1 /* Vector API for GNU compiler.
2 Copyright (C) 2004-2013 Free Software Foundation, Inc.
3 Contributed by Nathan Sidwell <nathan@codesourcery.com>
4 Re-implemented in C++ by Diego Novillo <dnovillo@google.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
25 /* FIXME - When compiling some of the gen* binaries, we cannot enable GC
26 support because the headers generated by gengtype are still not
27 present. In particular, the header file gtype-desc.h is missing,
28 so compilation may fail if we try to include ggc.h.
30 Since we use some of those declarations, we need to provide them
31 (even if the GC-based templates are not used). This is not a
32 problem because the code that runs before gengtype is built will
33 never need to use GC vectors. But it does force us to declare
34 these functions more than once. */
36 #define VEC_GC_ENABLED 0
38 #define VEC_GC_ENABLED 1
39 #endif // GENERATOR_FILE
41 #include "statistics.h" // For CXX_MEM_STAT_INFO.
47 /* Even if we think that GC is not enabled, the test that sets it is
48 weak. There are files compiled with -DGENERATOR_FILE that already
49 include ggc.h. We only need to provide these definitions if ggc.h
50 has not been included. Sigh. */
51 extern void ggc_free (void *);
52 extern size_t ggc_round_alloc_size (size_t requested_size);
53 extern void *ggc_realloc_stat (void *, size_t MEM_STAT_DECL);
55 #endif // VEC_GC_ENABLED
57 /* Templated vector type and associated interfaces.
59 The interface functions are typesafe and use inline functions,
60 sometimes backed by out-of-line generic functions. The vectors are
61 designed to interoperate with the GTY machinery.
63 There are both 'index' and 'iterate' accessors. The index accessor
64 is implemented by operator[]. The iterator returns a boolean
65 iteration condition and updates the iteration variable passed by
66 reference. Because the iterator will be inlined, the address-of
67 can be optimized away.
69 Each operation that increases the number of active elements is
70 available in 'quick' and 'safe' variants. The former presumes that
71 there is sufficient allocated space for the operation to succeed
72 (it dies if there is not). The latter will reallocate the
73 vector, if needed. Reallocation causes an exponential increase in
74 vector size. If you know you will be adding N elements, it would
75 be more efficient to use the reserve operation before adding the
76 elements with the 'quick' operation. This will ensure there are at
77 least as many elements as you ask for, it will exponentially
78 increase if there are too few spare slots. If you want reserve a
79 specific number of slots, but do not want the exponential increase
80 (for instance, you know this is the last allocation), use the
81 reserve_exact operation. You can also create a vector of a
82 specific size from the get go.
84 You should prefer the push and pop operations, as they append and
85 remove from the end of the vector. If you need to remove several
86 items in one go, use the truncate operation. The insert and remove
87 operations allow you to change elements in the middle of the
88 vector. There are two remove operations, one which preserves the
89 element ordering 'ordered_remove', and one which does not
90 'unordered_remove'. The latter function copies the end element
91 into the removed slot, rather than invoke a memmove operation. The
92 'lower_bound' function will determine where to place an item in the
93 array using insert that will maintain sorted order.
95 Vectors are template types with three arguments: the type of the
96 elements in the vector, the allocation strategy, and the physical
99 Four allocation strategies are supported:
101 - Heap: allocation is done using malloc/free. This is the
102 default allocation strategy.
104 - Stack: allocation is done using alloca.
106 - GC: allocation is done using ggc_alloc/ggc_free.
108 - GC atomic: same as GC with the exception that the elements
109 themselves are assumed to be of an atomic type that does
110 not need to be garbage collected. This means that marking
111 routines do not need to traverse the array marking the
112 individual elements. This increases the performance of
115 Two physical layouts are supported:
117 - Embedded: The vector is structured using the trailing array
118 idiom. The last member of the structure is an array of size
119 1. When the vector is initially allocated, a single memory
120 block is created to hold the vector's control data and the
121 array of elements. These vectors cannot grow without
122 reallocation (see discussion on embeddable vectors below).
124 - Space efficient: The vector is structured as a pointer to an
125 embedded vector. This is the default layout. It means that
126 vectors occupy a single word of storage before initial
127 allocation. Vectors are allowed to grow (the internal
128 pointer is reallocated but the main vector instance does not
131 The type, allocation and layout are specified when the vector is
134 If you need to directly manipulate a vector, then the 'address'
135 accessor will return the address of the start of the vector. Also
136 the 'space' predicate will tell you whether there is spare capacity
137 in the vector. You will not normally need to use these two functions.
139 Notes on the different layout strategies
141 * Embeddable vectors (vec<T, A, vl_embed>)
143 These vectors are suitable to be embedded in other data
144 structures so that they can be pre-allocated in a contiguous
147 Embeddable vectors are implemented using the trailing array
148 idiom, thus they are not resizeable without changing the address
149 of the vector object itself. This means you cannot have
150 variables or fields of embeddable vector type -- always use a
151 pointer to a vector. The one exception is the final field of a
152 structure, which could be a vector type.
