gcc/gimple-streamer-in.c

   1 /* Routines for reading GIMPLE from a file stream.
   2
   3    Copyright 2011 Free Software Foundation, Inc.
   4    Contributed by Diego Novillo <dnovillo@google.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "diagnostic.h"
  26 #include "tree.h"
  27 #include "tree-flow.h"
  28 #include "data-streamer.h"
  29 #include "tree-streamer.h"
  30 #include "gimple-streamer.h"
  31
  32 /* Read a PHI function for basic block BB in function FN.  DATA_IN is
  33    the file being read.  IB is the input block to use for reading.  */
  34
  35 static gimple
  36 input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
  37            struct function *fn)
  38 {
  39   unsigned HOST_WIDE_INT ix;
  40   tree phi_result;
  41   int i, len;
  42   gimple result;
  43
  44   ix = streamer_read_uhwi (ib);
  45   phi_result = VEC_index (tree, SSANAMES (fn), ix);
  46   len = EDGE_COUNT (bb->preds);
  47   result = create_phi_node (phi_result, bb);
  48
  49   /* We have to go through a lookup process here because the preds in the
  50      reconstructed graph are generally in a different order than they
  51      were in the original program.  */
  52   for (i = 0; i < len; i++)
  53     {
  54       tree def = stream_read_tree (ib, data_in);
  55       int src_index = streamer_read_uhwi (ib);
  56       location_t arg_loc = lto_input_location (ib, data_in);
  57       basic_block sbb = BASIC_BLOCK_FOR_FUNCTION (fn, src_index);
  58
  59       edge e = NULL;
  60       int j;
  61
  62       for (j = 0; j < len; j++)
  63         if (EDGE_PRED (bb, j)->src == sbb)
  64           {
  65             e = EDGE_PRED (bb, j);
  66             break;
  67           }
  68
  69       add_phi_arg (result, def, e, arg_loc);
  70     }
  71
  72   return result;
  73 }
  74
  75
  76 /* Read a statement with tag TAG in function FN from block IB using
  77    descriptors in DATA_IN.  */
  78
  79 static gimple
  80 input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
  81                    struct function *fn, enum LTO_tags tag)
  82 {
  83   gimple stmt;
  84   enum gimple_code code;
  85   unsigned HOST_WIDE_INT num_ops;
  86   size_t i;
  87   struct bitpack_d bp;
  88
  89   code = lto_tag_to_gimple_code (tag);
  90
  91   /* Read the tuple header.  */
  92   bp = streamer_read_bitpack (ib);
  93   num_ops = bp_unpack_var_len_unsigned (&bp);
  94   stmt = gimple_alloc (code, num_ops);
  95   stmt->gsbase.no_warning = bp_unpack_value (&bp, 1);
  96   if (is_gimple_assign (stmt))
  97     stmt->gsbase.nontemporal_move = bp_unpack_value (&bp, 1);
  98   stmt->gsbase.has_volatile_ops = bp_unpack_value (&bp, 1);
  99   stmt->gsbase.subcode = bp_unpack_var_len_unsigned (&bp);
 100
 101   /* Read location information.  */
 102   gimple_set_location (stmt, lto_input_location (ib, data_in));
 103
 104   /* Read lexical block reference.  */
 105   gimple_set_block (stmt, stream_read_tree (ib, data_in));
 106
 107   /* Read in all the operands.  */
 108   switch (code)
 109     {
 110     case GIMPLE_RESX:
 111       gimple_resx_set_region (stmt, streamer_read_hwi (ib));
 112       break;
 113
 114     case GIMPLE_EH_MUST_NOT_THROW:
 115       gimple_eh_must_not_throw_set_fndecl (stmt, stream_read_tree (ib, data_in));
 116       break;
 117
 118     case GIMPLE_EH_DISPATCH:
 119       gimple_eh_dispatch_set_region (stmt, streamer_read_hwi (ib));
 120       break;
 121
 122     case GIMPLE_ASM:
 123       {
 124         /* FIXME lto.  Move most of this into a new gimple_asm_set_string().  */
 125         tree str;
 126         stmt->gimple_asm.ni = streamer_read_uhwi (ib);
 127         stmt->gimple_asm.no = streamer_read_uhwi (ib);
 128         stmt->gimple_asm.nc = streamer_read_uhwi (ib);
 129         stmt->gimple_asm.nl = streamer_read_uhwi (ib);
 130         str = streamer_read_string_cst (data_in, ib);
 131         stmt->gimple_asm.string = TREE_STRING_POINTER (str);
 132       }
 133       /* Fallthru  */
 134
 135     case GIMPLE_ASSIGN:
 136     case GIMPLE_CALL:
