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[official-gcc.git] / gcc / cgraphunit.c
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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 "lto-section-names.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 (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_alloc_cleared_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 (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)
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 cgraph_make_edge_direct (edge, target);
908 cgraph_redirect_edge_call_stmt_to_callee (edge);
909 if (cgraph_dump_file)
911 fprintf (cgraph_dump_file,
912 "Devirtualized as: ");
913 print_gimple_stmt (cgraph_dump_file,
914 edge->call_stmt, 0,
915 TDF_SLIM);
922 /* Discover all functions and variables that are trivially needed, analyze
923 them as well as all functions and variables referred by them */
925 static void
926 analyze_functions (void)
928 /* Keep track of already processed nodes when called multiple times for
929 intermodule optimization. */
930 static struct cgraph_node *first_analyzed;
931 struct cgraph_node *first_handled = first_analyzed;
932 static varpool_node *first_analyzed_var;
933 varpool_node *first_handled_var = first_analyzed_var;
934 struct pointer_set_t *reachable_call_targets = pointer_set_create ();
936 symtab_node *node;
937 symtab_node *next;
938 int i;
939 struct ipa_ref *ref;
940 bool changed = true;
941 location_t saved_loc = input_location;
943 bitmap_obstack_initialize (NULL);
944 cgraph_state = CGRAPH_STATE_CONSTRUCTION;
945 input_location = UNKNOWN_LOCATION;
947 /* Ugly, but the fixup can not happen at a time same body alias is created;
948 C++ FE is confused about the COMDAT groups being right. */
949 if (cpp_implicit_aliases_done)
950 FOR_EACH_SYMBOL (node)
951 if (node->cpp_implicit_alias)
952 fixup_same_cpp_alias_visibility (node, symtab_alias_target (node));
953 if (optimize && flag_devirtualize)
954 build_type_inheritance_graph ();
956 /* Analysis adds static variables that in turn adds references to new functions.
957 So we need to iterate the process until it stabilize. */
958 while (changed)
960 changed = false;
961 process_function_and_variable_attributes (first_analyzed,
962 first_analyzed_var);
964 /* First identify the trivially needed symbols. */
965 for (node = symtab_nodes;
966 node != first_analyzed
967 && node != first_analyzed_var; node = node->next)
969 if (decide_is_symbol_needed (node))
971 enqueue_node (node);
972 if (!changed && cgraph_dump_file)
973 fprintf (cgraph_dump_file, "Trivially needed symbols:");
974 changed = true;
975 if (cgraph_dump_file)
976 fprintf (cgraph_dump_file, " %s", node->asm_name ());
977 if (!changed && cgraph_dump_file)
978 fprintf (cgraph_dump_file, "\n");
980 if (node == first_analyzed
981 || node == first_analyzed_var)
982 break;
984 cgraph_process_new_functions ();
985 first_analyzed_var = varpool_first_variable ();
986 first_analyzed = cgraph_first_function ();
988 if (changed && dump_file)
989 fprintf (cgraph_dump_file, "\n");
991 /* Lower representation, build callgraph edges and references for all trivially
992 needed symbols and all symbols referred by them. */
993 while (queued_nodes != &symtab_terminator)
995 changed = true;
996 node = queued_nodes;
997 queued_nodes = (symtab_node *)queued_nodes->aux;
998 cgraph_node *cnode = dyn_cast <cgraph_node> (node);
999 if (cnode && cnode->definition)
1001 struct cgraph_edge *edge;
1002 tree decl = cnode->decl;
1004 /* ??? It is possible to create extern inline function
1005 and later using weak alias attribute to kill its body.
1006 See gcc.c-torture/compile/20011119-1.c */
1007 if (!DECL_STRUCT_FUNCTION (decl)
1008 && !cnode->alias
1009 && !cnode->thunk.thunk_p
1010 && !cnode->dispatcher_function)
1012 cgraph_reset_node (cnode);
1013 cnode->local.redefined_extern_inline = true;
1014 continue;
1017 if (!cnode->analyzed)
1018 analyze_function (cnode);
1020 for (edge = cnode->callees; edge; edge = edge->next_callee)
1021 if (edge->callee->definition)
1022 enqueue_node (edge->callee);
1023 if (optimize && flag_devirtualize)
1025 struct cgraph_edge *next;
1027 for (edge = cnode->indirect_calls; edge; edge = next)
1029 next = edge->next_callee;
1030 if (edge->indirect_info->polymorphic)
1031 walk_polymorphic_call_targets (reachable_call_targets,
1032 edge);
1036 /* If decl is a clone of an abstract function,
1037 mark that abstract function so that we don't release its body.
