3 * File name: ir/st/exc.c
4 * Purpose: Helper functions for jack exceptions.
5 * Author: Florian Liekweg
9 * Copyright: (c) 2002-2003 Universität Karlsruhe
10 * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
17 Helper functions for exceptions
24 static char* exc_strings [] = {
25 "Invalid", /* invalid */
26 "Normal", /* normal */
27 "Entry", /* entry to region */
28 "Exit", /* exit of region */
29 "Handler", /* entry to handler */
35 Return true iff (block b is a handler entry AND a dominates b) OR
36 (b has a CFG successor that is both a handler entry AND is dominated
39 static bool has_handler (ir_graph *graph, ir_node *b, ir_node *a)
42 int n = get_irn_n_outs (b);
45 assert (0 && "Wrongly implemented");
46 /* must check for _immediate_ dominance !!! */
48 if (is_handler_entry (graph, b) && dominates (graph, a, b))
51 for (i = 0; i < n; i ++)
53 succ = get_irn_out (b, i);
55 if (has_handler (graph, succ, a))
63 Return true iff the given node represents an exception jump
65 static bool is_exc_jmp (ir_node *node)
67 ir_op *op = get_irn_op (node);
69 /* Proj_X (Load), Proj_X (Sto), Proj_X (Div_Int),
70 Proj_X (Raise), Proj_X (Call), Proj_X (Alloc) */
73 op = get_irn_op (get_Proj_pred (node));
75 assert ((is_fragile_op(get_Proj_pred(node))) &&
76 (op != op_Bad) /*&& (op != op_Unknown)*/ &&
77 (get_irn_mode(node) == mode_X));/* Check for proper Proj attr */
87 Return true iff the given node represents a normal cfg jump
90 static bool is_cfg_jmp (ir_node *node)
92 ir_op *op = get_irn_op (node);
96 op = get_irn_op (get_Proj_pred (node));
98 /* Proj_X (Proj_Cmp (Cond)) */
100 return (true); /* check for op == op_Cmp and op == op_Cond */
107 void set_Block_exc(ir_node *n, ir_node *exc) {
110 ir_node * get_Block_exc(ir_node *n) {
117 Return true iff a new exception region must be left upon entry of this block.
119 If all CFG preds of this block are exception jumps, then we must
122 bool is_handler_entry (ir_graph *graph, ir_node *block)
124 bool is_entry = true;
126 int n = get_irn_arity (block);
128 if (exc_invalid == get_Block_exc (block))
130 for (i = 0; (i < n) && (is_entry == true); i ++)
131 if (is_exc_jmp (get_irn_n (block, i)))
136 if (true == is_entry)
137 set_Block_exc (block, exc_handler);
140 return (exc_handler == get_Block_exc (block));
144 Return true iff a new exception region must be started upon entry of this block.
146 If this block immediately dominates a handler entry, we must return true.
148 bool is_region_entry (ir_graph *graph, ir_node *block)
150 assert (0 && "Not implemented");
152 if (exc_invalid == get_Block_exc (block))
155 int n = get_irn_n_outs (block);
158 bool no_handler = true;
160 for (i = 0; (i < n) && (no_handler == true); i ++)
162 succ = get_irn_out (block, i);
164 if (has_handler (graph, succ, block))
168 if (false == no_handler)
169 set_Block_exc (block, exc_region);
172 return (exc_region == get_Block_exc (block));
178 Return true iff this block is part of handler code.
180 If this block is dominated by a block for which {@link
181 is_handler_entry} is true, then this block is part of the handler.
183 bool is_handler_block (ir_graph *graph, ir_node *block)
185 assert (0 && "Not implemented");
187 if (exc_invalid == get_Block_exc (block))
189 bool no_handler = true;
190 dom_env_t *env = get_dom_env (graph, block);
191 int block_index = env->index_a;
192 bs_t block_mask = 0x00000001 << block_index;
193 int n_blocks = env->dt->n_blocks;
196 for (i = 0; (i < n_blocks) && (no_handler == true); i ++)
197 if (0 != (env->dt->masks [i] & block_mask)) /* if dominator */
198 if (is_handler_entry (graph, env->dt->blocks [i])) /* is handler entry */
201 delete_dom_env (env);
203 if (false == no_handler)
204 set_Block_exc (block, exc_handler);
207 return (exc_handler == get_Block_exc (block));
211 Convert a value of type exc_t to a descriptive string.
212 Returns a reference to a statically allocated, constant string.
215 const char *exc_to_string (exc_t exc)
217 int exc_val = (int) exc;
219 assert ((0 <= (int) exc_val) && (exc_val < (int) exc_max));
221 return (exc_strings [exc_val]);