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[official-gcc.git] / gcc / lto-section-out.c
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1 /* Functions for writing LTO sections.
3 Copyright (C) 2009-2014 Free Software Foundation, Inc.
4 Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "tree.h"
27 #include "basic-block.h"
28 #include "tree-ssa-alias.h"
29 #include "internal-fn.h"
30 #include "gimple-expr.h"
31 #include "is-a.h"
32 #include "gimple.h"
33 #include "expr.h"
34 #include "params.h"
35 #include "input.h"
36 #include "hashtab.h"
37 #include "function.h"
38 #include "except.h"
39 #include "langhooks.h"
40 #include "data-streamer.h"
41 #include "lto-streamer.h"
42 #include "lto-compress.h"
44 static vec<lto_out_decl_state_ptr> decl_state_stack;
46 /* List of out decl states used by functions. We use this to
47 generate the decl directory later. */
49 vec<lto_out_decl_state_ptr> lto_function_decl_states;
52 /*****************************************************************************
53 Output routines shared by all of the serialization passes.
54 *****************************************************************************/
57 /* Flush compressed stream data function, sends NUM_CHARS from CHARS
58 to the append lang hook, OPAQUE is currently always NULL. */
60 static void
61 lto_append_data (const char *chars, unsigned int num_chars, void *opaque)
63 gcc_assert (opaque == NULL);
64 lang_hooks.lto.append_data (chars, num_chars, opaque);
67 /* Pointer to the current compression stream. */
69 static struct lto_compression_stream *compression_stream = NULL;
71 /* Begin a new output section named NAME. If COMPRESS is true, zlib compress
72 the section. */
74 void
75 lto_begin_section (const char *name, bool compress)
77 lang_hooks.lto.begin_section (name);
79 /* FIXME lto: for now, suppress compression if the lang_hook that appends
80 data is anything other than assembler output. The effect here is that
81 we get compression of IL only in non-ltrans object files. */
82 gcc_assert (compression_stream == NULL);
83 if (compress)
84 compression_stream = lto_start_compression (lto_append_data, NULL);
88 /* End the current output section. */
90 void
91 lto_end_section (void)
93 if (compression_stream)
95 lto_end_compression (compression_stream);
96 compression_stream = NULL;
98 lang_hooks.lto.end_section ();
102 /* Write all of the chars in OBS to the assembler. Recycle the blocks
103 in obs as this is being done. */
105 void
106 lto_write_stream (struct lto_output_stream *obs)
108 unsigned int block_size = 1024;
109 struct lto_char_ptr_base *block;
110 struct lto_char_ptr_base *next_block;
111 if (!obs->first_block)
112 return;
114 for (block = obs->first_block; block; block = next_block)
116 const char *base = ((char *)block) + sizeof (struct lto_char_ptr_base);
117 unsigned int num_chars = block_size - sizeof (struct lto_char_ptr_base);
119 /* If this is not the last block, it is full. If it is the last
120 block, left_in_block indicates how many chars are unoccupied in
121 this block; subtract from num_chars to obtain occupancy. */
122 next_block = (struct lto_char_ptr_base *) block->ptr;
123 if (!next_block)
124 num_chars -= obs->left_in_block;
126 /* FIXME lto: WPA mode uses an ELF function as a lang_hook to append
127 output data. This hook is not happy with the way that compression
128 blocks up output differently to the way it's blocked here. So for
129 now, we don't compress WPA output. */
130 if (compression_stream)
132 lto_compress_block (compression_stream, base, num_chars);
133 lang_hooks.lto.append_data (NULL, 0, block);
135 else
136 lang_hooks.lto.append_data (base, num_chars, block);
137 block_size *= 2;
142 /* Adds a new block to output stream OBS. */
144 void
145 lto_append_block (struct lto_output_stream *obs)
147 struct lto_char_ptr_base *new_block;