1038 The DECL_INITIAL() of that abstract function declaration
1039 will be later needed to output debug info. */
1040 if (DECL_ABSTRACT_ORIGIN (decl))
1042 struct cgraph_node *origin_node
1043 = cgraph_get_node (DECL_ABSTRACT_ORIGIN (decl));
1044 origin_node->used_as_abstract_origin = true;
1047 else
1049 varpool_node *vnode = dyn_cast <varpool_node> (node);
1050 if (vnode && vnode->definition && !vnode->analyzed)
1051 varpool_analyze_node (vnode);
1054 if (node->same_comdat_group)
1056 symtab_node *next;
1057 for (next = node->same_comdat_group;
1058 next != node;
1059 next = next->same_comdat_group)
1060 enqueue_node (next);
1062 for (i = 0; ipa_ref_list_reference_iterate (&node->ref_list, i, ref); i++)
1063 if (ref->referred->definition)
1064 enqueue_node (ref->referred);
1065 cgraph_process_new_functions ();
1068 if (optimize && flag_devirtualize)
1069 update_type_inheritance_graph ();
1071 /* Collect entry points to the unit. */
1072 if (cgraph_dump_file)
1074 fprintf (cgraph_dump_file, "\n\nInitial ");
1075 dump_symtab (cgraph_dump_file);
1078 if (cgraph_dump_file)
1079 fprintf (cgraph_dump_file, "\nRemoving unused symbols:");
1081 for (node = symtab_nodes;
1082 node != first_handled
1083 && node != first_handled_var; node = next)
1085 next = node->next;
1086 if (!node->aux && !referred_to_p (node))
1088 if (cgraph_dump_file)
1089 fprintf (cgraph_dump_file, " %s", node->name ());
1090 symtab_remove_node (node);
1091 continue;
1093 if (cgraph_node *cnode = dyn_cast <cgraph_node> (node))
1095 tree decl = node->decl;
1097 if (cnode->definition && !gimple_has_body_p (decl)
1098 && !cnode->alias
1099 && !cnode->thunk.thunk_p)
1100 cgraph_reset_node (cnode);
1102 gcc_assert (!cnode->definition || cnode->thunk.thunk_p
1103 || cnode->alias
1104 || gimple_has_body_p (decl));
1105 gcc_assert (cnode->analyzed == cnode->definition);
1107 node->aux = NULL;
1109 for (;node; node = node->next)
1110 node->aux = NULL;
1111 first_analyzed = cgraph_first_function ();
1112 first_analyzed_var = varpool_first_variable ();
1113 if (cgraph_dump_file)
1115 fprintf (cgraph_dump_file, "\n\nReclaimed ");
1116 dump_symtab (cgraph_dump_file);
1118 bitmap_obstack_release (NULL);
1119 pointer_set_destroy (reachable_call_targets);
1120 ggc_collect ();
1121 /* Initialize assembler name hash, in particular we want to trigger C++
1122 mangling and same body alias creation before we free DECL_ARGUMENTS
1123 used by it. */
1124 if (!seen_error ())
1125 symtab_initialize_asm_name_hash ();
1127 input_location = saved_loc;
1130 /* Translate the ugly representation of aliases as alias pairs into nice
1131 representation in callgraph. We don't handle all cases yet,
1132 unfortunately. */
1134 static void
1135 handle_alias_pairs (void)
1137 alias_pair *p;
1138 unsigned i;
1140 for (i = 0; alias_pairs && alias_pairs->iterate (i, &p);)
1142 symtab_node *target_node = symtab_node_for_asm (p->target);
1144 /* Weakrefs with target not defined in current unit are easy to handle:
1145 they behave just as external variables except we need to note the
1146 alias flag to later output the weakref pseudo op into asm file. */
1147 if (!target_node
1148 && lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)) != NULL)
1150 symtab_node *node = symtab_get_node (p->decl);
1151 if (node)
1153 node->alias_target = p->target;
1154 node->weakref = true;
1155 node->alias = true;
1157 alias_pairs->unordered_remove (i);
1158 continue;
1160 else if (!target_node)
1162 error ("%q+D aliased to undefined symbol %qE", p->decl, p->target);
1163 symtab_node *node = symtab_get_node (p->decl);
1164 if (node)
1165 node->alias = false;
1166 alias_pairs->unordered_remove (i);
1167 continue;
1170 if (DECL_EXTERNAL (target_node->decl)
1171 /* We use local aliases for C++ thunks to force the tailcall
1172 to bind locally. This is a hack - to keep it working do
1173 the following (which is not strictly correct). */
1174 && (! TREE_CODE (target_node->decl) == FUNCTION_DECL
1175 || ! DECL_VIRTUAL_P (target_node->decl))
1176 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
1178 error ("%q+D aliased to external symbol %qE",
1179 p->decl, p->target);
1182 if (TREE_CODE (p->decl) == FUNCTION_DECL
1183 && target_node && is_a <cgraph_node> (target_node))
1185 struct cgraph_node *src_node = cgraph_get_node (p->decl);
1186 if (src_node && src_node->definition)
1187 cgraph_reset_node (src_node);
1188 cgraph_create_function_alias (p->decl, target_node->decl);
1189 alias_pairs->unordered_remove (i);
1191 else if (TREE_CODE (p->decl) == VAR_DECL
1192 && target_node && is_a <varpool_node> (target_node))
1194 varpool_create_variable_alias (p->decl, target_node->decl);
1195 alias_pairs->unordered_remove (i);
1197 else
1199 error ("%q+D alias in between function and variable is not supported",
1200 p->decl);
1201 warning (0, "%q+D aliased declaration",
1202 target_node->decl);
1203 alias_pairs->unordered_remove (i);
1206 vec_free (alias_pairs);
1210 /* Figure out what functions we want to assemble. */
1212 static void
1213 mark_functions_to_output (void)
1215 struct cgraph_node *node;
1216 #ifdef ENABLE_CHECKING
1217 bool check_same_comdat_groups = false;
1219 FOR_EACH_FUNCTION (node)
1220 gcc_assert (!node->process);
1221 #endif
1223 FOR_EACH_FUNCTION (node)
1225 tree decl = node->decl;
1227 gcc_assert (!node->process || node->same_comdat_group);
1228 if (node->process)
1229 continue;
1231 /* We need to output all local functions that are used and not
1232 always inlined, as well as those that are reachable from
1233 outside the current compilation unit. */
1234 if (node->analyzed
1235 && !node->thunk.thunk_p
1236 && !node->alias
1237 && !node->global.inlined_to
1238 && !TREE_ASM_WRITTEN (decl)
1239 && !DECL_EXTERNAL (decl))
1241 node->process = 1;
1242 if (node->same_comdat_group)
1244 struct cgraph_node *next;
1245 for (next = cgraph (node->same_comdat_group);
1246 next != node;
1247 next = cgraph (next->same_comdat_group))
1248 if (!next->thunk.thunk_p && !next->alias
1249 && !symtab_comdat_local_p (next))
1250 next->process = 1;
1253 else if (node->same_comdat_group)
1255 #ifdef ENABLE_CHECKING
1256 check_same_comdat_groups = true;
1257 #endif
1259 else
1261 /* We should've reclaimed all functions that are not needed. */
1262 #ifdef ENABLE_CHECKING
1263 if (!node->global.inlined_to
1264 && gimple_has_body_p (decl)
1265 /* FIXME: in ltrans unit when offline copy is outside partition but inline copies
1266 are inside partition, we can end up not removing the body since we no longer
1267 have analyzed node pointing to it. */
1268 && !node->in_other_partition
1269 && !node->alias
1270 && !node->clones
1271 && !DECL_EXTERNAL (decl))
1273 dump_cgraph_node (stderr, node);
1274 internal_error ("failed to reclaim unneeded function");
1276 #endif
1277 gcc_assert (node->global.inlined_to
1278 || !gimple_has_body_p (decl)
1279 || node->in_other_partition
1280 || node->clones
1281 || DECL_ARTIFICIAL (decl)
1282 || DECL_EXTERNAL (decl));
1287 #ifdef ENABLE_CHECKING
1288 if (check_same_comdat_groups)
1289 FOR_EACH_FUNCTION (node)
1290 if (node->same_comdat_group && !node->process)
1292 tree decl = node->decl;
1293 if (!node->global.inlined_to
1294 && gimple_has_body_p (decl)
1295 /* FIXME: in an ltrans unit when the offline copy is outside a
1296 partition but inline copies are inside a partition, we can
1297 end up not removing the body since we no longer have an
1298 analyzed node pointing to it. */
1299 && !node->in_other_partition
1300 && !node->clones
1301 && !DECL_EXTERNAL (decl))
1303 dump_cgraph_node (stderr, node);
1304 internal_error ("failed to reclaim unneeded function in same "
1305 "comdat group");
1308 #endif
1311 /* DECL is FUNCTION_DECL. Initialize datastructures so DECL is a function
1312 in lowered gimple form. IN_SSA is true if the gimple is in SSA.