154 You will have to use the embedded_size & embedded_init calls to
155 create such objects, and they will not be resizeable (so the
156 'safe' allocation variants are not available).
158 Properties of embeddable vectors:
160 - The whole vector and control data are allocated in a single
161 contiguous block. It uses the trailing-vector idiom, so
162 allocation must reserve enough space for all the elements
163 in the vector plus its control data.
164 - The vector cannot be re-allocated.
165 - The vector cannot grow nor shrink.
166 - No indirections needed for access/manipulation.
167 - It requires 2 words of storage (prior to vector allocation).
170 * Space efficient vector (vec<T, A, vl_ptr>)
172 These vectors can grow dynamically and are allocated together
173 with their control data. They are suited to be included in data
174 structures. Prior to initial allocation, they only take a single
177 These vectors are implemented as a pointer to embeddable vectors.
178 The semantics allow for this pointer to be NULL to represent
179 empty vectors. This way, empty vectors occupy minimal space in
180 the structure containing them.
184 - The whole vector and control data are allocated in a single
186 - The whole vector may be re-allocated.
187 - Vector data may grow and shrink.
188 - Access and manipulation requires a pointer test and
190 - It requires 1 word of storage (prior to vector allocation).
192 An example of their use would be,
195 // A space-efficient vector of tree pointers in GC memory.
196 vec<tree, va_gc, vl_ptr> v;
201 if (s->v.length ()) { we have some contents }
202 s->v.safe_push (decl); // append some decl onto the end
203 for (ix = 0; s->v.iterate (ix, &elt); ix++)
204 { do something with elt }
207 /* Support function for statistics. */
208 extern void dump_vec_loc_statistics (void);
211 /* Control data for vectors. This contains the number of allocated
212 and used slots inside a vector. */
216 /* FIXME - These fields should be private, but we need to cater to
217 compilers that have stricter notions of PODness for types. */
219 /* Memory allocation support routines in vec.c. */
220 void register_overhead (size_t, const char *, int, const char *);
221 void release_overhead (void);
222 static unsigned calculate_allocation (vec_prefix *, unsigned, bool);
224 /* Note that vec_prefix should be a base class for vec, but we use
225 offsetof() on vector fields of tree structures (e.g.,
226 tree_binfo::base_binfos), and offsetof only supports base types.
228 To compensate, we make vec_prefix a field inside vec and make
229 vec a friend class of vec_prefix so it can access its fields. */
230 template <typename, typename, typename> friend struct vec;
232 /* The allocator types also need access to our internals. */
234 friend struct va_gc_atomic;
235 friend struct va_heap;
236 friend struct va_stack;
242 template<typename, typename, typename> struct vec;
244 /* Valid vector layouts
246 vl_embed - Embeddable vector that uses the trailing array idiom.
247 vl_ptr - Space efficient vector that uses a pointer to an
248 embeddable vector. */
253 /* Types of supported allocations
255 va_heap - Allocation uses malloc/free.
256 va_gc - Allocation uses ggc_alloc.
257 va_gc_atomic - Same as GC, but individual elements of the array
258 do not need to be marked during collection.
259 va_stack - Allocation uses alloca. */
261 /* Allocator type for heap vectors. */
264 /* Heap vectors are frequently regular instances, so use the vl_ptr
266 typedef vl_ptr default_layout;
269 static void reserve (vec<T, va_heap, vl_embed> *&, unsigned, bool
273 static void release (vec<T, va_heap, vl_embed> *&);
277 /* Allocator for heap memory. Ensure there are at least RESERVE free
278 slots in V. If EXACT is true, grow exactly, else grow
279 exponentially. As a special case, if the vector had not been
280 allocated and and RESERVE is 0, no vector will be created. */
284 va_heap::reserve (vec<T, va_heap, vl_embed> *&v, unsigned reserve, bool exact
288 = vec_prefix::calculate_allocation (v ? &v->vecpfx_ : 0, reserve, exact);
295 if (GATHER_STATISTICS && v)
296 v->vecpfx_.release_overhead ();
298 size_t size = vec<T, va_heap, vl_embed>::embedded_size (alloc);
299 unsigned nelem = v ? v->length () : 0;
300 v = static_cast <vec<T, va_heap, vl_embed> *> (xrealloc (v, size));
301 v->embedded_init (alloc, nelem);
303 if (GATHER_STATISTICS)
304 v->vecpfx_.register_overhead (size FINAL_PASS_MEM_STAT);
308 /* Free the heap space allocated for vector V. */
