gcc/data-streamer-in.c

   1 /* Routines for restoring various data types from a file stream.  This deals
   2    with various data types like strings, integers, enums, etc.
   3
   4    Copyright (C) 2011-2015 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 "diagnostic.h"
  27 #include "hash-set.h"
  28 #include "machmode.h"
  29 #include "vec.h"
  30 #include "double-int.h"
  31 #include "input.h"
  32 #include "alias.h"
  33 #include "symtab.h"
  34 #include "options.h"
  35 #include "wide-int.h"
  36 #include "inchash.h"
  37 #include "tree.h"
  38 #include "fold-const.h"
  39 #include "predict.h"
  40 #include "vec.h"
  41 #include "tm.h"
  42 #include "hard-reg-set.h"
  43 #include "input.h"
  44 #include "function.h"
  45 #include "basic-block.h"
  46 #include "tree-ssa-alias.h"
  47 #include "internal-fn.h"
  48 #include "gimple-expr.h"
  49 #include "is-a.h"
  50 #include "gimple.h"
  51 #include "hash-map.h"
  52 #include "plugin-api.h"
  53 #include "ipa-ref.h"
  54 #include "cgraph.h"
  55 #include "data-streamer.h"
  56
  57 /* Read a string from the string table in DATA_IN using input block
  58    IB.  Write the length to RLEN.  */
  59
  60 static const char *
  61 string_for_index (struct data_in *data_in, unsigned int loc, unsigned int *rlen)
  62 {
  63   unsigned int len;
  64   const char *result;
  65
  66   if (!loc)
  67     {
  68       *rlen = 0;
  69       return NULL;
  70     }
  71
  72   /* Get the string stored at location LOC in DATA_IN->STRINGS.  */
  73   lto_input_block str_tab (data_in->strings, loc - 1, data_in->strings_len);
  74   len = streamer_read_uhwi (&str_tab);
  75   *rlen = len;
  76
  77   if (str_tab.p + len > data_in->strings_len)
  78     internal_error ("bytecode stream: string too long for the string table");
  79
  80   result = (const char *)(data_in->strings + str_tab.p);
  81
  82   return result;
  83 }
  84
  85
  86 /* Read a string from the string table in DATA_IN using input block
  87    IB.  Write the length to RLEN.  */
  88
  89 const char *
  90 streamer_read_indexed_string (struct data_in *data_in,
  91                               struct lto_input_block *ib, unsigned int *rlen)
  92 {
  93   return string_for_index (data_in, streamer_read_uhwi (ib), rlen);
  94 }
  95
  96
  97 /* Read a NULL terminated string from the string table in DATA_IN.  */
  98
  99 const char *
 100 streamer_read_string (struct data_in *data_in, struct lto_input_block *ib)
 101 {
 102   unsigned int len;
 103   const char *ptr;
 104
 105   ptr = streamer_read_indexed_string (data_in, ib, &len);
 106   if (!ptr)
 107     return NULL;
 108   if (ptr[len - 1] != '\0')
 109     internal_error ("bytecode stream: found non-null terminated string");
 110
 111   return ptr;
 112 }
 113
 114
 115 /* Read a string from the string table in DATA_IN using the bitpack BP.
 116    Write the length to RLEN.  */
 117
 118 const char *
 119 bp_unpack_indexed_string (struct data_in *data_in,
 120                           struct bitpack_d *bp, unsigned int *rlen)
 121 {
 122   return string_for_index (data_in, bp_unpack_var_len_unsigned (bp), rlen);
 123 }
 124
 125
 126 /* Read a NULL terminated string from the string table in DATA_IN.  */
 127
 128 const char *
 129 bp_unpack_string (struct data_in *data_in, struct bitpack_d *bp)
 130 {
 131   unsigned int len;
 132   const char *ptr;
 133
 134   ptr = bp_unpack_indexed_string (data_in, bp, &len);
 135   if (!ptr)
 136     return NULL;
 137   if (ptr[len - 1] != '\0')
 138     internal_error ("bytecode stream: found non-null terminated string");
 139
 140   return ptr;
 141 }
 142
 143
 144 /* Read an unsigned HOST_WIDE_INT number from IB.  */
 145
 146 unsigned HOST_WIDE_INT
 147 streamer_read_uhwi (struct lto_input_block *ib)
 148 {
 149   unsigned HOST_WIDE_INT result;
 150   int shift;
 151   unsigned HOST_WIDE_INT byte;
 152   unsigned int p = ib->p;
 153   unsigned int len = ib->len;
 154
 155   const char *data = ib->data;
 156   result = data[p++];
 157   if ((result & 0x80) != 0)
 158     {
 159       result &= 0x7f;
 160       shift = 7;
 161       do
 162         {
 163           byte = data[p++];
 164           result |= (byte & 0x7f) << shift;
 165           shift += 7;
 166         }
 167       while ((byte & 0x80) != 0);
 168     }
 169
 170   /* We check for section overrun after the fact for performance reason.  */
 171   if (p > len)
 172     lto_section_overrun (ib);
 173
 174   ib->p = p;
 175   return result;
 176 }
 177
 178
 179 /* Read a HOST_WIDE_INT number from IB.  */
 180
 181 HOST_WIDE_INT
 182 streamer_read_hwi (struct lto_input_block *ib)
 183 {
 184   HOST_WIDE_INT result = 0;
 185   int shift = 0;
 186   unsigned HOST_WIDE_INT byte;
 187
 188   while (true)
 189     {
 190       byte = streamer_read_uchar (ib);
 191       result |= (byte & 0x7f) << shift;
 192       shift += 7;
 193       if ((byte & 0x80) == 0)
 194         {
 195           if ((shift < HOST_BITS_PER_WIDE_INT) && (byte & 0x40))
 196             result |= - (HOST_WIDE_INT_1U << shift);
 197
 198           return result;
 199         }
 200     }
 201 }
 202
 203 /* Read gcov_type value from IB.  */
 204
 205 gcov_type
 206 streamer_read_gcov_count (struct lto_input_block *ib)
 207 {
 208   gcov_type ret = streamer_read_hwi (ib);
 209   gcc_assert (ret >= 0);
 210   return ret;
 211 }