]> git.ipfire.org Git - thirdparty/gcc.git/blame - gcc/cgraphunit.c
Provide _M_2_SQRTPI if missing.
[thirdparty/gcc.git] / gcc / cgraphunit.c
CommitLineData
da5e1e7c 1/* Driver of optimization process
711789cc 2 Copyright (C) 2003-2013 Free Software Foundation, Inc.
ae01b312 3 Contributed by Jan Hubicka
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
8c4c00c1 9Software Foundation; either version 3, or (at your option) any later
ae01b312 10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
8c4c00c1 18along with GCC; see the file COPYING3. If not see
19<http://www.gnu.org/licenses/>. */
ae01b312 20
da5e1e7c 21/* This module implements main driver of compilation process.
b0cdf642 22
23 The main scope of this file is to act as an interface in between
da5e1e7c 24 tree based frontends and the backend.
b0cdf642 25
26 The front-end is supposed to use following functionality:
27
28 - cgraph_finalize_function
29
30 This function is called once front-end has parsed whole body of function
31 and it is certain that the function body nor the declaration will change.
32
b326746d 33 (There is one exception needed for implementing GCC extern inline
34 function.)
b0cdf642 35
a2d67028 36 - varpool_finalize_decl
b0cdf642 37
7bd28bba 38 This function has same behavior as the above but is used for static
b0cdf642 39 variables.
40
cf951b1a 41 - add_asm_node
42
43 Insert new toplevel ASM statement
44
45 - finalize_compilation_unit
b0cdf642 46
b326746d 47 This function is called once (source level) compilation unit is finalized
48 and it will no longer change.
b0cdf642 49
da5e1e7c 50 The symbol table is constructed starting from the trivially needed
51 symbols finalized by the frontend. Functions are lowered into
52 GIMPLE representation and callgraph/reference lists are constructed.
9d75589a 53 Those are used to discover other necessary functions and variables.
da5e1e7c 54
55 At the end the bodies of unreachable functions are removed.
b0cdf642 56
b326746d 57 The function can be called multiple times when multiple source level
da5e1e7c 58 compilation units are combined.
b0cdf642 59
cf951b1a 60 - compile
b0cdf642 61
da5e1e7c 62 This passes control to the back-end. Optimizations are performed and
63 final assembler is generated. This is done in the following way. Note
64 that with link time optimization the process is split into three
65 stages (compile time, linktime analysis and parallel linktime as
66 indicated bellow).
67
68 Compile time:
69
70 1) Inter-procedural optimization.
71 (ipa_passes)
72
73 This part is further split into:
74
75 a) early optimizations. These are local passes executed in
76 the topological order on the callgraph.
77
78 The purpose of early optimiations is to optimize away simple
79 things that may otherwise confuse IP analysis. Very simple
80 propagation across the callgraph is done i.e. to discover
81 functions without side effects and simple inlining is performed.
82
83 b) early small interprocedural passes.
84
85 Those are interprocedural passes executed only at compilation
a04e8d62 86 time. These include, for example, transational memory lowering,
da5e1e7c 87 unreachable code removal and other simple transformations.
88
89 c) IP analysis stage. All interprocedural passes do their
90 analysis.
91
92 Interprocedural passes differ from small interprocedural
93 passes by their ability to operate across whole program
94 at linktime. Their analysis stage is performed early to
95 both reduce linking times and linktime memory usage by
96 not having to represent whole program in memory.
97
98 d) LTO sreaming. When doing LTO, everything important gets
99 streamed into the object file.
100
101 Compile time and or linktime analysis stage (WPA):
102
103 At linktime units gets streamed back and symbol table is
104 merged. Function bodies are not streamed in and not
105 available.
106 e) IP propagation stage. All IP passes execute their
107 IP propagation. This is done based on the earlier analysis
108 without having function bodies at hand.
109 f) Ltrans streaming. When doing WHOPR LTO, the program
110 is partitioned and streamed into multple object files.
b0cdf642 111
da5e1e7c 112 Compile time and/or parallel linktime stage (ltrans)
b0cdf642 113
da5e1e7c 114 Each of the object files is streamed back and compiled
115 separately. Now the function bodies becomes available
116 again.
b0cdf642 117
da5e1e7c 118 2) Virtual clone materialization
119 (cgraph_materialize_clone)
b0cdf642 120
da5e1e7c 121 IP passes can produce copies of existing functoins (such
122 as versioned clones or inline clones) without actually
123 manipulating their bodies by creating virtual clones in
124 the callgraph. At this time the virtual clones are
125 turned into real functions
126 3) IP transformation
b0cdf642 127
da5e1e7c 128 All IP passes transform function bodies based on earlier
129 decision of the IP propagation.
b0cdf642 130
da5e1e7c 131 4) late small IP passes
b0cdf642 132
da5e1e7c 133 Simple IP passes working within single program partition.
b0cdf642 134
da5e1e7c 135 5) Expansion
cf951b1a 136 (expand_all_functions)
b0cdf642 137
da5e1e7c 138 At this stage functions that needs to be output into
139 assembler are identified and compiled in topological order
140 6) Output of variables and aliases
141 Now it is known what variable references was not optimized
142 out and thus all variables are output to the file.
b0cdf642 143
da5e1e7c 144 Note that with -fno-toplevel-reorder passes 5 and 6
145 are combined together in cgraph_output_in_order.
b0cdf642 146
da5e1e7c 147 Finally there are functions to manipulate the callgraph from
148 backend.
149 - cgraph_add_new_function is used to add backend produced
150 functions introduced after the unit is finalized.
151 The functions are enqueue for later processing and inserted
152 into callgraph with cgraph_process_new_functions.
121f3051 153
da5e1e7c 154 - cgraph_function_versioning
155
156 produces a copy of function into new one (a version)
157 and apply simple transformations
158*/
acc70efa 159
ae01b312 160#include "config.h"
161#include "system.h"
162#include "coretypes.h"
163#include "tm.h"
164#include "tree.h"
9ed99284 165#include "varasm.h"
166#include "stor-layout.h"
167#include "stringpool.h"
941366fd 168#include "output.h"
b5530559 169#include "rtl.h"
bc61cadb 170#include "basic-block.h"
171#include "tree-ssa-alias.h"
172#include "internal-fn.h"
173#include "gimple-fold.h"
174#include "gimple-expr.h"
175#include "is-a.h"
e795d6e1 176#include "gimple.h"
a8783bee 177#include "gimplify.h"
dcf1a1ec 178#include "gimple-iterator.h"
e795d6e1 179#include "gimplify-me.h"
073c1fd5 180#include "gimple-ssa.h"
181#include "tree-cfg.h"
182#include "tree-into-ssa.h"
69ee5dbb 183#include "tree-ssa.h"
ae01b312 184#include "tree-inline.h"
185#include "langhooks.h"
ae01b312 186#include "toplev.h"
187#include "flags.h"
ae01b312 188#include "debug.h"
189#include "target.h"
80a85d8a 190#include "diagnostic.h"
d7c6d889 191#include "params.h"
192#include "fibheap.h"
611e5405 193#include "intl.h"
b69eb0ff 194#include "function.h"
b5d36404 195#include "ipa-prop.h"
75a70cf9 196#include "tree-iterator.h"
f1e2a033 197#include "tree-pass.h"
bfec3452 198#include "tree-dump.h"
da5e1e7c 199#include "gimple-pretty-print.h"
c1dcd13c 200#include "output.h"
9ed5b1f5 201#include "coverage.h"
c9036234 202#include "plugin.h"
a41f2a28 203#include "ipa-inline.h"
7771d558 204#include "ipa-utils.h"
a0605d65 205#include "lto-streamer.h"
3db65b62 206#include "except.h"
7eacb0dd 207#include "cfgloop.h"
941366fd 208#include "regset.h" /* FIXME: For reg_obstack. */
3ea50c01 209#include "context.h"
210#include "pass_manager.h"
e797f49f 211#include "tree-nested.h"
8a4a28a8 212#include "gimplify.h"
d7c6d889 213
ff2a5ada 214/* Queue of cgraph nodes scheduled to be added into cgraph. This is a
215 secondary queue used during optimization to accommodate passes that
216 may generate new functions that need to be optimized and expanded. */
217cgraph_node_set cgraph_new_nodes;
218
cf951b1a 219static void expand_all_functions (void);
220static void mark_functions_to_output (void);
221static void expand_function (struct cgraph_node *);
15ca8f90 222static void analyze_function (struct cgraph_node *);
18a71d50 223static void handle_alias_pairs (void);
25bb88de 224
ecb08119 225FILE *cgraph_dump_file;
121f3051 226
cf951b1a 227/* Linked list of cgraph asm nodes. */
228struct asm_node *asm_nodes;
229
230/* Last node in cgraph_asm_nodes. */
231static GTY(()) struct asm_node *asm_last_node;
232
28454517 233/* Used for vtable lookup in thunk adjusting. */
234static GTY (()) tree vtable_entry_type;
235
6a1c0403 236/* Determine if symbol DECL is needed. That is, visible to something
237 either outside this translation unit, something magic in the system
238 configury */
239bool
452659af 240decide_is_symbol_needed (symtab_node *node)
2c0b522d 241{
02774f2d 242 tree decl = node->decl;
05806473 243
8efa224a 244 /* Double check that no one output the function into assembly file
245 early. */
246 gcc_checking_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)
48669653 247 || !TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)));
3f82b628 248
02774f2d 249 if (!node->definition)
6a1c0403 250 return false;
55680bef 251
6a1c0403 252 if (DECL_EXTERNAL (decl))
253 return false;
8baa9d15 254
6a1c0403 255 /* If the user told us it is used, then it must be so. */
02774f2d 256 if (node->force_output)
6a1c0403 257 return true;
258
259 /* ABI forced symbols are needed when they are external. */
02774f2d 260 if (node->forced_by_abi && TREE_PUBLIC (decl))
6a1c0403 261 return true;
262
263 /* Keep constructors, destructors and virtual functions. */
264 if (TREE_CODE (decl) == FUNCTION_DECL
265 && (DECL_STATIC_CONSTRUCTOR (decl) || DECL_STATIC_DESTRUCTOR (decl)))
266 return true;
267
268 /* Externally visible variables must be output. The exception is
269 COMDAT variables that must be output only when they are needed. */
270 if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl))
2c0b522d 271 return true;
272
2c0b522d 273 return false;
274}
275
3cb3fce5 276/* Head and terminator of the queue of nodes to be processed while building
277 callgraph. */
ff2a5ada 278
3cb3fce5 279static symtab_node symtab_terminator;
280static symtab_node *queued_nodes = &symtab_terminator;
ff2a5ada 281
3cb3fce5 282/* Add NODE to queue starting at QUEUED_NODES.
