add dbgcnt support for devirt
[official-gcc.git] / gcc / cgraphunit.c
blob4084cc4ec1e5d237ac31a74119cb4a37a66f11b0
1 /* Driver of optimization process
2 Copyright (C) 2003-2014 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* This module implements main driver of compilation process.
23 The main scope of this file is to act as an interface in between
24 tree based frontends and the backend.
26 The front-end is supposed to use following functionality:
28 - cgraph_finalize_function
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.
33 (There is one exception needed for implementing GCC extern inline
34 function.)
36 - varpool_finalize_decl
38 This function has same behavior as the above but is used for static
39 variables.
41 - add_asm_node
43 Insert new toplevel ASM statement
45 - finalize_compilation_unit
47 This function is called once (source level) compilation unit is finalized
48 and it will no longer change.
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.
53 Those are used to discover other necessary functions and variables.
55 At the end the bodies of unreachable functions are removed.
57 The function can be called multiple times when multiple source level
58 compilation units are combined.
60 - compile
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).
68 Compile time:
70 1) Inter-procedural optimization.
71 (ipa_passes)
73 This part is further split into:
75 a) early optimizations. These are local passes executed in
76 the topological order on the callgraph.
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.
83 b) early small interprocedural passes.
85 Those are interprocedural passes executed only at compilation
86 time. These include, for example, transational memory lowering,
87 unreachable code removal and other simple transformations.
89 c) IP analysis stage. All interprocedural passes do their
90 analysis.
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.
98 d) LTO sreaming. When doing LTO, everything important gets
99 streamed into the object file.
101 Compile time and or linktime analysis stage (WPA):
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.
112 Compile time and/or parallel linktime stage (ltrans)
114 Each of the object files is streamed back and compiled
115 separately. Now the function bodies becomes available
116 again.
118 2) Virtual clone materialization
119 (cgraph_materialize_clone)
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
128 All IP passes transform function bodies based on earlier
129 decision of the IP propagation.
131 4) late small IP passes
133 Simple IP passes working within single program partition.
135 5) Expansion
136 (expand_all_functions)
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.
144 Note that with -fno-toplevel-reorder passes 5 and 6
145 are combined together in cgraph_output_in_order.
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.
154 - cgraph_function_versioning
156 produces a copy of function into new one (a version)
157 and apply simple transformations
160 #include "config.h"
161 #include "system.h"
162 #include "coretypes.h"
163 #include "tm.h"
164 #include "tree.h"
165 #include "varasm.h"
166 #include "stor-layout.h"
167 #include "stringpool.h"
168 #include "output.h"
169 #include "rtl.h"
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"
176 #include "gimple.h"
177 #include "gimplify.h"
178 #include "gimple-iterator.h"
179 #include "gimplify-me.h"
180 #include "gimple-ssa.h"
181 #include "tree-cfg.h"
182 #include "tree-into-ssa.h"
183 #include "tree-ssa.h"
184 #include "tree-inline.h"
185 #include "langhooks.h"
186 #include "toplev.h"
187 #include "flags.h"
188 #include "debug.h"
189 #include "target.h"
190 #include "diagnostic.h"
191 #include "params.h"
192 #include "fibheap.h"
193 #include "intl.h"
194 #include "function.h"
195 #include "ipa-prop.h"
196 #include "tree-iterator.h"
197 #include "tree-pass.h"
198 #include "tree-dump.h"
199 #include "gimple-pretty-print.h"
200 #include "output.h"
201 #include "coverage.h"
202 #include "plugin.h"
203 #include "ipa-inline.h"
204 #include "ipa-utils.h"
205 #include "lto-streamer.h"
206 #include "except.h"
207 #include "cfgloop.h"
208 #include "regset.h" /* FIXME: For reg_obstack. */
209 #include "context.h"
210 #include "pass_manager.h"
211 #include "tree-nested.h"
212 #include "gimplify.h"
213 #include "dbgcnt.h"
215 /* Queue of cgraph nodes scheduled to be added into cgraph. This is a
216 secondary queue used during optimization to accommodate passes that
217 may generate new functions that need to be optimized and expanded. */
218 cgraph_node_set cgraph_new_nodes;
220 static void expand_all_functions (void);
221 static void mark_functions_to_output (void);
222 static void expand_function (struct cgraph_node *);
223 static void analyze_function (struct cgraph_node *);
224 static void handle_alias_pairs (void);
226 FILE *cgraph_dump_file;
228 /* Linked list of cgraph asm nodes. */
229 struct asm_node *asm_nodes;
231 /* Last node in cgraph_asm_nodes. */
232 static GTY(()) struct asm_node *asm_last_node;
234 /* Used for vtable lookup in thunk adjusting. */
235 static GTY (()) tree vtable_entry_type;
237 /* Determine if symbol DECL is needed. That is, visible to something
238 either outside this translation unit, something magic in the system
239 configury */
240 bool
241 decide_is_symbol_needed (symtab_node *node)
243 tree decl = node->decl;
245 /* Double check that no one output the function into assembly file
246 early. */
247 gcc_checking_assert (!DECL_ASSEMBLER_NAME_SET_P (decl)
248 || !TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)));
250 if (!node->definition)
251 return false;
253 if (DECL_EXTERNAL (decl))
254 return false;
256 /* If the user told us it is used, then it must be so. */
257 if (node->force_output)
258 return true;
260 /* ABI forced symbols are needed when they are external. */
261 if (node->forced_by_abi && TREE_PUBLIC (decl))
262 return true;
264 /* Keep constructors, destructors and virtual functions. */
265 if (TREE_CODE (decl) == FUNCTION_DECL
266 && (DECL_STATIC_CONSTRUCTOR (decl) || DECL_STATIC_DESTRUCTOR (decl)))
267 return true;
269 /* Externally visible variables must be output. The exception is
270 COMDAT variables that must be output only when they are needed. */
271 if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl))
272 return true;
274 return false;
277 /* Head and terminator of the queue of nodes to be processed while building
278 callgraph. */
280 static symtab_node symtab_terminator;
281 static symtab_node *queued_nodes = &symtab_terminator;
283 /* Add NODE to queue starting at QUEUED_NODES.
284 The queue is linked via AUX pointers and terminated by pointer to 1. */
286 static void
287 enqueue_node (symtab_node *node)
289 if (node->aux)
290 return;
291 gcc_checking_assert (queued_nodes);
292 node->aux = queued_nodes;
293 queued_nodes = node;
296 /* Process CGRAPH_NEW_FUNCTIONS and perform actions necessary to add these
297 functions into callgraph in a way so they look like ordinary reachable
298 functions inserted into callgraph already at construction time. */
300 void
301 cgraph_process_new_functions (void)
303 tree fndecl;
304 struct cgraph_node *node;
305 cgraph_node_set_iterator csi;
307 if (!cgraph_new_nodes)
308 return;
309 handle_alias_pairs ();
310 /* Note that this queue may grow as its being processed, as the new
311 functions may generate new ones. */
312 for (csi = csi_start (cgraph_new_nodes); !csi_end_p (csi); csi_next (&csi))
314 node = csi_node (csi);
315 fndecl = node->decl;
316 switch (cgraph_state)
318 case CGRAPH_STATE_CONSTRUCTION:
319 /* At construction time we just need to finalize function and move
320 it into reachable functions list. */
322 cgraph_finalize_function (fndecl, false);
323 cgraph_call_function_insertion_hooks (node);
324 enqueue_node (node);
325 break;
327 case CGRAPH_STATE_IPA:
328 case CGRAPH_STATE_IPA_SSA:
329 /* When IPA optimization already started, do all essential
330 transformations that has been already performed on the whole
331 cgraph but not on this function. */
333 gimple_register_cfg_hooks ();
334 if (!node->analyzed)
335 analyze_function (node);
336 push_cfun (DECL_STRUCT_FUNCTION (fndecl));
337 if (cgraph_state == CGRAPH_STATE_IPA_SSA
338 && !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)))
339 g->get_passes ()->execute_early_local_passes ();
340 else if (inline_summary_vec != NULL)
341 compute_inline_parameters (node, true);
342 free_dominance_info (CDI_POST_DOMINATORS);
343 free_dominance_info (CDI_DOMINATORS);
344 pop_cfun ();
345 cgraph_call_function_insertion_hooks (node);
346 break;
348 case CGRAPH_STATE_EXPANSION:
349 /* Functions created during expansion shall be compiled
350 directly. */
351 node->process = 0;
352 cgraph_call_function_insertion_hooks (node);
353 expand_function (node);
354 break;
356 default:
357 gcc_unreachable ();
358 break;
361 free_cgraph_node_set (cgraph_new_nodes);
362 cgraph_new_nodes = NULL;
365 /* As an GCC extension we allow redefinition of the function. The
366 semantics when both copies of bodies differ is not well defined.
367 We replace the old body with new body so in unit at a time mode
368 we always use new body, while in normal mode we may end up with
369 old body inlined into some functions and new body expanded and
370 inlined in others.
372 ??? It may make more sense to use one body for inlining and other
373 body for expanding the function but this is difficult to do. */
375 void
376 cgraph_reset_node (struct cgraph_node *node)
378 /* If node->process is set, then we have already begun whole-unit analysis.