312 va_heap::release (vec<T, va_heap, vl_embed> *&v)
317 if (GATHER_STATISTICS)
318 v->vecpfx_.release_overhead ();
324 /* Allocator type for GC vectors. Notice that we need the structure
325 declaration even if GC is not enabled. */
329 /* Use vl_embed as the default layout for GC vectors. Due to GTY
330 limitations, GC vectors must always be pointers, so it is more
331 efficient to use a pointer to the vl_embed layout, rather than
332 using a pointer to a pointer as would be the case with vl_ptr. */
333 typedef vl_embed default_layout;
335 template<typename T, typename A>
336 static void reserve (vec<T, A, vl_embed> *&, unsigned, bool
339 template<typename T, typename A>
340 static void release (vec<T, A, vl_embed> *&v) { v = NULL; }
344 /* Allocator for GC memory. Ensure there are at least RESERVE free
345 slots in V. If EXACT is true, grow exactly, else grow
346 exponentially. As a special case, if the vector had not been
347 allocated and and RESERVE is 0, no vector will be created. */
349 template<typename T, typename A>
351 va_gc::reserve (vec<T, A, vl_embed> *&v, unsigned reserve, bool exact
355 = vec_prefix::calculate_allocation (v ? &v->vecpfx_ : 0, reserve, exact);
363 /* Calculate the amount of space we want. */
364 size_t size = vec<T, A, vl_embed>::embedded_size (alloc);
366 /* Ask the allocator how much space it will really give us. */
367 size = ::ggc_round_alloc_size (size);
369 /* Adjust the number of slots accordingly. */
370 size_t vec_offset = sizeof (vec_prefix);
371 size_t elt_size = sizeof (T);
372 alloc = (size - vec_offset) / elt_size;
374 /* And finally, recalculate the amount of space we ask for. */
375 size = vec_offset + alloc * elt_size;
377 unsigned nelem = v ? v->length () : 0;
378 v = static_cast <vec<T, A, vl_embed> *> (::ggc_realloc_stat (v, size
380 v->embedded_init (alloc, nelem);
384 /* Allocator type for GC vectors. This is for vectors of types
385 atomics w.r.t. collection, so allocation and deallocation is
386 completely inherited from va_gc. */
387 struct va_gc_atomic : va_gc
392 /* Allocator type for stack vectors. */
395 /* Use vl_ptr as the default layout for stack vectors. */
396 typedef vl_ptr default_layout;
399 static void alloc (vec<T, va_stack, vl_ptr>&, unsigned,
400 vec<T, va_stack, vl_embed> *);
402 template <typename T>
403 static void reserve (vec<T, va_stack, vl_embed> *&, unsigned, bool
406 template <typename T>
407 static void release (vec<T, va_stack, vl_embed> *&);
410 /* Helper functions to keep track of vectors allocated on the stack. */
411 void register_stack_vec (void *);
412 int stack_vec_register_index (void *);
413 void unregister_stack_vec (unsigned);
415 /* Allocate a vector V which uses alloca for the initial allocation.
416 SPACE is space allocated using alloca. NELEMS is the number of
417 entries allocated. */
421 va_stack::alloc (vec<T, va_stack, vl_ptr> &v, unsigned nelems,
422 vec<T, va_stack, vl_embed> *space)
425 register_stack_vec (static_cast<void *> (v.vec_));
426 v.vec_->embedded_init (nelems, 0);
430 /* Reserve NELEMS slots for a vector initially allocated on the stack.
431 When this happens, we switch back to heap allocation. We remove
432 the vector from stack_vecs, if it is there, since we no longer need
433 to avoid freeing it. If EXACT is true, grow exactly, otherwise
434 grow exponentially. */
438 va_stack::reserve (vec<T, va_stack, vl_embed> *&v, unsigned nelems, bool exact
441 int ix = stack_vec_register_index (static_cast<void *> (v));
443 unregister_stack_vec (ix);
446 /* V is already on the heap. */
447 va_heap::reserve (reinterpret_cast<vec<T, va_heap, vl_embed> *&> (v),
448 nelems, exact PASS_MEM_STAT);
452 /* Move VEC_ to the heap. */
453 nelems += v->vecpfx_.num_;
454 vec<T, va_stack, vl_embed> *oldvec = v;
456 va_heap::reserve (reinterpret_cast<vec<T, va_heap, vl_embed> *&>(v), nelems,
457 exact PASS_MEM_STAT);
460 v->vecpfx_.num_ = oldvec->length ();
463 oldvec->length () * sizeof (T));
468 /* Free a vector allocated on the stack. Don't actually free it if we
469 find it in the hash table. */
473 va_stack::release (vec<T, va_stack, vl_embed> *&v)
478 int ix = stack_vec_register_index (static_cast<void *> (v));
481 unregister_stack_vec (ix);
486 /* The vector was not on the list of vectors allocated on the stack, so it
487 must be allocated on the heap. */
488 va_heap::release (reinterpret_cast<vec<T, va_heap, vl_embed> *&> (v));
493 /* Generic vector template. Default values for A and L indicate the
494 most commonly used strategies.
