gcc/data-streamer-out.c

   1 /* Routines for saving various data types to a file stream.  This deals
   2    with various data types like strings, integers, enums, etc.
   3
   4    Copyright 2011 Free Software Foundation, Inc.
   5    Contributed by Diego Novillo <dnovillo@google.com>
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 3, or (at your option) any later
  12 version.
  13
  14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "data-streamer.h"
  27
  28 /* Return index used to reference STRING of LEN characters in the string table
  29    in OB.  The string might or might not include a trailing '\0'.
  30    Then put the index onto the INDEX_STREAM.
  31    When PERSISTENT is set, the string S is supposed to not change during
  32    duration of the OB and thus OB can keep pointer into it.  */
  33
  34 unsigned
  35 lto_string_index (struct output_block *ob, const char *s, unsigned int len,
  36                   bool persistent)
  37 {
  38   struct string_slot **slot;
  39   struct string_slot s_slot;
  40
  41   s_slot.s = s;
  42   s_slot.len = len;
  43   s_slot.slot_num = 0;
  44
  45   slot = (struct string_slot **) htab_find_slot (ob->string_hash_table,
  46                                                  &s_slot, INSERT);
  47   if (*slot == NULL)
  48     {
  49       struct lto_output_stream *string_stream = ob->string_stream;
  50       unsigned int start = string_stream->total_size;
  51       struct string_slot *new_slot = XOBNEW (&ob->obstack, struct string_slot);
  52       const char *string;
  53
  54       if (!persistent)
  55         {
  56           char *tmp;
  57           string = tmp = XOBNEWVEC (&ob->obstack, char, len);
  58           memcpy (tmp, s, len);
  59         }
  60       else
  61         string = s;
  62
  63       new_slot->s = string;
  64       new_slot->len = len;
  65       new_slot->slot_num = start;
  66       *slot = new_slot;
  67       lto_output_uleb128_stream (string_stream, len);
  68       lto_output_data_stream (string_stream, string, len);
  69       return start + 1;
  70     }
  71   else
  72     {
  73       struct string_slot *old_slot = *slot;
  74       return old_slot->slot_num + 1;
  75     }
  76 }
  77
  78
  79 /* Output STRING of LEN characters to the string table in OB. The
  80    string might or might not include a trailing '\0'. Then put the
  81    index onto the INDEX_STREAM.
  82    When PERSISTENT is set, the string S is supposed to not change during
  83    duration of the OB and thus OB can keep pointer into it.  */
  84
  85 void
  86 lto_output_string_with_length (struct output_block *ob,
  87                                struct lto_output_stream *index_stream,
  88                                const char *s, unsigned int len, bool persistent)
  89 {
  90   if (s)
  91     lto_output_uleb128_stream (index_stream,
  92                                lto_string_index (ob, s, len, persistent));
  93   else
  94     lto_output_1_stream (index_stream, 0);
  95 }
  96
  97
  98 /* Output the '\0' terminated STRING to the string
  99    table in OB.  Then put the index onto the INDEX_STREAM.
 100    When PERSISTENT is set, the string S is supposed to not change during
 101    duration of the OB and thus OB can keep pointer into it.  */
 102
 103 void
 104 lto_output_string (struct output_block *ob,
 105                    struct lto_output_stream *index_stream,
 106                    const char *string, bool persistent)
 107 {
 108   if (string)
 109     lto_output_string_with_length (ob, index_stream, string,
 110                                    strlen (string) + 1,
 111                                    persistent);
 112   else
 113     lto_output_1_stream (index_stream, 0);
 114 }
 115
 116
 117 /* Write a zero to the output stream.  */
 118
 119 void
 120 output_zero (struct output_block *ob)
 121 {
 122   lto_output_1_stream (ob->main_stream, 0);
 123 }
 124
 125
 126 /* Output an unsigned LEB128 quantity to OB->main_stream.  */
 127
 128 void
 129 output_uleb128 (struct output_block *ob, unsigned HOST_WIDE_INT work)
 130 {
 131   lto_output_uleb128_stream (ob->main_stream, work);
 132 }
 133
 134
 135 /* Output a signed LEB128 quantity to OB->main_stream.  */
 136
 137 void
 138 output_sleb128 (struct output_block *ob, HOST_WIDE_INT work)
 139 {
 140   lto_output_sleb128_stream (ob->main_stream, work);
 141 }
 142
 143
 144 /* Output an unsigned LEB128 quantity to OBS.  */
 145
 146 void
 147 lto_output_uleb128_stream (struct lto_output_stream *obs,
 148                            unsigned HOST_WIDE_INT work)
 149 {
 150   do
 151     {
 152       unsigned int byte = (work & 0x7f);
 153       work >>= 7;
 154       if (work != 0)
 155         /* More bytes to follow.  */
 156         byte |= 0x80;
 157
 158       lto_output_1_stream (obs, byte);
 159     }
 160   while (work != 0);
 161 }
 162
 163
 164 /* Identical to output_uleb128_stream above except using unsigned
 165    HOST_WIDEST_INT type.  For efficiency on host where unsigned HOST_WIDEST_INT
 166    is not native, we only use this if we know that HOST_WIDE_INT is not wide
 167    enough.  */
 168
 169 void
 170 lto_output_widest_uint_uleb128_stream (struct lto_output_stream *obs,
 171                                        unsigned HOST_WIDEST_INT work)
 172 {
 173   do
 174     {
 175       unsigned int byte = (work & 0x7f);
 176       work >>= 7;
 177       if (work != 0)
 178         /* More bytes to follow.  */
 179         byte |= 0x80;
 180
 181       lto_output_1_stream (obs, byte);
 182     }
 183   while (work != 0);
 184 }
 185
 186
 187 /* Output a signed LEB128 quantity.  */
 188
 189 void
 190 lto_output_sleb128_stream (struct lto_output_stream *obs, HOST_WIDE_INT work)
 191 {
 192   int more, byte;
 193
 194   do
 195     {
 196       byte = (work & 0x7f);
 197       /* arithmetic shift */
 198       work >>= 7;
 199       more = !((work == 0 && (byte & 0x40) == 0)
 200                || (work == -1 && (byte & 0x40) != 0));
 201       if (more)
 202         byte |= 0x80;
 203
 204       lto_output_1_stream (obs, byte);
 205     }
 206   while (more);
 207 }