379 This is *not* testing for whether we've already emitted the function.
380 That case can be sort-of legitimately seen with real function redefinition
381 errors. I would argue that the front end should never present us with
382 such a case, but don't enforce that for now. */
383 gcc_assert (!node->process);
385 /* Reset our data structures so we can analyze the function again. */
386 memset (&node->local, 0, sizeof (node->local));
387 memset (&node->global, 0, sizeof (node->global));
388 memset (&node->rtl, 0, sizeof (node->rtl));
389 node->analyzed = false;
390 node->definition = false;
391 node->alias = false;
392 node->weakref = false;
393 node->cpp_implicit_alias = false;
395 cgraph_node_remove_callees (node);
396 ipa_remove_all_references (&node->ref_list);
399 /* Return true when there are references to NODE. */
401 static bool
402 referred_to_p (symtab_node *node)
404 struct ipa_ref *ref;
406 /* See if there are any references at all. */
407 if (ipa_ref_list_referring_iterate (&node->ref_list, 0, ref))
408 return true;
409 /* For functions check also calls. */
410 cgraph_node *cn = dyn_cast <cgraph_node *> (node);
411 if (cn && cn->callers)
412 return true;
413 return false;
416 /* DECL has been parsed. Take it, queue it, compile it at the whim of the
417 logic in effect. If NO_COLLECT is true, then our caller cannot stand to have
418 the garbage collector run at the moment. We would need to either create
419 a new GC context, or just not compile right now. */
421 void
422 cgraph_finalize_function (tree decl, bool no_collect)
424 struct cgraph_node *node = cgraph_get_create_node (decl);
426 if (node->definition)
428 /* Nested functions should only be defined once. */
429 gcc_assert (!DECL_CONTEXT (decl)
430 || TREE_CODE (DECL_CONTEXT (decl)) != FUNCTION_DECL);
431 cgraph_reset_node (node);
432 node->local.redefined_extern_inline = true;
435 notice_global_symbol (decl);
436 node->definition = true;
437 node->lowered = DECL_STRUCT_FUNCTION (decl)->cfg != NULL;
439 /* With -fkeep-inline-functions we are keeping all inline functions except
440 for extern inline ones. */
441 if (flag_keep_inline_functions
442 && DECL_DECLARED_INLINE_P (decl)
443 && !DECL_EXTERNAL (decl)
444 && !DECL_DISREGARD_INLINE_LIMITS (decl))
445 node->force_output = 1;
447 /* When not optimizing, also output the static functions. (see
448 PR24561), but don't do so for always_inline functions, functions
449 declared inline and nested functions. These were optimized out
450 in the original implementation and it is unclear whether we want
451 to change the behavior here. */
452 if ((!optimize
453 && !node->cpp_implicit_alias
454 && !DECL_DISREGARD_INLINE_LIMITS (decl)
455 && !DECL_DECLARED_INLINE_P (decl)
456 && !(DECL_CONTEXT (decl)
457 && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL))
458 && !DECL_COMDAT (decl) && !DECL_EXTERNAL (decl))
459 node->force_output = 1;
461 /* If we've not yet emitted decl, tell the debug info about it. */
462 if (!TREE_ASM_WRITTEN (decl))
463 (*debug_hooks->deferred_inline_function) (decl);
465 /* Possibly warn about unused parameters. */
466 if (warn_unused_parameter)
467 do_warn_unused_parameter (decl);
469 if (!no_collect)
470 ggc_collect ();
472 if (cgraph_state == CGRAPH_STATE_CONSTRUCTION
473 && (decide_is_symbol_needed (node)
474 || referred_to_p (node)))
475 enqueue_node (node);
478 /* Add the function FNDECL to the call graph.
479 Unlike cgraph_finalize_function, this function is intended to be used
480 by middle end and allows insertion of new function at arbitrary point
481 of compilation. The function can be either in high, low or SSA form
482 GIMPLE.
484 The function is assumed to be reachable and have address taken (so no
485 API breaking optimizations are performed on it).
487 Main work done by this function is to enqueue the function for later
488 processing to avoid need the passes to be re-entrant. */
490 void
491 cgraph_add_new_function (tree fndecl, bool lowered)
493 gcc::pass_manager *passes = g->get_passes ();
494 struct cgraph_node *node;
495 switch (cgraph_state)
497 case CGRAPH_STATE_PARSING:
498 cgraph_finalize_function (fndecl, false);
499 break;
500 case CGRAPH_STATE_CONSTRUCTION:
501 /* Just enqueue function to be processed at nearest occurrence. */
502 node = cgraph_create_node (fndecl);
503 if (lowered)
504 node->lowered = true;
505 if (!cgraph_new_nodes)
506 cgraph_new_nodes = cgraph_node_set_new ();
507 cgraph_node_set_add (cgraph_new_nodes, node);
508 break;
510 case CGRAPH_STATE_IPA:
511 case CGRAPH_STATE_IPA_SSA:
512 case CGRAPH_STATE_EXPANSION:
513 /* Bring the function into finalized state and enqueue for later
514 analyzing and compilation. */
515 node = cgraph_get_create_node (fndecl);
516 node->local.local = false;
517 node->definition = true;
518 node->force_output = true;
519 if (!lowered && cgraph_state == CGRAPH_STATE_EXPANSION)
521 push_cfun (DECL_STRUCT_FUNCTION (fndecl));
522 gimple_register_cfg_hooks ();
523 bitmap_obstack_initialize (NULL);
524 execute_pass_list (cfun, passes->all_lowering_passes);
525 passes->execute_early_local_passes ();
526 bitmap_obstack_release (NULL);
527 pop_cfun ();
529 lowered = true;
531 if (lowered)
532 node->lowered = true;
533 if (!cgraph_new_nodes)
534 cgraph_new_nodes = cgraph_node_set_new ();
535 cgraph_node_set_add (cgraph_new_nodes, node);
536 break;
538 case CGRAPH_STATE_FINISHED:
539 /* At the very end of compilation we have to do all the work up
540 to expansion. */
541 node = cgraph_create_node (fndecl);
542 if (lowered)
543 node->lowered = true;
544 node->definition = true;
545 analyze_function (node);
546 push_cfun (DECL_STRUCT_FUNCTION (fndecl));
547 gimple_register_cfg_hooks ();
548 bitmap_obstack_initialize (NULL);
549 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (fndecl)))
550 g->get_passes ()->execute_early_local_passes ();
551 bitmap_obstack_release (NULL);
552 pop_cfun ();
553 expand_function (node);
554 break;
556 default:
557 gcc_unreachable ();
560 /* Set a personality if required and we already passed EH lowering. */
561 if (lowered
562 && (function_needs_eh_personality (DECL_STRUCT_FUNCTION (fndecl))
563 == eh_personality_lang))
564 DECL_FUNCTION_PERSONALITY (fndecl) = lang_hooks.eh_personality ();
567 /* Add a top-level asm statement to the list. */
569 struct asm_node *
570 add_asm_node (tree asm_str)
572 struct asm_node *node;
574 node = ggc_cleared_alloc<asm_node> ();
575 node->asm_str = asm_str;
576 node->order = symtab_order++;
577 node->next = NULL;
578 if (asm_nodes == NULL)
579 asm_nodes = node;
580 else
581 asm_last_node->next = node;
582 asm_last_node = node;
583 return node;
586 /* Output all asm statements we have stored up to be output. */
588 static void
589 output_asm_statements (void)
591 struct asm_node *can;
593 if (seen_error ())
594 return;
596 for (can = asm_nodes; can; can = can->next)
597 assemble_asm (can->asm_str);
598 asm_nodes = NULL;
601 /* Analyze the function scheduled to be output. */
602 static void
603 analyze_function (struct cgraph_node *node)
605 tree decl = node->decl;
606 location_t saved_loc = input_location;
607 input_location = DECL_SOURCE_LOCATION (decl);
609 if (node->thunk.thunk_p)
611 cgraph_create_edge (node, cgraph_get_node (node->thunk.alias),
612 NULL, 0, CGRAPH_FREQ_BASE);
613 if (!expand_thunk (node, false))
615 node->thunk.alias = NULL;
616 node->analyzed = true;
617 return;
619 node->thunk.alias = NULL;
621 if (node->alias)
622 symtab_resolve_alias
623 (node, cgraph_get_node (node->alias_target));
624 else if (node->dispatcher_function)
626 /* Generate the dispatcher body of multi-versioned functions. */
627 struct cgraph_function_version_info *dispatcher_version_info
628 = get_cgraph_node_version (node);
629 if (dispatcher_version_info != NULL
630 && (dispatcher_version_info->dispatcher_resolver
631 == NULL_TREE))
633 tree resolver = NULL_TREE;
634 gcc_assert (targetm.generate_version_dispatcher_body);
635 resolver = targetm.generate_version_dispatcher_body (node);
636 gcc_assert (resolver != NULL_TREE);
639 else
641 push_cfun (DECL_STRUCT_FUNCTION (decl));
643 assign_assembler_name_if_neeeded (node->decl);
645 /* Make sure to gimplify bodies only once. During analyzing a
646 function we lower it, which will require gimplified nested
647 functions, so we can end up here with an already gimplified
648 body. */
649 if (!gimple_has_body_p (decl))
650 gimplify_function_tree (decl);
651 dump_function (TDI_generic, decl);
653 /* Lower the function. */
654 if (!node->lowered)
656 if (node->nested)
657 lower_nested_functions (node->decl);
658 gcc_assert (!node->nested);
660 gimple_register_cfg_hooks ();
661 bitmap_obstack_initialize (NULL);
662 execute_pass_list (cfun, g->get_passes ()->all_lowering_passes);
663 free_dominance_info (CDI_POST_DOMINATORS);
664 free_dominance_info (CDI_DOMINATORS);
665 compact_blocks ();
666 bitmap_obstack_release (NULL);
667 node->lowered = true;
670 pop_cfun ();
672 node->analyzed = true;
674 input_location = saved_loc;
677 /* C++ frontend produce same body aliases all over the place, even before PCH
678 gets streamed out. It relies on us linking the aliases with their function
679 in order to do the fixups, but ipa-ref is not PCH safe. Consequentely we
680 first produce aliases without links, but once C++ FE is sure he won't sream
681 PCH we build the links via this function. */
683 void
684 cgraph_process_same_body_aliases (void)
686 symtab_node *node;
687 FOR_EACH_SYMBOL (node)
688 if (node->cpp_implicit_alias && !node->analyzed)
689 symtab_resolve_alias
690 (node,
691 TREE_CODE (node->alias_target) == VAR_DECL
692 ? (symtab_node *)varpool_node_for_decl (node->alias_target)
693 : (symtab_node *)cgraph_get_create_node (node->alias_target));
694 cpp_implicit_aliases_done = true;
697 /* Process attributes common for vars and functions. */
699 static void
700 process_common_attributes (tree decl)
702 tree weakref = lookup_attribute ("weakref", DECL_ATTRIBUTES (decl));
704 if (weakref && !lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
706 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wattributes,
707 "%<weakref%> attribute should be accompanied with"
708 " an %<alias%> attribute");
709 DECL_WEAK (decl) = 0;
710 DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
711 DECL_ATTRIBUTES (decl));
715 /* Look for externally_visible and used attributes and mark cgraph nodes
716 accordingly.