496 FIXME - Ideally, they would all be vl_ptr to encourage using regular
497 instances for vectors, but the existing GTY machinery is limited
498 in that it can only deal with GC objects that are pointers
501 This means that vector operations that need to deal with
502 potentially NULL pointers, must be provided as free
503 functions (see the vec_safe_* functions above). */
505 typename A = va_heap,
506 typename L = typename A::default_layout>
507 struct GTY((user)) vec
511 /* Type to provide NULL values for vec<T, A, L>. This is used to
512 provide nil initializers for vec instances. Since vec must be
513 a POD, we cannot have proper ctor/dtor for it. To initialize
514 a vec instance, you can assign it the value vNULL. */
517 template <typename T, typename A, typename L>
518 operator vec<T, A, L> () { return vec<T, A, L>(); }
523 /* Embeddable vector. These vectors are suitable to be embedded
524 in other data structures so that they can be pre-allocated in a
525 contiguous memory block.
527 Embeddable vectors are implemented using the trailing array idiom,
528 thus they are not resizeable without changing the address of the
529 vector object itself. This means you cannot have variables or
530 fields of embeddable vector type -- always use a pointer to a
531 vector. The one exception is the final field of a structure, which
532 could be a vector type.
534 You will have to use the embedded_size & embedded_init calls to
535 create such objects, and they will not be resizeable (so the 'safe'
536 allocation variants are not available).
540 - The whole vector and control data are allocated in a single
541 contiguous block. It uses the trailing-vector idiom, so
542 allocation must reserve enough space for all the elements
543 in the vector plus its control data.
544 - The vector cannot be re-allocated.
545 - The vector cannot grow nor shrink.
546 - No indirections needed for access/manipulation.
547 - It requires 2 words of storage (prior to vector allocation). */
549 template<typename T, typename A>
550 struct GTY((user)) vec<T, A, vl_embed>
553 unsigned allocated (void) const { return vecpfx_.alloc_; }
554 unsigned length (void) const { return vecpfx_.num_; }
555 bool is_empty (void) const { return vecpfx_.num_ == 0; }
556 T *address (void) { return vecdata_; }
557 const T *address (void) const { return vecdata_; }
558 const T &operator[] (unsigned) const;
559 T &operator[] (unsigned);
561 bool space (unsigned) const;
562 bool iterate (unsigned, T *) const;
563 bool iterate (unsigned, T **) const;
564 vec *copy (ALONE_CXX_MEM_STAT_INFO) const;
566 void splice (vec *src);
567 T *quick_push (const T &);
569 void truncate (unsigned);
570 void quick_insert (unsigned, const T &);
571 void ordered_remove (unsigned);
572 void unordered_remove (unsigned);
573 void block_remove (unsigned, unsigned);
574 void qsort (int (*) (const void *, const void *));
575 unsigned lower_bound (T, bool (*)(const T &, const T &)) const;
576 static size_t embedded_size (unsigned);
577 void embedded_init (unsigned, unsigned = 0);
578 void quick_grow (unsigned len);
579 void quick_grow_cleared (unsigned len);
581 /* vec class can access our internal data and functions. */
582 template <typename, typename, typename> friend struct vec;
584 /* The allocator types also need access to our internals. */
586 friend struct va_gc_atomic;
587 friend struct va_heap;
588 friend struct va_stack;
590 /* FIXME - These fields should be private, but we need to cater to
591 compilers that have stricter notions of PODness for types. */
597 /* Convenience wrapper functions to use when dealing with pointers to
598 embedded vectors. Some functionality for these vectors must be
599 provided via free functions for these reasons:
601 1- The pointer may be NULL (e.g., before initial allocation).
603 2- When the vector needs to grow, it must be reallocated, so
604 the pointer will change its value.
606 Because of limitations with the current GC machinery, all vectors
607 in GC memory *must* be pointers. */
610 /* If V contains no room for NELEMS elements, return false. Otherwise,
612 template<typename T, typename A>
614 vec_safe_space (const vec<T, A, vl_embed> *v, unsigned nelems)
616 return v ? v->space (nelems) : nelems == 0;
620 /* If V is NULL, return 0. Otherwise, return V->length(). */
621 template<typename T, typename A>
623 vec_safe_length (const vec<T, A, vl_embed> *v)
625 return v ? v->length () : 0;
629 /* If V is NULL, return NULL. Otherwise, return V->address(). */
630 template<typename T, typename A>
632 vec_safe_address (vec<T, A, vl_embed> *v)
634 return v ? v->address () : NULL;
638 /* If V is NULL, return true. Otherwise, return V->is_empty(). */
639 template<typename T, typename A>
641 vec_safe_is_empty (vec<T, A, vl_embed> *v)
643 return v ? v->is_empty () : true;
647 /* If V does not have space for NELEMS elements, call
648 V->reserve(NELEMS, EXACT). */
649 template<typename T, typename A>
651 vec_safe_reserve (vec<T, A, vl_embed> *&v, unsigned nelems, bool exact = false
654 bool extend = nelems ? !vec_safe_space (v, nelems) : false;
656 A::reserve (v, nelems, exact PASS_MEM_STAT);