ff2a5ada 283 The queue is linked via AUX pointers and terminated by pointer to 1. */
284
285static void
452659af 286enqueue_node (symtab_node *node)
ff2a5ada 287{
02774f2d 288 if (node->aux)
ff2a5ada 289 return;
3cb3fce5 290 gcc_checking_assert (queued_nodes);
291 node->aux = queued_nodes;
292 queued_nodes = node;
ff2a5ada 293}
294
bdc40eb8 295/* Process CGRAPH_NEW_FUNCTIONS and perform actions necessary to add these
523c1122 296 functions into callgraph in a way so they look like ordinary reachable
297 functions inserted into callgraph already at construction time. */
298
3cb3fce5 299void
523c1122 300cgraph_process_new_functions (void)
301{
523c1122 302 tree fndecl;
303 struct cgraph_node *node;
ff2a5ada 304 cgraph_node_set_iterator csi;
523c1122 305
ff2a5ada 306 if (!cgraph_new_nodes)
3cb3fce5 307 return;
18a71d50 308 handle_alias_pairs ();
523c1122 309 /* Note that this queue may grow as its being processed, as the new
310 functions may generate new ones. */
ff2a5ada 311 for (csi = csi_start (cgraph_new_nodes); !csi_end_p (csi); csi_next (&csi))
523c1122 312 {
ff2a5ada 313 node = csi_node (csi);
02774f2d 314 fndecl = node->decl;
523c1122 315 switch (cgraph_state)
316 {
317 case CGRAPH_STATE_CONSTRUCTION:
318 /* At construction time we just need to finalize function and move
319 it into reachable functions list. */
320
523c1122 321 cgraph_finalize_function (fndecl, false);
4f7a1122 322 cgraph_call_function_insertion_hooks (node);
02774f2d 323 enqueue_node (node);
523c1122 324 break;
325
326 case CGRAPH_STATE_IPA:
f517b36e 327 case CGRAPH_STATE_IPA_SSA:
523c1122 328 /* When IPA optimization already started, do all essential
329 transformations that has been already performed on the whole
330 cgraph but not on this function. */
331
75a70cf9 332 gimple_register_cfg_hooks ();
02774f2d 333 if (!node->analyzed)
15ca8f90 334 analyze_function (node);
523c1122 335 push_cfun (DECL_STRUCT_FUNCTION (fndecl));
f2c6b33f 336 if (cgraph_state == CGRAPH_STATE_IPA_SSA
f517b36e 337 && !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)))
bcfddb5b 338 g->get_passes ()->execute_early_local_passes ();
f2c6b33f 339 else if (inline_summary_vec != NULL)
a41f2a28 340 compute_inline_parameters (node, true);
523c1122 341 free_dominance_info (CDI_POST_DOMINATORS);
342 free_dominance_info (CDI_DOMINATORS);
343 pop_cfun ();
4f7a1122 344 cgraph_call_function_insertion_hooks (node);
523c1122 345 break;
346
347 case CGRAPH_STATE_EXPANSION:
348 /* Functions created during expansion shall be compiled
349 directly. */
09fc9532 350 node->process = 0;
4f7a1122 351 cgraph_call_function_insertion_hooks (node);
cf951b1a 352 expand_function (node);
523c1122 353 break;
354
355 default:
356 gcc_unreachable ();
357 break;
358 }
359 }
ff2a5ada 360 free_cgraph_node_set (cgraph_new_nodes);
361 cgraph_new_nodes = NULL;
523c1122 362}
363
9b8fb23a 364/* As an GCC extension we allow redefinition of the function. The
365 semantics when both copies of bodies differ is not well defined.
366 We replace the old body with new body so in unit at a time mode
367 we always use new body, while in normal mode we may end up with
368 old body inlined into some functions and new body expanded and
369 inlined in others.
370
371 ??? It may make more sense to use one body for inlining and other
372 body for expanding the function but this is difficult to do. */
373
15ca8f90 374void
9b8fb23a 375cgraph_reset_node (struct cgraph_node *node)
376{
09fc9532 377 /* If node->process is set, then we have already begun whole-unit analysis.
6329636b 378 This is *not* testing for whether we've already emitted the function.
379 That case can be sort-of legitimately seen with real function redefinition
380 errors. I would argue that the front end should never present us with
381 such a case, but don't enforce that for now. */
09fc9532 382 gcc_assert (!node->process);
9b8fb23a 383
384 /* Reset our data structures so we can analyze the function again. */
385 memset (&node->local, 0, sizeof (node->local));
386 memset (&node->global, 0, sizeof (node->global));
387 memset (&node->rtl, 0, sizeof (node->rtl));
02774f2d 388 node->analyzed = false;
389 node->definition = false;
390 node->alias = false;
391 node->weakref = false;
392 node->cpp_implicit_alias = false;
9b8fb23a 393
9b8fb23a 394 cgraph_node_remove_callees (node);
02774f2d 395 ipa_remove_all_references (&node->ref_list);
9b8fb23a 396}
c08871a9 397
9a2639fc 398/* Return true when there are references to NODE. */
399
400static bool
452659af 401referred_to_p (symtab_node *node)
9a2639fc 402{
9a2639fc 403 struct ipa_ref *ref;
404
9d75589a 405 /* See if there are any references at all. */
02774f2d 406 if (ipa_ref_list_referring_iterate (&node->ref_list, 0, ref))
9a2639fc 407 return true;
cf951b1a 408 /* For functions check also calls. */
2dc9831f 409 cgraph_node *cn = dyn_cast <cgraph_node> (node);
410 if (cn && cn->callers)
9a2639fc 411 return true;
412 return false;
413}
414
28df663b 415/* DECL has been parsed. Take it, queue it, compile it at the whim of the
1f7747bd 416 logic in effect. If NO_COLLECT is true, then our caller cannot stand to have
28df663b 417 the garbage collector run at the moment. We would need to either create
418 a new GC context, or just not compile right now. */
ae01b312 419
420void
1f7747bd 421cgraph_finalize_function (tree decl, bool no_collect)
ae01b312 422{
5a90471f 423 struct cgraph_node *node = cgraph_get_create_node (decl);
ae01b312 424
02774f2d 425 if (node->definition)
443089c1 426 {
1f7747bd 427 /* Nested functions should only be defined once. */
428 gcc_assert (!DECL_CONTEXT (decl)
429 || TREE_CODE (DECL_CONTEXT (decl)) != FUNCTION_DECL);
443089c1 430 cgraph_reset_node (node);
431 node->local.redefined_extern_inline = true;
432 }
28df663b 433
c08871a9 434 notice_global_symbol (decl);
02774f2d 435 node->definition = true;
e27482aa 436 node->lowered = DECL_STRUCT_FUNCTION (decl)->cfg != NULL;
ae01b312 437
8efa224a 438 /* With -fkeep-inline-functions we are keeping all inline functions except
439 for extern inline ones. */
440 if (flag_keep_inline_functions
441 && DECL_DECLARED_INLINE_P (decl)
442 && !DECL_EXTERNAL (decl)
443 && !DECL_DISREGARD_INLINE_LIMITS (decl))
02774f2d 444 node->force_output = 1;
2c0b522d 445
8efa224a 446 /* When not optimizing, also output the static functions. (see
447 PR24561), but don't do so for always_inline functions, functions
448 declared inline and nested functions. These were optimized out
449 in the original implementation and it is unclear whether we want
450 to change the behavior here. */
451 if ((!optimize
02774f2d 452 && !node->cpp_implicit_alias
8efa224a 453 && !DECL_DISREGARD_INLINE_LIMITS (decl)
454 && !DECL_DECLARED_INLINE_P (decl)
455 && !(DECL_CONTEXT (decl)
456 && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL))
457 && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl))
02774f2d 458 node->force_output = 1;
8efa224a 459
2c0b522d 460 /* If we've not yet emitted decl, tell the debug info about it. */
28df663b 461 if (!TREE_ASM_WRITTEN (decl))
2c0b522d 462 (*debug_hooks->deferred_inline_function) (decl);
4e8871a0 463
b69eb0ff 464 /* Possibly warn about unused parameters. */
465 if (warn_unused_parameter)
466 do_warn_unused_parameter (decl);
6329636b 467
1f7747bd 468 if (!no_collect)
6329636b 469 ggc_collect ();
9a2639fc 470
471 if (cgraph_state == CGRAPH_STATE_CONSTRUCTION
02774f2d 472 && (decide_is_symbol_needed (node)
473 || referred_to_p (node)))
474 enqueue_node (node);
ae01b312 475}
476
3db65b62 477/* Add the function FNDECL to the call graph.
478 Unlike cgraph_finalize_function, this function is intended to be used
479 by middle end and allows insertion of new function at arbitrary point
480 of compilation. The function can be either in high, low or SSA form
481 GIMPLE.
482
483 The function is assumed to be reachable and have address taken (so no
484 API breaking optimizations are performed on it).
485
486 Main work done by this function is to enqueue the function for later
487 processing to avoid need the passes to be re-entrant. */
488
489void
490cgraph_add_new_function (tree fndecl, bool lowered)
491{
3ea50c01 492 gcc::pass_manager *passes = g->get_passes ();
3db65b62 493 struct cgraph_node *node;
494 switch (cgraph_state)
495 {
ff2a5ada 496 case CGRAPH_STATE_PARSING:
497 cgraph_finalize_function (fndecl, false);
498 break;
3db65b62 499 case CGRAPH_STATE_CONSTRUCTION:
500 /* Just enqueue function to be processed at nearest occurrence. */
501 node = cgraph_create_node (fndecl);
3db65b62 502 if (lowered)
503 node->lowered = true;
ff2a5ada 504 if (!cgraph_new_nodes)
505 cgraph_new_nodes = cgraph_node_set_new ();
506 cgraph_node_set_add (cgraph_new_nodes, node);
3db65b62 507 break;
508
509 case CGRAPH_STATE_IPA:
510 case CGRAPH_STATE_IPA_SSA:
511 case CGRAPH_STATE_EXPANSION:
512 /* Bring the function into finalized state and enqueue for later
513 analyzing and compilation. */
514 node = cgraph_get_create_node (fndecl);
515 node->local.local = false;
02774f2d 516 node->definition = true;
517 node->force_output = true;
3db65b62 518 if (!lowered && cgraph_state == CGRAPH_STATE_EXPANSION)
519 {
520 push_cfun (DECL_STRUCT_FUNCTION (fndecl));
3db65b62 521 gimple_register_cfg_hooks ();
522 bitmap_obstack_initialize (NULL);
3ea50c01 523 execute_pass_list (passes->all_lowering_passes);
bcfddb5b 524 passes->execute_early_local_passes ();
3db65b62 525 bitmap_obstack_release (NULL);
526 pop_cfun ();
3db65b62 527
528 lowered = true;
529 }
530 if (lowered)
531 node->lowered = true;
ff2a5ada 532 if (!cgraph_new_nodes)
533 cgraph_new_nodes = cgraph_node_set_new ();
534 cgraph_node_set_add (cgraph_new_nodes, node);
3db65b62 535 break;
536
537 case CGRAPH_STATE_FINISHED:
538 /* At the very end of compilation we have to do all the work up
539 to expansion. */
540 node = cgraph_create_node (fndecl);
541 if (lowered)
542 node->lowered = true;
02774f2d 543 node->definition = true;
15ca8f90 544 analyze_function (node);
3db65b62 545 push_cfun (DECL_STRUCT_FUNCTION (fndecl));
3db65b62 546 gimple_register_cfg_hooks ();
547 bitmap_obstack_initialize (NULL);
548 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)))
bcfddb5b 549 g->get_passes ()->execute_early_local_passes ();
3db65b62 550 bitmap_obstack_release (NULL);
3db65b62 551 pop_cfun ();
cf951b1a 552 expand_function (node);
3db65b62 553 break;
554
555 default:
556 gcc_unreachable ();
557 }
558
559 /* Set a personality if required and we already passed EH lowering. */
560 if (lowered
561 && (function_needs_eh_personality (DECL_STRUCT_FUNCTION (fndecl))
562 == eh_personality_lang))
563 DECL_FUNCTION_PERSONALITY (fndecl) = lang_hooks.eh_personality ();
564}
565
cf951b1a 566/* Add a top-level asm statement to the list. */
567
568struct asm_node *
569add_asm_node (tree asm_str)
570{
571 struct asm_node *node;
572
573 node = ggc_alloc_cleared_asm_node ();
574 node->asm_str = asm_str;
575 node->order = symtab_order++;
576 node->next = NULL;
577 if (asm_nodes == NULL)
578 asm_nodes = node;
579 else
580 asm_last_node->next = node;
581 asm_last_node = node;
582 return node;
583}
584
56af936e 585/* Output all asm statements we have stored up to be output. */
586
587static void
cf951b1a 588output_asm_statements (void)
56af936e 589{
cf951b1a 590 struct asm_node *can;
56af936e 591
852f689e 592 if (seen_error ())
56af936e 593 return;
594
cf951b1a 595 for (can = asm_nodes; can; can = can->next)
56af936e 596 assemble_asm (can->asm_str);
cf951b1a 597 asm_nodes = NULL;
598}
599
0785e435 600/* Analyze the function scheduled to be output. */
da5e1e7c 601static void
15ca8f90 602analyze_function (struct cgraph_node *node)
0785e435 603{
02774f2d 604 tree decl = node->decl;
da5e1e7c 605 location_t saved_loc = input_location;
606 input_location = DECL_SOURCE_LOCATION (decl);
0785e435 607
6e1aa353 608 if (node->thunk.thunk_p)
91bf9d9a 609 {
610 cgraph_create_edge (node, cgraph_get_node (node->thunk.alias),
6e1aa353 611 NULL, 0, CGRAPH_FREQ_BASE);
612 if (!expand_thunk (node, false))
613 {
614 node->thunk.alias = NULL;
02774f2d 615 node->analyzed = true;
6e1aa353 616 return;
617 }
48669653 618 node->thunk.alias = NULL;
91bf9d9a 619 }
02774f2d 620 if (node->alias)
6e1aa353 621 symtab_resolve_alias
02774f2d 622 (node, cgraph_get_node (node->alias_target));
cc8ef84f 623 else if (node->dispatcher_function)
624 {
625 /* Generate the dispatcher body of multi-versioned functions. */
626 struct cgraph_function_version_info *dispatcher_version_info
627 = get_cgraph_node_version (node);
628 if (dispatcher_version_info != NULL
629 && (dispatcher_version_info->dispatcher_resolver
630 == NULL_TREE))
631 {
632 tree resolver = NULL_TREE;
633 gcc_assert (targetm.generate_version_dispatcher_body);
634 resolver = targetm.generate_version_dispatcher_body (node);
635 gcc_assert (resolver != NULL_TREE);
636 }
637 }
91bf9d9a 638 else
639 {
91bf9d9a 640 push_cfun (DECL_STRUCT_FUNCTION (decl));
bfec3452 641
02774f2d 642 assign_assembler_name_if_neeeded (node->decl);
6816d0c4 643
91bf9d9a 644 /* Make sure to gimplify bodies only once. During analyzing a
645 function we lower it, which will require gimplified nested
646 functions, so we can end up here with an already gimplified
647 body. */
e3a19533 648 if (!gimple_has_body_p (decl))
91bf9d9a 649 gimplify_function_tree (decl);
650 dump_function (TDI_generic, decl);
bfec3452 651
47199071 652 /* Lower the function. */
653 if (!node->lowered)
654 {
655 if (node->nested)
02774f2d 656 lower_nested_functions (node->decl);
47199071 657 gcc_assert (!node->nested);
658
659 gimple_register_cfg_hooks ();
660 bitmap_obstack_initialize (NULL);
3ea50c01 661 execute_pass_list (g->get_passes ()->all_lowering_passes);
47199071 662 free_dominance_info (CDI_POST_DOMINATORS);
663 free_dominance_info (CDI_DOMINATORS);
664 compact_blocks ();
665 bitmap_obstack_release (NULL);
666 node->lowered = true;
667 }
668
91bf9d9a 669 pop_cfun ();
670 }
02774f2d 671 node->analyzed = true;
0785e435 672
da5e1e7c 673 input_location = saved_loc;
0785e435 674}
675
c70f46b0 676/* C++ frontend produce same body aliases all over the place, even before PCH
677 gets streamed out. It relies on us linking the aliases with their function
678 in order to do the fixups, but ipa-ref is not PCH safe. Consequentely we
679 first produce aliases without links, but once C++ FE is sure he won't sream
680 PCH we build the links via this function. */
681
682void
683cgraph_process_same_body_aliases (void)
684{
452659af 685 symtab_node *node;
48669653 686 FOR_EACH_SYMBOL (node)
02774f2d 687 if (node->cpp_implicit_alias && !node->analyzed)
a55453ec 688 symtab_resolve_alias
689 (node,
02774f2d 690 TREE_CODE (node->alias_target) == VAR_DECL
452659af 691 ? (symtab_node *)varpool_node_for_decl (node->alias_target)
692 : (symtab_node *)cgraph_get_create_node (node->alias_target));
48669653 693 cpp_implicit_aliases_done = true;
c70f46b0 694}
695
d05db70d 696/* Process attributes common for vars and functions. */
697
698static void
699process_common_attributes (tree decl)
700{
701 tree weakref = lookup_attribute ("weakref", DECL_ATTRIBUTES (decl));
702
703 if (weakref && !lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
704 {
705 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wattributes,
706 "%<weakref%> attribute should be accompanied with"
707 " an %<alias%> attribute");
708 DECL_WEAK (decl) = 0;
40b32d93 709 DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
710 DECL_ATTRIBUTES (decl));
d05db70d 711 }
712}
713
05806473 714/* Look for externally_visible and used attributes and mark cgraph nodes
715 accordingly.
716
717 We cannot mark the nodes at the point the attributes are processed (in
718 handle_*_attribute) because the copy of the declarations available at that
719 point may not be canonical. For example, in:
720
721 void f();
722 void f() __attribute__((used));
723
724 the declaration we see in handle_used_attribute will be the second
725 declaration -- but the front end will subsequently merge that declaration
726 with the original declaration and discard the second declaration.
727
728 Furthermore, we can't mark these nodes in cgraph_finalize_function because:
729
730 void f() {}
731 void f() __attribute__((externally_visible));
732
733 is valid.
734
735 So, we walk the nodes at the end of the translation unit, applying the
736 attributes at that point. */
737
738static void
739process_function_and_variable_attributes (struct cgraph_node *first,
1d416bd7 740 struct varpool_node *first_var)
05806473 741{
742 struct cgraph_node *node;
1d416bd7 743 struct varpool_node *vnode;
05806473 744
0704fb2e 745 for (node = cgraph_first_function (); node != first;
746 node = cgraph_next_function (node))
05806473 747 {
02774f2d 748 tree decl = node->decl;
83a23b05 749 if (DECL_PRESERVE_P (decl))
8efa224a 750 cgraph_mark_force_output_node (node);
62433d51 751 else if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (decl)))
05806473 752 {
02774f2d 753 if (! TREE_PUBLIC (node->decl))
754 warning_at (DECL_SOURCE_LOCATION (node->decl), OPT_Wattributes,
712d2297 755 "%<externally_visible%>"
756 " attribute have effect only on public objects");
05806473 757 }
40b32d93 758 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))
02774f2d 759 && (node->definition && !node->alias))
40b32d93 760 {
02774f2d 761 warning_at (DECL_SOURCE_LOCATION (node->decl), OPT_Wattributes,
40b32d93 762 "%<weakref%> attribute ignored"
763 " because function is defined");
764 DECL_WEAK (decl) = 0;
765 DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
766 DECL_ATTRIBUTES (decl));
767 }
a522e9eb 768
769 if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (decl))
770 && !DECL_DECLARED_INLINE_P (decl)
771 /* redefining extern inline function makes it DECL_UNINLINABLE. */
772 && !DECL_UNINLINABLE (decl))
773 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wattributes,
774 "always_inline function might not be inlinable");
775
d05db70d 776 process_common_attributes (decl);
05806473 777 }
0704fb2e 778 for (vnode = varpool_first_variable (); vnode != first_var;
779 vnode = varpool_next_variable (vnode))
05806473 780 {
02774f2d 781 tree decl = vnode->decl;
aa419a52 782 if (DECL_EXTERNAL (decl)
df8d3e89 783 && DECL_INITIAL (decl))
aa419a52 784 varpool_finalize_decl (decl);
83a23b05 785 if (DECL_PRESERVE_P (decl))
02774f2d 786 vnode->force_output = true;
62433d51 787 else if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (decl)))
05806473 788 {
02774f2d 789 if (! TREE_PUBLIC (vnode->decl))
790 warning_at (DECL_SOURCE_LOCATION (vnode->decl), OPT_Wattributes,
712d2297 791 "%<externally_visible%>"
792 " attribute have effect only on public objects");
05806473 793 }
40b32d93 794 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))
02774f2d 795 && vnode->definition
40b32d93 796 && DECL_INITIAL (decl))
797 {
02774f2d 798 warning_at (DECL_SOURCE_LOCATION (vnode->decl), OPT_Wattributes,
40b32d93 799 "%<weakref%> attribute ignored"
800 " because variable is initialized");
801 DECL_WEAK (decl) = 0;
802 DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
803 DECL_ATTRIBUTES (decl));
804 }
d05db70d 805 process_common_attributes (decl);
05806473 806 }
807}
808
ff2a5ada 809/* Mark DECL as finalized. By finalizing the declaration, frontend instruct the
810 middle end to output the variable to asm file, if needed or externally
811 visible. */
812
813void
814varpool_finalize_decl (tree decl)
815{
2dc9831f 816 struct varpool_node *node = varpool_node_for_decl (decl);
ff2a5ada 817
2d4bf241 818 gcc_assert (TREE_STATIC (decl) || DECL_EXTERNAL (decl));
ff2a5ada 819
02774f2d 820 if (node->definition)
ff2a5ada 821 return;
822 notice_global_symbol (decl);
02774f2d 823 node->definition = true;
ff2a5ada 824 if (TREE_THIS_VOLATILE (decl) || DECL_PRESERVE_P (decl)
825 /* Traditionally we do not eliminate static variables when not
826 optimizing and when not doing toplevel reoder. */
02774f2d 827 || (!flag_toplevel_reorder && !DECL_COMDAT (node->decl)
828 && !DECL_ARTIFICIAL (node->decl)))
829 node->force_output = true;
ff2a5ada 830
831 if (cgraph_state == CGRAPH_STATE_CONSTRUCTION
02774f2d 832 && (decide_is_symbol_needed (node)
833 || referred_to_p (node)))
834 enqueue_node (node);
ff2a5ada 835 if (cgraph_state >= CGRAPH_STATE_IPA_SSA)
836 varpool_analyze_node (node);
3d1c0354 837 /* Some frontends produce various interface variables after compilation
838 finished. */
19b928d9 839 if (cgraph_state == CGRAPH_STATE_FINISHED
840 || (!flag_toplevel_reorder && cgraph_state == CGRAPH_STATE_EXPANSION))
3d1c0354 841 varpool_assemble_decl (node);
ff2a5ada 842}
843
98e7a67f 844/* EDGE is an polymorphic call. Mark all possible targets as reachable
845 and if there is only one target, perform trivial devirtualization.