718 We cannot mark the nodes at the point the attributes are processed (in
719 handle_*_attribute) because the copy of the declarations available at that
720 point may not be canonical. For example, in:
722 void f();
723 void f() __attribute__((used));
725 the declaration we see in handle_used_attribute will be the second
726 declaration -- but the front end will subsequently merge that declaration
727 with the original declaration and discard the second declaration.
729 Furthermore, we can't mark these nodes in cgraph_finalize_function because:
731 void f() {}
732 void f() __attribute__((externally_visible));
734 is valid.
736 So, we walk the nodes at the end of the translation unit, applying the
737 attributes at that point. */
739 static void
740 process_function_and_variable_attributes (struct cgraph_node *first,
741 varpool_node *first_var)
743 struct cgraph_node *node;
744 varpool_node *vnode;
746 for (node = cgraph_first_function (); node != first;
747 node = cgraph_next_function (node))
749 tree decl = node->decl;
750 if (DECL_PRESERVE_P (decl))
751 cgraph_mark_force_output_node (node);
752 else if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (decl)))
754 if (! TREE_PUBLIC (node->decl))
755 warning_at (DECL_SOURCE_LOCATION (node->decl), OPT_Wattributes,
756 "%<externally_visible%>"
757 " attribute have effect only on public objects");
759 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))
760 && (node->definition && !node->alias))
762 warning_at (DECL_SOURCE_LOCATION (node->decl), OPT_Wattributes,
763 "%<weakref%> attribute ignored"
764 " because function is defined");
765 DECL_WEAK (decl) = 0;
766 DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
767 DECL_ATTRIBUTES (decl));
770 if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (decl))
771 && !DECL_DECLARED_INLINE_P (decl)
772 /* redefining extern inline function makes it DECL_UNINLINABLE. */
773 && !DECL_UNINLINABLE (decl))
774 warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wattributes,
775 "always_inline function might not be inlinable");
777 process_common_attributes (decl);
779 for (vnode = varpool_first_variable (); vnode != first_var;
780 vnode = varpool_next_variable (vnode))
782 tree decl = vnode->decl;
783 if (DECL_EXTERNAL (decl)
784 && DECL_INITIAL (decl))
785 varpool_finalize_decl (decl);
786 if (DECL_PRESERVE_P (decl))
787 vnode->force_output = true;
788 else if (lookup_attribute ("externally_visible", DECL_ATTRIBUTES (decl)))
790 if (! TREE_PUBLIC (vnode->decl))
791 warning_at (DECL_SOURCE_LOCATION (vnode->decl), OPT_Wattributes,
792 "%<externally_visible%>"
793 " attribute have effect only on public objects");
795 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))
796 && vnode->definition
797 && DECL_INITIAL (decl))
799 warning_at (DECL_SOURCE_LOCATION (vnode->decl), OPT_Wattributes,
800 "%<weakref%> attribute ignored"
801 " because variable is initialized");
802 DECL_WEAK (decl) = 0;
803 DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
804 DECL_ATTRIBUTES (decl));
806 process_common_attributes (decl);
810 /* Mark DECL as finalized. By finalizing the declaration, frontend instruct the
811 middle end to output the variable to asm file, if needed or externally
812 visible. */
814 void
815 varpool_finalize_decl (tree decl)
817 varpool_node *node = varpool_node_for_decl (decl);
819 gcc_assert (TREE_STATIC (decl) || DECL_EXTERNAL (decl));
821 if (node->definition)
822 return;
823 notice_global_symbol (decl);
824 node->definition = true;
825 if (TREE_THIS_VOLATILE (decl) || DECL_PRESERVE_P (decl)
826 /* Traditionally we do not eliminate static variables when not
827 optimizing and when not doing toplevel reoder. */
828 || (!flag_toplevel_reorder && !DECL_COMDAT (node->decl)
829 && !DECL_ARTIFICIAL (node->decl)))
830 node->force_output = true;
832 if (cgraph_state == CGRAPH_STATE_CONSTRUCTION
833 && (decide_is_symbol_needed (node)
834 || referred_to_p (node)))
835 enqueue_node (node);
836 if (cgraph_state >= CGRAPH_STATE_IPA_SSA)
837 varpool_analyze_node (node);
838 /* Some frontends produce various interface variables after compilation
839 finished. */
840 if (cgraph_state == CGRAPH_STATE_FINISHED
841 || (!flag_toplevel_reorder && cgraph_state == CGRAPH_STATE_EXPANSION))
842 varpool_assemble_decl (node);
845 /* EDGE is an polymorphic call. Mark all possible targets as reachable
846 and if there is only one target, perform trivial devirtualization.
847 REACHABLE_CALL_TARGETS collects target lists we already walked to
848 avoid udplicate work. */
850 static void
851 walk_polymorphic_call_targets (pointer_set_t *reachable_call_targets,
852 struct cgraph_edge *edge)
854 unsigned int i;
855 void *cache_token;
856 bool final;
857 vec <cgraph_node *>targets
858 = possible_polymorphic_call_targets
859 (edge, &final, &cache_token);
861 if (!pointer_set_insert (reachable_call_targets,
862 cache_token))
864 if (cgraph_dump_file)
865 dump_possible_polymorphic_call_targets
866 (cgraph_dump_file, edge);
868 for (i = 0; i < targets.length (); i++)
870 /* Do not bother to mark virtual methods in anonymous namespace;
871 either we will find use of virtual table defining it, or it is
872 unused. */
873 if (targets[i]->definition
874 && TREE_CODE
875 (TREE_TYPE (targets[i]->decl))
876 == METHOD_TYPE
877 && !type_in_anonymous_namespace_p
878 (method_class_type
879 (TREE_TYPE (targets[i]->decl))))
880 enqueue_node (targets[i]);
884 /* Very trivial devirtualization; when the type is
885 final or anonymous (so we know all its derivation)
886 and there is only one possible virtual call target,
887 make the edge direct. */
888 if (final)
890 if (targets.length () <= 1 && dbg_cnt (devirt))
892 cgraph_node *target;
893 if (targets.length () == 1)
894 target = targets[0];
895 else
896 target = cgraph_get_create_node
897 (builtin_decl_implicit (BUILT_IN_UNREACHABLE));
899 if (cgraph_dump_file)
901 fprintf (cgraph_dump_file,
902 "Devirtualizing call: ");
903 print_gimple_stmt (cgraph_dump_file,
904 edge->call_stmt, 0,
905 TDF_SLIM);
907 if (dump_enabled_p ())
909 location_t locus = gimple_location (edge->call_stmt);
910 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, locus,
911 "devirtualizing call in %s to %s\n",
912 edge->caller->name (), target->name ());
915 cgraph_make_edge_direct (edge, target);
916 cgraph_redirect_edge_call_stmt_to_callee (edge);
917 if (cgraph_dump_file)
919 fprintf (cgraph_dump_file,
920 "Devirtualized as: ");
921 print_gimple_stmt (cgraph_dump_file,
922 edge->call_stmt, 0,
923 TDF_SLIM);
930 /* Discover all functions and variables that are trivially needed, analyze
931 them as well as all functions and variables referred by them */
933 static void
934 analyze_functions (void)
936 /* Keep track of already processed nodes when called multiple times for
937 intermodule optimization. */
938 static struct cgraph_node *first_analyzed;
939 struct cgraph_node *first_handled = first_analyzed;
940 static varpool_node *first_analyzed_var;
941 varpool_node *first_handled_var = first_analyzed_var;
942 struct pointer_set_t *reachable_call_targets = pointer_set_create ();
944 symtab_node *node;
945 symtab_node *next;
946 int i;
947 struct ipa_ref *ref;
948 bool changed = true;
949 location_t saved_loc = input_location;
951 bitmap_obstack_initialize (NULL);
952 cgraph_state = CGRAPH_STATE_CONSTRUCTION;
953 input_location = UNKNOWN_LOCATION;
955 /* Ugly, but the fixup can not happen at a time same body alias is created;
956 C++ FE is confused about the COMDAT groups being right. */
957 if (cpp_implicit_aliases_done)
958 FOR_EACH_SYMBOL (node)
959 if (node->cpp_implicit_alias)
960 fixup_same_cpp_alias_visibility (node, symtab_alias_target (node));
961 if (optimize && flag_devirtualize)
962 build_type_inheritance_graph ();
964 /* Analysis adds static variables that in turn adds references to new functions.
