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 streamer_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       streamer_write_uhwi_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 streamer_write_string_with_length (struct output_block *ob,
  87                                    struct lto_output_stream *index_stream,
  88                                    const char *s, unsigned int len,
  89                                    bool persistent)
  90 {
  91   if (s)
  92     streamer_write_uhwi_stream (index_stream,
  93                                 streamer_string_index (ob, s, len, persistent));
  94   else
  95     streamer_write_char_stream (index_stream, 0);
  96 }
  97
  98
  99 /* Output the '\0' terminated STRING to the string
 100    table in OB.  Then put the index onto the INDEX_STREAM.
 101    When PERSISTENT is set, the string S is supposed to not change during
 102    duration of the OB and thus OB can keep pointer into it.  */
 103
 104 void
 105 streamer_write_string (struct output_block *ob,
 106                        struct lto_output_stream *index_stream,
 107                        const char *string, bool persistent)
 108 {
 109   if (string)
 110     streamer_write_string_with_length (ob, index_stream, string,
 111                                        strlen (string) + 1,
 112                                        persistent);
 113   else
 114     streamer_write_char_stream (index_stream, 0);
 115 }
 116
 117
 118 /* Write a zero to the output stream.  */
 119
 120 void
 121 streamer_write_zero (struct output_block *ob)
 122 {
 123   streamer_write_char_stream (ob->main_stream, 0);
 124 }
 125
 126
 127 /* Write an unsigned HOST_WIDE_INT value WORK to OB->main_stream.  */
 128
 129 void
 130 streamer_write_uhwi (struct output_block *ob, unsigned HOST_WIDE_INT work)
 131 {
 132   streamer_write_uhwi_stream (ob->main_stream, work);
 133 }
 134
 135
 136 /* Write a HOST_WIDE_INT value WORK to OB->main_stream.  */
 137
 138 void
 139 streamer_write_hwi (struct output_block *ob, HOST_WIDE_INT work)
 140 {
 141   streamer_write_hwi_stream (ob->main_stream, work);
 142 }
 143
 144
 145 /* Write an unsigned HOST_WIDE_INT value WORK to OBS.  */
 146
 147 void
 148 streamer_write_uhwi_stream (struct lto_output_stream *obs,
 149                             unsigned HOST_WIDE_INT work)
 150 {
 151   do
 152     {
 153       unsigned int byte = (work & 0x7f);
 154       work >>= 7;
 155       if (work != 0)
 156         /* More bytes to follow.  */
 157         byte |= 0x80;
 158
 159       streamer_write_char_stream (obs, byte);
 160     }
 161   while (work != 0);
 162 }
 163
 164
 165 /* Write a HOST_WIDE_INT value WORK to OBS.  */
 166
 167 void
 168 streamer_write_hwi_stream (struct lto_output_stream *obs, HOST_WIDE_INT work)
 169 {
 170   int more, byte;
 171
 172   do
 173     {
 174       byte = (work & 0x7f);
 175       /* arithmetic shift */
 176       work >>= 7;
 177       more = !((work == 0 && (byte & 0x40) == 0)
 178                || (work == -1 && (byte & 0x40) != 0));
 179       if (more)
 180         byte |= 0x80;
 181
 182       streamer_write_char_stream (obs, byte);
 183     }
 184   while (more);
 185 }