1/* Functions for writing LTO sections.
2
3   Copyright (C) 2009-2015 Free Software Foundation, Inc.
4   Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3.  If not see
20<http://www.gnu.org/licenses/>.  */
21
22#include "config.h"
23#include "system.h"
24#include "coretypes.h"
25#include "tm.h"
26#include "hash-set.h"
27#include "machmode.h"
28#include "vec.h"
29#include "double-int.h"
30#include "input.h"
31#include "alias.h"
32#include "symtab.h"
33#include "wide-int.h"
34#include "inchash.h"
35#include "tree.h"
36#include "fold-const.h"
37#include "predict.h"
38#include "hard-reg-set.h"
39#include "function.h"
40#include "basic-block.h"
41#include "tree-ssa-alias.h"
42#include "internal-fn.h"
43#include "gimple-expr.h"
44#include "is-a.h"
45#include "gimple.h"
46#include "hashtab.h"
47#include "rtl.h"
48#include "flags.h"
49#include "statistics.h"
50#include "real.h"
51#include "fixed-value.h"
52#include "insn-config.h"
53#include "expmed.h"
54#include "dojump.h"
55#include "explow.h"
56#include "calls.h"
57#include "emit-rtl.h"
58#include "varasm.h"
59#include "stmt.h"
60#include "expr.h"
61#include "params.h"
62#include "except.h"
63#include "langhooks.h"
64#include "hash-map.h"
65#include "plugin-api.h"
66#include "ipa-ref.h"
67#include "cgraph.h"
68#include "data-streamer.h"
69#include "lto-streamer.h"
70#include "lto-compress.h"
71
72static vec<lto_out_decl_state_ptr> decl_state_stack;
73
74/* List of out decl states used by functions.  We use this to
75   generate the decl directory later. */
76
77vec<lto_out_decl_state_ptr> lto_function_decl_states;
78
79
80/*****************************************************************************
81   Output routines shared by all of the serialization passes.
82*****************************************************************************/
83
84
85/* Flush compressed stream data function, sends NUM_CHARS from CHARS
86   to the append lang hook, OPAQUE is currently always NULL.  */
87
88static void
89lto_append_data (const char *chars, unsigned int num_chars, void *opaque)
90{
91  gcc_assert (opaque == NULL);
92  lang_hooks.lto.append_data (chars, num_chars, opaque);
93}
94
95/* Pointer to the current compression stream.  */
96
97static struct lto_compression_stream *compression_stream = NULL;
98
99/* Begin a new output section named NAME. If COMPRESS is true, zlib compress
100   the section. */
101
102void
103lto_begin_section (const char *name, bool compress)
104{
105  lang_hooks.lto.begin_section (name);
106
107  /* FIXME lto: for now, suppress compression if the lang_hook that appends
108     data is anything other than assembler output.  The effect here is that
109     we get compression of IL only in non-ltrans object files.  */
110  gcc_assert (compression_stream == NULL);
111  if (compress)
112    compression_stream = lto_start_compression (lto_append_data, NULL);
113}
114
115
116/* End the current output section.  */
117
118void
119lto_end_section (void)
120{
121  if (compression_stream)
122    {
123      lto_end_compression (compression_stream);
124      compression_stream = NULL;
125    }
126  lang_hooks.lto.end_section ();
127}
128
129/* Write SIZE bytes starting at DATA to the assembler.  */
130
131void
132lto_write_data (const void *data, unsigned int size)
133{
134  if (compression_stream)
135    lto_compress_block (compression_stream, (const char *)data, size);
136  else
137    lang_hooks.lto.append_data ((const char *)data, size, NULL);
138}
139
140/* Write all of the chars in OBS to the assembler.  Recycle the blocks
141   in obs as this is being done.  */
142
143void
144lto_write_stream (struct lto_output_stream *obs)
145{
146  unsigned int block_size = 1024;