149 gcc_assert (obs->left_in_block == 0);
151 if (obs->first_block == NULL)
153 /* This is the first time the stream has been written
154 into. */
155 obs->block_size = 1024;
156 new_block = (struct lto_char_ptr_base*) xmalloc (obs->block_size);
157 obs->first_block = new_block;
159 else
161 struct lto_char_ptr_base *tptr;
162 /* Get a new block that is twice as big as the last block
163 and link it into the list. */
164 obs->block_size *= 2;
165 new_block = (struct lto_char_ptr_base*) xmalloc (obs->block_size);
166 /* The first bytes of the block are reserved as a pointer to
167 the next block. Set the chain of the full block to the
168 pointer to the new block. */
169 tptr = obs->current_block;
170 tptr->ptr = (char *) new_block;
173 /* Set the place for the next char at the first position after the
174 chain to the next block. */
175 obs->current_pointer
176 = ((char *) new_block) + sizeof (struct lto_char_ptr_base);
177 obs->current_block = new_block;
178 /* Null out the newly allocated block's pointer to the next block. */
179 new_block->ptr = NULL;
180 obs->left_in_block = obs->block_size - sizeof (struct lto_char_ptr_base);
184 /* Write raw DATA of length LEN to the output block OB. */
186 void
187 lto_output_data_stream (struct lto_output_stream *obs, const void *data,
188 size_t len)
190 while (len)
192 size_t copy;
194 /* No space left. */
195 if (obs->left_in_block == 0)
196 lto_append_block (obs);
198 /* Determine how many bytes to copy in this loop. */
199 if (len <= obs->left_in_block)
200 copy = len;
201 else
202 copy = obs->left_in_block;
204 /* Copy the data and do bookkeeping. */
205 memcpy (obs->current_pointer, data, copy);
206 obs->current_pointer += copy;
207 obs->total_size += copy;
208 obs->left_in_block -= copy;
209 data = (const char *) data + copy;
210 len -= copy;
215 /* Lookup NAME in ENCODER. If NAME is not found, create a new entry in
216 ENCODER for NAME with the next available index of ENCODER, then
217 print the index to OBS. True is returned if NAME was added to
218 ENCODER. The resulting index is stored in THIS_INDEX.
220 If OBS is NULL, the only action is to add NAME to the encoder. */
222 bool
223 lto_output_decl_index (struct lto_output_stream *obs,
224 struct lto_tree_ref_encoder *encoder,
225 tree name, unsigned int *this_index)
227 unsigned *slot;
228 unsigned int index;
229 bool new_entry_p = FALSE;
230 bool existed_p;
232 slot = encoder->tree_hash_table->insert (name, &existed_p);
233 if (!existed_p)
235 index = encoder->trees.length ();
236 *slot = index;
237 encoder->trees.safe_push (name);
238 new_entry_p = TRUE;
240 else
241 index = *slot;
243 if (obs)
244 streamer_write_uhwi_stream (obs, index);
245 *this_index = index;
246 return new_entry_p;
249 /* Output a field DECL to OBS. */
251 void
252 lto_output_field_decl_index (struct lto_out_decl_state *decl_state,
253 struct lto_output_stream * obs, tree decl)
255 unsigned int index;
256 lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_FIELD_DECL],
257 decl, &index);
260 /* Output a function DECL to OBS. */
262 void
263 lto_output_fn_decl_index (struct lto_out_decl_state *decl_state,
264 struct lto_output_stream * obs, tree decl)
266 unsigned int index;
267 lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_FN_DECL],
268 decl, &index);
271 /* Output a namespace DECL to OBS. */
273 void
274 lto_output_namespace_decl_index (struct lto_out_decl_state *decl_state,
275 struct lto_output_stream * obs, tree decl)
277 unsigned int index;
278 lto_output_decl_index (obs,
279 &decl_state->streams[LTO_DECL_STREAM_NAMESPACE_DECL],
280 decl, &index);
283 /* Output a static or extern var DECL to OBS. */
285 void
286 lto_output_var_decl_index (struct lto_out_decl_state *decl_state,
287 struct lto_output_stream * obs, tree decl)
289 unsigned int index;
290 lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_VAR_DECL],