660 template<typename T, typename A>
662 vec_safe_reserve_exact (vec<T, A, vl_embed> *&v, unsigned nelems
665 return vec_safe_reserve (v, nelems, true PASS_MEM_STAT);
669 /* Allocate GC memory for V with space for NELEMS slots. If NELEMS
670 is 0, V is initialized to NULL. */
672 template<typename T, typename A>
674 vec_alloc (vec<T, A, vl_embed> *&v, unsigned nelems CXX_MEM_STAT_INFO)
677 vec_safe_reserve (v, nelems, false PASS_MEM_STAT);
681 /* Free the GC memory allocated by vector V and set it to NULL. */
683 template<typename T, typename A>
685 vec_free (vec<T, A, vl_embed> *&v)
691 /* Grow V to length LEN. Allocate it, if necessary. */
692 template<typename T, typename A>
694 vec_safe_grow (vec<T, A, vl_embed> *&v, unsigned len CXX_MEM_STAT_INFO)
696 unsigned oldlen = vec_safe_length (v);
697 gcc_checking_assert (len >= oldlen);
698 vec_safe_reserve_exact (v, len - oldlen PASS_MEM_STAT);
703 /* If V is NULL, allocate it. Call V->safe_grow_cleared(LEN). */
704 template<typename T, typename A>
706 vec_safe_grow_cleared (vec<T, A, vl_embed> *&v, unsigned len CXX_MEM_STAT_INFO)
708 unsigned oldlen = vec_safe_length (v);
709 vec_safe_grow (v, len PASS_MEM_STAT);
710 memset (&(v->address()[oldlen]), 0, sizeof (T) * (len - oldlen));
714 /* If V is NULL return false, otherwise return V->iterate(IX, PTR). */
715 template<typename T, typename A>
717 vec_safe_iterate (const vec<T, A, vl_embed> *v, unsigned ix, T **ptr)
720 return v->iterate (ix, ptr);
728 template<typename T, typename A>
730 vec_safe_iterate (const vec<T, A, vl_embed> *v, unsigned ix, T *ptr)
733 return v->iterate (ix, ptr);
742 /* If V has no room for one more element, reallocate it. Then call
743 V->quick_push(OBJ). */
744 template<typename T, typename A>
746 vec_safe_push (vec<T, A, vl_embed> *&v, const T &obj CXX_MEM_STAT_INFO)
748 vec_safe_reserve (v, 1, false PASS_MEM_STAT);
749 return v->quick_push (obj);
753 /* if V has no room for one more element, reallocate it. Then call
754 V->quick_insert(IX, OBJ). */
755 template<typename T, typename A>
757 vec_safe_insert (vec<T, A, vl_embed> *&v, unsigned ix, const T &obj
760 vec_safe_reserve (v, 1, false PASS_MEM_STAT);
761 v->quick_insert (ix, obj);
765 /* If V is NULL, do nothing. Otherwise, call V->truncate(SIZE). */
766 template<typename T, typename A>
768 vec_safe_truncate (vec<T, A, vl_embed> *v, unsigned size)
775 /* If SRC is not NULL, return a pointer to a copy of it. */
776 template<typename T, typename A>
777 inline vec<T, A, vl_embed> *
778 vec_safe_copy (vec<T, A, vl_embed> *src)
780 return src ? src->copy () : NULL;
783 /* Copy the elements from SRC to the end of DST as if by memcpy.
784 Reallocate DST, if necessary. */
785 template<typename T, typename A>
787 vec_safe_splice (vec<T, A, vl_embed> *&dst, vec<T, A, vl_embed> *src
790 unsigned src_len = vec_safe_length (src);
793 vec_safe_reserve_exact (dst, vec_safe_length (dst) + src_len
800 /* Index into vector. Return the IX'th element. IX must be in the
801 domain of the vector. */
803 template<typename T, typename A>
805 vec<T, A, vl_embed>::operator[] (unsigned ix) const
807 gcc_checking_assert (ix < vecpfx_.num_);
811 template<typename T, typename A>
813 vec<T, A, vl_embed>::operator[] (unsigned ix)
815 gcc_checking_assert (ix < vecpfx_.num_);
820 /* Get the final element of the vector, which must not be empty. */
822 template<typename T, typename A>
824 vec<T, A, vl_embed>::last (void)
826 gcc_checking_assert (vecpfx_.num_ > 0);
827 return (*this)[vecpfx_.num_ - 1];
831 /* If this vector has space for NELEMS additional entries, return
832 true. You usually only need to use this if you are doing your
833 own vector reallocation, for instance on an embedded vector. This
834 returns true in exactly the same circumstances that vec::reserve
837 template<typename T, typename A>
839 vec<T, A, vl_embed>::space (unsigned nelems) const
841 return vecpfx_.alloc_ - vecpfx_.num_ >= nelems;
845 /* Return iteration condition and update PTR to point to the IX'th
846 element of this vector. Use this to iterate over the elements of a
849 for (ix = 0; vec<T, A>::iterate(v, ix, &ptr); ix++)
852 template<typename T, typename A>
854 vec<T, A, vl_embed>::iterate (unsigned ix, T *ptr) const
856 if (ix < vecpfx_.num_)
869 /* Return iteration condition and update *PTR to point to the
870 IX'th element of this vector. Use this to iterate over the
871 elements of a vector as follows,
873 for (ix = 0; v->iterate(ix, &ptr); ix++)
876 This variant is for vectors of objects. */
878 template<typename T, typename A>
880 vec<T, A, vl_embed>::iterate (unsigned ix, T **ptr) const
882 if (ix < vecpfx_.num_)
884 *ptr = CONST_CAST (T *, &vecdata_[ix]);
895 /* Return a pointer to a copy of this vector. */
897 template<typename T, typename A>
898 inline vec<T, A, vl_embed> *
899 vec<T, A, vl_embed>::copy (ALONE_MEM_STAT_DECL) const
901 vec<T, A, vl_embed> *new_vec = NULL;
902 unsigned len = length ();
905 vec_alloc (new_vec, len PASS_MEM_STAT);
906 new_vec->embedded_init (len, len);
907 memcpy (new_vec->address(), vecdata_, sizeof (T) * len);
913 /* Copy the elements from SRC to the end of this vector as if by memcpy.