846 REACHABLE_CALL_TARGETS collects target lists we already walked to
847 avoid udplicate work. */
848
849static void
850walk_polymorphic_call_targets (pointer_set_t *reachable_call_targets,
851 struct cgraph_edge *edge)
852{
853 unsigned int i;
854 void *cache_token;
855 bool final;
856 vec <cgraph_node *>targets
857 = possible_polymorphic_call_targets
858 (edge, &final, &cache_token);
859
860 if (!pointer_set_insert (reachable_call_targets,
861 cache_token))
862 {
863 if (cgraph_dump_file)
864 dump_possible_polymorphic_call_targets
865 (cgraph_dump_file, edge);
866
9af5ce0c 867 for (i = 0; i < targets.length (); i++)
98e7a67f 868 {
869 /* Do not bother to mark virtual methods in anonymous namespace;
870 either we will find use of virtual table defining it, or it is
871 unused. */
02774f2d 872 if (targets[i]->definition
98e7a67f 873 && TREE_CODE
02774f2d 874 (TREE_TYPE (targets[i]->decl))
98e7a67f 875 == METHOD_TYPE
876 && !type_in_anonymous_namespace_p
877 (method_class_type
02774f2d 878 (TREE_TYPE (targets[i]->decl))))
879 enqueue_node (targets[i]);
98e7a67f 880 }
881 }
882
883 /* Very trivial devirtualization; when the type is
884 final or anonymous (so we know all its derivation)
885 and there is only one possible virtual call target,
886 make the edge direct. */
887 if (final)
888 {
9af5ce0c 889 if (targets.length () <= 1)
98e7a67f 890 {
e2fa5d74 891 cgraph_node *target;
892 if (targets.length () == 1)
893 target = targets[0];
894 else
895 target = cgraph_get_create_node
896 (builtin_decl_implicit (BUILT_IN_UNREACHABLE));
897
98e7a67f 898 if (cgraph_dump_file)
899 {
900 fprintf (cgraph_dump_file,
901 "Devirtualizing call: ");
902 print_gimple_stmt (cgraph_dump_file,
903 edge->call_stmt, 0,
904 TDF_SLIM);
905 }
e2fa5d74 906 cgraph_make_edge_direct (edge, target);
98e7a67f 907 cgraph_redirect_edge_call_stmt_to_callee (edge);
908 if (cgraph_dump_file)
909 {
910 fprintf (cgraph_dump_file,
911 "Devirtualized as: ");
912 print_gimple_stmt (cgraph_dump_file,
913 edge->call_stmt, 0,
914 TDF_SLIM);
915 }
916 }
917 }
918}
919
2dc9831f 920
ff2a5ada 921/* Discover all functions and variables that are trivially needed, analyze
922 them as well as all functions and variables referred by them */
ae01b312 923
aeeb194b 924static void
15ca8f90 925analyze_functions (void)
ae01b312 926{
c1dcd13c 927 /* Keep track of already processed nodes when called multiple times for
06b27565 928 intermodule optimization. */
c1dcd13c 929 static struct cgraph_node *first_analyzed;
ff2a5ada 930 struct cgraph_node *first_handled = first_analyzed;
1d416bd7 931 static struct varpool_node *first_analyzed_var;
ff2a5ada 932 struct varpool_node *first_handled_var = first_analyzed_var;
5514adf9 933 struct pointer_set_t *reachable_call_targets = pointer_set_create ();
ff2a5ada 934
452659af 935 symtab_node *node;
936 symtab_node *next;
ff2a5ada 937 int i;
938 struct ipa_ref *ref;
939 bool changed = true;
fd9fde78 940 location_t saved_loc = input_location;
ae01b312 941
f1c35659 942 bitmap_obstack_initialize (NULL);
ff2a5ada 943 cgraph_state = CGRAPH_STATE_CONSTRUCTION;
fd9fde78 944 input_location = UNKNOWN_LOCATION;
ae01b312 945
48669653 946 /* Ugly, but the fixup can not happen at a time same body alias is created;
947 C++ FE is confused about the COMDAT groups being right. */
948 if (cpp_implicit_aliases_done)
949 FOR_EACH_SYMBOL (node)
02774f2d 950 if (node->cpp_implicit_alias)
48669653 951 fixup_same_cpp_alias_visibility (node, symtab_alias_target (node));
5514adf9 952 if (optimize && flag_devirtualize)
953 build_type_inheritance_graph ();
48669653 954
ff2a5ada 955 /* Analysis adds static variables that in turn adds references to new functions.
956 So we need to iterate the process until it stabilize. */
957 while (changed)
ae01b312 958 {
ff2a5ada 959 changed = false;
960 process_function_and_variable_attributes (first_analyzed,
961 first_analyzed_var);
962
963 /* First identify the trivially needed symbols. */
964 for (node = symtab_nodes;
02774f2d 965 node != first_analyzed
966 && node != first_analyzed_var; node = node->next)
9b8fb23a 967 {
6a1c0403 968 if (decide_is_symbol_needed (node))
ff2a5ada 969 {
970 enqueue_node (node);
971 if (!changed && cgraph_dump_file)
972 fprintf (cgraph_dump_file, "Trivially needed symbols:");
973 changed = true;
974 if (cgraph_dump_file)
f1c8b4d7 975 fprintf (cgraph_dump_file, " %s", node->asm_name ());
5514adf9 976 if (!changed && cgraph_dump_file)
977 fprintf (cgraph_dump_file, "\n");
ff2a5ada 978 }
02774f2d 979 if (node == first_analyzed
980 || node == first_analyzed_var)
ff2a5ada 981 break;
9b8fb23a 982 }
ff2a5ada 983 cgraph_process_new_functions ();
984 first_analyzed_var = varpool_first_variable ();
985 first_analyzed = cgraph_first_function ();
638531ad 986
ff2a5ada 987 if (changed && dump_file)
988 fprintf (cgraph_dump_file, "\n");
2c0b522d 989
ff2a5ada 990 /* Lower representation, build callgraph edges and references for all trivially
991 needed symbols and all symbols referred by them. */
3cb3fce5 992 while (queued_nodes != &symtab_terminator)
61c2c7b1 993 {
ff2a5ada 994 changed = true;
3cb3fce5 995 node = queued_nodes;
996 queued_nodes = (symtab_node *)queued_nodes->aux;
2dc9831f 997 cgraph_node *cnode = dyn_cast <cgraph_node> (node);
02774f2d 998 if (cnode && cnode->definition)
ff2a5ada 999 {
1000 struct cgraph_edge *edge;
02774f2d 1001 tree decl = cnode->decl;
ff2a5ada 1002
2dc9831f 1003 /* ??? It is possible to create extern inline function
1004 and later using weak alias attribute to kill its body.
1005 See gcc.c-torture/compile/20011119-1.c */
ff2a5ada 1006 if (!DECL_STRUCT_FUNCTION (decl)
02774f2d 1007 && !cnode->alias
cc8ef84f 1008 && !cnode->thunk.thunk_p
1009 && !cnode->dispatcher_function)
ff2a5ada 1010 {
1011 cgraph_reset_node (cnode);
1012 cnode->local.redefined_extern_inline = true;
1013 continue;
1014 }
61c2c7b1 1015
02774f2d 1016 if (!cnode->analyzed)
15ca8f90 1017 analyze_function (cnode);
d544ceff 1018
ff2a5ada 1019 for (edge = cnode->callees; edge; edge = edge->next_callee)
02774f2d 1020 if (edge->callee->definition)
1021 enqueue_node (edge->callee);
5514adf9 1022 if (optimize && flag_devirtualize)
1023 {
1e4f4118 1024 struct cgraph_edge *next;
98e7a67f 1025
1026 for (edge = cnode->indirect_calls; edge; edge = next)
1e4f4118 1027 {
1028 next = edge->next_callee;
1029 if (edge->indirect_info->polymorphic)
98e7a67f 1030 walk_polymorphic_call_targets (reachable_call_targets,
1031 edge);
1e4f4118 1032 }
5514adf9 1033 }
ff2a5ada 1034
2dc9831f 1035 /* If decl is a clone of an abstract function,
1036 mark that abstract function so that we don't release its body.
1037 The DECL_INITIAL() of that abstract function declaration
1038 will be later needed to output debug info. */
ff2a5ada 1039 if (DECL_ABSTRACT_ORIGIN (decl))
1040 {
2dc9831f 1041 struct cgraph_node *origin_node
1042 = cgraph_get_node (DECL_ABSTRACT_ORIGIN (decl));
abb1a237 1043 origin_node->used_as_abstract_origin = true;
ff2a5ada 1044 }
ff2a5ada 1045 }
2dc9831f 1046 else
1047 {
1048 varpool_node *vnode = dyn_cast <varpool_node> (node);
02774f2d 1049 if (vnode && vnode->definition && !vnode->analyzed)
2dc9831f 1050 varpool_analyze_node (vnode);
1051 }
ff2a5ada 1052
02774f2d 1053 if (node->same_comdat_group)
ff2a5ada 1054 {
452659af 1055 symtab_node *next;
02774f2d 1056 for (next = node->same_comdat_group;
ff2a5ada 1057 next != node;
02774f2d 1058 next = next->same_comdat_group)
ff2a5ada 1059 enqueue_node (next);
1060 }
02774f2d 1061 for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list, i, ref); i++)
1062 if (ref->referred->definition)
ff2a5ada 1063 enqueue_node (ref->referred);
1064 cgraph_process_new_functions ();
1065 }
ae01b312 1066 }
07c6dcc3 1067 if (optimize && flag_devirtualize)
1068 update_type_inheritance_graph ();
2c0b522d 1069
aa5e06c7 1070 /* Collect entry points to the unit. */
f79b6507 1071 if (cgraph_dump_file)
3d7bfc56 1072 {
e4200070 1073 fprintf (cgraph_dump_file, "\n\nInitial ");
18841b0c 1074 dump_symtab (cgraph_dump_file);
3d7bfc56 1075 }
e6d2b2d8 1076
f79b6507 1077 if (cgraph_dump_file)
ff2a5ada 1078 fprintf (cgraph_dump_file, "\nRemoving unused symbols:");
ae01b312 1079
ff2a5ada 1080 for (node = symtab_nodes;
02774f2d 1081 node != first_handled
1082 && node != first_handled_var; node = next)
ae01b312 1083 {
02774f2d 1084 next = node->next;
1085 if (!node->aux && !referred_to_p (node))
ae01b312 1086 {
f79b6507 1087 if (cgraph_dump_file)
f1c8b4d7 1088 fprintf (cgraph_dump_file, " %s", node->name ());
ff2a5ada 1089 symtab_remove_node (node);
9b8fb23a 1090 continue;
ae01b312 1091 }
2dc9831f 1092 if (cgraph_node *cnode = dyn_cast <cgraph_node> (node))
ff2a5ada 1093 {
02774f2d 1094 tree decl = node->decl;
ff2a5ada 1095
02774f2d 1096 if (cnode->definition && !gimple_has_body_p (decl)
1097 && !cnode->alias
ff2a5ada 1098 && !cnode->thunk.thunk_p)
1099 cgraph_reset_node (cnode);
1100
02774f2d 1101 gcc_assert (!cnode->definition || cnode->thunk.thunk_p
1102 || cnode->alias
ff2a5ada 1103 || gimple_has_body_p (decl));
02774f2d 1104 gcc_assert (cnode->analyzed == cnode->definition);
ff2a5ada 1105 }
02774f2d 1106 node->aux = NULL;
ae01b312 1107 }
02774f2d 1108 for (;node; node = node->next)
1109 node->aux = NULL;
ff2a5ada 1110 first_analyzed = cgraph_first_function ();
1111 first_analyzed_var = varpool_first_variable ();
f79b6507 1112 if (cgraph_dump_file)
e4200070 1113 {
1114 fprintf (cgraph_dump_file, "\n\nReclaimed ");
18841b0c 1115 dump_symtab (cgraph_dump_file);
e4200070 1116 }
f1c35659 1117 bitmap_obstack_release (NULL);
5514adf9 1118 pointer_set_destroy (reachable_call_targets);
ae01b312 1119 ggc_collect ();
d5b66e83 1120 /* Initialize assembler name hash, in particular we want to trigger C++
1121 mangling and same body alias creation before we free DECL_ARGUMENTS
1122 used by it. */
1123 if (!seen_error ())
e2fa5d74 1124 symtab_initialize_asm_name_hash ();
fd9fde78 1125
1126 input_location = saved_loc;
aeeb194b 1127}
1128
3a849bc1 1129/* Translate the ugly representation of aliases as alias pairs into nice
1130 representation in callgraph. We don't handle all cases yet,
a3ddd82f 1131 unfortunately. */
3a849bc1 1132
1133static void
1134handle_alias_pairs (void)
1135{
1136 alias_pair *p;
1137 unsigned i;
3a849bc1 1138
f1f41a6c 1139 for (i = 0; alias_pairs && alias_pairs->iterate (i, &p);)
3a849bc1 1140 {
452659af 1141 symtab_node *target_node = symtab_node_for_asm (p->target);
48c84ee3 1142
a3ddd82f 1143 /* Weakrefs with target not defined in current unit are easy to handle:
1144 they behave just as external variables except we need to note the
1145 alias flag to later output the weakref pseudo op into asm file. */
1146 if (!target_node
1147 && lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)) != NULL)
badeded8 1148 {
452659af 1149 symtab_node *node = symtab_get_node (p->decl);
48669653 1150 if (node)
