gcc/java/java-gimplify.c

   1 /* Java(TM) language-specific gimplification routines.
   2    Copyright (C) 2003, 2004 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 2, 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 COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.
  20
  21 Java and all Java-based marks are trademarks or registered trademarks
  22 of Sun Microsystems, Inc. in the United States and other countries.
  23 The Free Software Foundation is independent of Sun Microsystems, Inc.  */
  24
  25 #include "config.h"
  26 #include "system.h"
  27 #include "coretypes.h"
  28 #include "tm.h"
  29 #include "tree.h"
  30 #include "java-tree.h"
  31 #include "tree-dump.h"
  32 #include "tree-gimple.h"
  33 #include "toplev.h"
  34
  35 static tree java_gimplify_case_expr (tree);
  36 static tree java_gimplify_default_expr (tree);
  37 static tree java_gimplify_block (tree);
  38 static tree java_gimplify_new_array_init (tree);
  39 static tree java_gimplify_try_expr (tree);
  40
  41 static void dump_java_tree (enum tree_dump_index, tree);
  42
  43 /* Convert a Java tree to GENERIC.  */
  44
  45 void
  46 java_genericize (tree fndecl)
  47 {
  48   dump_java_tree (TDI_original, fndecl);
  49
  50   /* Genericize with the gimplifier.  */
  51   gimplify_function_tree (fndecl);
  52
  53   dump_function (TDI_generic, fndecl);
  54 }
  55
  56 /* Gimplify a Java tree.  */
  57
  58 int
  59 java_gimplify_expr (tree *expr_p, tree *pre_p ATTRIBUTE_UNUSED,
  60                     tree *post_p ATTRIBUTE_UNUSED)
  61 {
  62   char code_class = TREE_CODE_CLASS(TREE_CODE (*expr_p));
  63
  64   /* Java insists on strict left-to-right evaluation of expressions.
  65      A problem may arise if a variable used in the LHS of a binary
  66      operation is altered by an assignment to that value in the RHS
  67      before we've performed the operation.  So, we always copy every
  68      LHS to a temporary variable.
  69
  70      FIXME: Are there any other cases where we should do this?
  71      Parameter lists, maybe?  Or perhaps that's unnecessary because
  72      the front end already generates SAVE_EXPRs.  */
  73   if (code_class == '2')
  74     {
  75       tree lhs = TREE_OPERAND (*expr_p, 0);
  76       enum gimplify_status stat
  77         = gimplify_expr (&lhs, pre_p, post_p, is_gimple_tmp_var, fb_rvalue);
  78       if (stat == GS_ERROR)
  79         return stat;
  80       TREE_OPERAND (*expr_p, 0) = lhs;
  81     }
  82
  83   switch (TREE_CODE (*expr_p))
  84     {
  85     case BLOCK:
  86       *expr_p = java_gimplify_block (*expr_p);
  87       break;
  88
  89     case EXPR_WITH_FILE_LOCATION:
  90       input_location.file = EXPR_WFL_FILENAME (*expr_p);
  91       input_location.line = EXPR_WFL_LINENO (*expr_p);
  92       *expr_p = EXPR_WFL_NODE (*expr_p);
  93       annotate_with_locus (*expr_p, input_location);
  94       break;
  95
  96     case CASE_EXPR:
  97       *expr_p = java_gimplify_case_expr (*expr_p);
  98       break;
  99
 100     case DEFAULT_EXPR:
 101       *expr_p = java_gimplify_default_expr (*expr_p);
 102       break;
 103
 104     case NEW_ARRAY_INIT:
 105       *expr_p = java_gimplify_new_array_init (*expr_p);
 106       break;
 107
 108     case TRY_EXPR:
 109       *expr_p = java_gimplify_try_expr (*expr_p);
 110       break;
 111
 112     case JAVA_CATCH_EXPR:
 113       *expr_p = TREE_OPERAND (*expr_p, 0);
 114       break;
 115
 116     case JAVA_EXC_OBJ_EXPR:
 117       *expr_p = build_exception_object_ref (TREE_TYPE (*expr_p));
 118       break;
 119
 120     /* These should already be lowered before we get here.  */
 121     case URSHIFT_EXPR:
 122     case COMPARE_EXPR:
 123     case COMPARE_L_EXPR:
 124     case COMPARE_G_EXPR:
 125     case UNARY_PLUS_EXPR:
 126     case NEW_ARRAY_EXPR:
 127     case NEW_ANONYMOUS_ARRAY_EXPR:
 128     case NEW_CLASS_EXPR:
 129     case THIS_EXPR:
 130     case SYNCHRONIZED_EXPR:
 131     case CONDITIONAL_EXPR:
 132     case INSTANCEOF_EXPR:
 133     case CLASS_LITERAL:
 134       abort ();
 135
 136     default:
 137       return GS_UNHANDLED;
 138     }
 139
 140   return GS_OK;
 141 }
 142
 143 static tree
 144 java_gimplify_case_expr (tree expr)
 145 {
 146   tree label = create_artificial_label ();
 147   return build (CASE_LABEL_EXPR, void_type_node,
 148                 TREE_OPERAND (expr, 0), NULL_TREE, label);
 149 }
 150
 151 static tree
 152 java_gimplify_default_expr (tree expr ATTRIBUTE_UNUSED)
 153 {
 154   tree label = create_artificial_label ();
 155   return build (CASE_LABEL_EXPR, void_type_node, NULL_TREE, NULL_TREE, label);
 156 }
 157