914 The vector must have sufficient headroom available. */
916 template<typename T, typename A>
918 vec<T, A, vl_embed>::splice (vec<T, A, vl_embed> &src)
920 unsigned len = src.length();
923 gcc_checking_assert (space (len));
924 memcpy (address() + length(), src.address(), len * sizeof (T));
929 template<typename T, typename A>
931 vec<T, A, vl_embed>::splice (vec<T, A, vl_embed> *src)
938 /* Push OBJ (a new element) onto the end of the vector. There must be
939 sufficient space in the vector. Return a pointer to the slot
940 where OBJ was inserted. */
942 template<typename T, typename A>
944 vec<T, A, vl_embed>::quick_push (const T &obj)
946 gcc_checking_assert (space (1));
947 T *slot = &vecdata_[vecpfx_.num_++];
953 /* Pop and return the last element off the end of the vector. */
955 template<typename T, typename A>
957 vec<T, A, vl_embed>::pop (void)
959 gcc_checking_assert (length () > 0);
960 return vecdata_[--vecpfx_.num_];
964 /* Set the length of the vector to SIZE. The new length must be less
965 than or equal to the current length. This is an O(1) operation. */
967 template<typename T, typename A>
969 vec<T, A, vl_embed>::truncate (unsigned size)
971 gcc_checking_assert (length () >= size);
976 /* Insert an element, OBJ, at the IXth position of this vector. There
977 must be sufficient space. */
979 template<typename T, typename A>
981 vec<T, A, vl_embed>::quick_insert (unsigned ix, const T &obj)
983 gcc_checking_assert (length () < allocated ());
984 gcc_checking_assert (ix <= length ());
985 T *slot = &vecdata_[ix];
986 memmove (slot + 1, slot, (vecpfx_.num_++ - ix) * sizeof (T));
991 /* Remove an element from the IXth position of this vector. Ordering of
992 remaining elements is preserved. This is an O(N) operation due to
995 template<typename T, typename A>
997 vec<T, A, vl_embed>::ordered_remove (unsigned ix)
999 gcc_checking_assert (ix < length());
1000 T *slot = &vecdata_[ix];
1001 memmove (slot, slot + 1, (--vecpfx_.num_ - ix) * sizeof (T));
1005 /* Remove an element from the IXth position of this vector. Ordering of
1006 remaining elements is destroyed. This is an O(1) operation. */
1008 template<typename T, typename A>
1010 vec<T, A, vl_embed>::unordered_remove (unsigned ix)
1012 gcc_checking_assert (ix < length());
1013 vecdata_[ix] = vecdata_[--vecpfx_.num_];
1017 /* Remove LEN elements starting at the IXth. Ordering is retained.
1018 This is an O(N) operation due to memmove. */
1020 template<typename T, typename A>
1022 vec<T, A, vl_embed>::block_remove (unsigned ix, unsigned len)
1024 gcc_checking_assert (ix + len <= length());
1025 T *slot = &vecdata_[ix];
1026 vecpfx_.num_ -= len;
1027 memmove (slot, slot + len, (vecpfx_.num_ - ix) * sizeof (T));
1031 /* Sort the contents of this vector with qsort. CMP is the comparison
1032 function to pass to qsort. */
1034 template<typename T, typename A>
1036 vec<T, A, vl_embed>::qsort (int (*cmp) (const void *, const void *))
1038 ::qsort (address(), length(), sizeof (T), cmp);
1042 /* Find and return the first position in which OBJ could be inserted
1043 without changing the ordering of this vector. LESSTHAN is a
1044 function that returns true if the first argument is strictly less
1047 template<typename T, typename A>
1049 vec<T, A, vl_embed>::lower_bound (T obj, bool (*lessthan)(const T &, const T &))
1052 unsigned int len = length ();
1053 unsigned int half, middle;
1054 unsigned int first = 0;
1060 T middle_elem = (*this)[middle];
1061 if (lessthan (middle_elem, obj))
1065 len = len - half - 1;
1074 /* Return the number of bytes needed to embed an instance of an
1075 embeddable vec inside another data structure.