1314 Set current_function_decl and cfun to newly constructed empty function body.
1315 return basic block in the function body. */
1317 basic_block
1318 init_lowered_empty_function (tree decl, bool in_ssa)
1320 basic_block bb;
1322 current_function_decl = decl;
1323 allocate_struct_function (decl, false);
1324 gimple_register_cfg_hooks ();
1325 init_empty_tree_cfg ();
1327 if (in_ssa)
1329 init_tree_ssa (cfun);
1330 init_ssa_operands (cfun);
1331 cfun->gimple_df->in_ssa_p = true;
1332 cfun->curr_properties |= PROP_ssa;
1335 DECL_INITIAL (decl) = make_node (BLOCK);
1337 DECL_SAVED_TREE (decl) = error_mark_node;
1338 cfun->curr_properties |= (PROP_gimple_lcf | PROP_gimple_leh | PROP_gimple_any
1339 | PROP_cfg | PROP_loops);
1341 set_loops_for_fn (cfun, ggc_alloc_cleared_loops ());
1342 init_loops_structure (cfun, loops_for_fn (cfun), 1);
1343 loops_for_fn (cfun)->state |= LOOPS_MAY_HAVE_MULTIPLE_LATCHES;
1345 /* Create BB for body of the function and connect it properly. */
1346 bb = create_basic_block (NULL, (void *) 0, ENTRY_BLOCK_PTR_FOR_FN (cfun));
1347 make_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun), bb, EDGE_FALLTHRU);
1348 make_edge (bb, EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
1349 add_bb_to_loop (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->loop_father);
1351 return bb;
1354 /* Adjust PTR by the constant FIXED_OFFSET, and by the vtable
1355 offset indicated by VIRTUAL_OFFSET, if that is
1356 non-null. THIS_ADJUSTING is nonzero for a this adjusting thunk and
1357 zero for a result adjusting thunk. */
1359 static tree
1360 thunk_adjust (gimple_stmt_iterator * bsi,
1361 tree ptr, bool this_adjusting,
1362 HOST_WIDE_INT fixed_offset, tree virtual_offset)
1364 gimple stmt;
1365 tree ret;
1367 if (this_adjusting
1368 && fixed_offset != 0)
1370 stmt = gimple_build_assign
1371 (ptr, fold_build_pointer_plus_hwi_loc (input_location,
1372 ptr,
1373 fixed_offset));
1374 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1377 /* If there's a virtual offset, look up that value in the vtable and
1378 adjust the pointer again. */
1379 if (virtual_offset)
1381 tree vtabletmp;
1382 tree vtabletmp2;
1383 tree vtabletmp3;
1385 if (!vtable_entry_type)
1387 tree vfunc_type = make_node (FUNCTION_TYPE);
1388 TREE_TYPE (vfunc_type) = integer_type_node;
1389 TYPE_ARG_TYPES (vfunc_type) = NULL_TREE;
1390 layout_type (vfunc_type);
1392 vtable_entry_type = build_pointer_type (vfunc_type);
1395 vtabletmp =
1396 create_tmp_reg (build_pointer_type
1397 (build_pointer_type (vtable_entry_type)), "vptr");
1399 /* The vptr is always at offset zero in the object. */
1400 stmt = gimple_build_assign (vtabletmp,
1401 build1 (NOP_EXPR, TREE_TYPE (vtabletmp),
1402 ptr));
1403 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1405 /* Form the vtable address. */
1406 vtabletmp2 = create_tmp_reg (TREE_TYPE (TREE_TYPE (vtabletmp)),
1407 "vtableaddr");
1408 stmt = gimple_build_assign (vtabletmp2,
1409 build_simple_mem_ref (vtabletmp));
1410 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1412 /* Find the entry with the vcall offset. */
1413 stmt = gimple_build_assign (vtabletmp2,
1414 fold_build_pointer_plus_loc (input_location,
1415 vtabletmp2,
1416 virtual_offset));
1417 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1419 /* Get the offset itself. */
1420 vtabletmp3 = create_tmp_reg (TREE_TYPE (TREE_TYPE (vtabletmp2)),
1421 "vcalloffset");
1422 stmt = gimple_build_assign (vtabletmp3,
1423 build_simple_mem_ref (vtabletmp2));
1424 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1426 /* Adjust the `this' pointer. */
1427 ptr = fold_build_pointer_plus_loc (input_location, ptr, vtabletmp3);
1428 ptr = force_gimple_operand_gsi (bsi, ptr, true, NULL_TREE, false,
1429 GSI_CONTINUE_LINKING);
1432 if (!this_adjusting
1433 && fixed_offset != 0)
1434 /* Adjust the pointer by the constant. */
1436 tree ptrtmp;
1438 if (TREE_CODE (ptr) == VAR_DECL)
1439 ptrtmp = ptr;
1440 else
1442 ptrtmp = create_tmp_reg (TREE_TYPE (ptr), "ptr");
1443 stmt = gimple_build_assign (ptrtmp, ptr);
1444 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1446 ptr = fold_build_pointer_plus_hwi_loc (input_location,
1447 ptrtmp, fixed_offset);
1450 /* Emit the statement and gimplify the adjustment expression. */
1451 ret = create_tmp_reg (TREE_TYPE (ptr), "adjusted_this");
1452 stmt = gimple_build_assign (ret, ptr);
1453 gsi_insert_after (bsi, stmt, GSI_NEW_STMT);
1455 return ret;
1458 /* Expand thunk NODE to gimple if possible.