fc8456b4 1151 {
02774f2d 1152 node->alias_target = p->target;
1153 node->weakref = true;
1154 node->alias = true;
fc8456b4 1155 }
f1f41a6c 1156 alias_pairs->unordered_remove (i);
48c84ee3 1157 continue;
badeded8 1158 }
48c84ee3 1159 else if (!target_node)
3a849bc1 1160 {
48c84ee3 1161 error ("%q+D aliased to undefined symbol %qE", p->decl, p->target);
452659af 1162 symtab_node *node = symtab_get_node (p->decl);
a3ddd82f 1163 if (node)
02774f2d 1164 node->alias = false;
f1f41a6c 1165 alias_pairs->unordered_remove (i);
48c84ee3 1166 continue;
1167 }
1168
02774f2d 1169 if (DECL_EXTERNAL (target_node->decl)
afea39ad 1170 /* We use local aliases for C++ thunks to force the tailcall
1171 to bind locally. This is a hack - to keep it working do
1172 the following (which is not strictly correct). */
02774f2d 1173 && (! TREE_CODE (target_node->decl) == FUNCTION_DECL
1174 || ! DECL_VIRTUAL_P (target_node->decl))
afea39ad 1175 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
1176 {
1177 error ("%q+D aliased to external symbol %qE",
1178 p->decl, p->target);
1179 }
1180
48c84ee3 1181 if (TREE_CODE (p->decl) == FUNCTION_DECL
2dc9831f 1182 && target_node && is_a <cgraph_node> (target_node))
48c84ee3 1183 {
1184 struct cgraph_node *src_node = cgraph_get_node (p->decl);
02774f2d 1185 if (src_node && src_node->definition)
48c84ee3 1186 cgraph_reset_node (src_node);
02774f2d 1187 cgraph_create_function_alias (p->decl, target_node->decl);
f1f41a6c 1188 alias_pairs->unordered_remove (i);
48c84ee3 1189 }
1190 else if (TREE_CODE (p->decl) == VAR_DECL
2dc9831f 1191 && target_node && is_a <varpool_node> (target_node))
48c84ee3 1192 {
02774f2d 1193 varpool_create_variable_alias (p->decl, target_node->decl);
f1f41a6c 1194 alias_pairs->unordered_remove (i);
48c84ee3 1195 }
1196 else
1197 {
1198 error ("%q+D alias in between function and variable is not supported",
1199 p->decl);
1200 warning (0, "%q+D aliased declaration",
02774f2d 1201 target_node->decl);
f1f41a6c 1202 alias_pairs->unordered_remove (i);
3a849bc1 1203 }
1204 }
f1f41a6c 1205 vec_free (alias_pairs);
3a849bc1 1206}
1207
8f69fd82 1208
ae01b312 1209/* Figure out what functions we want to assemble. */
1210
1211static void
cf951b1a 1212mark_functions_to_output (void)
ae01b312 1213{
1214 struct cgraph_node *node;
61c2c7b1 1215#ifdef ENABLE_CHECKING
1216 bool check_same_comdat_groups = false;
1217
7c455d87 1218 FOR_EACH_FUNCTION (node)
61c2c7b1 1219 gcc_assert (!node->process);
1220#endif
ae01b312 1221
7c455d87 1222 FOR_EACH_FUNCTION (node)
ae01b312 1223 {
02774f2d 1224 tree decl = node->decl;
a0c938f0 1225
02774f2d 1226 gcc_assert (!node->process || node->same_comdat_group);
61c2c7b1 1227 if (node->process)
1228 continue;
d7c6d889 1229
e6d2b2d8 1230 /* We need to output all local functions that are used and not
1231 always inlined, as well as those that are reachable from
1232 outside the current compilation unit. */
02774f2d 1233 if (node->analyzed
91bf9d9a 1234 && !node->thunk.thunk_p
02774f2d 1235 && !node->alias
b0cdf642 1236 && !node->global.inlined_to
4ee9c684 1237 && !TREE_ASM_WRITTEN (decl)
ae01b312 1238 && !DECL_EXTERNAL (decl))
61c2c7b1 1239 {
1240 node->process = 1;
02774f2d 1241 if (node->same_comdat_group)
61c2c7b1 1242 {
1243 struct cgraph_node *next;
02774f2d 1244 for (next = cgraph (node->same_comdat_group);
61c2c7b1 1245 next != node;
02774f2d 1246 next = cgraph (next->same_comdat_group))
1247 if (!next->thunk.thunk_p && !next->alias)
91bf9d9a 1248 next->process = 1;
61c2c7b1 1249 }
1250 }
02774f2d 1251 else if (node->same_comdat_group)
61c2c7b1 1252 {
1253#ifdef ENABLE_CHECKING
1254 check_same_comdat_groups = true;
1255#endif
1256 }
cc636d56 1257 else
9cee7c3f 1258 {
1259 /* We should've reclaimed all functions that are not needed. */
1260#ifdef ENABLE_CHECKING
75a70cf9 1261 if (!node->global.inlined_to
1a1a827a 1262 && gimple_has_body_p (decl)
08843223 1263 /* FIXME: in ltrans unit when offline copy is outside partition but inline copies
1264 are inside partition, we can end up not removing the body since we no longer
1265 have analyzed node pointing to it. */
02774f2d 1266 && !node->in_other_partition
1267 && !node->alias
2d4bf241 1268 && !node->clones
9cee7c3f 1269 && !DECL_EXTERNAL (decl))
1270 {
1271 dump_cgraph_node (stderr, node);
1272 internal_error ("failed to reclaim unneeded function");
1273 }
1274#endif
75a70cf9 1275 gcc_assert (node->global.inlined_to
1a1a827a 1276 || !gimple_has_body_p (decl)
02774f2d 1277 || node->in_other_partition
aa419a52 1278 || node->clones
1279 || DECL_ARTIFICIAL (decl)
9cee7c3f 1280 || DECL_EXTERNAL (decl));
1281
1282 }
a0c938f0 1283
961e3b13 1284 }
61c2c7b1 1285#ifdef ENABLE_CHECKING
1286 if (check_same_comdat_groups)
7c455d87 1287 FOR_EACH_FUNCTION (node)
02774f2d 1288 if (node->same_comdat_group && !node->process)
61c2c7b1 1289 {
02774f2d 1290 tree decl = node->decl;
61c2c7b1 1291 if (!node->global.inlined_to
1292 && gimple_has_body_p (decl)
6d36105a 1293 /* FIXME: in an ltrans unit when the offline copy is outside a
1294 partition but inline copies are inside a partition, we can
1295 end up not removing the body since we no longer have an
1296 analyzed node pointing to it. */
02774f2d 1297 && !node->in_other_partition
afea39ad 1298 && !node->clones
61c2c7b1 1299 && !DECL_EXTERNAL (decl))
1300 {
1301 dump_cgraph_node (stderr, node);
6d36105a 1302 internal_error ("failed to reclaim unneeded function in same "
1303 "comdat group");
61c2c7b1 1304 }
1305 }
1306#endif
961e3b13 1307}
1308
28454517 1309/* DECL is FUNCTION_DECL. Initialize datastructures so DECL is a function
cc8ef84f 1310 in lowered gimple form. IN_SSA is true if the gimple is in SSA.
28454517 1311
1312 Set current_function_decl and cfun to newly constructed empty function body.
1313 return basic block in the function body. */
1314
cc8ef84f 1315basic_block
1316init_lowered_empty_function (tree decl, bool in_ssa)
28454517 1317{
1318 basic_block bb;
1319
1320 current_function_decl = decl;
1321 allocate_struct_function (decl, false);
1322 gimple_register_cfg_hooks ();
1323 init_empty_tree_cfg ();
cc8ef84f 1324
1325 if (in_ssa)
1326 {
1327 init_tree_ssa (cfun);
1328 init_ssa_operands (cfun);
1329 cfun->gimple_df->in_ssa_p = true;
7eacb0dd 1330 cfun->curr_properties |= PROP_ssa;
cc8ef84f 1331 }
1332
28454517 1333 DECL_INITIAL (decl) = make_node (BLOCK);
1334
1335 DECL_SAVED_TREE (decl) = error_mark_node;
7eacb0dd 1336 cfun->curr_properties |= (PROP_gimple_lcf | PROP_gimple_leh | PROP_gimple_any
1337 | PROP_cfg | PROP_loops);
1338
1339 set_loops_for_fn (cfun, ggc_alloc_cleared_loops ());
1340 init_loops_structure (cfun, loops_for_fn (cfun), 1);
1341 loops_for_fn (cfun)->state |= LOOPS_MAY_HAVE_MULTIPLE_LATCHES;
28454517 1342
1343 /* Create BB for body of the function and connect it properly. */
34154e27 1344 bb = create_basic_block (NULL, (void *) 0, ENTRY_BLOCK_PTR_FOR_FN (cfun));
1345 make_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb, EDGE_FALLTHRU);
1346 make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
1347 add_bb_to_loop (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->loop_father);
28454517 1348
1349 return bb;
1350}
1351
1352/* Adjust PTR by the constant FIXED_OFFSET, and by the vtable
1353 offset indicated by VIRTUAL_OFFSET, if that is
1354 non-null. THIS_ADJUSTING is nonzero for a this adjusting thunk and
1355 zero for a result adjusting thunk. */
1356
1357static tree
1358thunk_adjust (gimple_stmt_iterator * bsi,
1359 tree ptr, bool this_adjusting,
1360 HOST_WIDE_INT fixed_offset, tree virtual_offset)
1361{
1362 gimple stmt;
1363 tree ret;
1364
55d6cb23 1365 if (this_adjusting
1366 && fixed_offset != 0)
28454517 1367 {
2cc66f2a 1368 stmt = gimple_build_assign
1369 (ptr, fold_build_pointer_plus_hwi_loc (input_location,
1370 ptr,
1371 fixed_offset));
28454517 1372 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1373 }
1374
1375 /* If there's a virtual offset, look up that value in the vtable and
1376 adjust the pointer again. */
1377 if (virtual_offset)
1378 {
1379 tree vtabletmp;
1380 tree vtabletmp2;
1381 tree vtabletmp3;
28454517 1382
1383 if (!vtable_entry_type)
1384 {
1385 tree vfunc_type = make_node (FUNCTION_TYPE);
1386 TREE_TYPE (vfunc_type) = integer_type_node;
1387 TYPE_ARG_TYPES (vfunc_type) = NULL_TREE;
1388 layout_type (vfunc_type);
1389
1390 vtable_entry_type = build_pointer_type (vfunc_type);
1391 }
1392
1393 vtabletmp =
072f7ab1 1394 create_tmp_reg (build_pointer_type
37ffa8fe 1395 (build_pointer_type (vtable_entry_type)), "vptr");
28454517 1396
1397 /* The vptr is always at offset zero in the object. */
1398 stmt = gimple_build_assign (vtabletmp,
1399 build1 (NOP_EXPR, TREE_TYPE (vtabletmp),
1400 ptr));
1401 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
28454517 1402
1403 /* Form the vtable address. */
072f7ab1 1404 vtabletmp2 = create_tmp_reg (TREE_TYPE (TREE_TYPE (vtabletmp)),
37ffa8fe 1405 "vtableaddr");
28454517 1406 stmt = gimple_build_assign (vtabletmp2,
182cf5a9 1407 build_simple_mem_ref (vtabletmp));
28454517 1408 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
28454517 1409
1410 /* Find the entry with the vcall offset. */
1411 stmt = gimple_build_assign (vtabletmp2,
2cc66f2a 1412 fold_build_pointer_plus_loc (input_location,
1413 vtabletmp2,
1414 virtual_offset));
28454517 1415 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1416
1417 /* Get the offset itself. */
072f7ab1 1418 vtabletmp3 = create_tmp_reg (TREE_TYPE (TREE_TYPE (vtabletmp2)),
37ffa8fe 1419 "vcalloffset");
28454517 1420 stmt = gimple_build_assign (vtabletmp3,
182cf5a9 1421 build_simple_mem_ref (vtabletmp2));
28454517 1422 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
28454517 1423
28454517 1424 /* Adjust the `this' pointer. */
a0553bff 1425 ptr = fold_build_pointer_plus_loc (input_location, ptr, vtabletmp3);
1426 ptr = force_gimple_operand_gsi (bsi, ptr, true, NULL_TREE, false,
1427 GSI_CONTINUE_LINKING);
28454517 1428 }
1429
55d6cb23 1430 if (!this_adjusting
1431 && fixed_offset != 0)
28454517 1432 /* Adjust the pointer by the constant. */
1433 {
1434 tree ptrtmp;
1435
1436 if (TREE_CODE (ptr) == VAR_DECL)
1437 ptrtmp = ptr;
1438 else
1439 {
072f7ab1 1440 ptrtmp = create_tmp_reg (TREE_TYPE (ptr), "ptr");
28454517 1441 stmt = gimple_build_assign (ptrtmp, ptr);
1442 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
28454517 1443 }
2cc66f2a 1444 ptr = fold_build_pointer_plus_hwi_loc (input_location,
1445 ptrtmp, fixed_offset);
28454517 1446 }
1447
1448 /* Emit the statement and gimplify the adjustment expression. */
072f7ab1 1449 ret = create_tmp_reg (TREE_TYPE (ptr), "adjusted_this");
28454517 1450 stmt = gimple_build_assign (ret, ptr);
28454517 1451 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1452
1453 return ret;
1454}
1455
6e1aa353 1456/* Expand thunk NODE to gimple if possible.