965 So we need to iterate the process until it stabilize. */
966 while (changed)
968 changed = false;
969 process_function_and_variable_attributes (first_analyzed,
970 first_analyzed_var);
972 /* First identify the trivially needed symbols. */
973 for (node = symtab_nodes;
974 node != first_analyzed
975 && node != first_analyzed_var; node = node->next)
977 if (decide_is_symbol_needed (node))
979 enqueue_node (node);
980 if (!changed && cgraph_dump_file)
981 fprintf (cgraph_dump_file, "Trivially needed symbols:");
982 changed = true;
983 if (cgraph_dump_file)
984 fprintf (cgraph_dump_file, " %s", node->asm_name ());
985 if (!changed && cgraph_dump_file)
986 fprintf (cgraph_dump_file, "\n");
988 if (node == first_analyzed
989 || node == first_analyzed_var)
990 break;
992 cgraph_process_new_functions ();
993 first_analyzed_var = varpool_first_variable ();
994 first_analyzed = cgraph_first_function ();
996 if (changed && cgraph_dump_file)
997 fprintf (cgraph_dump_file, "\n");
999 /* Lower representation, build callgraph edges and references for all trivially
1000 needed symbols and all symbols referred by them. */
1001 while (queued_nodes != &symtab_terminator)
1003 changed = true;
1004 node = queued_nodes;
1005 queued_nodes = (symtab_node *)queued_nodes->aux;
1006 cgraph_node *cnode = dyn_cast <cgraph_node *> (node);
1007 if (cnode && cnode->definition)
1009 struct cgraph_edge *edge;
1010 tree decl = cnode->decl;
1012 /* ??? It is possible to create extern inline function
1013 and later using weak alias attribute to kill its body.
1014 See gcc.c-torture/compile/20011119-1.c */
1015 if (!DECL_STRUCT_FUNCTION (decl)
1016 && !cnode->alias
1017 && !cnode->thunk.thunk_p
1018 && !cnode->dispatcher_function)
1020 cgraph_reset_node (cnode);
1021 cnode->local.redefined_extern_inline = true;
1022 continue;
1025 if (!cnode->analyzed)
1026 analyze_function (cnode);
1028 for (edge = cnode->callees; edge; edge = edge->next_callee)
1029 if (edge->callee->definition)
1030 enqueue_node (edge->callee);
1031 if (optimize && flag_devirtualize)
1033 struct cgraph_edge *next;
1035 for (edge = cnode->indirect_calls; edge; edge = next)
1037 next = edge->next_callee;
1038 if (edge->indirect_info->polymorphic)
1039 walk_polymorphic_call_targets (reachable_call_targets,
1040 edge);
1044 /* If decl is a clone of an abstract function,
1045 mark that abstract function so that we don't release its body.
1046 The DECL_INITIAL() of that abstract function declaration
1047 will be later needed to output debug info. */
1048 if (DECL_ABSTRACT_ORIGIN (decl))
1050 struct cgraph_node *origin_node
1051 = cgraph_get_node (DECL_ABSTRACT_ORIGIN (decl));
1052 origin_node->used_as_abstract_origin = true;
1055 else
1057 varpool_node *vnode = dyn_cast <varpool_node *> (node);
1058 if (vnode && vnode->definition && !vnode->analyzed)
1059 varpool_analyze_node (vnode);
1062 if (node->same_comdat_group)
1064 symtab_node *next;
1065 for (next = node->same_comdat_group;
1066 next != node;
1067 next = next->same_comdat_group)
1068 enqueue_node (next);
1070 for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list, i, ref); i++)
1071 if (ref->referred->definition)
1072 enqueue_node (ref->referred);
1073 cgraph_process_new_functions ();
1076 if (optimize && flag_devirtualize)
1077 update_type_inheritance_graph ();
1079 /* Collect entry points to the unit. */
1080 if (cgraph_dump_file)
1082 fprintf (cgraph_dump_file, "\n\nInitial ");
1083 dump_symtab (cgraph_dump_file);
1086 if (cgraph_dump_file)
1087 fprintf (cgraph_dump_file, "\nRemoving unused symbols:");
1089 for (node = symtab_nodes;
1090 node != first_handled
1091 && node != first_handled_var; node = next)
1093 next = node->next;
1094 if (!node->aux && !referred_to_p (node))
1096 if (cgraph_dump_file)
1097 fprintf (cgraph_dump_file, " %s", node->name ());
1098 symtab_remove_node (node);
1099 continue;
1101 if (cgraph_node *cnode = dyn_cast <cgraph_node *> (node))
1103 tree decl = node->decl;
1105 if (cnode->definition && !gimple_has_body_p (decl)
1106 && !cnode->alias
1107 && !cnode->thunk.thunk_p)
1108 cgraph_reset_node (cnode);
1110 gcc_assert (!cnode->definition || cnode->thunk.thunk_p
1111 || cnode->alias
1112 || gimple_has_body_p (decl));
1113 gcc_assert (cnode->analyzed == cnode->definition);
1115 node->aux = NULL;
1117 for (;node; node = node->next)
1118 node->aux = NULL;
1119 first_analyzed = cgraph_first_function ();
1120 first_analyzed_var = varpool_first_variable ();
1121 if (cgraph_dump_file)
1123 fprintf (cgraph_dump_file, "\n\nReclaimed ");
1124 dump_symtab (cgraph_dump_file);
1126 bitmap_obstack_release (NULL);
1127 pointer_set_destroy (reachable_call_targets);
1128 ggc_collect ();
1129 /* Initialize assembler name hash, in particular we want to trigger C++
1130 mangling and same body alias creation before we free DECL_ARGUMENTS
1131 used by it. */
1132 if (!seen_error ())
1133 symtab_initialize_asm_name_hash ();
1135 input_location = saved_loc;
1138 /* Translate the ugly representation of aliases as alias pairs into nice
1139 representation in callgraph. We don't handle all cases yet,
1140 unfortunately. */
1142 static void
1143 handle_alias_pairs (void)
1145 alias_pair *p;
1146 unsigned i;
1148 for (i = 0; alias_pairs && alias_pairs->iterate (i, &p);)
1150 symtab_node *target_node = symtab_node_for_asm (p->target);
1152 /* Weakrefs with target not defined in current unit are easy to handle:
1153 they behave just as external variables except we need to note the
1154 alias flag to later output the weakref pseudo op into asm file. */
1155 if (!target_node
1156 && lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)) != NULL)
1158 symtab_node *node = symtab_get_node (p->decl);
1159 if (node)
1161 node->alias_target = p->target;
1162 node->weakref = true;
1163 node->alias = true;
1165 alias_pairs->unordered_remove (i);
1166 continue;
1168 else if (!target_node)
1170 error ("%q+D aliased to undefined symbol %qE", p->decl, p->target);
1171 symtab_node *node = symtab_get_node (p->decl);
1172 if (node)
1173 node->alias = false;
1174 alias_pairs->unordered_remove (i);
1175 continue;
1178 if (DECL_EXTERNAL (target_node->decl)
1179 /* We use local aliases for C++ thunks to force the tailcall
1180 to bind locally. This is a hack - to keep it working do
1181 the following (which is not strictly correct). */
1182 && (! TREE_CODE (target_node->decl) == FUNCTION_DECL
1183 || ! DECL_VIRTUAL_P (target_node->decl))
1184 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
1186 error ("%q+D aliased to external symbol %qE",
1187 p->decl, p->target);
1190 if (TREE_CODE (p->decl) == FUNCTION_DECL
1191 && target_node && is_a <cgraph_node *> (target_node))
1193 struct cgraph_node *src_node = cgraph_get_node (p->decl);
1194 if (src_node && src_node->definition)
1195 cgraph_reset_node (src_node);
1196 cgraph_create_function_alias (p->decl, target_node->decl);
1197 alias_pairs->unordered_remove (i);
1199 else if (TREE_CODE (p->decl) == VAR_DECL
1200 && target_node && is_a <varpool_node *> (target_node))
1202 varpool_create_variable_alias (p->decl, target_node->decl);
1203 alias_pairs->unordered_remove (i);
1205 else
1207 error ("%q+D alias in between function and variable is not supported",
1208 p->decl);
1209 warning (0, "%q+D aliased declaration",
1210 target_node->decl);
1211 alias_pairs->unordered_remove (i);
1214 vec_free (alias_pairs);
1218 /* Figure out what functions we want to assemble. */
1220 static void
1221 mark_functions_to_output (void)
1223 struct cgraph_node *node;
1224 #ifdef ENABLE_CHECKING
1225 bool check_same_comdat_groups = false;
1227 FOR_EACH_FUNCTION (node)
1228 gcc_assert (!node->process);
1229 #endif
1231 FOR_EACH_FUNCTION (node)
1233 tree decl = node->decl;
1235 gcc_assert (!node->process || node->same_comdat_group);
1236 if (node->process)
1237 continue;
1239 /* We need to output all local functions that are used and not
1240 always inlined, as well as those that are reachable from
1241 outside the current compilation unit. */
1242 if (node->analyzed
1243 && !node->thunk.thunk_p
1244 && !node->alias
1245 && !node->global.inlined_to
1246 && !TREE_ASM_WRITTEN (decl)
1247 && !DECL_EXTERNAL (decl))
1249 node->process = 1;
1250 if (node->same_comdat_group)
1252 struct cgraph_node *next;
1253 for (next = cgraph (node->same_comdat_group);
1254 next != node;
1255 next = cgraph (next->same_comdat_group))
1256 if (!next->thunk.thunk_p && !next->alias
1257 && !symtab_comdat_local_p (next))
1258 next->process = 1;
1261 else if (node->same_comdat_group)
1263 #ifdef ENABLE_CHECKING
1264 check_same_comdat_groups = true;
1265 #endif
1267 else
1269 /* We should've reclaimed all functions that are not needed. */
1270 #ifdef ENABLE_CHECKING
1271 if (!node->global.inlined_to
1272 && gimple_has_body_p (decl)
1273 /* FIXME: in ltrans unit when offline copy is outside partition but inline copies
1274 are inside partition, we can end up not removing the body since we no longer
1275 have analyzed node pointing to it. */
1276 && !node->in_other_partition
1277 && !node->alias
1278 && !node->clones
1279 && !DECL_EXTERNAL (decl))
1281 dump_cgraph_node (stderr, node);
1282 internal_error ("failed to reclaim unneeded function");
1284 #endif
1285 gcc_assert (node->global.inlined_to
1286 || !gimple_has_body_p (decl)
1287 || node->in_other_partition
1288 || node->clones
1289 || DECL_ARTIFICIAL (decl)
1290 || DECL_EXTERNAL (decl));
1295 #ifdef ENABLE_CHECKING
1296 if (check_same_comdat_groups)
1297 FOR_EACH_FUNCTION (node)
1298 if (node->same_comdat_group && !node->process)
1300 tree decl = node->decl;
1301 if (!node->global.inlined_to
1302 && gimple_has_body_p (decl)
1303 /* FIXME: in an ltrans unit when the offline copy is outside a
1304 partition but inline copies are inside a partition, we can
1305 end up not removing the body since we no longer have an
1306 analyzed node pointing to it. */
1307 && !node->in_other_partition
1308 && !node->clones
1309 && !DECL_EXTERNAL (decl))
1311 dump_cgraph_node (stderr, node);
1312 internal_error ("failed to reclaim unneeded function in same "
1313 "comdat group");
1316 #endif
1319 /* DECL is FUNCTION_DECL. Initialize datastructures so DECL is a function
1320 in lowered gimple form. IN_SSA is true if the gimple is in SSA.