1459 When OUTPUT_ASM_THUNK is true, also produce assembler for
1460 thunks that are not lowered. */
1462 bool
1463 expand_thunk (struct cgraph_node *node, bool output_asm_thunks)
1465 bool this_adjusting = node->thunk.this_adjusting;
1466 HOST_WIDE_INT fixed_offset = node->thunk.fixed_offset;
1467 HOST_WIDE_INT virtual_value = node->thunk.virtual_value;
1468 tree virtual_offset = NULL;
1469 tree alias = node->callees->callee->decl;
1470 tree thunk_fndecl = node->decl;
1471 tree a;
1474 if (this_adjusting
1475 && targetm.asm_out.can_output_mi_thunk (thunk_fndecl, fixed_offset,
1476 virtual_value, alias))
1478 const char *fnname;
1479 tree fn_block;
1480 tree restype = TREE_TYPE (TREE_TYPE (thunk_fndecl));
1482 if (!output_asm_thunks)
1483 return false;
1485 if (in_lto_p)
1486 cgraph_get_body (node);
1487 a = DECL_ARGUMENTS (thunk_fndecl);
1489 current_function_decl = thunk_fndecl;
1491 /* Ensure thunks are emitted in their correct sections. */
1492 resolve_unique_section (thunk_fndecl, 0, flag_function_sections);
1494 DECL_RESULT (thunk_fndecl)
1495 = build_decl (DECL_SOURCE_LOCATION (thunk_fndecl),
1496 RESULT_DECL, 0, restype);
1497 DECL_CONTEXT (DECL_RESULT (thunk_fndecl)) = thunk_fndecl;
1498 fnname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (thunk_fndecl));
1500 /* The back end expects DECL_INITIAL to contain a BLOCK, so we
1501 create one. */
1502 fn_block = make_node (BLOCK);
1503 BLOCK_VARS (fn_block) = a;
1504 DECL_INITIAL (thunk_fndecl) = fn_block;
1505 init_function_start (thunk_fndecl);
1506 cfun->is_thunk = 1;
1507 insn_locations_init ();
1508 set_curr_insn_location (DECL_SOURCE_LOCATION (thunk_fndecl));
1509 prologue_location = curr_insn_location ();
1510 assemble_start_function (thunk_fndecl, fnname);
1512 targetm.asm_out.output_mi_thunk (asm_out_file, thunk_fndecl,
1513 fixed_offset, virtual_value, alias);
1515 assemble_end_function (thunk_fndecl, fnname);
1516 insn_locations_finalize ();
1517 init_insn_lengths ();
1518 free_after_compilation (cfun);
1519 set_cfun (NULL);
1520 TREE_ASM_WRITTEN (thunk_fndecl) = 1;
1521 node->thunk.thunk_p = false;
1522 node->analyzed = false;
1524 else
1526 tree restype;
1527 basic_block bb, then_bb, else_bb, return_bb;
1528 gimple_stmt_iterator bsi;
1529 int nargs = 0;
1530 tree arg;
1531 int i;
1532 tree resdecl;
1533 tree restmp = NULL;
1535 gimple call;
1536 gimple ret;
1538 if (in_lto_p)
1539 cgraph_get_body (node);
1540 a = DECL_ARGUMENTS (thunk_fndecl);
1542 current_function_decl = thunk_fndecl;
1544 /* Ensure thunks are emitted in their correct sections. */
1545 resolve_unique_section (thunk_fndecl, 0, flag_function_sections);
1547 DECL_IGNORED_P (thunk_fndecl) = 1;
1548 bitmap_obstack_initialize (NULL);
1550 if (node->thunk.virtual_offset_p)
1551 virtual_offset = size_int (virtual_value);
1553 /* Build the return declaration for the function. */
1554 restype = TREE_TYPE (TREE_TYPE (thunk_fndecl));
1555 if (DECL_RESULT (thunk_fndecl) == NULL_TREE)
1557 resdecl = build_decl (input_location, RESULT_DECL, 0, restype);
1558 DECL_ARTIFICIAL (resdecl) = 1;
1559 DECL_IGNORED_P (resdecl) = 1;
1560 DECL_RESULT (thunk_fndecl) = resdecl;
1561 DECL_CONTEXT (DECL_RESULT (thunk_fndecl)) = thunk_fndecl;
1563 else
1564 resdecl = DECL_RESULT (thunk_fndecl);
1566 bb = then_bb = else_bb = return_bb = init_lowered_empty_function (thunk_fndecl, true);
1568 bsi = gsi_start_bb (bb);
1570 /* Build call to the function being thunked. */
1571 if (!VOID_TYPE_P (restype))
1573 if (DECL_BY_REFERENCE (resdecl))
1574 restmp = gimple_fold_indirect_ref (resdecl);
1575 else if (!is_gimple_reg_type (restype))
1577 restmp = resdecl;
1578 add_local_decl (cfun, restmp);
1579 BLOCK_VARS (DECL_INITIAL (current_function_decl)) = restmp;
1581 else
1582 restmp = create_tmp_reg (restype, "retval");
1585 for (arg = a; arg; arg = DECL_CHAIN (arg))
1586 nargs++;
1587 auto_vec<tree> vargs (nargs);
1588 if (this_adjusting)
1589 vargs.quick_push (thunk_adjust (&bsi, a, 1, fixed_offset,
1590 virtual_offset));
1591 else if (nargs)
1592 vargs.quick_push (a);
1594 if (nargs)
1595 for (i = 1, arg = DECL_CHAIN (a); i < nargs; i++, arg = DECL_CHAIN (arg))
1597 tree tmp = arg;
1598 if (!is_gimple_val (arg))
1600 tmp = create_tmp_reg (TYPE_MAIN_VARIANT
1601 (TREE_TYPE (arg)), "arg");
1602 gimple stmt = gimple_build_assign (tmp, arg);
1603 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1605 vargs.quick_push (tmp);
1607 call = gimple_build_call_vec (build_fold_addr_expr_loc (0, alias), vargs);
1608 node->callees->call_stmt = call;
1609 gimple_call_set_from_thunk (call, true);
1610 if (restmp)
1612 gimple_call_set_lhs (call, restmp);
1613 gcc_assert (useless_type_conversion_p (TREE_TYPE (restmp),
1614 TREE_TYPE (TREE_TYPE (alias))));
1616 gsi_insert_after (&bsi, call, GSI_NEW_STMT);
1617 if (!(gimple_call_flags (call) & ECF_NORETURN))
1619 if (restmp && !this_adjusting
1620 && (fixed_offset || virtual_offset))
1622 tree true_label = NULL_TREE;
1624 if (TREE_CODE (TREE_TYPE (restmp)) == POINTER_TYPE)
1626 gimple stmt;
1627 /* If the return type is a pointer, we need to
1628 protect against NULL. We know there will be an
1629 adjustment, because that's why we're emitting a
1630 thunk. */
1631 then_bb = create_basic_block (NULL, (void *) 0, bb);
1632 return_bb = create_basic_block (NULL, (void *) 0, then_bb);
1633 else_bb = create_basic_block (NULL, (void *) 0, else_bb);