 137     case GIMPLE_RETURN:
 138     case GIMPLE_SWITCH:
 139     case GIMPLE_LABEL:
 140     case GIMPLE_COND:
 141     case GIMPLE_GOTO:
 142     case GIMPLE_DEBUG:
 143       for (i = 0; i < num_ops; i++)
 144         {
 145           tree op = stream_read_tree (ib, data_in);
 146           gimple_set_op (stmt, i, op);
 147           if (!op)
 148             continue;
 149
 150           /* Fixup FIELD_DECLs in COMPONENT_REFs, they are not handled
 151              by decl merging.  */
 152           if (TREE_CODE (op) == ADDR_EXPR)
 153             op = TREE_OPERAND (op, 0);
 154           while (handled_component_p (op))
 155             {
 156               if (TREE_CODE (op) == COMPONENT_REF)
 157                 {
 158                   tree field, type, tem;
 159                   tree closest_match = NULL_TREE;
 160                   field = TREE_OPERAND (op, 1);
 161                   type = DECL_CONTEXT (field);
 162                   for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem))
 163                     {
 164                       if (TREE_CODE (tem) != FIELD_DECL)
 165                         continue;
 166                       if (tem == field)
 167                         break;
 168                       if (DECL_NONADDRESSABLE_P (tem)
 169                           == DECL_NONADDRESSABLE_P (field)
 170                           && gimple_compare_field_offset (tem, field))
 171                         {
 172                           if (types_compatible_p (TREE_TYPE (tem),
 173                                                   TREE_TYPE (field)))
 174                             break;
 175                           else
 176                             closest_match = tem;
 177                         }
 178                     }
 179                   /* In case of type mismatches across units we can fail
 180                      to unify some types and thus not find a proper
 181                      field-decl here.  */
 182                   if (tem == NULL_TREE)
 183                     {
 184                       /* Thus, emit a ODR violation warning.  */
 185                       if (warning_at (gimple_location (stmt), 0,
 186                                       "use of type %<%E%> with two mismatching "
 187                                       "declarations at field %<%E%>",
 188                                       type, TREE_OPERAND (op, 1)))
 189                         {
 190                           if (TYPE_FIELDS (type))
 191                             inform (DECL_SOURCE_LOCATION (TYPE_FIELDS (type)),
 192                                     "original type declared here");
 193                           inform (DECL_SOURCE_LOCATION (TREE_OPERAND (op, 1)),
 194                                   "field in mismatching type declared here");
 195                           if (TYPE_NAME (TREE_TYPE (field))
 196                               && (TREE_CODE (TYPE_NAME (TREE_TYPE (field)))
 197                                   == TYPE_DECL))
 198                             inform (DECL_SOURCE_LOCATION
 199                                       (TYPE_NAME (TREE_TYPE (field))),
 200                                     "type of field declared here");
 201                           if (closest_match
 202                               && TYPE_NAME (TREE_TYPE (closest_match))
 203                               && (TREE_CODE (TYPE_NAME
 204                                    (TREE_TYPE (closest_match))) == TYPE_DECL))
 205                             inform (DECL_SOURCE_LOCATION
 206                                       (TYPE_NAME (TREE_TYPE (closest_match))),
 207                                     "type of mismatching field declared here");
 208                         }
 209                       /* And finally fixup the types.  */
 210                       TREE_OPERAND (op, 0)
 211                         = build1 (VIEW_CONVERT_EXPR, type,
 212                                   TREE_OPERAND (op, 0));
 213                     }