1322 Set current_function_decl and cfun to newly constructed empty function body.
1323 return basic block in the function body. */
1325 basic_block
1326 init_lowered_empty_function (tree decl, bool in_ssa)
1328 basic_block bb;
1330 current_function_decl = decl;
1331 allocate_struct_function (decl, false);
1332 gimple_register_cfg_hooks ();
1333 init_empty_tree_cfg ();
1335 if (in_ssa)
1337 init_tree_ssa (cfun);
1338 init_ssa_operands (cfun);
1339 cfun->gimple_df->in_ssa_p = true;
1340 cfun->curr_properties |= PROP_ssa;
1343 DECL_INITIAL (decl) = make_node (BLOCK);
1345 DECL_SAVED_TREE (decl) = error_mark_node;
1346 cfun->curr_properties |= (PROP_gimple_lcf | PROP_gimple_leh | PROP_gimple_any
1347 | PROP_cfg | PROP_loops);
1349 set_loops_for_fn (cfun, ggc_cleared_alloc<loops> ());
1350 init_loops_structure (cfun, loops_for_fn (cfun), 1);
1351 loops_for_fn (cfun)->state |= LOOPS_MAY_HAVE_MULTIPLE_LATCHES;
1353 /* Create BB for body of the function and connect it properly. */
1354 bb = create_basic_block (NULL, (void *) 0, ENTRY_BLOCK_PTR_FOR_FN (cfun));
1355 make_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb, EDGE_FALLTHRU);
1356 make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
1357 add_bb_to_loop (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->loop_father);
1359 return bb;
1362 /* Adjust PTR by the constant FIXED_OFFSET, and by the vtable
1363 offset indicated by VIRTUAL_OFFSET, if that is
1364 non-null. THIS_ADJUSTING is nonzero for a this adjusting thunk and
1365 zero for a result adjusting thunk. */
1367 static tree
1368 thunk_adjust (gimple_stmt_iterator * bsi,
1369 tree ptr, bool this_adjusting,
1370 HOST_WIDE_INT fixed_offset, tree virtual_offset)
1372 gimple stmt;
1373 tree ret;
1375 if (this_adjusting
1376 && fixed_offset != 0)
1378 stmt = gimple_build_assign
1379 (ptr, fold_build_pointer_plus_hwi_loc (input_location,
1380 ptr,
1381 fixed_offset));
1382 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1385 /* If there's a virtual offset, look up that value in the vtable and
1386 adjust the pointer again. */
1387 if (virtual_offset)
1389 tree vtabletmp;
1390 tree vtabletmp2;
1391 tree vtabletmp3;
1393 if (!vtable_entry_type)
1395 tree vfunc_type = make_node (FUNCTION_TYPE);
1396 TREE_TYPE (vfunc_type) = integer_type_node;
1397 TYPE_ARG_TYPES (vfunc_type) = NULL_TREE;
1398 layout_type (vfunc_type);
1400 vtable_entry_type = build_pointer_type (vfunc_type);
1403 vtabletmp =
1404 create_tmp_reg (build_pointer_type
1405 (build_pointer_type (vtable_entry_type)), "vptr");
1407 /* The vptr is always at offset zero in the object. */
1408 stmt = gimple_build_assign (vtabletmp,
1409 build1 (NOP_EXPR, TREE_TYPE (vtabletmp),
1410 ptr));
1411 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1413 /* Form the vtable address. */
1414 vtabletmp2 = create_tmp_reg (TREE_TYPE (TREE_TYPE (vtabletmp)),
1415 "vtableaddr");
1416 stmt = gimple_build_assign (vtabletmp2,
1417 build_simple_mem_ref (vtabletmp));
1418 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1420 /* Find the entry with the vcall offset. */
1421 stmt = gimple_build_assign (vtabletmp2,
1422 fold_build_pointer_plus_loc (input_location,
1423 vtabletmp2,
1424 virtual_offset));
1425 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1427 /* Get the offset itself. */
1428 vtabletmp3 = create_tmp_reg (TREE_TYPE (TREE_TYPE (vtabletmp2)),
1429 "vcalloffset");
1430 stmt = gimple_build_assign (vtabletmp3,
1431 build_simple_mem_ref (vtabletmp2));
1432 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1434 /* Adjust the `this' pointer. */
1435 ptr = fold_build_pointer_plus_loc (input_location, ptr, vtabletmp3);
1436 ptr = force_gimple_operand_gsi (bsi, ptr, true, NULL_TREE, false,
1437 GSI_CONTINUE_LINKING);
1440 if (!this_adjusting
1441 && fixed_offset != 0)
1442 /* Adjust the pointer by the constant. */
1444 tree ptrtmp;
1446 if (TREE_CODE (ptr) == VAR_DECL)
1447 ptrtmp = ptr;
1448 else
1450 ptrtmp = create_tmp_reg (TREE_TYPE (ptr), "ptr");
1451 stmt = gimple_build_assign (ptrtmp, ptr);
1452 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1454 ptr = fold_build_pointer_plus_hwi_loc (input_location,
1455 ptrtmp, fixed_offset);
1458 /* Emit the statement and gimplify the adjustment expression. */
1459 ret = create_tmp_reg (TREE_TYPE (ptr), "adjusted_this");
1460 stmt = gimple_build_assign (ret, ptr);
1461 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1463 return ret;
1466 /* Expand thunk NODE to gimple if possible.