1634 add_bb_to_loop (then_bb, bb->loop_father);
1635 add_bb_to_loop (return_bb, bb->loop_father);
1636 add_bb_to_loop (else_bb, bb->loop_father);
1637 remove_edge (single_succ_edge (bb));
1638 true_label = gimple_block_label (then_bb);
1639 stmt = gimple_build_cond (NE_EXPR, restmp,
1640 build_zero_cst (TREE_TYPE (restmp)),
1641 NULL_TREE, NULL_TREE);
1642 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1643 make_edge (bb, then_bb, EDGE_TRUE_VALUE);
1644 make_edge (bb, else_bb, EDGE_FALSE_VALUE);
1645 make_edge (return_bb, EXIT_BLOCK_PTR_FOR_FN (cfun), 0);
1646 make_edge (then_bb, return_bb, EDGE_FALLTHRU);
1647 make_edge (else_bb, return_bb, EDGE_FALLTHRU);
1648 bsi = gsi_last_bb (then_bb);
1651 restmp = thunk_adjust (&bsi, restmp, /*this_adjusting=*/0,
1652 fixed_offset, virtual_offset);
1653 if (true_label)
1655 gimple stmt;
1656 bsi = gsi_last_bb (else_bb);
1657 stmt = gimple_build_assign (restmp,
1658 build_zero_cst (TREE_TYPE (restmp)));
1659 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
1660 bsi = gsi_last_bb (return_bb);
1663 else
1664 gimple_call_set_tail (call, true);
1666 /* Build return value. */
1667 ret = gimple_build_return (restmp);
1668 gsi_insert_after (&bsi, ret, GSI_NEW_STMT);
1670 else
1672 gimple_call_set_tail (call, true);
1673 remove_edge (single_succ_edge (bb));
1676 cfun->gimple_df->in_ssa_p = true;
1677 /* FIXME: C++ FE should stop setting TREE_ASM_WRITTEN on thunks. */
1678 TREE_ASM_WRITTEN (thunk_fndecl) = false;
1679 delete_unreachable_blocks ();
1680 update_ssa (TODO_update_ssa);
1681 #ifdef ENABLE_CHECKING
1682 verify_flow_info ();
1683 #endif
1685 /* Since we want to emit the thunk, we explicitly mark its name as
1686 referenced. */
1687 node->thunk.thunk_p = false;
1688 node->lowered = true;
1689 bitmap_obstack_release (NULL);
1691 current_function_decl = NULL;
1692 set_cfun (NULL);
1693 return true;
1696 /* Assemble thunks and aliases associated to NODE. */
1698 static void
1699 assemble_thunks_and_aliases (struct cgraph_node *node)
1701 struct cgraph_edge *e;
1702 int i;
1703 struct ipa_ref *ref;
1705 for (e = node->callers; e;)
1706 if (e->caller->thunk.thunk_p)
1708 struct cgraph_node *thunk = e->caller;
1710 e = e->next_caller;
1711 assemble_thunks_and_aliases (thunk);
1712 expand_thunk (thunk, true);
1714 else
1715 e = e->next_caller;
1716 for (i = 0; ipa_ref_list_referring_iterate (&node->ref_list,
1717 i, ref); i++)
1718 if (ref->use == IPA_REF_ALIAS)
1720 struct cgraph_node *alias = ipa_ref_referring_node (ref);
1721 bool saved_written = TREE_ASM_WRITTEN (node->decl);
1723 /* Force assemble_alias to really output the alias this time instead
1724 of buffering it in same alias pairs. */
1725 TREE_ASM_WRITTEN (node->decl) = 1;
1726 do_assemble_alias (alias->decl,
1727 DECL_ASSEMBLER_NAME (node->decl));
1728 assemble_thunks_and_aliases (alias);
1729 TREE_ASM_WRITTEN (node->decl) = saved_written;
1733 /* Expand function specified by NODE. */
1735 static void
1736 expand_function (struct cgraph_node *node)
1738 tree decl = node->decl;
1739 location_t saved_loc;
1741 /* We ought to not compile any inline clones. */
1742 gcc_assert (!node->global.inlined_to);
1744 announce_function (decl);
1745 node->process = 0;
1746 gcc_assert (node->lowered);
1747 cgraph_get_body (node);
1749 /* Generate RTL for the body of DECL. */
1751 timevar_push (TV_REST_OF_COMPILATION);
1753 gcc_assert (cgraph_global_info_ready);
1755 /* Initialize the default bitmap obstack. */
1756 bitmap_obstack_initialize (NULL);
1758 /* Initialize the RTL code for the function. */
1759 current_function_decl = decl;
1760 saved_loc = input_location;
1761 input_location = DECL_SOURCE_LOCATION (decl);
1762 init_function_start (decl);
1764 gimple_register_cfg_hooks ();
1766 bitmap_obstack_initialize (&reg_obstack); /* FIXME, only at RTL generation*/
1768 execute_all_ipa_transforms ();
1770 /* Perform all tree transforms and optimizations. */
1772 /* Signal the start of passes. */
1773 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_START, NULL);
1775 execute_pass_list (g->get_passes ()->all_passes);
1777 /* Signal the end of passes. */
1778 invoke_plugin_callbacks (PLUGIN_ALL_PASSES_END, NULL);
1780 bitmap_obstack_release (&reg_obstack);
1782 /* Release the default bitmap obstack. */
1783 bitmap_obstack_release (NULL);
1785 /* If requested, warn about function definitions where the function will
1786 return a value (usually of some struct or union type) which itself will
1787 take up a lot of stack space. */
1788 if (warn_larger_than && !DECL_EXTERNAL (decl) && TREE_TYPE (decl))
1790 tree ret_type = TREE_TYPE (TREE_TYPE (decl));
1792 if (ret_type && TYPE_SIZE_UNIT (ret_type)
1793 && TREE_CODE (TYPE_SIZE_UNIT (ret_type)) == INTEGER_CST
1794 && 0 < compare_tree_int (TYPE_SIZE_UNIT (ret_type),
1795 larger_than_size))
1797 unsigned int size_as_int
1798 = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (ret_type));
1800 if (compare_tree_int (TYPE_SIZE_UNIT (ret_type), size_as_int) == 0)
1801 warning (OPT_Wlarger_than_, "size of return value of %q+D is %u bytes",
1802 decl, size_as_int);
1803 else
1804 warning (OPT_Wlarger_than_, "size of return value of %q+D is larger than %wd bytes",
1805 decl, larger_than_size);
1809 gimple_set_body (decl, NULL);
1810 if (DECL_STRUCT_FUNCTION (decl) == 0
1811 && !cgraph_get_node (decl)->origin)
1813 /* Stop pointing to the local nodes about to be freed.
