gcc/data-streamer-in.cc

   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) 2011-2023 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 "backend.h"
  27 #include "tree.h"
  28 #include "gimple.h"
  29 #include "cgraph.h"
  30 #include "data-streamer.h"
  31 #include "value-range.h"
  32 #include "streamer-hooks.h"
  33
  34 /* Read a string from the string table in DATA_IN using input block
  35    IB.  Write the length to RLEN.  */
  36
  37 static const char *
  38 string_for_index (class data_in *data_in, unsigned int loc, unsigned int *rlen)
  39 {
  40   unsigned int len;
  41   const char *result;
  42
  43   if (!loc)
  44     {
  45       *rlen = 0;
  46       return NULL;
  47     }
  48
  49   /* Get the string stored at location LOC in DATA_IN->STRINGS.  */
  50   lto_input_block str_tab (data_in->strings, loc - 1, data_in->strings_len, NULL);
  51   len = streamer_read_uhwi (&str_tab);
  52   *rlen = len;
  53
  54   if (str_tab.p + len > data_in->strings_len)
  55     internal_error ("bytecode stream: string too long for the string table");
  56
  57   result = (const char *)(data_in->strings + str_tab.p);
  58
  59   return result;
  60 }
  61
  62
  63 /* Read a string from the string table in DATA_IN using input block
  64    IB.  Write the length to RLEN.  */
  65
  66 const char *
  67 streamer_read_indexed_string (class data_in *data_in,
  68                               class lto_input_block *ib, unsigned int *rlen)
  69 {
  70   return string_for_index (data_in, streamer_read_uhwi (ib), rlen);
  71 }
  72
  73
  74 /* Read a NULL terminated string from the string table in DATA_IN.  */
  75
  76 const char *
  77 streamer_read_string (class data_in *data_in, class lto_input_block *ib)
  78 {
  79   unsigned int len;
  80   const char *ptr;
  81
  82   ptr = streamer_read_indexed_string (data_in, ib, &len);
  83   if (!ptr)
  84     return NULL;
  85   if (ptr[len - 1] != '\0')
  86     internal_error ("bytecode stream: found non-null terminated string");
  87
  88   return ptr;
  89 }
  90
  91
  92 /* Read a string from the string table in DATA_IN using the bitpack BP.
  93    Write the length to RLEN.  */
  94
  95 const char *
  96 bp_unpack_indexed_string (class data_in *data_in,
  97                           struct bitpack_d *bp, unsigned int *rlen)
  98 {
  99   return string_for_index (data_in, bp_unpack_var_len_unsigned (bp), rlen);
 100 }
 101
 102
 103 /* Read a NULL terminated string from the string table in DATA_IN.  */
 104
 105 const char *
 106 bp_unpack_string (class data_in *data_in, struct bitpack_d *bp)
 107 {
 108   unsigned int len;
 109   const char *ptr;
 110
 111   ptr = bp_unpack_indexed_string (data_in, bp, &len);
 112   if (!ptr)
 113     return NULL;
 114   if (ptr[len - 1] != '\0')
 115     internal_error ("bytecode stream: found non-null terminated string");
 116
 117   return ptr;
 118 }
 119
 120
 121 /* Read an unsigned HOST_WIDE_INT number from IB.  */
 122
 123 unsigned HOST_WIDE_INT
 124 streamer_read_uhwi (class lto_input_block *ib)
 125 {
 126   unsigned HOST_WIDE_INT result;
 127   int shift;
 128   unsigned HOST_WIDE_INT byte;
 129   unsigned int p = ib->p;
 130   unsigned int len = ib->len;
 131
 132   const char *data = ib->data;
 133   result = data[p++];
 134   if ((result & 0x80) != 0)
 135     {
 136       result &= 0x7f;
 137       shift = 7;
 138       do
 139         {
 140           byte = data[p++];
 141           result |= (byte & 0x7f) << shift;
 142           shift += 7;
 143         }
 144       while ((byte & 0x80) != 0);
 145     }
 146
 147   /* We check for section overrun after the fact for performance reason.  */
 148   if (p > len)
 149     lto_section_overrun (ib);
 150
 151   ib->p = p;
 152   return result;
 153 }
 154
 155
 156 /* Read a HOST_WIDE_INT number from IB.  */
 157
 158 HOST_WIDE_INT
 159 streamer_read_hwi (class lto_input_block *ib)
 160 {
 161   HOST_WIDE_INT result = 0;
 162   int shift = 0;
 163   unsigned HOST_WIDE_INT byte;
 164
 165   while (true)
 166     {
 167       byte = streamer_read_uchar (ib);
 168       result |= (byte & 0x7f) << shift;
 169       shift += 7;
 170       if ((byte & 0x80) == 0)
 171         {
 172           if ((shift < HOST_BITS_PER_WIDE_INT) && (byte & 0x40))
 173             result |= - (HOST_WIDE_INT_1U << shift);
 174
 175           return result;
 176         }
 177     }
 178 }
 179
 180 /* Read a poly_uint64 from IB.  */
 181
 182 poly_uint64
 183 streamer_read_poly_uint64 (class lto_input_block *ib)
 184 {
 185   poly_uint64 res;
 186   for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
 187     res.coeffs[i] = streamer_read_uhwi (ib);
 188   return res;
 189 }
 190
 191 /* Read a poly_int64 from IB.  */
 192
 193 poly_int64
 194 streamer_read_poly_int64 (class lto_input_block *ib)
 195 {
 196   poly_int64 res;
 197   for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i)
 198     res.coeffs[i] = streamer_read_hwi (ib);
 199   return res;
 200 }
 201
 202 /* Read gcov_type value from IB.  */
 203
 204 gcov_type
 205 streamer_read_gcov_count (class lto_input_block *ib)
 206 {
 207   gcov_type ret = streamer_read_hwi (ib);
 208   return ret;
 209 }
 210
 211 /* Read REAL_VALUE_TYPE from IB.  */
 212
 213 void
 214 streamer_read_real_value (class lto_input_block *ib, REAL_VALUE_TYPE *r)
 215 {
 216   struct bitpack_d bp = streamer_read_bitpack (ib);
 217   bp_unpack_real_value (&bp, r);
 218 }
 219
 220 void
 221 streamer_read_value_range (class lto_input_block *ib, data_in *data_in,
 222                            Value_Range &vr)
 223 {
 224   // Read the common fields to all vranges.
