xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/tree-streamer.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /* Miscellaneous utilities for tree streaming.  Things that are used
2    in both input and output are here.
3 
4    Copyright (C) 2011-2013 Free Software Foundation, Inc.
5    Contributed by Diego Novillo <dnovillo@google.com>
6 
7 This file is part of GCC.
8 
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
12 version.
13 
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
17 for more details.
18 
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3.  If not see
21 <http://www.gnu.org/licenses/>.  */
22 
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "streamer-hooks.h"
27 #include "tree-streamer.h"
28 
29 /* Check that all the TS_* structures handled by the streamer_write_* and
30    streamer_read_* routines are exactly ALL the structures defined in
31    treestruct.def.  */
32 
33 void
34 streamer_check_handled_ts_structures (void)
35 {
36   bool handled_p[LAST_TS_ENUM];
37   unsigned i;
38 
39   memset (&handled_p, 0, sizeof (handled_p));
40 
41   /* These are the TS_* structures that are either handled or
42      explicitly ignored by the streamer routines.  */
43   handled_p[TS_BASE] = true;
44   handled_p[TS_TYPED] = true;
45   handled_p[TS_COMMON] = true;
46   handled_p[TS_INT_CST] = true;
47   handled_p[TS_REAL_CST] = true;
48   handled_p[TS_FIXED_CST] = true;
49   handled_p[TS_VECTOR] = true;
50   handled_p[TS_STRING] = true;
51   handled_p[TS_COMPLEX] = true;
52   handled_p[TS_IDENTIFIER] = true;
53   handled_p[TS_DECL_MINIMAL] = true;
54   handled_p[TS_DECL_COMMON] = true;
55   handled_p[TS_DECL_WRTL] = true;
56   handled_p[TS_DECL_NON_COMMON] = true;
57   handled_p[TS_DECL_WITH_VIS] = true;
58   handled_p[TS_FIELD_DECL] = true;
59   handled_p[TS_VAR_DECL] = true;
60   handled_p[TS_PARM_DECL] = true;
61   handled_p[TS_LABEL_DECL] = true;
62   handled_p[TS_RESULT_DECL] = true;
63   handled_p[TS_CONST_DECL] = true;
64   handled_p[TS_TYPE_DECL] = true;
65   handled_p[TS_FUNCTION_DECL] = true;
66   handled_p[TS_TYPE_COMMON] = true;
67   handled_p[TS_TYPE_WITH_LANG_SPECIFIC] = true;
68   handled_p[TS_TYPE_NON_COMMON] = true;
69   handled_p[TS_LIST] = true;
70   handled_p[TS_VEC] = true;
71   handled_p[TS_EXP] = true;
72   handled_p[TS_SSA_NAME] = true;
73   handled_p[TS_BLOCK] = true;
74   handled_p[TS_BINFO] = true;
75   handled_p[TS_STATEMENT_LIST] = true;
76   handled_p[TS_CONSTRUCTOR] = true;
77   handled_p[TS_OMP_CLAUSE] = true;
78   handled_p[TS_OPTIMIZATION] = true;
79   handled_p[TS_TARGET_OPTION] = true;
80   handled_p[TS_TRANSLATION_UNIT_DECL] = true;
81 
82   /* Anything not marked above will trigger the following assertion.
83      If this assertion triggers, it means that there is a new TS_*
84      structure that should be handled by the streamer.  */
85   for (i = 0; i < LAST_TS_ENUM; i++)
86     gcc_assert (handled_p[i]);
87 }
88 
89 
90 /* Helper for streamer_tree_cache_insert_1.  Add T to CACHE->NODES at
91    slot IX.  */
92 
93 static void
94 streamer_tree_cache_add_to_node_array (struct streamer_tree_cache_d *cache,
95 				       unsigned ix, tree t)
96 {
97   /* Make sure we're either replacing an old element or
98      appending consecutively.  */
99   gcc_assert (ix <= cache->nodes.length ());
100 
101   if (ix == cache->nodes.length ())
102     cache->nodes.safe_push (t);
103   else
104     cache->nodes[ix] = t;
105 }
106 
107 
108 /* Helper for streamer_tree_cache_insert and streamer_tree_cache_insert_at.