291 decl, &index);
294 /* Output a type DECL to OBS. */
296 void
297 lto_output_type_decl_index (struct lto_out_decl_state *decl_state,
298 struct lto_output_stream * obs, tree decl)
300 unsigned int index;
301 lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_TYPE_DECL],
302 decl, &index);
305 /* Output a type REF to OBS. */
307 void
308 lto_output_type_ref_index (struct lto_out_decl_state *decl_state,
309 struct lto_output_stream *obs, tree ref)
311 unsigned int index;
312 lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_TYPE],
313 ref, &index);
317 /* Create the output block and return it. */
319 struct lto_simple_output_block *
320 lto_create_simple_output_block (enum lto_section_type section_type)
322 struct lto_simple_output_block *ob
323 = ((struct lto_simple_output_block *)
324 xcalloc (1, sizeof (struct lto_simple_output_block)));
326 ob->section_type = section_type;
327 ob->decl_state = lto_get_out_decl_state ();
328 ob->main_stream = ((struct lto_output_stream *)
329 xcalloc (1, sizeof (struct lto_output_stream)));
331 return ob;
335 /* Produce a simple section for one of the ipa passes. */
337 void
338 lto_destroy_simple_output_block (struct lto_simple_output_block *ob)
340 char *section_name;
341 struct lto_simple_header header;
342 struct lto_output_stream *header_stream;
344 section_name = lto_get_section_name (ob->section_type, NULL, NULL);
345 lto_begin_section (section_name, !flag_wpa);
346 free (section_name);
348 /* Write the header which says how to decode the pieces of the
349 t. */
350 memset (&header, 0, sizeof (struct lto_simple_header));
351 header.lto_header.major_version = LTO_major_version;
352 header.lto_header.minor_version = LTO_minor_version;
354 header.compressed_size = 0;
356 header.main_size = ob->main_stream->total_size;
358 header_stream = XCNEW (struct lto_output_stream);
359 lto_output_data_stream (header_stream, &header, sizeof header);
360 lto_write_stream (header_stream);
361 free (header_stream);
363 lto_write_stream (ob->main_stream);
365 /* Put back the assembly section that was there before we started
366 writing lto info. */
367 lto_end_section ();
369 free (ob->main_stream);
370 free (ob);
374 /* Return a new lto_out_decl_state. */
376 struct lto_out_decl_state *
377 lto_new_out_decl_state (void)
379 struct lto_out_decl_state *state = XCNEW (struct lto_out_decl_state);
380 int i;
382 for (i = 0; i < LTO_N_DECL_STREAMS; i++)
383 lto_init_tree_ref_encoder (&state->streams[i]);
385 return state;
389 /* Delete STATE and components. */
391 void
392 lto_delete_out_decl_state (struct lto_out_decl_state *state)
394 int i;
396 for (i = 0; i < LTO_N_DECL_STREAMS; i++)
397 lto_destroy_tree_ref_encoder (&state->streams[i]);
399 free (state);
403 /* Get the currently used lto_out_decl_state structure. */
405 struct lto_out_decl_state *
406 lto_get_out_decl_state (void)
408 return decl_state_stack.last ();
411 /* Push STATE to top of out decl stack. */
413 void
414 lto_push_out_decl_state (struct lto_out_decl_state *state)
416 decl_state_stack.safe_push (state);
419 /* Pop the currently used out-decl state from top of stack. */
421 struct lto_out_decl_state *
422 lto_pop_out_decl_state (void)
424 return decl_state_stack.pop ();
427 /* Record STATE after it has been used in serializing the body of
428 FN_DECL. STATE should no longer be used by the caller. The ownership
429 of it is taken over from this point. */
431 void
432 lto_record_function_out_decl_state (tree fn_decl,
433 struct lto_out_decl_state *state)
435 int i;
437 /* Strip all hash tables to save some memory. */
438 for (i = 0; i < LTO_N_DECL_STREAMS; i++)
439 if (state->streams[i].tree_hash_table)
441 delete state->streams[i].tree_hash_table;
442 state->streams[i].tree_hash_table = NULL;
444 state->fn_decl = fn_decl;
445 lto_function_decl_states.safe_push (state);