1814 But DECL_INITIAL must remain nonzero so we know this
1815 was an actual function definition.
1816 For a nested function, this is done in c_pop_function_context.
1817 If rest_of_compilation set this to 0, leave it 0. */
1818 if (DECL_INITIAL (decl) != 0)
1819 DECL_INITIAL (decl) = error_mark_node;
1822 input_location = saved_loc;
1824 ggc_collect ();
1825 timevar_pop (TV_REST_OF_COMPILATION);
1827 /* Make sure that BE didn't give up on compiling. */
1828 gcc_assert (TREE_ASM_WRITTEN (decl));
1829 set_cfun (NULL);
1830 current_function_decl = NULL;
1832 /* It would make a lot more sense to output thunks before function body to get more
1833 forward and lest backwarding jumps. This however would need solving problem
1834 with comdats. See PR48668. Also aliases must come after function itself to
1835 make one pass assemblers, like one on AIX, happy. See PR 50689.
1836 FIXME: Perhaps thunks should be move before function IFF they are not in comdat
1837 groups. */
1838 assemble_thunks_and_aliases (node);
1839 cgraph_release_function_body (node);
1840 /* Eliminate all call edges. This is important so the GIMPLE_CALL no longer
1841 points to the dead function body. */
1842 cgraph_node_remove_callees (node);
1843 ipa_remove_all_references (&node->ref_list);
1846 /* Node comparer that is responsible for the order that corresponds
1847 to time when a function was launched for the first time. */
1849 static int
1850 node_cmp (const void *pa, const void *pb)
1852 const struct cgraph_node *a = *(const struct cgraph_node * const *) pa;
1853 const struct cgraph_node *b = *(const struct cgraph_node * const *) pb;
1855 /* Functions with time profile must be before these without profile. */
1856 if (!a->tp_first_run || !b->tp_first_run)
1857 return a->tp_first_run - b->tp_first_run;
1859 return a->tp_first_run != b->tp_first_run
1860 ? b->tp_first_run - a->tp_first_run
1861 : b->order - a->order;
1864 /* Expand all functions that must be output.
1866 Attempt to topologically sort the nodes so function is output when
1867 all called functions are already assembled to allow data to be
1868 propagated across the callgraph. Use a stack to get smaller distance
1869 between a function and its callees (later we may choose to use a more
1870 sophisticated algorithm for function reordering; we will likely want
1871 to use subsections to make the output functions appear in top-down
1872 order). */
1874 static void
1875 expand_all_functions (void)
1877 struct cgraph_node *node;
1878 struct cgraph_node **order = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
1879 unsigned int expanded_func_count = 0, profiled_func_count = 0;
1880 int order_pos, new_order_pos = 0;
1881 int i;
1883 order_pos = ipa_reverse_postorder (order);
1884 gcc_assert (order_pos == cgraph_n_nodes);
1886 /* Garbage collector may remove inline clones we eliminate during
1887 optimization. So we must be sure to not reference them. */
1888 for (i = 0; i < order_pos; i++)
1889 if (order[i]->process)
1890 order[new_order_pos++] = order[i];
1892 if (flag_profile_reorder_functions)
1893 qsort (order, new_order_pos, sizeof (struct cgraph_node *), node_cmp);
1895 for (i = new_order_pos - 1; i >= 0; i--)
1897 node = order[i];
1899 if (node->process)
1901 expanded_func_count++;
1902 if(node->tp_first_run)
1903 profiled_func_count++;
1905 if (cgraph_dump_file)
1906 fprintf (cgraph_dump_file, "Time profile order in expand_all_functions:%s:%d\n", node->asm_name (), node->tp_first_run);
1908 node->process = 0;
1909 expand_function (node);
1913 if (dump_file)
1914 fprintf (dump_file, "Expanded functions with time profile (%s):%u/%u\n",
1915 main_input_filename, profiled_func_count, expanded_func_count);
1917 if (cgraph_dump_file && flag_profile_reorder_functions)
1918 fprintf (cgraph_dump_file, "Expanded functions with time profile:%u/%u\n",
1919 profiled_func_count, expanded_func_count);
1921 cgraph_process_new_functions ();
1922 free_gimplify_stack ();
1924 free (order);
1927 /* This is used to sort the node types by the cgraph order number. */
1929 enum cgraph_order_sort_kind
1931 ORDER_UNDEFINED = 0,
1932 ORDER_FUNCTION,
1933 ORDER_VAR,
1934 ORDER_ASM
1937 struct cgraph_order_sort
1939 enum cgraph_order_sort_kind kind;
1940 union
1942 struct cgraph_node *f;
1943 varpool_node *v;
1944 struct asm_node *a;
1945 } u;
1948 /* Output all functions, variables, and asm statements in the order