1467 When OUTPUT_ASM_THUNK is true, also produce assembler for
1468 thunks that are not lowered. */
1470 bool
1471 expand_thunk (struct cgraph_node *node, bool output_asm_thunks)
1473 bool this_adjusting = node->thunk.this_adjusting;
1474 HOST_WIDE_INT fixed_offset = node->thunk.fixed_offset;
1475 HOST_WIDE_INT virtual_value = node->thunk.virtual_value;
1476 tree virtual_offset = NULL;
1477 tree alias = node->callees->callee->decl;
1478 tree thunk_fndecl = node->decl;
1479 tree a;
1482 if (this_adjusting
1483 && targetm.asm_out.can_output_mi_thunk (thunk_fndecl, fixed_offset,
1484 virtual_value, alias))
1486 const char *fnname;
1487 tree fn_block;
1488 tree restype = TREE_TYPE (TREE_TYPE (thunk_fndecl));
1490 if (!output_asm_thunks)
1491 return false;
1493 if (in_lto_p)
1494 cgraph_get_body (node);
1495 a = DECL_ARGUMENTS (thunk_fndecl);
1497 current_function_decl = thunk_fndecl;
1499 /* Ensure thunks are emitted in their correct sections. */
1500 resolve_unique_section (thunk_fndecl, 0, flag_function_sections);
1502 DECL_RESULT (thunk_fndecl)
1503 = build_decl (DECL_SOURCE_LOCATION (thunk_fndecl),
1504 RESULT_DECL, 0, restype);
1505 DECL_CONTEXT (DECL_RESULT (thunk_fndecl)) = thunk_fndecl;
1506 fnname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (thunk_fndecl));
1508 /* The back end expects DECL_INITIAL to contain a BLOCK, so we
1509 create one. */
1510 fn_block = make_node (BLOCK);
1511 BLOCK_VARS (fn_block) = a;
1512 DECL_INITIAL (thunk_fndecl) = fn_block;
1513 init_function_start (thunk_fndecl);
1514 cfun->is_thunk = 1;
1515 insn_locations_init ();
1516 set_curr_insn_location (DECL_SOURCE_LOCATION (thunk_fndecl));
1517 prologue_location = curr_insn_location ();
1518 assemble_start_function (thunk_fndecl, fnname);
1520 targetm.asm_out.output_mi_thunk (asm_out_file, thunk_fndecl,
1521 fixed_offset, virtual_value, alias);
1523 assemble_end_function (thunk_fndecl, fnname);
1524 insn_locations_finalize ();
1525 init_insn_lengths ();
1526 free_after_compilation (cfun);
1527 set_cfun (NULL);
1528 TREE_ASM_WRITTEN (thunk_fndecl) = 1;
1529 node->thunk.thunk_p = false;
1530 node->analyzed = false;
1532 else
1534 tree restype;
1535 basic_block bb, then_bb, else_bb, return_bb;
1536 gimple_stmt_iterator bsi;
1537 int nargs = 0;
1538 tree arg;
1539 int i;
1540 tree resdecl;
1541 tree restmp = NULL;
1543 gimple call;
1544 gimple ret;
1546 if (in_lto_p)
1547 cgraph_get_body (node);
1548 a = DECL_ARGUMENTS (thunk_fndecl);
1550 current_function_decl = thunk_fndecl;
1552 /* Ensure thunks are emitted in their correct sections. */
1553 resolve_unique_section (thunk_fndecl, 0, flag_function_sections);
1555 DECL_IGNORED_P (thunk_fndecl) = 1;
1556 bitmap_obstack_initialize (NULL);
1558 if (node->thunk.virtual_offset_p)
1559 virtual_offset = size_int (virtual_value);
1561 /* Build the return declaration for the function. */
1562 restype = TREE_TYPE (TREE_TYPE (thunk_fndecl));
1563 if (DECL_RESULT (thunk_fndecl) == NULL_TREE)
1565 resdecl = build_decl (input_location, RESULT_DECL, 0, restype);
1566 DECL_ARTIFICIAL (resdecl) = 1;
1567 DECL_IGNORED_P (resdecl) = 1;
1568 DECL_RESULT (thunk_fndecl) = resdecl;
1569 DECL_CONTEXT (DECL_RESULT (thunk_fndecl)) = thunk_fndecl;
1571 else
1572 resdecl = DECL_RESULT (thunk_fndecl);
1574 bb = then_bb = else_bb = return_bb = init_lowered_empty_function (thunk_fndecl, true);
1576 bsi = gsi_start_bb (bb);
1578 /* Build call to the function being thunked. */
1579 if (!VOID_TYPE_P (restype))
1581 if (DECL_BY_REFERENCE (resdecl))
1582 restmp = gimple_fold_indirect_ref (resdecl);
1583 else if (!is_gimple_reg_type (restype))
1585 restmp = resdecl;
1586 add_local_decl (cfun, restmp);
1587 BLOCK_VARS (DECL_INITIAL (current_function_decl)) = restmp;
1589 else
1590 restmp = create_tmp_reg (restype, "retval");
1593 for (arg = a; arg; arg = DECL_CHAIN (arg))
1594 nargs++;
1595 auto_vec<tree> vargs (nargs);
1596 if (this_adjusting)
1597 vargs.quick_push (thunk_adjust (&bsi, a, 1, fixed_offset,
1598 virtual_offset));
1599 else if (nargs)
1600 vargs.quick_push (a);
1602 if (nargs)
1603 for (i = 1, arg = DECL_CHAIN (a); i < nargs; i++, arg = DECL_CHAIN (arg))
1605 tree tmp = arg;
1606 if (!is_gimple_val (arg))
1608 tmp = create_tmp_reg (TYPE_MAIN_VARIANT
1609 (TREE_TYPE (arg)), "arg");
1610 gimple stmt = gimple_build_assign (tmp, arg);
1611 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1613 vargs.quick_push (tmp);
1615 call = gimple_build_call_vec (build_fold_addr_expr_loc (0, alias), vargs);
1616 node->callees->call_stmt = call;
1617 gimple_call_set_from_thunk (call, true);
1618 if (restmp)
1620 gimple_call_set_lhs (call, restmp);
1621 gcc_assert (useless_type_conversion_p (TREE_TYPE (restmp),
1622 TREE_TYPE (TREE_TYPE (alias))));
1624 gsi_insert_after (&bsi, call, GSI_NEW_STMT);
1625 if (!(gimple_call_flags (call) & ECF_NORETURN))
1627 if (restmp && !this_adjusting
1628 && (fixed_offset || virtual_offset))
1630 tree true_label = NULL_TREE;
1632 if (TREE_CODE (TREE_TYPE (restmp)) == POINTER_TYPE)
1634 gimple stmt;
1635 /* If the return type is a pointer, we need to
1636 protect against NULL. We know there will be an
1637 adjustment, because that's why we're emitting a
1638 thunk. */
1639 then_bb = create_basic_block (NULL, (void *) 0, bb);
1640 return_bb = create_basic_block (NULL, (void *) 0, then_bb);
1641 else_bb = create_basic_block (NULL, (void *) 0, else_bb);
1642 add_bb_to_loop (then_bb, bb->loop_father);
1643 add_bb_to_loop (return_bb, bb->loop_father);
1644 add_bb_to_loop (else_bb, bb->loop_father);
1645 remove_edge (single_succ_edge (bb));
1646 true_label = gimple_block_label (then_bb);
1647 stmt = gimple_build_cond (NE_EXPR, restmp,
1648 build_zero_cst (TREE_TYPE (restmp)),
1649 NULL_TREE, NULL_TREE);
1650 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1651 make_edge (bb, then_bb, EDGE_TRUE_VALUE);
1652 make_edge (bb, else_bb, EDGE_FALSE_VALUE);
1653 make_edge (return_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
1654 make_edge (then_bb, return_bb, EDGE_FALLTHRU);
1655 make_edge (else_bb, return_bb, EDGE_FALLTHRU);
1656 bsi = gsi_last_bb (then_bb);
1659 restmp = thunk_adjust (&bsi, restmp, /*this_adjusting=*/0,
1660 fixed_offset, virtual_offset);
1661 if (true_label)
1663 gimple stmt;
1664 bsi = gsi_last_bb (else_bb);
1665 stmt = gimple_build_assign (restmp,
1666 build_zero_cst (TREE_TYPE (restmp)));
1667 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1668 bsi = gsi_last_bb (return_bb);
1671 else
1672 gimple_call_set_tail (call, true);
1674 /* Build return value. */
1675 ret = gimple_build_return (restmp);
1676 gsi_insert_after (&bsi, ret, GSI_NEW_STMT);
1678 else
1680 gimple_call_set_tail (call, true);
1681 remove_edge (single_succ_edge (bb));
1684 cfun->gimple_df->in_ssa_p = true;
1685 /* FIXME: C++ FE should stop setting TREE_ASM_WRITTEN on thunks. */
1686 TREE_ASM_WRITTEN (thunk_fndecl) = false;
1687 delete_unreachable_blocks ();
1688 update_ssa (TODO_update_ssa);
1689 #ifdef ENABLE_CHECKING
1690 verify_flow_info ();
1691 #endif
1693 /* Since we want to emit the thunk, we explicitly mark its name as
1694 referenced. */
1695 node->thunk.thunk_p = false;
1696 node->lowered = true;
1697 bitmap_obstack_release (NULL);
1699 current_function_decl = NULL;
1700 set_cfun (NULL);
1701 return true;
1704 /* Assemble thunks and aliases associated to NODE. */
1706 static void
1707 assemble_thunks_and_aliases (struct cgraph_node *node)
1709 struct cgraph_edge *e;
1710 int i;
1711 struct ipa_ref *ref;
1713 for (e = node->callers; e;)
1714 if (e->caller->thunk.thunk_p)
1716 struct cgraph_node *thunk = e->caller;
1718 e = e->next_caller;
1719 assemble_thunks_and_aliases (thunk);
1720 expand_thunk (thunk, true);
1722 else
1723 e = e->next_caller;
1724 for (i = 0; ipa_ref_list_referring_iterate (&node->ref_list,
1725 i, ref); i++)
1726 if (ref->use == IPA_REF_ALIAS)
1728 struct cgraph_node *alias = ipa_ref_referring_node (ref);
1729 bool saved_written = TREE_ASM_WRITTEN (node->decl);
1731 /* Force assemble_alias to really output the alias this time instead
1732 of buffering it in same alias pairs. */
1733 TREE_ASM_WRITTEN (node->decl) = 1;
1734 do_assemble_alias (alias->decl,
1735 DECL_ASSEMBLER_NAME (node->decl));
1736 assemble_thunks_and_aliases (alias);
1737 TREE_ASM_WRITTEN (node->decl) = saved_written;
1741 /* Expand function specified by NODE. */
1743 static void
1744 expand_function (struct cgraph_node *node)
1746 tree decl = node->decl;
1747 location_t saved_loc;
1749 /* We ought to not compile any inline clones. */
1750 gcc_assert (!node->global.inlined_to);
1752 announce_function (decl);
1753 node->process = 0;
1754 gcc_assert (node->lowered);
1755 cgraph_get_body (node);
1757 /* Generate RTL for the body of DECL. */
1759 timevar_push (TV_REST_OF_COMPILATION);
1761 gcc_assert (cgraph_global_info_ready);
1763 /* Initialize the default bitmap obstack. */
1764 bitmap_obstack_initialize (NULL);
1766 /* Initialize the RTL code for the function. */
1767 current_function_decl = decl;
1768 saved_loc = input_location;
1769 input_location = DECL_SOURCE_LOCATION (decl);
1770 init_function_start (decl);
1772 gimple_register_cfg_hooks ();
1774 bitmap_obstack_initialize (&reg_obstack); /* FIXME, only at RTL generation*/
1776 execute_all_ipa_transforms ();
1778 /* Perform all tree transforms and optimizations. */
1780 /* Signal the start of passes. */
1781 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_START, NULL);
1783 execute_pass_list (cfun, g->get_passes ()->all_passes);
1785 /* Signal the end of passes. */
1786 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_END, NULL);
1788 bitmap_obstack_release (&reg_obstack);
1790 /* Release the default bitmap obstack. */
1791 bitmap_obstack_release (NULL);
1793 /* If requested, warn about function definitions where the function will
1794 return a value (usually of some struct or union type) which itself will
1795 take up a lot of stack space. */
1796 if (warn_larger_than && !DECL_EXTERNAL (decl) && TREE_TYPE (decl))
1798 tree ret_type = TREE_TYPE (TREE_TYPE (decl));
1800 if (ret_type && TYPE_SIZE_UNIT (ret_type)
1801 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
1802 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
1803 larger_than_size))
1805 unsigned int size_as_int
1806 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
1808 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
1809 warning (OPT_Wlarger_than_, "size of return value of %q+D is %u bytes",
1810 decl, size_as_int);
1811 else
1812 warning (OPT_Wlarger_than_, "size of return value of %q+D is larger than %wd bytes",
1813 decl, larger_than_size);
1817 gimple_set_body (decl, NULL);
1818 if (DECL_STRUCT_FUNCTION (decl) == 0
1819 && !cgraph_get_node (decl)->origin)
1821 /* Stop pointing to the local nodes about to be freed.
