gcc/java/java-gimplify.c

   1 /* Java(TM) language-specific gimplification routines.
   2    Copyright (C) 2003-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 3, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.
  19
  20 Java and all Java-based marks are trademarks or registered trademarks
  21 of Sun Microsystems, Inc. in the United States and other countries.
  22 The Free Software Foundation is independent of Sun Microsystems, Inc.  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "coretypes.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 "java-tree.h"
  40 #include "dumpfile.h"
  41 #include "predict.h"
  42 #include "tm.h"
  43 #include "hard-reg-set.h"
  44 #include "input.h"
  45 #include "function.h"
  46 #include "basic-block.h"
  47 #include "tree-ssa-alias.h"
  48 #include "internal-fn.h"
  49 #include "gimple-expr.h"
  50 #include "is-a.h"
  51 #include "gimple.h"
  52 #include "gimplify.h"
  53
  54 static tree java_gimplify_block (tree);
  55 static enum gimplify_status java_gimplify_modify_expr (tree *);
  56 static enum gimplify_status java_gimplify_self_mod_expr (tree *, gimple_seq *,
  57                                                          gimple_seq *);
  58
  59 static void dump_java_tree (enum tree_dump_index, tree);
  60
  61 /* Convert a Java tree to GENERIC.  */
  62
  63 void
  64 java_genericize (tree fndecl)
  65 {
  66   walk_tree (&DECL_SAVED_TREE (fndecl), java_replace_references, NULL, NULL);
  67   dump_java_tree (TDI_original, fndecl);
  68 }
  69
  70 /* Gimplify a Java tree.  */
  71
  72 int
  73 java_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
  74 {
  75   enum tree_code code = TREE_CODE (*expr_p);
  76
  77   switch (code)
  78     {
  79     case BLOCK:
  80       *expr_p = java_gimplify_block (*expr_p);
  81       break;
  82
  83     case MODIFY_EXPR:
  84       return java_gimplify_modify_expr (expr_p);
  85
  86     case POSTINCREMENT_EXPR:
  87     case POSTDECREMENT_EXPR:
  88     case PREINCREMENT_EXPR:
  89     case PREDECREMENT_EXPR:
  90       return java_gimplify_self_mod_expr (expr_p, pre_p, post_p);
  91
  92     /* These should already be lowered before we get here.  */
  93     case URSHIFT_EXPR:
  94     case COMPARE_EXPR:
  95     case COMPARE_L_EXPR:
  96     case COMPARE_G_EXPR:
  97       gcc_unreachable ();
  98
  99     default:
 100       return GS_UNHANDLED;
 101     }
 102
 103   return GS_OK;
 104 }
 105
 106 static enum gimplify_status
 107 java_gimplify_modify_expr (tree *modify_expr_p)
 108 {
 109   tree modify_expr = *modify_expr_p;
 110   tree lhs = TREE_OPERAND (modify_expr, 0);
 111   tree rhs = TREE_OPERAND (modify_expr, 1);
 112   tree lhs_type = TREE_TYPE (lhs);
 113
 114   if (lhs_type != TREE_TYPE (rhs))
 115     /* Fix up type mismatches to make legal GIMPLE.  These are
 116        generated in several places, in particular null pointer
 117        assignment and subclass assignment.  */
 118     TREE_OPERAND (modify_expr, 1) = convert (lhs_type, rhs);
 119
 120   return GS_UNHANDLED;
 121 }
 122
 123 /*  Special case handling for volatiles: we need to generate a barrier
 124     between the reading and the writing.  */
 125
 126 static enum gimplify_status
 127 java_gimplify_self_mod_expr (tree *expr_p, gimple_seq *pre_p ATTRIBUTE_UNUSED,
 128                              gimple_seq *post_p ATTRIBUTE_UNUSED)
 129 {
 130   tree lhs = TREE_OPERAND (*expr_p, 0);
 131
 132   if (TREE_CODE (lhs) == COMPONENT_REF
 133       && TREE_THIS_VOLATILE (TREE_OPERAND (lhs, 1)))
 134     TREE_THIS_VOLATILE (lhs) = 1;
 135
 136   return GS_UNHANDLED;
 137 }
 138
 139
 140 /* Gimplify BLOCK into a BIND_EXPR.  */
 141
 142 static tree
 143 java_gimplify_block (tree java_block)
 144 {
 145   tree decls = BLOCK_VARS (java_block);
 146   tree body = BLOCK_EXPR_BODY (java_block);
 147   gbind *outer = gimple_current_bind_expr ();
 148   tree block;
 149
 150   /* Don't bother with empty blocks.  */
 151   if (! body)
 152     return build_empty_stmt (input_location);
 153
 154   if (IS_EMPTY_STMT (body))
 155     return body;
 156
 157   /* Make a proper block.  Java blocks are unsuitable for BIND_EXPR
 158      because they use BLOCK_SUBBLOCKS for another purpose.  */
 159   block = make_node (BLOCK);
 160   BLOCK_VARS (block) = decls;
 161
 162   /* The TREE_USED flag on a block determines whether the debug output
 163      routines generate info for the variables in that block.  */
 164   TREE_USED (block) = 1;
 165
 166   if (outer != NULL)
 167     {
 168       tree b = gimple_bind_block (outer);
 169       BLOCK_SUBBLOCKS (b) = chainon (BLOCK_SUBBLOCKS (b), block);
 170     }
 171   BLOCK_EXPR_BODY (java_block) = NULL_TREE;
 172
 173   return build3 (BIND_EXPR, TREE_TYPE (java_block), decls, body, block);
 174 }
 175
 176 /* Dump a tree of some kind.  This is a convenience wrapper for the
 177    dump_* functions in tree-dump.c.  */
 178 static void
 179 dump_java_tree (enum tree_dump_index phase, tree t)
 180 {
 181   FILE *stream;
 182   int flags;
 183
 184   stream = dump_begin (phase, &flags);
 185   flags |= TDF_SLIM;
 186   if (stream)
 187     {
 188       dump_node (t, flags, stream);
 189       dump_end (phase, stream);
 190     }
 191 }