 158 /* Gimplify BLOCK into a BIND_EXPR.  */
 159
 160 static tree
 161 java_gimplify_block (tree java_block)
 162 {
 163   tree decls = BLOCK_VARS (java_block);
 164   tree body = BLOCK_EXPR_BODY (java_block);
 165   tree outer = gimple_current_bind_expr ();
 166   tree block;
 167
 168   /* Don't bother with empty blocks.  */
 169   if (! body)
 170     return build_empty_stmt ();
 171
 172   if (IS_EMPTY_STMT (body))
 173     return body;
 174
 175   /* Make a proper block.  Java blocks are unsuitable for BIND_EXPR
 176      because they use BLOCK_SUBBLOCKS for another purpose.  */
 177   block = make_node (BLOCK);
 178   BLOCK_VARS (block) = decls;
 179
 180   /* The TREE_USED flag on a block determines whether the debug ouput
 181      routines generate info for the variables in that block.  */
 182   TREE_USED (block) = 1;
 183
 184   if (outer != NULL_TREE)
 185     {
 186       outer = BIND_EXPR_BLOCK (outer);
 187       BLOCK_SUBBLOCKS (outer) = chainon (BLOCK_SUBBLOCKS (outer), block);
 188     }
 189
 190   return build (BIND_EXPR, TREE_TYPE (java_block), decls, body, block);
 191 }
 192
 193 /* Gimplify a NEW_ARRAY_INIT node into array/element assignments.  */
 194
 195 static tree
 196 java_gimplify_new_array_init (tree exp)
 197 {
 198   tree array_type = TREE_TYPE (TREE_TYPE (exp));
 199   tree data_field = lookup_field (&array_type, get_identifier ("data"));
 200   tree element_type = TYPE_ARRAY_ELEMENT (array_type);
 201   HOST_WIDE_INT ilength = java_array_type_length (array_type);
 202   tree length = build_int_2 (ilength, 0);
 203   tree init = TREE_OPERAND (exp, 0);
 204   tree values = CONSTRUCTOR_ELTS (init);
 205
 206   tree array_ptr_type = build_pointer_type (array_type);
 207   tree block = build (BLOCK, array_ptr_type);
 208   tree tmp = build_decl (VAR_DECL, get_identifier ("<tmp>"), array_ptr_type);
 209   tree array = build_decl (VAR_DECL, get_identifier ("<array>"), array_ptr_type);
 210   tree body = build (MODIFY_EXPR, array_ptr_type, tmp,
 211                      build_new_array (element_type, length));
 212
 213   int index = 0;
 214
 215   DECL_CONTEXT (array) = current_function_decl;
 216   DECL_CONTEXT (tmp) = current_function_decl;
 217
 218   /* FIXME: try to allocate array statically?  */
 219   while (values != NULL_TREE)
 220     {
 221       /* FIXME: Should use build_java_arrayaccess here, but avoid
 222          bounds checking.  */
 223       tree lhs = build (COMPONENT_REF, TREE_TYPE (data_field),
 224                         build_java_indirect_ref (array_type, tmp, 0),
 225                         data_field, NULL_TREE);
 226       tree assignment = build (MODIFY_EXPR, element_type,
 227                                build (ARRAY_REF, element_type, lhs,
 228                                       build_int_2 (index++, 0),
 229                                       NULL_TREE, NULL_TREE),
 230                                TREE_VALUE (values));
 231       body = build (COMPOUND_EXPR, element_type, body, assignment);
 232       values = TREE_CHAIN (values);
 233     }
 234
 235   body = build (COMPOUND_EXPR, array_ptr_type, body,
 236                 build (MODIFY_EXPR, array_ptr_type, array, tmp));
 237   TREE_CHAIN (tmp) = array;
 238   BLOCK_VARS (block) = tmp;
 239   BLOCK_EXPR_BODY (block) = body;
 240   return java_gimplify_block (block);
 241 }
 242
 243 static tree
 244 java_gimplify_try_expr (tree try_expr)
 245 {
 246   tree body = TREE_OPERAND (try_expr, 0);
 247   tree handler = TREE_OPERAND (try_expr, 1);
 248   tree catch = NULL_TREE;
 249
 250   /* Build a CATCH_EXPR for each handler.  */
 251   while (handler)
 252     {
 253       tree java_catch = TREE_OPERAND (handler, 0);
 254       tree catch_type = TREE_TYPE (TREE_TYPE (BLOCK_EXPR_DECLS (java_catch)));
 255       tree expr = build (CATCH_EXPR, void_type_node,
 256                          prepare_eh_table_type (catch_type),
 257                          handler);
 258       if (catch)
 259         catch = build (COMPOUND_EXPR, void_type_node, catch, expr);
 260       else
 261         catch = expr;
 262       handler = TREE_CHAIN (handler);
 263     }
 264   return build (TRY_CATCH_EXPR, void_type_node, body, catch);
 265 }
 266
 267 /* Dump a tree of some kind.  This is a convenience wrapper for the
 268    dump_* functions in tree-dump.c.  */
 269 static void
 270 dump_java_tree (enum tree_dump_index phase, tree t)
 271 {
 272   FILE *stream;
 273   int flags;
 274
 275   stream = dump_begin (phase, &flags);
 276   flags |= TDF_SLIM;
 277   if (stream)
 278     {
 279       dump_node (t, flags, stream);
 280       dump_end (phase, stream);
 281     }
 282 }