109    CACHE, T, and IX_P are as in streamer_tree_cache_insert.
110 
111    If INSERT_AT_NEXT_SLOT_P is true, T is inserted at the next available
112    slot in the cache.  Otherwise, T is inserted at the position indicated
113    in *IX_P.
114 
115    If T already existed in CACHE, return true.  Otherwise,
116    return false.  */
117 
118 static bool
119 streamer_tree_cache_insert_1 (struct streamer_tree_cache_d *cache,
120 			      tree t, unsigned *ix_p,
121 			      bool insert_at_next_slot_p)
122 {
123   void **slot;
124   unsigned ix;
125   bool existed_p;
126 
127   gcc_assert (t);
128 
129   slot = pointer_map_insert (cache->node_map, t);
130   if (!*slot)
131     {
132       /* Determine the next slot to use in the cache.  */
133       if (insert_at_next_slot_p)
134 	ix = cache->nodes.length ();
135       else
136 	ix = *ix_p;
137        *slot = (void *)(size_t) (ix + 1);
138 
139       streamer_tree_cache_add_to_node_array (cache, ix, t);
140 
141       /* Indicate that the item was not present in the cache.  */
142       existed_p = false;
143     }
144   else
145     {
146       ix = (size_t) *slot - 1;
147 
148       if (!insert_at_next_slot_p && ix != *ix_p)
149 	{
150 	  /* If the caller wants to insert T at a specific slot
151 	     location, and ENTRY->TO does not match *IX_P, add T to
152 	     the requested location slot.  */
153 	  ix = *ix_p;
154 	  streamer_tree_cache_add_to_node_array (cache, ix, t);
155 	}
156 
157       /* Indicate that T was already in the cache.  */
158       existed_p = true;
159     }
160 
161   if (ix_p)
162     *ix_p = ix;
163 
164   return existed_p;
165 }
166 
167 
168 /* Insert tree node T in CACHE.  If T already existed in the cache
169    return true.  Otherwise, return false.
170 
171    If IX_P is non-null, update it with the index into the cache where
172    T has been stored.  */
173 
174 bool
175 streamer_tree_cache_insert (struct streamer_tree_cache_d *cache, tree t,
176 			    unsigned *ix_p)
177 {
178   return streamer_tree_cache_insert_1 (cache, t, ix_p, true);
179 }
180 
181 
182 /* Insert tree node T in CACHE at slot IX.  If T already
183    existed in the cache return true.  Otherwise, return false.  */
184 
185 bool
186 streamer_tree_cache_insert_at (struct streamer_tree_cache_d *cache,
187 			       tree t, unsigned ix)
188 {
189   return streamer_tree_cache_insert_1 (cache, t, &ix, false);
190 }
191 
192 
193 /* Appends tree node T to CACHE, even if T already existed in it.  */
194 
195 void
196 streamer_tree_cache_append (struct streamer_tree_cache_d *cache, tree t)
197 {
198   unsigned ix = cache->nodes.length ();
199   streamer_tree_cache_insert_1 (cache, t, &ix, false);
200 }
201 
202 /* Return true if tree node T exists in CACHE, otherwise false.  If IX_P is
203    not NULL, write to *IX_P the index into the cache where T is stored
204    ((unsigned)-1 if T is not found).  */
205 
206 bool
207 streamer_tree_cache_lookup (struct streamer_tree_cache_d *cache, tree t,
208 			    unsigned *ix_p)
209 {
210   void **slot;
211   bool retval;
212   unsigned ix;
213 
214   gcc_assert (t);
215 
216   slot = pointer_map_contains  (cache->node_map, t);
217   if (slot == NULL)
218     {
219       retval = false;
220       ix = -1;
221     }
222   else
223     {
224       retval = true;
225       ix = (size_t) *slot - 1;
226     }
227 
228   if (ix_p)
229     *ix_p = ix;
230 
231   return retval;
232 }
233 
234 
235 /* Record NODE in CACHE.  */
236 
237 static void
238 record_common_node (struct streamer_tree_cache_d *cache, tree node)
239 {
240   /* If we recursively end up at nodes we do not want to preload simply don't.