1457 When OUTPUT_ASM_THUNK is true, also produce assembler for
1458 thunks that are not lowered. */
28454517 1459
6e1aa353 1460bool
1461expand_thunk (struct cgraph_node *node, bool output_asm_thunks)
28454517 1462{
1463 bool this_adjusting = node->thunk.this_adjusting;
1464 HOST_WIDE_INT fixed_offset = node->thunk.fixed_offset;
1465 HOST_WIDE_INT virtual_value = node->thunk.virtual_value;
1466 tree virtual_offset = NULL;
02774f2d 1467 tree alias = node->callees->callee->decl;
1468 tree thunk_fndecl = node->decl;
bb251465 1469 tree a;
1470
aed6e608 1471
28454517 1472 if (this_adjusting
1473 && targetm.asm_out.can_output_mi_thunk (thunk_fndecl, fixed_offset,
1474 virtual_value, alias))
1475 {
1476 const char *fnname;
1477 tree fn_block;
28b2c6a7 1478 tree restype = TREE_TYPE (TREE_TYPE (thunk_fndecl));
6e1aa353 1479
1480 if (!output_asm_thunks)
1481 return false;
1482
1483 if (in_lto_p)
1484 cgraph_get_body (node);
1485 a = DECL_ARGUMENTS (thunk_fndecl);
28454517 1486
6e1aa353 1487 current_function_decl = thunk_fndecl;
1488
1489 /* Ensure thunks are emitted in their correct sections. */
1490 resolve_unique_section (thunk_fndecl, 0, flag_function_sections);
1491
28454517 1492 DECL_RESULT (thunk_fndecl)
1493 = build_decl (DECL_SOURCE_LOCATION (thunk_fndecl),
28b2c6a7 1494 RESULT_DECL, 0, restype);
6e1aa353 1495 DECL_CONTEXT (DECL_RESULT (thunk_fndecl)) = thunk_fndecl;
22ea3b47 1496 fnname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (thunk_fndecl));
28454517 1497
1498 /* The back end expects DECL_INITIAL to contain a BLOCK, so we
1499 create one. */
1500 fn_block = make_node (BLOCK);
1501 BLOCK_VARS (fn_block) = a;
1502 DECL_INITIAL (thunk_fndecl) = fn_block;
1503 init_function_start (thunk_fndecl);
1504 cfun->is_thunk = 1;
32c7c682 1505 insn_locations_init ();
1506 set_curr_insn_location (DECL_SOURCE_LOCATION (thunk_fndecl));
1507 prologue_location = curr_insn_location ();
28454517 1508 assemble_start_function (thunk_fndecl, fnname);
1509
1510 targetm.asm_out.output_mi_thunk (asm_out_file, thunk_fndecl,
1511 fixed_offset, virtual_value, alias);
1512
1513 assemble_end_function (thunk_fndecl, fnname);
32c7c682 1514 insn_locations_finalize ();
28454517 1515 init_insn_lengths ();
1516 free_after_compilation (cfun);
1517 set_cfun (NULL);
1518 TREE_ASM_WRITTEN (thunk_fndecl) = 1;
91bf9d9a 1519 node->thunk.thunk_p = false;
02774f2d 1520 node->analyzed = false;
28454517 1521 }
1522 else
1523 {
1524 tree restype;
1525 basic_block bb, then_bb, else_bb, return_bb;
1526 gimple_stmt_iterator bsi;
1527 int nargs = 0;
1528 tree arg;
1529 int i;
1530 tree resdecl;
1531 tree restmp = NULL;
28454517 1532
1533 gimple call;
1534 gimple ret;
1535
6e1aa353 1536 if (in_lto_p)
1537 cgraph_get_body (node);
1538 a = DECL_ARGUMENTS (thunk_fndecl);
1539
1540 current_function_decl = thunk_fndecl;
1541
1542 /* Ensure thunks are emitted in their correct sections. */
1543 resolve_unique_section (thunk_fndecl, 0, flag_function_sections);
1544
28454517 1545 DECL_IGNORED_P (thunk_fndecl) = 1;
1546 bitmap_obstack_initialize (NULL);
1547
1548 if (node->thunk.virtual_offset_p)
1549 virtual_offset = size_int (virtual_value);
1550
1551 /* Build the return declaration for the function. */
1552 restype = TREE_TYPE (TREE_TYPE (thunk_fndecl));
1553 if (DECL_RESULT (thunk_fndecl) == NULL_TREE)
1554 {
1555 resdecl = build_decl (input_location, RESULT_DECL, 0, restype);
1556 DECL_ARTIFICIAL (resdecl) = 1;
1557 DECL_IGNORED_P (resdecl) = 1;
1558 DECL_RESULT (thunk_fndecl) = resdecl;
6e1aa353 1559 DECL_CONTEXT (DECL_RESULT (thunk_fndecl)) = thunk_fndecl;
28454517 1560 }
1561 else
1562 resdecl = DECL_RESULT (thunk_fndecl);
1563
cc8ef84f 1564 bb = then_bb = else_bb = return_bb = init_lowered_empty_function (thunk_fndecl, true);
28454517 1565
1566 bsi = gsi_start_bb (bb);
1567
1568 /* Build call to the function being thunked. */
1569 if (!VOID_TYPE_P (restype))
1570 {
f2c6b33f 1571 if (DECL_BY_REFERENCE (resdecl))
1572 restmp = gimple_fold_indirect_ref (resdecl);
1573 else if (!is_gimple_reg_type (restype))
28454517 1574 {
1575 restmp = resdecl;
2ab2ce89 1576 add_local_decl (cfun, restmp);
28454517 1577 BLOCK_VARS (DECL_INITIAL (current_function_decl)) = restmp;
1578 }
1579 else
072f7ab1 1580 restmp = create_tmp_reg (restype, "retval");
28454517 1581 }
1582
1767a056 1583 for (arg = a; arg; arg = DECL_CHAIN (arg))
28454517 1584 nargs++;
c2078b80 1585 auto_vec<tree> vargs (nargs);
28454517 1586 if (this_adjusting)
f1f41a6c 1587 vargs.quick_push (thunk_adjust (&bsi, a, 1, fixed_offset,
1588 virtual_offset));
f2c6b33f 1589 else if (nargs)
f1f41a6c 1590 vargs.quick_push (a);
f2c6b33f 1591
1592 if (nargs)
1593 for (i = 1, arg = DECL_CHAIN (a); i < nargs; i++, arg = DECL_CHAIN (arg))
1594 vargs.quick_push (arg);
28454517 1595 call = gimple_build_call_vec (build_fold_addr_expr_loc (0, alias), vargs);
6e1aa353 1596 node->callees->call_stmt = call;
28454517 1597 gimple_call_set_from_thunk (call, true);
1598 if (restmp)
f2c6b33f 1599 {
1600 gimple_call_set_lhs (call, restmp);
1601 gcc_assert (useless_type_conversion_p (TREE_TYPE (restmp),
1602 TREE_TYPE (TREE_TYPE (alias))));
1603 }
28454517 1604 gsi_insert_after (&bsi, call, GSI_NEW_STMT);
f2c6b33f 1605 if (!(gimple_call_flags (call) & ECF_NORETURN))
1606 {
1607 if (restmp && !this_adjusting
1608 && (fixed_offset || virtual_offset))
1609 {
1610 tree true_label = NULL_TREE;
28454517 1611
f2c6b33f 1612 if (TREE_CODE (TREE_TYPE (restmp)) == POINTER_TYPE)
1613 {
1614 gimple stmt;
1615 /* If the return type is a pointer, we need to
1616 protect against NULL. We know there will be an
1617 adjustment, because that's why we're emitting a
1618 thunk. */
1619 then_bb = create_basic_block (NULL, (void *) 0, bb);
1620 return_bb = create_basic_block (NULL, (void *) 0, then_bb);
1621 else_bb = create_basic_block (NULL, (void *) 0, else_bb);
1622 add_bb_to_loop (then_bb, bb->loop_father);
1623 add_bb_to_loop (return_bb, bb->loop_father);
1624 add_bb_to_loop (else_bb, bb->loop_father);
1625 remove_edge (single_succ_edge (bb));
1626 true_label = gimple_block_label (then_bb);
1627 stmt = gimple_build_cond (NE_EXPR, restmp,
1628 build_zero_cst (TREE_TYPE (restmp)),
1629 NULL_TREE, NULL_TREE);
1630 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1631 make_edge (bb, then_bb, EDGE_TRUE_VALUE);
1632 make_edge (bb, else_bb, EDGE_FALSE_VALUE);
34154e27 1633 make_edge (return_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
f2c6b33f 1634 make_edge (then_bb, return_bb, EDGE_FALLTHRU);
1635 make_edge (else_bb, return_bb, EDGE_FALLTHRU);
1636 bsi = gsi_last_bb (then_bb);
1637 }
28454517 1638
f2c6b33f 1639 restmp = thunk_adjust (&bsi, restmp, /*this_adjusting=*/0,
1640 fixed_offset, virtual_offset);
1641 if (true_label)
1642 {
1643 gimple stmt;
1644 bsi = gsi_last_bb (else_bb);
1645 stmt = gimple_build_assign (restmp,
1646 build_zero_cst (TREE_TYPE (restmp)));
1647 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1648 bsi = gsi_last_bb (return_bb);
1649 }
28454517 1650 }
f2c6b33f 1651 else
1652 gimple_call_set_tail (call, true);
28454517 1653
f2c6b33f 1654 /* Build return value. */
1655 ret = gimple_build_return (restmp);
1656 gsi_insert_after (&bsi, ret, GSI_NEW_STMT);
28454517 1657 }
1658 else
f2c6b33f 1659 {
1660 gimple_call_set_tail (call, true);
1661 remove_edge (single_succ_edge (bb));
1662 }
28454517 1663
6e1aa353 1664 cfun->gimple_df->in_ssa_p = true;
1665 /* FIXME: C++ FE should stop setting TREE_ASM_WRITTEN on thunks. */
1666 TREE_ASM_WRITTEN (thunk_fndecl) = false;
28454517 1667 delete_unreachable_blocks ();
1668 update_ssa (TODO_update_ssa);
f2c6b33f 1669#ifdef ENABLE_CHECKING
1670 verify_flow_info ();
1671#endif
28454517 1672
28454517 1673 /* Since we want to emit the thunk, we explicitly mark its name as
1674 referenced. */
91bf9d9a 1675 node->thunk.thunk_p = false;
6e1aa353 1676 node->lowered = true;
28454517 1677 bitmap_obstack_release (NULL);
1678 }
1679 current_function_decl = NULL;
9078126c 1680 set_cfun (NULL);
6e1aa353 1681 return true;
28454517 1682}
1683
9d75589a 1684/* Assemble thunks and aliases associated to NODE. */
91bf9d9a 1685
1686static void
c70f46b0 1687assemble_thunks_and_aliases (struct cgraph_node *node)
91bf9d9a 1688{
1689 struct cgraph_edge *e;
c70f46b0 1690 int i;
1691 struct ipa_ref *ref;
1692
91bf9d9a 1693 for (e = node->callers; e;)
1694 if (e->caller->thunk.thunk_p)
1695 {
1696 struct cgraph_node *thunk = e->caller;
1697
1698 e = e->next_caller;
c70f46b0 1699 assemble_thunks_and_aliases (thunk);
6e1aa353 1700 expand_thunk (thunk, true);
91bf9d9a 1701 }
1702 else
1703 e = e->next_caller;
02774f2d 1704 for (i = 0; ipa_ref_list_referring_iterate (&node->ref_list,
7d0d0ce1 1705 i, ref); i++)
c70f46b0 1706 if (ref->use == IPA_REF_ALIAS)
1707 {
04ec15fa 1708 struct cgraph_node *alias = ipa_ref_referring_node (ref);
02774f2d 1709 bool saved_written = TREE_ASM_WRITTEN (node->decl);
968b8c52 1710
1711 /* Force assemble_alias to really output the alias this time instead
1712 of buffering it in same alias pairs. */
02774f2d 1713 TREE_ASM_WRITTEN (node->decl) = 1;
1714 do_assemble_alias (alias->decl,
1715 DECL_ASSEMBLER_NAME (node->decl));
c70f46b0 1716 assemble_thunks_and_aliases (alias);
02774f2d 1717 TREE_ASM_WRITTEN (node->decl) = saved_written;
c70f46b0 1718 }
91bf9d9a 1719}
1720
da5e1e7c 1721/* Expand function specified by NODE. */
941366fd 1722
3db65b62 1723static void
cf951b1a 1724expand_function (struct cgraph_node *node)
941366fd 1725{
02774f2d 1726 tree decl = node->decl;
941366fd 1727 location_t saved_loc;
1728
da5e1e7c 1729 /* We ought to not compile any inline clones. */
1730 gcc_assert (!node->global.inlined_to);
1731
1732 announce_function (decl);
1733 node->process = 0;
1734 gcc_assert (node->lowered);
eaad46f2 1735 cgraph_get_body (node);
da5e1e7c 1736
1737 /* Generate RTL for the body of DECL. */
1738
941366fd 1739 timevar_push (TV_REST_OF_COMPILATION);
1740
1741 gcc_assert (cgraph_global_info_ready);
1742
1743 /* Initialize the default bitmap obstack. */
1744 bitmap_obstack_initialize (NULL);
1745
1746 /* Initialize the RTL code for the function. */
da5e1e7c 1747 current_function_decl = decl;
941366fd 1748 saved_loc = input_location;
da5e1e7c 1749 input_location = DECL_SOURCE_LOCATION (decl);
1750 init_function_start (decl);
941366fd 1751
1752 gimple_register_cfg_hooks ();
1753
1754 bitmap_obstack_initialize (&reg_obstack); /* FIXME, only at RTL generation*/
1755
1756 execute_all_ipa_transforms ();
1757
1758 /* Perform all tree transforms and optimizations. */
1759
1760 /* Signal the start of passes. */
