gcc/java/java-gimplify.c

   1 /* Java(TM) language-specific gimplification routines.
   2    Copyright (C) 2003-2014 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 "tree.h"
  28 #include "java-tree.h"
  29 #include "dumpfile.h"
  30 #include "predict.h"
  31 #include "vec.h"
  32 #include "hashtab.h"
  33 #include "hash-set.h"
  34 #include "machmode.h"
  35 #include "tm.h"
  36 #include "hard-reg-set.h"
  37 #include "input.h"
  38 #include "function.h"
  39 #include "basic-block.h"
  40 #include "tree-ssa-alias.h"
  41 #include "internal-fn.h"
  42 #include "gimple-expr.h"
  43 #include "is-a.h"
  44 #include "gimple.h"
  45 #include "gimplify.h"
  46
  47 static tree java_gimplify_block (tree);
  48 static enum gimplify_status java_gimplify_modify_expr (tree *);
  49 static enum gimplify_status java_gimplify_self_mod_expr (tree *, gimple_seq *,
  50                                                          gimple_seq *);
  51
  52 static void dump_java_tree (enum tree_dump_index, tree);
  53
  54 /* Convert a Java tree to GENERIC.  */
  55
  56 void
  57 java_genericize (tree fndecl)
  58 {
  59   walk_tree (&DECL_SAVED_TREE (fndecl), java_replace_references, NULL, NULL);
  60   dump_java_tree (TDI_original, fndecl);
  61 }
  62
  63 /* Gimplify a Java tree.  */
  64
  65 int
  66 java_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
  67 {
  68   enum tree_code code = TREE_CODE (*expr_p);
  69
  70   switch (code)
  71     {
  72     case BLOCK:
  73       *expr_p = java_gimplify_block (*expr_p);
  74       break;
  75
  76     case MODIFY_EXPR:
  77       return java_gimplify_modify_expr (expr_p);
  78
  79     case POSTINCREMENT_EXPR:
  80     case POSTDECREMENT_EXPR:
  81     case PREINCREMENT_EXPR:
  82     case PREDECREMENT_EXPR:
  83       return java_gimplify_self_mod_expr (expr_p, pre_p, post_p);
  84
  85     /* These should already be lowered before we get here.  */
  86     case URSHIFT_EXPR:
  87     case COMPARE_EXPR:
  88     case COMPARE_L_EXPR:
  89     case COMPARE_G_EXPR:
  90       gcc_unreachable ();
  91
  92     default:
  93       return GS_UNHANDLED;
  94     }
  95
  96   return GS_OK;
  97 }
  98
  99 static enum gimplify_status
 100 java_gimplify_modify_expr (tree *modify_expr_p)
 101 {
 102   tree modify_expr = *modify_expr_p;
 103   tree lhs = TREE_OPERAND (modify_expr, 0);
 104   tree rhs = TREE_OPERAND (modify_expr, 1);
 105   tree lhs_type = TREE_TYPE (lhs);
 106
 107   if (lhs_type != TREE_TYPE (rhs))
 108     /* Fix up type mismatches to make legal GIMPLE.  These are
 109        generated in several places, in particular null pointer
 110        assignment and subclass assignment.  */
 111     TREE_OPERAND (modify_expr, 1) = convert (lhs_type, rhs);
 112
 113   return GS_UNHANDLED;
 114 }
 115
 116 /*  Special case handling for volatiles: we need to generate a barrier
 117     between the reading and the writing.  */
 118
 119 static enum gimplify_status
 120 java_gimplify_self_mod_expr (tree *expr_p, gimple_seq *pre_p ATTRIBUTE_UNUSED,
 121                              gimple_seq *post_p ATTRIBUTE_UNUSED)
 122 {
 123   tree lhs = TREE_OPERAND (*expr_p, 0);
 124
 125   if (TREE_CODE (lhs) == COMPONENT_REF
 126       && TREE_THIS_VOLATILE (TREE_OPERAND (lhs, 1)))
 127     TREE_THIS_VOLATILE (lhs) = 1;
 128
 129   return GS_UNHANDLED;
 130 }
 131
 132
 133 /* Gimplify BLOCK into a BIND_EXPR.  */
 134
 135 static tree
 136 java_gimplify_block (tree java_block)
 137 {
 138   tree decls = BLOCK_VARS (java_block);
 139   tree body = BLOCK_EXPR_BODY (java_block);
 140   gbind *outer = gimple_current_bind_expr ();
 141   tree block;
 142
 143   /* Don't bother with empty blocks.  */
 144   if (! body)
 145     return build_empty_stmt (input_location);
 146
 147   if (IS_EMPTY_STMT (body))
 148     return body;
 149
 150   /* Make a proper block.  Java blocks are unsuitable for BIND_EXPR
 151      because they use BLOCK_SUBBLOCKS for another purpose.  */
 152   block = make_node (BLOCK);
 153   BLOCK_VARS (block) = decls;
 154
 155   /* The TREE_USED flag on a block determines whether the debug output
 156      routines generate info for the variables in that block.  */
 157   TREE_USED (block) = 1;
 158
 159   if (outer != NULL)
 160     {
 161       tree b = gimple_bind_block (outer);
 162       BLOCK_SUBBLOCKS (b) = chainon (BLOCK_SUBBLOCKS (b), block);
 163     }
 164   BLOCK_EXPR_BODY (java_block) = NULL_TREE;
 165
 166   return build3 (BIND_EXPR, TREE_TYPE (java_block), decls, body, block);
 167 }
 168
 169 /* Dump a tree of some kind.  This is a convenience wrapper for the
 170    dump_* functions in tree-dump.c.  */
 171 static void
 172 dump_java_tree (enum tree_dump_index phase, tree t)
 173 {
 174   FILE *stream;
 175   int flags;
 176
 177   stream = dump_begin (phase, &flags);
 178   flags |= TDF_SLIM;
 179   if (stream)
 180     {
 181       dump_node (t, flags, stream);
 182       dump_end (phase, stream);
 183     }
 184 }