241      ???  We'd want to verify that this doesn't happen, or alternatively
242      do not recurse at all.  */
243   if (node == char_type_node)
244     return;
245 
246   gcc_checking_assert (node != boolean_type_node
247 		       && node != boolean_true_node
248 		       && node != boolean_false_node);
249 
250   /* We have to make sure to fill exactly the same number of
251      elements for all frontends.  That can include NULL trees.
252      As our hash table can't deal with zero entries we'll simply stream
253      a random other tree.  A NULL tree never will be looked up so it
254      doesn't matter which tree we replace it with, just to be sure
255      use error_mark_node.  */
256   if (!node)
257     node = error_mark_node;
258 
259   streamer_tree_cache_append (cache, node);
260 
261   if (POINTER_TYPE_P (node)
262       || TREE_CODE (node) == COMPLEX_TYPE
263       || TREE_CODE (node) == ARRAY_TYPE)
264     record_common_node (cache, TREE_TYPE (node));
265   else if (TREE_CODE (node) == RECORD_TYPE)
266     {
267       /* The FIELD_DECLs of structures should be shared, so that every
268 	 COMPONENT_REF uses the same tree node when referencing a field.
269 	 Pointer equality between FIELD_DECLs is used by the alias
270 	 machinery to compute overlapping memory references (See
271 	 nonoverlapping_component_refs_p).  */
272       tree f;
273       for (f = TYPE_FIELDS (node); f; f = TREE_CHAIN (f))
274 	record_common_node (cache, f);
275     }
276 }
277 
278 
279 /* Preload common nodes into CACHE and make sure they are merged
280    properly according to the gimple type table.  */
281 
282 static void
283 preload_common_nodes (struct streamer_tree_cache_d *cache)
284 {
285   unsigned i;
286 
287   for (i = 0; i < itk_none; i++)
288     /* Skip itk_char.  char_type_node is dependent on -f[un]signed-char.  */
289     if (i != itk_char)
290       record_common_node (cache, integer_types[i]);
291 
292   for (i = 0; i < stk_type_kind_last; i++)
293     record_common_node (cache, sizetype_tab[i]);
294 
295   for (i = 0; i < TI_MAX; i++)
296     /* Skip boolean type and constants, they are frontend dependent.  */
297     if (i != TI_BOOLEAN_TYPE
298 	&& i != TI_BOOLEAN_FALSE
299 	&& i != TI_BOOLEAN_TRUE)
300       record_common_node (cache, global_trees[i]);
301 }
302 
303 
304 /* Create a cache of pickled nodes.  */
305 
306 struct streamer_tree_cache_d *
307 streamer_tree_cache_create (void)
308 {
309   struct streamer_tree_cache_d *cache;
310 
311   cache = XCNEW (struct streamer_tree_cache_d);
312 
313   cache->node_map = pointer_map_create ();
314 
315   /* Load all the well-known tree nodes that are always created by
316      the compiler on startup.  This prevents writing them out
317      unnecessarily.  */
318   preload_common_nodes (cache);
319 
320   return cache;
321 }
322 
323 
324 /* Delete the streamer cache C.  */
325 
326 void
327 streamer_tree_cache_delete (struct streamer_tree_cache_d *c)
328 {
329   if (c == NULL)
330     return;
331 
332   pointer_map_destroy (c->node_map);
333   c->nodes.release ();
334   free (c);
335 }
336