1761 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_START, NULL);
1762
3ea50c01 1763 execute_pass_list (g->get_passes ()->all_passes);
941366fd 1764
1765 /* Signal the end of passes. */
1766 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_END, NULL);
1767
1768 bitmap_obstack_release (&reg_obstack);
1769
1770 /* Release the default bitmap obstack. */
1771 bitmap_obstack_release (NULL);
1772
941366fd 1773 /* If requested, warn about function definitions where the function will
1774 return a value (usually of some struct or union type) which itself will
1775 take up a lot of stack space. */
da5e1e7c 1776 if (warn_larger_than && !DECL_EXTERNAL (decl) && TREE_TYPE (decl))
941366fd 1777 {
da5e1e7c 1778 tree ret_type = TREE_TYPE (TREE_TYPE (decl));
941366fd 1779
1780 if (ret_type && TYPE_SIZE_UNIT (ret_type)
1781 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
1782 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
1783 larger_than_size))
1784 {
1785 unsigned int size_as_int
1786 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
1787
1788 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
1789 warning (OPT_Wlarger_than_, "size of return value of %q+D is %u bytes",
da5e1e7c 1790 decl, size_as_int);
941366fd 1791 else
1792 warning (OPT_Wlarger_than_, "size of return value of %q+D is larger than %wd bytes",
da5e1e7c 1793 decl, larger_than_size);
941366fd 1794 }
1795 }
1796
da5e1e7c 1797 gimple_set_body (decl, NULL);
1798 if (DECL_STRUCT_FUNCTION (decl) == 0
1799 && !cgraph_get_node (decl)->origin)
941366fd 1800 {
1801 /* Stop pointing to the local nodes about to be freed.
1802 But DECL_INITIAL must remain nonzero so we know this
1803 was an actual function definition.
1804 For a nested function, this is done in c_pop_function_context.
1805 If rest_of_compilation set this to 0, leave it 0. */
da5e1e7c 1806 if (DECL_INITIAL (decl) != 0)
1807 DECL_INITIAL (decl) = error_mark_node;
941366fd 1808 }
1809
1810 input_location = saved_loc;
1811
1812 ggc_collect ();
1813 timevar_pop (TV_REST_OF_COMPILATION);
f7777314 1814
1815 /* Make sure that BE didn't give up on compiling. */
1816 gcc_assert (TREE_ASM_WRITTEN (decl));
9078126c 1817 set_cfun (NULL);
f7777314 1818 current_function_decl = NULL;
f76f7453 1819
1820 /* It would make a lot more sense to output thunks before function body to get more
cf951b1a 1821 forward and lest backwarding jumps. This however would need solving problem
f76f7453 1822 with comdats. See PR48668. Also aliases must come after function itself to
cf951b1a 1823 make one pass assemblers, like one on AIX, happy. See PR 50689.
f76f7453 1824 FIXME: Perhaps thunks should be move before function IFF they are not in comdat
1825 groups. */
1826 assemble_thunks_and_aliases (node);
1a1a827a 1827 cgraph_release_function_body (node);
1828 /* Eliminate all call edges. This is important so the GIMPLE_CALL no longer
1829 points to the dead function body. */
1830 cgraph_node_remove_callees (node);
02774f2d 1831 ipa_remove_all_references (&node->ref_list);
ae01b312 1832}
1833
acc70efa 1834
d9d9733a 1835/* Expand all functions that must be output.
1836
d7c6d889 1837 Attempt to topologically sort the nodes so function is output when
1838 all called functions are already assembled to allow data to be
91c82c20 1839 propagated across the callgraph. Use a stack to get smaller distance
3927afe0 1840 between a function and its callees (later we may choose to use a more
d7c6d889 1841 sophisticated algorithm for function reordering; we will likely want
1842 to use subsections to make the output functions appear in top-down
1843 order). */
1844
1845static void
cf951b1a 1846expand_all_functions (void)
d7c6d889 1847{
1848 struct cgraph_node *node;
4c36ffe6 1849 struct cgraph_node **order = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
c04e3894 1850 int order_pos, new_order_pos = 0;
d7c6d889 1851 int i;
1852
7771d558 1853 order_pos = ipa_reverse_postorder (order);
cc636d56 1854 gcc_assert (order_pos == cgraph_n_nodes);
d7c6d889 1855
7bd28bba 1856 /* Garbage collector may remove inline clones we eliminate during
b0cdf642 1857 optimization. So we must be sure to not reference them. */
1858 for (i = 0; i < order_pos; i++)
09fc9532 1859 if (order[i]->process)
b0cdf642 1860 order[new_order_pos++] = order[i];
1861
1862 for (i = new_order_pos - 1; i >= 0; i--)
d7c6d889 1863 {
1864 node = order[i];
09fc9532 1865 if (node->process)
d7c6d889 1866 {
09fc9532 1867 node->process = 0;
cf951b1a 1868 expand_function (node);
d7c6d889 1869 }
1870 }
523c1122 1871 cgraph_process_new_functions ();
8a4a28a8 1872 free_gimplify_stack ();
773c5ba7 1873
d7c6d889 1874 free (order);
773c5ba7 1875
d7c6d889 1876}
1877
56af936e 1878/* This is used to sort the node types by the cgraph order number. */
1879
0b09525f 1880enum cgraph_order_sort_kind
1881{
1882 ORDER_UNDEFINED = 0,
1883 ORDER_FUNCTION,
1884 ORDER_VAR,
1885 ORDER_ASM
1886};
1887
56af936e 1888struct cgraph_order_sort
1889{
0b09525f 1890 enum cgraph_order_sort_kind kind;
56af936e 1891 union
1892 {
1893 struct cgraph_node *f;
1d416bd7 1894 struct varpool_node *v;
cf951b1a 1895 struct asm_node *a;
56af936e 1896 } u;
1897};
1898
1899/* Output all functions, variables, and asm statements in the order
1900 according to their order fields, which is the order in which they
1901 appeared in the file. This implements -fno-toplevel-reorder. In
1902 this mode we may output functions and variables which don't really
1903 need to be output. */
1904
1905static void
cf951b1a 1906output_in_order (void)
56af936e 1907{
1908 int max;
56af936e 1909 struct cgraph_order_sort *nodes;
1910 int i;
1911 struct cgraph_node *pf;
1d416bd7 1912 struct varpool_node *pv;
cf951b1a 1913 struct asm_node *pa;
56af936e 1914
0704fb2e 1915 max = symtab_order;
3e1cde87 1916 nodes = XCNEWVEC (struct cgraph_order_sort, max);
56af936e 1917
7c455d87 1918 FOR_EACH_DEFINED_FUNCTION (pf)
56af936e 1919 {
02774f2d 1920 if (pf->process && !pf->thunk.thunk_p && !pf->alias)
56af936e 1921 {
02774f2d 1922 i = pf->order;
56af936e 1923 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1924 nodes[i].kind = ORDER_FUNCTION;
1925 nodes[i].u.f = pf;
1926 }
1927 }
1928
7c455d87 1929 FOR_EACH_DEFINED_VARIABLE (pv)
02774f2d 1930 if (!DECL_EXTERNAL (pv->decl))
aa419a52 1931 {
02774f2d 1932 i = pv->order;
aa419a52 1933 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1934 nodes[i].kind = ORDER_VAR;
1935 nodes[i].u.v = pv;
1936 }
56af936e 1937
cf951b1a 1938 for (pa = asm_nodes; pa; pa = pa->next)
56af936e 1939 {
1940 i = pa->order;
1941 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1942 nodes[i].kind = ORDER_ASM;
1943 nodes[i].u.a = pa;
1944 }
56af936e 1945
304e5318 1946 /* In toplevel reorder mode we output all statics; mark them as needed. */
304e5318 1947
91da0f1c 1948 for (i = 0; i < max; ++i)
1949 if (nodes[i].kind == ORDER_VAR)
1950 varpool_finalize_named_section_flags (nodes[i].u.v);
1951
56af936e 1952 for (i = 0; i < max; ++i)
1953 {
1954 switch (nodes[i].kind)
1955 {
1956 case ORDER_FUNCTION:
09fc9532 1957 nodes[i].u.f->process = 0;
cf951b1a 1958 expand_function (nodes[i].u.f);
56af936e 1959 break;
1960
1961 case ORDER_VAR:
1d416bd7 1962 varpool_assemble_decl (nodes[i].u.v);
56af936e 1963 break;
1964
1965 case ORDER_ASM:
1966 assemble_asm (nodes[i].u.a->asm_str);
1967 break;
1968
1969 case ORDER_UNDEFINED:
1970 break;
1971
1972 default:
1973 gcc_unreachable ();
1974 }
1975 }
4b4ea2db 1976
cf951b1a 1977 asm_nodes = NULL;
3e1cde87 1978 free (nodes);
56af936e 1979}
1980
77fce4cd 1981static void
1982ipa_passes (void)
1983{
3ea50c01 1984 gcc::pass_manager *passes = g->get_passes ();
1985
87d4aa85 1986 set_cfun (NULL);
4b14adf9 1987 current_function_decl = NULL;
75a70cf9 1988 gimple_register_cfg_hooks ();
77fce4cd 1989 bitmap_obstack_initialize (NULL);
59dd4830 1990
c9036234 1991 invoke_plugin_callbacks (PLUGIN_ALL_IPA_PASSES_START, NULL);
1992
59dd4830 1993 if (!in_lto_p)
7b2e8956 1994 {
3ea50c01 1995 execute_ipa_pass_list (passes->all_small_ipa_passes);
7b2e8956 1996 if (seen_error ())
1997 return;
1998 }
9ed5b1f5 1999
941125aa 2000 /* We never run removal of unreachable nodes after early passes. This is
2001 because TODO is run before the subpasses. It is important to remove
2002 the unreachable functions to save works at IPA level and to get LTO
2003 symbol tables right. */
91f0ab48 2004 symtab_remove_unreachable_nodes (true, cgraph_dump_file);
941125aa 2005
7bfefa9d 2006 /* If pass_all_early_optimizations was not scheduled, the state of
2007 the cgraph will not be properly updated. Update it now. */
2008 if (cgraph_state < CGRAPH_STATE_IPA_SSA)
2009 cgraph_state = CGRAPH_STATE_IPA_SSA;
9ed5b1f5 2010
7bfefa9d 2011 if (!in_lto_p)
2012 {
2013 /* Generate coverage variables and constructors. */
2014 coverage_finish ();
2015
2016 /* Process new functions added. */
2017 set_cfun (NULL);
2018 current_function_decl = NULL;
2019 cgraph_process_new_functions ();
7bfefa9d 2020
c9036234 2021 execute_ipa_summary_passes
3ea50c01 2022 ((struct ipa_opt_pass_d *) passes->all_regular_ipa_passes);
8867b500 2023 }
23433d72 2024
2025 /* Some targets need to handle LTO assembler output specially. */
2026 if (flag_generate_lto)
2027 targetm.asm_out.lto_start ();
2028
7bfefa9d 2029 if (!in_lto_p)
2030 ipa_write_summaries ();
2031
23433d72 2032 if (flag_generate_lto)
2033 targetm.asm_out.lto_end ();
2034
b33542ab 2035 if (!flag_ltrans && (in_lto_p || !flag_lto || flag_fat_lto_objects))
3ea50c01 2036 execute_ipa_pass_list (passes->all_regular_ipa_passes);
c9036234 2037 invoke_plugin_callbacks (PLUGIN_ALL_IPA_PASSES_END, NULL);
9ed5b1f5 2038
77fce4cd 2039 bitmap_obstack_release (NULL);
2040}
2041
badeded8 2042
2043/* Return string alias is alias of. */
2044
2045static tree
2046get_alias_symbol (tree decl)
2047{
2048 tree alias = lookup_attribute ("alias", DECL_ATTRIBUTES (decl));
2049 return get_identifier (TREE_STRING_POINTER
2050 (TREE_VALUE (TREE_VALUE (alias))));
2051}
2052
2053
5e712541 2054/* Weakrefs may be associated to external decls and thus not output
9d75589a 2055 at expansion time. Emit all necessary aliases. */
5e712541 2056
5139ff04 2057static void
5e712541 2058output_weakrefs (void)
2059{
452659af 2060 symtab_node *node;
48669653 2061 FOR_EACH_SYMBOL (node)
02774f2d 2062 if (node->alias
2063 && !TREE_ASM_WRITTEN (node->decl)
2064 && node->weakref)
48669653 2065 {
2066 tree target;
2067
2068 /* Weakrefs are special by not requiring target definition in current
2069 compilation unit. It is thus bit hard to work out what we want to
2070 alias.
