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