1949 according to their order fields, which is the order in which they
1950 appeared in the file. This implements -fno-toplevel-reorder. In
1951 this mode we may output functions and variables which don't really
1952 need to be output. */
1954 static void
1955 output_in_order (void)
1957 int max;
1958 struct cgraph_order_sort *nodes;
1959 int i;
1960 struct cgraph_node *pf;
1961 varpool_node *pv;
1962 struct asm_node *pa;
1964 max = symtab_order;
1965 nodes = XCNEWVEC (struct cgraph_order_sort, max);
1967 FOR_EACH_DEFINED_FUNCTION (pf)
1969 if (pf->process && !pf->thunk.thunk_p && !pf->alias)
1971 i = pf->order;
1972 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1973 nodes[i].kind = ORDER_FUNCTION;
1974 nodes[i].u.f = pf;
1978 FOR_EACH_DEFINED_VARIABLE (pv)
1979 if (!DECL_EXTERNAL (pv->decl))
1981 i = pv->order;
1982 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1983 nodes[i].kind = ORDER_VAR;
1984 nodes[i].u.v = pv;
1987 for (pa = asm_nodes; pa; pa = pa->next)
1989 i = pa->order;
1990 gcc_assert (nodes[i].kind == ORDER_UNDEFINED);
1991 nodes[i].kind = ORDER_ASM;
1992 nodes[i].u.a = pa;
1995 /* In toplevel reorder mode we output all statics; mark them as needed. */
1997 for (i = 0; i < max; ++i)
1998 if (nodes[i].kind == ORDER_VAR)
1999 varpool_finalize_named_section_flags (nodes[i].u.v);
2001 for (i = 0; i < max; ++i)
2003 switch (nodes[i].kind)
2005 case ORDER_FUNCTION:
2006 nodes[i].u.f->process = 0;
2007 expand_function (nodes[i].u.f);
2008 break;
2010 case ORDER_VAR:
2011 varpool_assemble_decl (nodes[i].u.v);
2012 break;
2014 case ORDER_ASM:
2015 assemble_asm (nodes[i].u.a->asm_str);
2016 break;
2018 case ORDER_UNDEFINED:
2019 break;
2021 default:
2022 gcc_unreachable ();
2026 asm_nodes = NULL;
2027 free (nodes);
2030 static void
2031 ipa_passes (void)
2033 gcc::pass_manager *passes = g->get_passes ();
2035 set_cfun (NULL);
2036 current_function_decl = NULL;
2037 gimple_register_cfg_hooks ();
2038 bitmap_obstack_initialize (NULL);
2040 invoke_plugin_callbacks (PLUGIN_ALL_IPA_PASSES_START, NULL);
2042 if (!in_lto_p)
2044 execute_ipa_pass_list (passes->all_small_ipa_passes);
2045 if (seen_error ())
2046 return;
2049 /* We never run removal of unreachable nodes after early passes. This is
2050 because TODO is run before the subpasses. It is important to remove
2051 the unreachable functions to save works at IPA level and to get LTO
2052 symbol tables right. */
2053 symtab_remove_unreachable_nodes (true, cgraph_dump_file);
2055 /* If pass_all_early_optimizations was not scheduled, the state of
2056 the cgraph will not be properly updated. Update it now. */
2057 if (cgraph_state < CGRAPH_STATE_IPA_SSA)
2058 cgraph_state = CGRAPH_STATE_IPA_SSA;
2060 if (!in_lto_p)
2062 /* Generate coverage variables and constructors. */
2063 coverage_finish ();
2065 /* Process new functions added. */
2066 set_cfun (NULL);
2067 current_function_decl = NULL;
2068 cgraph_process_new_functions ();
2070 execute_ipa_summary_passes
2071 ((ipa_opt_pass_d *) passes->all_regular_ipa_passes);
2074 /* Some targets need to handle LTO assembler output specially. */
2075 if (flag_generate_lto)
2076 targetm.asm_out.lto_start ();
2078 if (!in_lto_p)
2080 if (flag_openmp)
2082 section_name_prefix = OMP_SECTION_NAME_PREFIX;
2083 ipa_write_summaries (true);
2085 if (flag_lto)
2087 section_name_prefix = LTO_SECTION_NAME_PREFIX;
2088 ipa_write_summaries (false);
2092 if (flag_generate_lto)
2093 targetm.asm_out.lto_end ();
2095 if (!flag_ltrans && (in_lto_p || !flag_lto || flag_fat_lto_objects))
2096 execute_ipa_pass_list (passes->all_regular_ipa_passes);
2097 invoke_plugin_callbacks (PLUGIN_ALL_IPA_PASSES_END, NULL);
2099 bitmap_obstack_release (NULL);
2103 /* Return string alias is alias of. */
2105 static tree
2106 get_alias_symbol (tree decl)
2108 tree alias = lookup_attribute ("alias", DECL_ATTRIBUTES (decl));
2109 return get_identifier (TREE_STRING_POINTER
2110 (TREE_VALUE (TREE_VALUE (alias))));
2114 /* Weakrefs may be associated to external decls and thus not output
2115 at expansion time. Emit all necessary aliases. */
2117 static void
2118 output_weakrefs (void)
2120 symtab_node *node;
2121 FOR_EACH_SYMBOL (node)
2122 if (node->alias
2123 && !TREE_ASM_WRITTEN (node->decl)
2124 && node->weakref)
2126 tree target;
2128 /* Weakrefs are special by not requiring target definition in current
2129 compilation unit. It is thus bit hard to work out what we want to
2130 alias.