1822 But DECL_INITIAL must remain nonzero so we know this
1823 was an actual function definition.
1824 For a nested function, this is done in c_pop_function_context.
1825 If rest_of_compilation set this to 0, leave it 0. */
1826 if (DECL_INITIAL (decl) != 0)
1827 DECL_INITIAL (decl) = error_mark_node;
1830 input_location = saved_loc;
1832 ggc_collect ();
1833 timevar_pop (TV_REST_OF_COMPILATION);
1835 /* Make sure that BE didn't give up on compiling. */
1836 gcc_assert (TREE_ASM_WRITTEN (decl));
1837 set_cfun (NULL);
1838 current_function_decl = NULL;
1840 /* It would make a lot more sense to output thunks before function body to get more
1841 forward and lest backwarding jumps. This however would need solving problem
1842 with comdats. See PR48668. Also aliases must come after function itself to
1843 make one pass assemblers, like one on AIX, happy. See PR 50689.
1844 FIXME: Perhaps thunks should be move before function IFF they are not in comdat
1845 groups. */
1846 assemble_thunks_and_aliases (node);
1847 cgraph_release_function_body (node);
1848 /* Eliminate all call edges. This is important so the GIMPLE_CALL no longer
1849 points to the dead function body. */
1850 cgraph_node_remove_callees (node);
1851 ipa_remove_all_references (&node->ref_list);
1854 /* Node comparer that is responsible for the order that corresponds
1855 to time when a function was launched for the first time. */
1857 static int
1858 node_cmp (const void *pa, const void *pb)
1860 const struct cgraph_node *a = *(const struct cgraph_node * const *) pa;
1861 const struct cgraph_node *b = *(const struct cgraph_node * const *) pb;
1863 /* Functions with time profile must be before these without profile. */
1864 if (!a->tp_first_run || !b->tp_first_run)
1865 return a->tp_first_run - b->tp_first_run;
1867 return a->tp_first_run != b->tp_first_run
1868 ? b->tp_first_run - a->tp_first_run
1869 : b->order - a->order;
1872 /* Expand all functions that must be output.
1874 Attempt to topologically sort the nodes so function is output when
1875 all called functions are already assembled to allow data to be
1876 propagated across the callgraph. Use a stack to get smaller distance
1877 between a function and its callees (later we may choose to use a more
1878 sophisticated algorithm for function reordering; we will likely want
1879 to use subsections to make the output functions appear in top-down
1880 order). */
1882 static void
1883 expand_all_functions (void)
1885 struct cgraph_node *node;
1886 struct cgraph_node **order = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
1887 unsigned int expanded_func_count = 0, profiled_func_count = 0;
1888 int order_pos, new_order_pos = 0;
1889 int i;
1891 order_pos = ipa_reverse_postorder (order);
1892 gcc_assert (order_pos == cgraph_n_nodes);
1894 /* Garbage collector may remove inline clones we eliminate during
1895 optimization. So we must be sure to not reference them. */
1896 for (i = 0; i < order_pos; i++)
1897 if (order[i]->process)
1898 order[new_order_pos++] = order[i];
1900 if (flag_profile_reorder_functions)
1901 qsort (order, new_order_pos, sizeof (struct cgraph_node *), node_cmp);
1903 for (i = new_order_pos - 1; i >= 0; i--)
1905 node = order[i];
1907 if (node->process)
1909 expanded_func_count++;
1910 if(node->tp_first_run)
1911 profiled_func_count++;
1913 if (cgraph_dump_file)
1914 fprintf (cgraph_dump_file, "Time profile order in expand_all_functions:%s:%d\n", node->asm_name (), node->tp_first_run);
1916 node->process = 0;
1917 expand_function (node);
1921 if (dump_file)
1922 fprintf (dump_file, "Expanded functions with time profile (%s):%u/%u\n",
1923 main_input_filename, profiled_func_count, expanded_func_count);
1925 if (cgraph_dump_file && flag_profile_reorder_functions)
1926 fprintf (cgraph_dump_file, "Expanded functions with time profile:%u/%u\n",
1927 profiled_func_count, expanded_func_count);
1929 cgraph_process_new_functions ();
1930 free_gimplify_stack ();
1932 free (order);
1935 /* This is used to sort the node types by the cgraph order number. */
1937 enum cgraph_order_sort_kind
1939 ORDER_UNDEFINED = 0,
1940 ORDER_FUNCTION,
1941 ORDER_VAR,
1942 ORDER_ASM
1945 struct cgraph_order_sort
1947 enum cgraph_order_sort_kind kind;
1948 union
1950 struct cgraph_node *f;
1951 varpool_node *v;
1952 struct asm_node *a;
1953 } u;
1956 /* Output all functions, variables, and asm statements in the order
1957 according to their order fields, which is the order in which they
1958 appeared in the file. This implements -fno-toplevel-reorder. In
1959 this mode we may output functions and variables which don't really
1960 need to be output. */
1962 static void
1963 output_in_order (void)
1965 int max;
1966 struct cgraph_order_sort *nodes;
1967 int i;
1968 struct cgraph_node *pf;
1969 varpool_node *pv;
1970 struct asm_node *pa;
1972 max = symtab_order;
1973 nodes = XCNEWVEC (struct cgraph_order_sort, max);
1975 FOR_EACH_DEFINED_FUNCTION (pf)
1977 if (pf->process && !pf->thunk.thunk_p && !pf->alias)
1979 i = pf->order;
1980 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1981 nodes[i].kind = ORDER_FUNCTION;
1982 nodes[i].u.f = pf;
1986 FOR_EACH_DEFINED_VARIABLE (pv)
1987 if (!DECL_EXTERNAL (pv->decl))
1989 i = pv->order;
1990 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1991 nodes[i].kind = ORDER_VAR;
1992 nodes[i].u.v = pv;
1995 for (pa = asm_nodes; pa; pa = pa->next)
1997 i = pa->order;
1998 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1999 nodes[i].kind = ORDER_ASM;
2000 nodes[i].u.a = pa;
2003 /* In toplevel reorder mode we output all statics; mark them as needed. */
2005 for (i = 0; i < max; ++i)
2006 if (nodes[i].kind == ORDER_VAR)
2007 varpool_finalize_named_section_flags (nodes[i].u.v);
2009 for (i = 0; i < max; ++i)
2011 switch (nodes[i].kind)
2013 case ORDER_FUNCTION:
2014 nodes[i].u.f->process = 0;
2015 expand_function (nodes[i].u.f);
2016 break;
2018 case ORDER_VAR:
2019 varpool_assemble_decl (nodes[i].u.v);
2020 break;
2022 case ORDER_ASM:
2023 assemble_asm (nodes[i].u.a->asm_str);
2024 break;
2026 case ORDER_UNDEFINED:
2027 break;
2029 default:
2030 gcc_unreachable ();
2034 asm_nodes = NULL;
2035 free (nodes);
2038 static void
2039 ipa_passes (void)
2041 gcc::pass_manager *passes = g->get_passes ();
2043 set_cfun (NULL);
2044 current_function_decl = NULL;
2045 gimple_register_cfg_hooks ();
2046 bitmap_obstack_initialize (NULL);
2048 invoke_plugin_callbacks (PLUGIN_ALL_IPA_PASSES_START, NULL);
2050 if (!in_lto_p)
2052 execute_ipa_pass_list (passes->all_small_ipa_passes);
2053 if (seen_error ())
2054 return;
2057 /* We never run removal of unreachable nodes after early passes. This is
2058 because TODO is run before the subpasses. It is important to remove
2059 the unreachable functions to save works at IPA level and to get LTO
2060 symbol tables right. */
2061 symtab_remove_unreachable_nodes (true, cgraph_dump_file);
2063 /* If pass_all_early_optimizations was not scheduled, the state of
2064 the cgraph will not be properly updated. Update it now. */
2065 if (cgraph_state < CGRAPH_STATE_IPA_SSA)
2066 cgraph_state = CGRAPH_STATE_IPA_SSA;
2068 if (!in_lto_p)
2070 /* Generate coverage variables and constructors. */
2071 coverage_finish ();
2073 /* Process new functions added. */
2074 set_cfun (NULL);
2075 current_function_decl = NULL;
2076 cgraph_process_new_functions ();
2078 execute_ipa_summary_passes
2079 ((ipa_opt_pass_d *) passes->all_regular_ipa_passes);
2082 /* Some targets need to handle LTO assembler output specially. */
2083 if (flag_generate_lto)
2084 targetm.asm_out.lto_start ();
2086 if (!in_lto_p)
2087 ipa_write_summaries ();
2089 if (flag_generate_lto)
2090 targetm.asm_out.lto_end ();
2092 if (!flag_ltrans && (in_lto_p || !flag_lto || flag_fat_lto_objects))
2093 execute_ipa_pass_list (passes->all_regular_ipa_passes);
2094 invoke_plugin_callbacks (PLUGIN_ALL_IPA_PASSES_END, NULL);
2096 bitmap_obstack_release (NULL);
2100 /* Return string alias is alias of. */
2102 static tree
2103 get_alias_symbol (tree decl)
2105 tree alias = lookup_attribute ("alias", DECL_ATTRIBUTES (decl));
2106 return get_identifier (TREE_STRING_POINTER
2107 (TREE_VALUE (TREE_VALUE (alias))));
2111 /* Weakrefs may be associated to external decls and thus not output
2112 at expansion time. Emit all necessary aliases. */
2114 static void
2115 output_weakrefs (void)
2117 symtab_node *node;
2118 FOR_EACH_SYMBOL (node)
2119 if (node->alias
2120 && !TREE_ASM_WRITTEN (node->decl)
2121 && node->weakref)
2123 tree target;
2125 /* Weakrefs are special by not requiring target definition in current
2126 compilation unit. It is thus bit hard to work out what we want to
2127 alias.