147  struct lto_char_ptr_base *block;
148  struct lto_char_ptr_base *next_block;
149  if (!obs->first_block)
150    return;
151
152  for (block = obs->first_block; block; block = next_block)
153    {
154      const char *base = ((char *)block) + sizeof (struct lto_char_ptr_base);
155      unsigned int num_chars = block_size - sizeof (struct lto_char_ptr_base);
156
157      /* If this is not the last block, it is full.  If it is the last
158	 block, left_in_block indicates how many chars are unoccupied in
159	 this block; subtract from num_chars to obtain occupancy.  */
160      next_block = (struct lto_char_ptr_base *) block->ptr;
161      if (!next_block)
162	num_chars -= obs->left_in_block;
163
164      /* FIXME lto: WPA mode uses an ELF function as a lang_hook to append
165         output data.  This hook is not happy with the way that compression
166         blocks up output differently to the way it's blocked here.  So for
167         now, we don't compress WPA output.  */
168      if (compression_stream)
169	lto_compress_block (compression_stream, base, num_chars);
170      else
171	lang_hooks.lto.append_data (base, num_chars, block);
172      free (block);
173      block_size *= 2;
174    }
175}
176
177
178/* Lookup NAME in ENCODER.  If NAME is not found, create a new entry in
179   ENCODER for NAME with the next available index of ENCODER,  then
180   print the index to OBS.  True is returned if NAME was added to
181   ENCODER.  The resulting index is stored in THIS_INDEX.
182
183   If OBS is NULL, the only action is to add NAME to the encoder. */
184
185bool
186lto_output_decl_index (struct lto_output_stream *obs,
187		       struct lto_tree_ref_encoder *encoder,
188		       tree name, unsigned int *this_index)
189{
190  bool new_entry_p = FALSE;
191  bool existed_p;
192
193  unsigned int &index
194    = encoder->tree_hash_table->get_or_insert (name, &existed_p);
195  if (!existed_p)
196    {
197      index = encoder->trees.length ();
198      encoder->trees.safe_push (name);
199      new_entry_p = TRUE;
200    }
201
202  if (obs)
203    streamer_write_uhwi_stream (obs, index);
204  *this_index = index;
205  return new_entry_p;
206}
207
208/* Output a field DECL to OBS.  */
209
210void
211lto_output_field_decl_index (struct lto_out_decl_state *decl_state,
212			     struct lto_output_stream * obs, tree decl)
213{
214  unsigned int index;
215  lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_FIELD_DECL],
216			 decl, &index);
217}
218
219/* Output a function DECL to OBS.  */
220
221void
222lto_output_fn_decl_index (struct lto_out_decl_state *decl_state,
223			  struct lto_output_stream * obs, tree decl)
224{
225  unsigned int index;
226  lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_FN_DECL],
227			 decl, &index);
228}
229
230/* Output a namespace DECL to OBS.  */
231
232void
233lto_output_namespace_decl_index (struct lto_out_decl_state *decl_state,
234				 struct lto_output_stream * obs, tree decl)
235{
236  unsigned int index;
237  lto_output_decl_index (obs,
238			 &decl_state->streams[LTO_DECL_STREAM_NAMESPACE_DECL],
239			 decl, &index);
240}
241
242/* Output a static or extern var DECL to OBS.  */
243
244void
245lto_output_var_decl_index (struct lto_out_decl_state *decl_state,
246			   struct lto_output_stream * obs, tree decl)
247{
248  unsigned int index;
249  lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_VAR_DECL],
250			 decl, &index);
251}
252
253/* Output a type DECL to OBS.  */
254
255void
256lto_output_type_decl_index (struct lto_out_decl_state *decl_state,
257			    struct lto_output_stream * obs, tree decl)
258{
259  unsigned int index;
260  lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_TYPE_DECL],