2131 When alias target is defined, we need to fetch it from symtab reference,
2132 otherwise it is pointed to by alias_target. */
2133 if (node->alias_target)
2134 target = (DECL_P (node->alias_target)
2135 ? DECL_ASSEMBLER_NAME (node->alias_target)
2136 : node->alias_target);
2137 else if (node->analyzed)
2138 target = DECL_ASSEMBLER_NAME (symtab_alias_target (node)->decl);
2139 else
2141 gcc_unreachable ();
2142 target = get_alias_symbol (node->decl);
2144 do_assemble_alias (node->decl, target);
2148 /* Initialize callgraph dump file. */
2150 void
2151 init_cgraph (void)
2153 if (!cgraph_dump_file)
2154 cgraph_dump_file = dump_begin (TDI_cgraph, NULL);
2158 /* Perform simple optimizations based on callgraph. */
2160 void
2161 compile (void)
2163 if (seen_error ())
2164 return;
2166 #ifdef ENABLE_CHECKING
2167 verify_symtab ();
2168 #endif
2170 timevar_push (TV_CGRAPHOPT);
2171 if (pre_ipa_mem_report)
2173 fprintf (stderr, "Memory consumption before IPA\n");
2174 dump_memory_report (false);
2176 if (!quiet_flag)
2177 fprintf (stderr, "Performing interprocedural optimizations\n");
2178 cgraph_state = CGRAPH_STATE_IPA;
2180 /* If LTO is enabled, initialize the streamer hooks needed by GIMPLE. */
2181 if (flag_lto || flag_openmp)
2182 lto_streamer_hooks_init ();
2184 /* Don't run the IPA passes if there was any error or sorry messages. */
2185 if (!seen_error ())
2186 ipa_passes ();
2188 /* Do nothing else if any IPA pass found errors or if we are just streaming LTO. */
2189 if (seen_error ()
2190 || (!in_lto_p && flag_lto && !flag_fat_lto_objects))
2192 timevar_pop (TV_CGRAPHOPT);
2193 return;
2196 /* This pass remove bodies of extern inline functions we never inlined.
2197 Do this later so other IPA passes see what is really going on. */
2198 symtab_remove_unreachable_nodes (false, dump_file);
2199 cgraph_global_info_ready = true;
2200 if (cgraph_dump_file)
2202 fprintf (cgraph_dump_file, "Optimized ");
2203 dump_symtab (cgraph_dump_file);
2205 if (post_ipa_mem_report)
2207 fprintf (stderr, "Memory consumption after IPA\n");
2208 dump_memory_report (false);
2210 timevar_pop (TV_CGRAPHOPT);
2212 /* Output everything. */
2213 (*debug_hooks->assembly_start) ();
2214 if (!quiet_flag)
2215 fprintf (stderr, "Assembling functions:\n");
2216 #ifdef ENABLE_CHECKING
2217 verify_symtab ();
2218 #endif
2220 cgraph_materialize_all_clones ();
2221 bitmap_obstack_initialize (NULL);
2222 execute_ipa_pass_list (g->get_passes ()->all_late_ipa_passes);
2223 symtab_remove_unreachable_nodes (true, dump_file);
2224 #ifdef ENABLE_CHECKING
2225 verify_symtab ();
2226 #endif
2227 bitmap_obstack_release (NULL);
2228 mark_functions_to_output ();
2230 /* When weakref support is missing, we autmatically translate all
2231 references to NODE to references to its ultimate alias target.
2232 The renaming mechanizm uses flag IDENTIFIER_TRANSPARENT_ALIAS and
2233 TREE_CHAIN.
2235 Set up this mapping before we output any assembler but once we are sure
2236 that all symbol renaming is done.
2238 FIXME: All this uglyness can go away if we just do renaming at gimple
2239 level by physically rewritting the IL. At the moment we can only redirect
2240 calls, so we need infrastructure for renaming references as well. */
2241 #ifndef ASM_OUTPUT_WEAKREF
2242 symtab_node *node;
2244 FOR_EACH_SYMBOL (node)
2245 if (node->alias
2246 && lookup_attribute ("weakref", DECL_ATTRIBUTES (node->decl)))
2248 IDENTIFIER_TRANSPARENT_ALIAS
2249 (DECL_ASSEMBLER_NAME (node->decl)) = 1;
2250 TREE_CHAIN (DECL_ASSEMBLER_NAME (node->decl))
2251 = (node->alias_target ? node->alias_target
2252 : DECL_ASSEMBLER_NAME (symtab_alias_target (node)->decl));
2254 #endif
2256 cgraph_state = CGRAPH_STATE_EXPANSION;
2258 if (!flag_toplevel_reorder)
2259 output_in_order ();
2260 else
2262 output_asm_statements ();
2264 expand_all_functions ();
2265 varpool_output_variables ();
2268 cgraph_process_new_functions ();
2269 cgraph_state = CGRAPH_STATE_FINISHED;
2270 output_weakrefs ();
2272 if (cgraph_dump_file)
2274 fprintf (cgraph_dump_file, "\nFinal ");
2275 dump_symtab (cgraph_dump_file);
2277 #ifdef ENABLE_CHECKING
2278 verify_symtab ();
2279 /* Double check that all inline clones are gone and that all
2280 function bodies have been released from memory. */
2281 if (!seen_error ())
2283 struct cgraph_node *node;
2284 bool error_found = false;
2286 FOR_EACH_DEFINED_FUNCTION (node)
2287 if (node->global.inlined_to
2288 || gimple_has_body_p (node->decl))
2290 error_found = true;
2291 dump_cgraph_node (stderr, node);
2293 if (error_found)
2294 internal_error ("nodes with unreleased memory found");
2296 #endif
2300 /* Analyze the whole compilation unit once it is parsed completely. */
2302 void
2303 finalize_compilation_unit (void)
2305 timevar_push (TV_CGRAPH);
2307 /* If we're here there's no current function anymore. Some frontends
2308 are lazy in clearing these. */
2309 current_function_decl = NULL;
2310 set_cfun (NULL);
2312 /* Do not skip analyzing the functions if there were errors, we
2313 miss diagnostics for following functions otherwise. */
2315 /* Emit size functions we didn't inline. */
2316 finalize_size_functions ();
2318 /* Mark alias targets necessary and emit diagnostics. */
2319 handle_alias_pairs ();
2321 if (!quiet_flag)
2323 fprintf (stderr, "\nAnalyzing compilation unit\n");
2324 fflush (stderr);
2327 if (flag_dump_passes)
2328 dump_passes ();
2330 /* Gimplify and lower all functions, compute reachability and
2331 remove unreachable nodes. */
2332 analyze_functions ();
2334 /* Mark alias targets necessary and emit diagnostics. */
2335 handle_alias_pairs ();
2337 /* Gimplify and lower thunks. */
2338 analyze_functions ();
2340 /* Finally drive the pass manager. */
2341 compile ();
2343 timevar_pop (TV_CGRAPH);
2347 #include "gt-cgraphunit.h"