 214                   else
 215                     TREE_OPERAND (op, 1) = tem;
 216                 }
 217
 218               op = TREE_OPERAND (op, 0);
 219             }
 220         }
 221       if (is_gimple_call (stmt))
 222         {
 223           if (gimple_call_internal_p (stmt))
 224             gimple_call_set_internal_fn
 225               (stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 226           else
 227             gimple_call_set_fntype (stmt, stream_read_tree (ib, data_in));
 228         }
 229       break;
 230
 231     case GIMPLE_NOP:
 232     case GIMPLE_PREDICT:
 233       break;
 234
 235     case GIMPLE_TRANSACTION:
 236       gimple_transaction_set_label (stmt, stream_read_tree (ib, data_in));
 237       break;
 238
 239     default:
 240       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 241                       lto_tag_name (tag));
 242     }
 243
 244   /* Update the properties of symbols, SSA names and labels associated
 245      with STMT.  */
 246   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 247     {
 248       tree lhs = gimple_get_lhs (stmt);
 249       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 250         SSA_NAME_DEF_STMT (lhs) = stmt;
 251     }
 252   else if (code == GIMPLE_LABEL)
 253     gcc_assert (emit_label_in_global_context_p (gimple_label_label (stmt))
 254                 || DECL_CONTEXT (gimple_label_label (stmt)) == fn->decl);
 255   else if (code == GIMPLE_ASM)
 256     {
 257       unsigned i;
 258
 259       for (i = 0; i < gimple_asm_noutputs (stmt); i++)
 260         {
 261           tree op = TREE_VALUE (gimple_asm_output_op (stmt, i));
 262           if (TREE_CODE (op) == SSA_NAME)
 263             SSA_NAME_DEF_STMT (op) = stmt;
 264         }
 265     }
 266
 267   /* Reset alias information.  */
 268   if (code == GIMPLE_CALL)
 269     gimple_call_reset_alias_info (stmt);
 270
 271   /* Mark the statement modified so its operand vectors can be filled in.  */
 272   gimple_set_modified (stmt, true);
 273
 274   return stmt;
 275 }
 276
 277
 278 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 279    FN is the function being processed.  */
 280
 281 void
 282 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 283           struct data_in *data_in, struct function *fn,
 284           int count_materialization_scale)
 285 {
 286   unsigned int index;
 287   basic_block bb;
 288   gimple_stmt_iterator bsi;
 289
 290   /* This routine assumes that CFUN is set to FN, as it needs to call
 291      basic GIMPLE routines that use CFUN.  */
 292   gcc_assert (cfun == fn);
 293
 294   index = streamer_read_uhwi (ib);
 295   bb = BASIC_BLOCK_FOR_FUNCTION (fn, index);
 296
 297   bb->count = (streamer_read_hwi (ib) * count_materialization_scale
 298                + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
 299   bb->frequency = streamer_read_hwi (ib);
 300   bb->flags = streamer_read_hwi (ib);
 301
 302   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 303   if (tag == LTO_bb0)
 304     return;
 305
 306   bsi = gsi_start_bb (bb);
 307   tag = streamer_read_record_start (ib);
 308   while (tag)
 309     {
 310       gimple stmt = input_gimple_stmt (ib, data_in, fn, tag);
 311       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 312
 313       /* After the statement, expect a 0 delimiter or the EH region
 314          that the previous statement belongs to.  */
 315       tag = streamer_read_record_start (ib);
 316       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 317
 318       if (tag == LTO_eh_region)
 319         {
 320           HOST_WIDE_INT region = streamer_read_hwi (ib);
 321           gcc_assert (region == (int) region);
 322           add_stmt_to_eh_lp (stmt, region);
 323         }
 324
 325       tag = streamer_read_record_start (ib);
 326     }
 327
 328   tag = streamer_read_record_start (ib);
 329   while (tag)
 330     {
 331       input_phi (ib, bb, data_in, fn);
 332       tag = streamer_read_record_start (ib);
 333     }
 334 }