1077 Use these methods to determine the required size and initialization
1078 of a vector V of type T embedded within another structure (as the
1081 size_t vec<T, A, vl_embed>::embedded_size (unsigned alloc);
1082 void v->embedded_init(unsigned alloc, unsigned num);
1084 These allow the caller to perform the memory allocation. */
1086 template<typename T, typename A>
1088 vec<T, A, vl_embed>::embedded_size (unsigned alloc)
1090 typedef vec<T, A, vl_embed> vec_embedded;
1091 return offsetof (vec_embedded, vecdata_) + alloc * sizeof (T);
1095 /* Initialize the vector to contain room for ALLOC elements and
1096 NUM active elements. */
1098 template<typename T, typename A>
1100 vec<T, A, vl_embed>::embedded_init (unsigned alloc, unsigned num)
1102 vecpfx_.alloc_ = alloc;
1107 /* Grow the vector to a specific length. LEN must be as long or longer than
1108 the current length. The new elements are uninitialized. */
1110 template<typename T, typename A>
1112 vec<T, A, vl_embed>::quick_grow (unsigned len)
1114 gcc_checking_assert (length () <= len && len <= vecpfx_.alloc_);
1119 /* Grow the vector to a specific length. LEN must be as long or longer than
1120 the current length. The new elements are initialized to zero. */
1122 template<typename T, typename A>
1124 vec<T, A, vl_embed>::quick_grow_cleared (unsigned len)
1126 unsigned oldlen = length ();
1128 memset (&(address()[oldlen]), 0, sizeof (T) * (len - oldlen));
1132 /* Garbage collection support for vec<T, A, vl_embed>. */
1134 template<typename T>
1136 gt_ggc_mx (vec<T, va_gc> *v)
1138 extern void gt_ggc_mx (T &);
1139 for (unsigned i = 0; i < v->length (); i++)
1140 gt_ggc_mx ((*v)[i]);
1143 template<typename T>
1145 gt_ggc_mx (vec<T, va_gc_atomic, vl_embed> *v ATTRIBUTE_UNUSED)
1147 /* Nothing to do. Vectors of atomic types wrt GC do not need to
1152 /* PCH support for vec<T, A, vl_embed>. */
1154 template<typename T, typename A>
1156 gt_pch_nx (vec<T, A, vl_embed> *v)
1158 extern void gt_pch_nx (T &);
1159 for (unsigned i = 0; i < v->length (); i++)
1160 gt_pch_nx ((*v)[i]);
1163 template<typename T, typename A>
1165 gt_pch_nx (vec<T *, A, vl_embed> *v, gt_pointer_operator op, void *cookie)
1167 for (unsigned i = 0; i < v->length (); i++)
1168 op (&((*v)[i]), cookie);
1171 template<typename T, typename A>
1173 gt_pch_nx (vec<T, A, vl_embed> *v, gt_pointer_operator op, void *cookie)
1175 extern void gt_pch_nx (T *, gt_pointer_operator, void *);
1176 for (unsigned i = 0; i < v->length (); i++)
1177 gt_pch_nx (&((*v)[i]), op, cookie);
1181 /* Space efficient vector. These vectors can grow dynamically and are
1182 allocated together with their control data. They are suited to be
1183 included in data structures. Prior to initial allocation, they
1184 only take a single word of storage.
1186 These vectors are implemented as a pointer to an embeddable vector.
1187 The semantics allow for this pointer to be NULL to represent empty
1188 vectors. This way, empty vectors occupy minimal space in the
1189 structure containing them.
1193 - The whole vector and control data are allocated in a single
1195 - The whole vector may be re-allocated.
1196 - Vector data may grow and shrink.
1197 - Access and manipulation requires a pointer test and
1199 - It requires 1 word of storage (prior to vector allocation).
1204 These vectors must be PODs because they are stored in unions.
1205 (http://en.wikipedia.org/wiki/Plain_old_data_structures).
1206 As long as we use C++03, we cannot have constructors nor
1207 destructors in classes that are stored in unions. */
1209 template<typename T, typename A>
1210 struct vec<T, A, vl_ptr>
1213 /* Memory allocation and deallocation for the embedded vector.