 225   value_range_kind kind = streamer_read_enum (ib, value_range_kind, VR_LAST);
 226   gcc_checking_assert (kind != VR_UNDEFINED);
 227   tree type = stream_read_tree (ib, data_in);
 228
 229   // Initialize the Value_Range to the correct type.
 230   vr.set_type (type);
 231
 232   if (is_a <irange> (vr))
 233     {
 234       irange &r = as_a <irange> (vr);
 235       r.set_undefined ();
 236       unsigned HOST_WIDE_INT num_pairs = streamer_read_uhwi (ib);
 237       for (unsigned i = 0; i < num_pairs; ++i)
 238         {
 239           wide_int lb = streamer_read_wide_int (ib);
 240           wide_int ub = streamer_read_wide_int (ib);
 241           int_range<2> tmp (type, lb, ub);
 242           r.union_ (tmp);
 243         }
 244       wide_int value = streamer_read_wide_int (ib);
 245       wide_int mask = streamer_read_wide_int (ib);
 246       irange_bitmask bm (value, mask);
 247       r.update_bitmask (bm);
 248       return;
 249     }
 250   if (is_a <frange> (vr))
 251     {
 252       frange &r = as_a <frange> (vr);
 253
 254       // Stream in NAN bits.
 255       struct bitpack_d bp = streamer_read_bitpack (ib);
 256       bool pos_nan = (bool) bp_unpack_value (&bp, 1);
 257       bool neg_nan = (bool) bp_unpack_value (&bp, 1);
 258       nan_state nan (pos_nan, neg_nan);
 259
 260       if (kind == VR_NAN)
 261         r.set_nan (type, nan);
 262       else
 263         {
 264           REAL_VALUE_TYPE lb, ub;
 265           streamer_read_real_value (ib, &lb);
 266           streamer_read_real_value (ib, &ub);
 267           r.set (type, lb, ub, nan);
 268         }
 269       return;
 270     }
 271   gcc_unreachable ();
 272 }
 273
 274 /* Read the physical representation of a wide_int val from
 275    input block IB.  */
 276
 277 wide_int
 278 streamer_read_wide_int (class lto_input_block *ib)
 279 {
 280   HOST_WIDE_INT abuf[WIDE_INT_MAX_INL_ELTS], *a = abuf;
 281   int i;
 282   int prec = streamer_read_uhwi (ib);
 283   int len = streamer_read_uhwi (ib);
 284   if (UNLIKELY (len > WIDE_INT_MAX_INL_ELTS))
 285     a = XALLOCAVEC (HOST_WIDE_INT, len);
 286   for (i = 0; i < len; i++)
 287     a[i] = streamer_read_hwi (ib);
 288   return wide_int::from_array (a, len, prec);
 289 }
 290
 291 /* Read the physical representation of a widest_int val from
 292    input block IB.  */
 293
 294 widest_int
 295 streamer_read_widest_int (class lto_input_block *ib)
 296 {
 297   HOST_WIDE_INT abuf[WIDE_INT_MAX_INL_ELTS], *a = abuf;
 298   int i;
 299   int prec ATTRIBUTE_UNUSED = streamer_read_uhwi (ib);
 300   int len = streamer_read_uhwi (ib);
 301   if (UNLIKELY (len > WIDE_INT_MAX_INL_ELTS))
 302     a = XALLOCAVEC (HOST_WIDE_INT, len);
 303   for (i = 0; i < len; i++)
 304     a[i] = streamer_read_hwi (ib);
 305   return widest_int::from_array (a, len);
 306 }
 307