name (char *name)
 177 {
 178   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop,
 179      SunPRO) convert file static variables into global values, a
 180      process known as globalization.  In order to do this, the
 181      compiler will create a unique prefix and prepend it to each file
 182      static variable.  For static variables within a function, this
 183      globalization prefix is followed by the function name (nested
 184      static variables within a function are supposed to generate a
 185      warning message, and are left alone).  The procedure is
 186      documented in the Stabs Interface Manual, which is distrubuted
 187      with the compilers, although version 4.0 of the manual seems to
 188      be incorrect in some places, at least for SPARC.  The
 189      globalization prefix is encoded into an N_OPT stab, with the form
 190      "G=<prefix>".  The globalization prefix always seems to start
 191      with a dollar sign '$'; a dot '.' is used as a seperator.  So we
 192      simply strip everything up until the last dot.  */
 193
 194   if (name[0] == '$')
 195     {
 196       char *p = strrchr (name, '.');
 197       if (p)
 198         return p + 1;
 199     }
 200
 201   return name;
 202 }
 203 \f
 204
 205 void
 206 sparc32_sol2_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 207 {
 208   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 209
 210   /* The Sun compilers (Sun ONE Studio, Forte Developer, Sun WorkShop, SunPRO)
 211      compiler puts out 0 instead of the address in N_SO stabs.  Starting with
 212      SunPRO 3.0, the compiler does this for N_FUN stabs too.  */
 213   set_gdbarch_sofun_address_maybe_missing (gdbarch, 1);
 214
 215   /* The Sun compilers also do "globalization"; see the comment in
 216      sparc_sol2_static_transform_name for more information.  */
 217   set_gdbarch_static_transform_name
 218     (gdbarch, sparc_sol2_static_transform_name);
 219
 220   /* Solaris has SVR4-style shared libraries...  */
 221   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 222   set_gdbarch_skip_solib_resolver (gdbarch, sol2_skip_solib_resolver);
 223   set_solib_svr4_fetch_link_map_offsets
 224     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 225
 226   /* ...which means that we need some special handling when doing
 227      prologue analysis.  */
 228   tdep->plt_entry_size = 12;
 229
 230   /* Solaris has kernel-assisted single-stepping support.  */
 231   set_gdbarch_software_single_step (gdbarch, NULL);
 232
 233   frame_unwind_append_unwinder (gdbarch, &sparc32_sol2_sigtramp_frame_unwind);
 234
 235   /* Solaris encodes the pid of the inferior in regset section
 236      names.  */
 237   set_gdbarch_core_reg_section_encodes_pid (gdbarch, 1);
 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 }