2071 When alias target is defined, we need to fetch it from symtab reference,
2072 otherwise it is pointed to by alias_target. */
02774f2d 2073 if (node->alias_target)
2074 target = (DECL_P (node->alias_target)
2075 ? DECL_ASSEMBLER_NAME (node->alias_target)
2076 : node->alias_target);
2077 else if (node->analyzed)
2078 target = DECL_ASSEMBLER_NAME (symtab_alias_target (node)->decl);
48669653 2079 else
2080 {
2081 gcc_unreachable ();
02774f2d 2082 target = get_alias_symbol (node->decl);
48669653 2083 }
02774f2d 2084 do_assemble_alias (node->decl, target);
48669653 2085 }
5e712541 2086}
2087
da5e1e7c 2088/* Initialize callgraph dump file. */
34e5cced 2089
121f3051 2090void
2091init_cgraph (void)
2092{
01ec0a6c 2093 if (!cgraph_dump_file)
2094 cgraph_dump_file = dump_begin (TDI_cgraph, NULL);
121f3051 2095}
b5d36404 2096
d2bb3f9d 2097
2098/* Perform simple optimizations based on callgraph. */
2099
2100void
cf951b1a 2101compile (void)
d2bb3f9d 2102{
2103 if (seen_error ())
2104 return;
2105
2106#ifdef ENABLE_CHECKING
3e7775f6 2107 verify_symtab ();
d2bb3f9d 2108#endif
2109
d2bb3f9d 2110 timevar_push (TV_CGRAPHOPT);
2111 if (pre_ipa_mem_report)
2112 {
2113 fprintf (stderr, "Memory consumption before IPA\n");
2114 dump_memory_report (false);
2115 }
2116 if (!quiet_flag)
2117 fprintf (stderr, "Performing interprocedural optimizations\n");
2118 cgraph_state = CGRAPH_STATE_IPA;
2119
cf951b1a 2120 /* If LTO is enabled, initialize the streamer hooks needed by GIMPLE. */
2121 if (flag_lto)
2122 lto_streamer_hooks_init ();
2123
d2bb3f9d 2124 /* Don't run the IPA passes if there was any error or sorry messages. */
2125 if (!seen_error ())
2126 ipa_passes ();
2127
2128 /* Do nothing else if any IPA pass found errors or if we are just streaming LTO. */
2129 if (seen_error ()
2130 || (!in_lto_p && flag_lto && !flag_fat_lto_objects))
2131 {
2132 timevar_pop (TV_CGRAPHOPT);
2133 return;
2134 }
2135
2136 /* This pass remove bodies of extern inline functions we never inlined.
2137 Do this later so other IPA passes see what is really going on. */
91f0ab48 2138 symtab_remove_unreachable_nodes (false, dump_file);
d2bb3f9d 2139 cgraph_global_info_ready = true;
2140 if (cgraph_dump_file)
2141 {
2142 fprintf (cgraph_dump_file, "Optimized ");
18841b0c 2143 dump_symtab (cgraph_dump_file);
d2bb3f9d 2144 }
2145 if (post_ipa_mem_report)
2146 {
2147 fprintf (stderr, "Memory consumption after IPA\n");
2148 dump_memory_report (false);
2149 }
2150 timevar_pop (TV_CGRAPHOPT);
2151
2152 /* Output everything. */
2153 (*debug_hooks->assembly_start) ();
2154 if (!quiet_flag)
2155 fprintf (stderr, "Assembling functions:\n");
2156#ifdef ENABLE_CHECKING
3e7775f6 2157 verify_symtab ();
d2bb3f9d 2158#endif
2159
2160 cgraph_materialize_all_clones ();
2161 bitmap_obstack_initialize (NULL);
3ea50c01 2162 execute_ipa_pass_list (g->get_passes ()->all_late_ipa_passes);
91f0ab48 2163 symtab_remove_unreachable_nodes (true, dump_file);
d2bb3f9d 2164#ifdef ENABLE_CHECKING
3e7775f6 2165 verify_symtab ();
d2bb3f9d 2166#endif
2167 bitmap_obstack_release (NULL);
cf951b1a 2168 mark_functions_to_output ();
d2bb3f9d 2169
4cd8ae4b 2170 /* When weakref support is missing, we autmatically translate all
2171 references to NODE to references to its ultimate alias target.
2172 The renaming mechanizm uses flag IDENTIFIER_TRANSPARENT_ALIAS and
2173 TREE_CHAIN.
2174
2175 Set up this mapping before we output any assembler but once we are sure
2176 that all symbol renaming is done.
2177
2178 FIXME: All this uglyness can go away if we just do renaming at gimple
2179 level by physically rewritting the IL. At the moment we can only redirect
2180 calls, so we need infrastructure for renaming references as well. */
2181#ifndef ASM_OUTPUT_WEAKREF
452659af 2182 symtab_node *node;
4cd8ae4b 2183
2184 FOR_EACH_SYMBOL (node)
02774f2d 2185 if (node->alias
2186 && lookup_attribute ("weakref", DECL_ATTRIBUTES (node->decl)))
4cd8ae4b 2187 {
2188 IDENTIFIER_TRANSPARENT_ALIAS
02774f2d 2189 (DECL_ASSEMBLER_NAME (node->decl)) = 1;
2190 TREE_CHAIN (DECL_ASSEMBLER_NAME (node->decl))
2191 = (node->alias_target ? node->alias_target
2192 : DECL_ASSEMBLER_NAME (symtab_alias_target (node)->decl));
4cd8ae4b 2193 }
2194#endif
2195
d2bb3f9d 2196 cgraph_state = CGRAPH_STATE_EXPANSION;
2197 if (!flag_toplevel_reorder)
cf951b1a 2198 output_in_order ();
d2bb3f9d 2199 else
2200 {
cf951b1a 2201 output_asm_statements ();
d2bb3f9d 2202
cf951b1a 2203 expand_all_functions ();
2204 varpool_output_variables ();
d2bb3f9d 2205 }
2206
2207 cgraph_process_new_functions ();
2208 cgraph_state = CGRAPH_STATE_FINISHED;
afea39ad 2209 output_weakrefs ();
d2bb3f9d 2210
2211 if (cgraph_dump_file)
2212 {
2213 fprintf (cgraph_dump_file, "\nFinal ");
18841b0c 2214 dump_symtab (cgraph_dump_file);
d2bb3f9d 2215 }
2216#ifdef ENABLE_CHECKING
3e7775f6 2217 verify_symtab ();
d2bb3f9d 2218 /* Double check that all inline clones are gone and that all
2219 function bodies have been released from memory. */
2220 if (!seen_error ())
2221 {
2222 struct cgraph_node *node;
2223 bool error_found = false;
2224
7c455d87 2225 FOR_EACH_DEFINED_FUNCTION (node)
2226 if (node->global.inlined_to
02774f2d 2227 || gimple_has_body_p (node->decl))
d2bb3f9d 2228 {
2229 error_found = true;
2230 dump_cgraph_node (stderr, node);
2231 }
2232 if (error_found)
2233 internal_error ("nodes with unreleased memory found");
2234 }
2235#endif
2236}
2237
2238
2239/* Analyze the whole compilation unit once it is parsed completely. */
2240
2241void
cf951b1a 2242finalize_compilation_unit (void)
d2bb3f9d 2243{
2244 timevar_push (TV_CGRAPH);
2245
d2bb3f9d 2246 /* If we're here there's no current function anymore. Some frontends
2247 are lazy in clearing these. */
2248 current_function_decl = NULL;
2249 set_cfun (NULL);
2250
2251 /* Do not skip analyzing the functions if there were errors, we
2252 miss diagnostics for following functions otherwise. */
2253
2254 /* Emit size functions we didn't inline. */
2255 finalize_size_functions ();
2256
2257 /* Mark alias targets necessary and emit diagnostics. */
d2bb3f9d 2258 handle_alias_pairs ();
2259
2260 if (!quiet_flag)
2261 {
2262 fprintf (stderr, "\nAnalyzing compilation unit\n");
2263 fflush (stderr);
2264 }
2265
2266 if (flag_dump_passes)
2267 dump_passes ();
2268
2269 /* Gimplify and lower all functions, compute reachability and
2270 remove unreachable nodes. */
15ca8f90 2271 analyze_functions ();
d2bb3f9d 2272
2273 /* Mark alias targets necessary and emit diagnostics. */
d2bb3f9d 2274 handle_alias_pairs ();
2275
2276 /* Gimplify and lower thunks. */
15ca8f90 2277 analyze_functions ();
d2bb3f9d 2278
2279 /* Finally drive the pass manager. */
cf951b1a 2280 compile ();
d2bb3f9d 2281
2282 timevar_pop (TV_CGRAPH);
2283}
2284
2285
a861fe52 2286#include "gt-cgraphunit.h"