2128 When alias target is defined, we need to fetch it from symtab reference,
2129 otherwise it is pointed to by alias_target. */
2130 if (node->alias_target)
2131 target = (DECL_P (node->alias_target)
2132 ? DECL_ASSEMBLER_NAME (node->alias_target)
2133 : node->alias_target);
2134 else if (node->analyzed)
2135 target = DECL_ASSEMBLER_NAME (symtab_alias_target (node)->decl);
2136 else
2138 gcc_unreachable ();
2139 target = get_alias_symbol (node->decl);
2141 do_assemble_alias (node->decl, target);
2145 /* Initialize callgraph dump file. */
2147 void
2148 init_cgraph (void)
2150 if (!cgraph_dump_file)
2151 cgraph_dump_file = dump_begin (TDI_cgraph, NULL);
2155 /* Perform simple optimizations based on callgraph. */
2157 void
2158 compile (void)
2160 if (seen_error ())
2161 return;
2163 #ifdef ENABLE_CHECKING
2164 verify_symtab ();
2165 #endif
2167 timevar_push (TV_CGRAPHOPT);
2168 if (pre_ipa_mem_report)
2170 fprintf (stderr, "Memory consumption before IPA\n");
2171 dump_memory_report (false);
2173 if (!quiet_flag)
2174 fprintf (stderr, "Performing interprocedural optimizations\n");
2175 cgraph_state = CGRAPH_STATE_IPA;
2177 /* If LTO is enabled, initialize the streamer hooks needed by GIMPLE. */
2178 if (flag_lto)
2179 lto_streamer_hooks_init ();
2181 /* Don't run the IPA passes if there was any error or sorry messages. */
2182 if (!seen_error ())
2183 ipa_passes ();
2185 /* Do nothing else if any IPA pass found errors or if we are just streaming LTO. */
2186 if (seen_error ()
2187 || (!in_lto_p && flag_lto && !flag_fat_lto_objects))
2189 timevar_pop (TV_CGRAPHOPT);
2190 return;
2193 /* This pass remove bodies of extern inline functions we never inlined.
2194 Do this later so other IPA passes see what is really going on. */
2195 symtab_remove_unreachable_nodes (false, dump_file);
2196 cgraph_global_info_ready = true;
2197 if (cgraph_dump_file)
2199 fprintf (cgraph_dump_file, "Optimized ");
2200 dump_symtab (cgraph_dump_file);
2202 if (post_ipa_mem_report)
2204 fprintf (stderr, "Memory consumption after IPA\n");
2205 dump_memory_report (false);
2207 timevar_pop (TV_CGRAPHOPT);
2209 /* Output everything. */
2210 (*debug_hooks->assembly_start) ();
2211 if (!quiet_flag)
2212 fprintf (stderr, "Assembling functions:\n");
2213 #ifdef ENABLE_CHECKING
2214 verify_symtab ();
2215 #endif
2217 cgraph_materialize_all_clones ();
2218 bitmap_obstack_initialize (NULL);
2219 execute_ipa_pass_list (g->get_passes ()->all_late_ipa_passes);
2220 symtab_remove_unreachable_nodes (true, dump_file);
2221 #ifdef ENABLE_CHECKING
2222 verify_symtab ();
2223 #endif
2224 bitmap_obstack_release (NULL);
2225 mark_functions_to_output ();
2227 /* When weakref support is missing, we autmatically translate all
2228 references to NODE to references to its ultimate alias target.
2229 The renaming mechanizm uses flag IDENTIFIER_TRANSPARENT_ALIAS and
2230 TREE_CHAIN.
2232 Set up this mapping before we output any assembler but once we are sure
2233 that all symbol renaming is done.
2235 FIXME: All this uglyness can go away if we just do renaming at gimple
2236 level by physically rewritting the IL. At the moment we can only redirect
2237 calls, so we need infrastructure for renaming references as well. */
2238 #ifndef ASM_OUTPUT_WEAKREF
2239 symtab_node *node;
2241 FOR_EACH_SYMBOL (node)
2242 if (node->alias
2243 && lookup_attribute ("weakref", DECL_ATTRIBUTES (node->decl)))
2245 IDENTIFIER_TRANSPARENT_ALIAS
2246 (DECL_ASSEMBLER_NAME (node->decl)) = 1;
2247 TREE_CHAIN (DECL_ASSEMBLER_NAME (node->decl))
2248 = (node->alias_target ? node->alias_target
2249 : DECL_ASSEMBLER_NAME (symtab_alias_target (node)->decl));
2251 #endif
2253 cgraph_state = CGRAPH_STATE_EXPANSION;
2255 if (!flag_toplevel_reorder)
2256 output_in_order ();
2257 else
2259 output_asm_statements ();
2261 expand_all_functions ();
2262 varpool_output_variables ();
2265 cgraph_process_new_functions ();
2266 cgraph_state = CGRAPH_STATE_FINISHED;
2267 output_weakrefs ();
2269 if (cgraph_dump_file)
2271 fprintf (cgraph_dump_file, "\nFinal ");
2272 dump_symtab (cgraph_dump_file);
2274 #ifdef ENABLE_CHECKING
2275 verify_symtab ();
2276 /* Double check that all inline clones are gone and that all
2277 function bodies have been released from memory. */
2278 if (!seen_error ())
2280 struct cgraph_node *node;
2281 bool error_found = false;
2283 FOR_EACH_DEFINED_FUNCTION (node)
2284 if (node->global.inlined_to
2285 || gimple_has_body_p (node->decl))
2287 error_found = true;
2288 dump_cgraph_node (stderr, node);
2290 if (error_found)
2291 internal_error ("nodes with unreleased memory found");
2293 #endif
2297 /* Analyze the whole compilation unit once it is parsed completely. */
2299 void
2300 finalize_compilation_unit (void)
2302 timevar_push (TV_CGRAPH);
2304 /* If we're here there's no current function anymore. Some frontends
2305 are lazy in clearing these. */
2306 current_function_decl = NULL;
2307 set_cfun (NULL);
2309 /* Do not skip analyzing the functions if there were errors, we
2310 miss diagnostics for following functions otherwise. */
2312 /* Emit size functions we didn't inline. */
2313 finalize_size_functions ();
2315 /* Mark alias targets necessary and emit diagnostics. */
2316 handle_alias_pairs ();
2318 if (!quiet_flag)
2320 fprintf (stderr, "\nAnalyzing compilation unit\n");
2321 fflush (stderr);
2324 if (flag_dump_passes)
2325 dump_passes ();
2327 /* Gimplify and lower all functions, compute reachability and
2328 remove unreachable nodes. */
2329 analyze_functions ();
2331 /* Mark alias targets necessary and emit diagnostics. */
2332 handle_alias_pairs ();
2334 /* Gimplify and lower thunks. */
2335 analyze_functions ();
2337 /* Finally drive the pass manager. */
2338 compile ();
2340 timevar_pop (TV_CGRAPH);
2344 #include "gt-cgraphunit.h"