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