1 /* Handle exceptions for GNU compiler for the Java(TM) language.
2 Copyright (C) 1997 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC 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)
11 GNU CC 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.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA.
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. */
30 #include "java-tree.h"
32 #include "java-opcodes.h"
35 #include "java-except.h"
36 #include "eh-common.h"
39 extern struct obstack permanent_obstack;
41 struct eh_range *current_method_handlers;
43 struct eh_range *current_try_block = NULL;
45 struct eh_range *eh_range_freelist = NULL;
47 /* These variables are used to speed up find_handler. */
49 static int cache_range_start, cache_range_end;
50 static struct eh_range *cache_range;
51 static struct eh_range *cache_next_child;
53 /* A dummy range that represents the entire method. */
55 struct eh_range whole_range;
57 /* Search for the most specific eh_range containing PC.
58 Assume PC is within RANGE.
59 CHILD is a list of children of RANGE such that any
60 previous children have end_pc values that are too low. */
62 static struct eh_range *
63 find_handler_in_range (pc, range, child)
65 struct eh_range *range;
66 register struct eh_range *child;
68 for (; child != NULL; child = child->next_sibling)
70 if (pc < child->start_pc)
72 if (pc <= child->end_pc)
73 return find_handler_in_range (pc, child, child->first_child);
76 cache_range_start = pc;
77 cache_next_child = child;
78 cache_range_end = child == NULL ? range->end_pc : child->start_pc;
82 /* Find the inner-most handler that contains PC. */
89 if (pc >= cache_range_start)
92 if (pc < cache_range_end)
94 while (pc >= h->end_pc)
96 cache_next_child = h->next_sibling;
103 cache_next_child = h->first_child;
105 return find_handler_in_range (pc, h, cache_next_child);
114 /* Recursive helper routine for add_handler. */
117 link_handler (start_pc, end_pc, handler, type, outer)
118 int start_pc, end_pc;
121 struct eh_range *outer;
123 struct eh_range **ptr;
124 if (start_pc < outer->start_pc || end_pc > outer->end_pc)
125 return 0; /* invalid or non-nested exception range */
126 if (start_pc == outer->start_pc && end_pc == outer->end_pc)
128 outer->handlers = tree_cons (type, handler, outer->handlers);
131 ptr = &outer->first_child;
132 for (;; ptr = &(*ptr)->next_sibling)
134 if (*ptr == NULL || end_pc <= (*ptr)->start_pc)
136 struct eh_range *h = (struct eh_range *)
137 oballoc (sizeof (struct eh_range));
138 h->start_pc = start_pc;
140 h->next_sibling = *ptr;
141 h->first_child = NULL;
143 h->handlers = build_tree_list (type, handler);
147 else if (start_pc < (*ptr)->end_pc)
148 return link_handler (start_pc, end_pc, handler, type, *ptr);
149 /* end_pc > (*ptr)->start_pc && start_pc >= (*ptr)->end_pc. */
153 /* Called to re-initialize the exception machinery for a new method. */
156 method_init_exceptions ()
158 whole_range.start_pc = 0;
159 whole_range.end_pc = DECL_CODE_LENGTH (current_function_decl) + 1;
160 whole_range.outer = NULL;
161 whole_range.first_child = NULL;
162 whole_range.next_sibling = NULL;
163 cache_range_start = 0xFFFFFF;
164 java_set_exception_lang_code ();
168 java_set_exception_lang_code ()
170 set_exception_lang_code (EH_LANG_Java);
171 set_exception_version_code (1);
175 add_handler (start_pc, end_pc, handler, type)
176 int start_pc, end_pc;
180 return link_handler (start_pc, end_pc, handler, type, &whole_range);
184 /* if there are any handlers for this range, issue start of region */
186 expand_start_java_handler (range)
187 struct eh_range *range;
189 expand_eh_region_start ();
193 prepare_eh_table_type (type)
198 /* The "type" (metch_info) in a (Java) exception table is one:
199 * a) NULL - meaning match any type in a try-finally.
200 * b) a pointer to a (ccmpiled) class (low-order bit 0).
201 * c) a pointer to the Utf8Const name of the class, plus one
202 * (which yields a value with low-order bit 1). */
204 push_obstacks (&permanent_obstack, &permanent_obstack);
205 if (type == NULL_TREE)
206 exp = null_pointer_node;
207 else if (is_compiled_class (type))
208 exp = build_class_ref (type);
211 (PLUS_EXPR, ptr_type_node,
212 build_utf8_ref (build_internal_class_name (type)),
218 /* if there are any handlers for this range, isssue end of range,
219 and then all handler blocks */
221 expand_end_java_handler (range)
222 struct eh_range *range;
224 tree handler = range->handlers;
225 expand_start_all_catch ();
226 for ( ; handler != NULL_TREE; handler = TREE_CHAIN (handler))
228 start_catch_handler (prepare_eh_table_type (TREE_PURPOSE (handler)));
229 /* Push the thrown object on the top of the stack */
230 expand_goto (TREE_VALUE (handler));
232 expand_end_all_catch ();
235 /* Recursive helper routine for maybe_start_handlers. */
238 check_start_handlers (range, pc)
239 struct eh_range *range;
242 if (range != NULL_EH_RANGE && range->start_pc == pc)
244 check_start_handlers (range->outer, pc);
245 expand_start_java_handler (range);
249 struct eh_range *current_range;
251 /* Emit any start-of-try-range start at PC. */
260 current_range = find_handler (pc);
261 check_start_handlers (current_range, pc);
264 /* Emit any end-of-try-range end at PC. */
273 while (current_range != NULL_EH_RANGE && current_range->end_pc <= pc)
275 expand_end_java_handler (current_range);
276 current_range = current_range->outer;
280 /* Emit the handler labels and their code */
287 rtx funcend = gen_label_rtx ();
290 emit_insns (catch_clauses);
291 expand_leftover_cleanups ();
293 emit_label (funcend);