261			 decl, &index);
262}
263
264/* Output a type REF to OBS.  */
265
266void
267lto_output_type_ref_index (struct lto_out_decl_state *decl_state,
268			   struct lto_output_stream *obs, tree ref)
269{
270  unsigned int index;
271  lto_output_decl_index (obs, &decl_state->streams[LTO_DECL_STREAM_TYPE],
272			 ref, &index);
273}
274
275
276/* Create the output block and return it.  */
277
278struct lto_simple_output_block *
279lto_create_simple_output_block (enum lto_section_type section_type)
280{
281  struct lto_simple_output_block *ob
282    = ((struct lto_simple_output_block *)
283       xcalloc (1, sizeof (struct lto_simple_output_block)));
284
285  ob->section_type = section_type;
286  ob->decl_state = lto_get_out_decl_state ();
287  ob->main_stream = ((struct lto_output_stream *)
288		     xcalloc (1, sizeof (struct lto_output_stream)));
289
290  return ob;
291}
292
293
294/* Produce a simple section for one of the ipa passes.  */
295
296void
297lto_destroy_simple_output_block (struct lto_simple_output_block *ob)
298{
299  char *section_name;
300  struct lto_simple_header header;
301
302  section_name = lto_get_section_name (ob->section_type, NULL, NULL);
303  lto_begin_section (section_name, !flag_wpa);
304  free (section_name);
305
306  /* Write the header which says how to decode the pieces of the
307     t.  */
308  memset (&header, 0, sizeof (struct lto_simple_header));
309  header.major_version = LTO_major_version;
310  header.minor_version = LTO_minor_version;
311  header.main_size = ob->main_stream->total_size;
312  lto_write_data (&header, sizeof header);
313
314  lto_write_stream (ob->main_stream);
315
316  /* Put back the assembly section that was there before we started
317     writing lto info.  */
318  lto_end_section ();
319
320  free (ob->main_stream);
321  free (ob);
322}
323
324
325/* Return a new lto_out_decl_state. */
326
327struct lto_out_decl_state *
328lto_new_out_decl_state (void)
329{
330  struct lto_out_decl_state *state = XCNEW (struct lto_out_decl_state);
331  int i;
332
333  for (i = 0; i < LTO_N_DECL_STREAMS; i++)
334    lto_init_tree_ref_encoder (&state->streams[i]);
335
336  return state;
337}
338
339
340/* Delete STATE and components.  */
341
342void
343lto_delete_out_decl_state (struct lto_out_decl_state *state)
344{
345  int i;
346
347  for (i = 0; i < LTO_N_DECL_STREAMS; i++)
348    lto_destroy_tree_ref_encoder (&state->streams[i]);
349
350  free (state);
351}
352
353
354/* Get the currently used lto_out_decl_state structure. */
355
356struct lto_out_decl_state *
357lto_get_out_decl_state (void)
358{
359  return decl_state_stack.last ();
360}
361
362/* Push STATE to top of out decl stack. */
363
364void
365lto_push_out_decl_state (struct lto_out_decl_state *state)
366{
367  decl_state_stack.safe_push (state);
368}
369
370/* Pop the currently used out-decl state from top of stack. */
371
372struct lto_out_decl_state *
373lto_pop_out_decl_state (void)
374{
375  return decl_state_stack.pop ();
376}
377
378/* Record STATE after it has been used in serializing the body of
379   FN_DECL.  STATE should no longer be used by the caller.  The ownership
380   of it is taken over from this point.  */
381
382void
383lto_record_function_out_decl_state (tree fn_decl,
384				    struct lto_out_decl_state *state)
385{
386  int i;
387
388  /* Strip all hash tables to save some memory. */
389  for (i = 0; i < LTO_N_DECL_STREAMS; i++)
390    if (state->streams[i].tree_hash_table)
391      {
392	delete state->streams[i].tree_hash_table;
393	state->streams[i].tree_hash_table = NULL;
394      }
395  state->fn_decl = fn_decl;
396  lto_function_decl_states.safe_push (state);
397}
398