1214 Needed because we cannot have proper ctors/dtors defined. */
1215 void create (unsigned nelems CXX_MEM_STAT_INFO);
1216 void release (void);
1218 /* Vector operations. */
1219 bool exists (void) const
1220 { return vec_ != NULL; }
1222 bool is_empty (void) const
1223 { return vec_ ? vec_->is_empty() : true; }
1225 unsigned length (void) const
1226 { return vec_ ? vec_->length() : 0; }
1229 { return vec_ ? vec_->vecdata_ : NULL; }
1231 const T *address (void) const
1232 { return vec_ ? vec_->vecdata_ : NULL; }
1234 const T &operator[] (unsigned ix) const
1235 { return (*vec_)[ix]; }
1237 bool operator!=(const vec &other) const
1238 { return !(*this == other); }
1240 bool operator==(const vec &other) const
1241 { return address() == other.address(); }
1243 T &operator[] (unsigned ix)
1244 { return (*vec_)[ix]; }
1247 { return vec_->last(); }
1249 bool space (int nelems) const
1250 { return vec_ ? vec_->space (nelems) : nelems == 0; }
1252 bool iterate (unsigned ix, T *p) const;
1253 bool iterate (unsigned ix, T **p) const;
1254 vec copy (ALONE_CXX_MEM_STAT_INFO) const;
1255 bool reserve (unsigned, bool = false CXX_MEM_STAT_INFO);
1256 bool reserve_exact (unsigned CXX_MEM_STAT_INFO);
1257 void splice (vec &);
1258 void safe_splice (vec & CXX_MEM_STAT_INFO);
1259 T *quick_push (const T &);
1260 T *safe_push (const T &CXX_MEM_STAT_INFO);
1262 void truncate (unsigned);
1263 void safe_grow (unsigned CXX_MEM_STAT_INFO);
1264 void safe_grow_cleared (unsigned CXX_MEM_STAT_INFO);
1265 void quick_grow (unsigned);
1266 void quick_grow_cleared (unsigned);
1267 void quick_insert (unsigned, const T &);
1268 void safe_insert (unsigned, const T & CXX_MEM_STAT_INFO);
1269 void ordered_remove (unsigned);
1270 void unordered_remove (unsigned);
1271 void block_remove (unsigned, unsigned);
1272 void qsort (int (*) (const void *, const void *));
1273 unsigned lower_bound (T, bool (*)(const T &, const T &)) const;
1275 template<typename T1>
1276 friend void va_stack::alloc(vec<T1, va_stack, vl_ptr>&, unsigned,
1277 vec<T1, va_stack, vl_embed> *);
1279 /* FIXME - This field should be private, but we need to cater to
1280 compilers that have stricter notions of PODness for types. */
1281 vec<T, A, vl_embed> *vec_;
1285 /* Empty specialization for GC allocation. This will prevent GC
1286 vectors from using the vl_ptr layout. FIXME: This is needed to
1287 circumvent limitations in the GTY machinery. */
1289 template<typename T>
1290 struct vec<T, va_gc, vl_ptr>
1295 /* Allocate heap memory for pointer V and create the internal vector
1296 with space for NELEMS elements. If NELEMS is 0, the internal
1297 vector is initialized to empty. */
1299 template<typename T>
1301 vec_alloc (vec<T> *&v, unsigned nelems CXX_MEM_STAT_INFO)
1304 v->create (nelems PASS_MEM_STAT);
1308 /* Conditionally allocate heap memory for VEC and its internal vector. */
1310 template<typename T>
1312 vec_check_alloc (vec<T, va_heap> *&vec, unsigned nelems CXX_MEM_STAT_INFO)
1315 vec_alloc (vec, nelems PASS_MEM_STAT);
1319 /* Free the heap memory allocated by vector V and set it to NULL. */
1321 template<typename T>
1323 vec_free (vec<T> *&v)
1334 /* Allocate a new stack vector with space for exactly NELEMS objects.
1335 If NELEMS is zero, NO vector is created.
1337 For the stack allocator, no memory is really allocated. The vector
1338 is initialized to be at address SPACE and contain NELEMS slots.
1339 Memory allocation actually occurs in the expansion of VEC_alloc.
1343 * This does not allocate an instance of vec<T, A>. It allocates the
1344 actual vector of elements (i.e., vec<T, A, vl_embed>) inside a
1347 * This allocator must always be a macro:
1349 We support a vector which starts out with space on the stack and
1350 switches to heap space when forced to reallocate. This works a
1351 little differently. In the case of stack vectors, vec_alloc will
1352 expand to a call to vec_alloc_1 that calls XALLOCAVAR to request
1353 the initial allocation. This uses alloca to get the initial
1354 space. Since alloca can not be usefully called in an inline
1355 function, vec_alloc must always be a macro.
1357 Important limitations of stack vectors:
1359 - Only the initial allocation will be made using alloca, so pass
1360 a reasonable estimate that doesn't use too much stack space;
1363 - Don't return a stack-allocated vector from the function which
1366 #define vec_stack_alloc(T,V,N) \
1368 typedef vec<T, va_stack, vl_embed> stackv; \
1369 va_stack::alloc (V, N, XALLOCAVAR (stackv, stackv::embedded_size (N)));\
1373 /* Return iteration condition and update PTR to point to the IX'th
1374 element of this vector. Use this to iterate over the elements of a
1377 for (ix = 0; v.iterate(ix, &ptr); ix++)
1380 template<typename T, typename A>
1382 vec<T, A, vl_ptr>::iterate (unsigned ix, T *ptr) const
1385 return vec_->iterate (ix, ptr);
1394 /* Return iteration condition and update *PTR to point to the
1395 IX'th element of this vector. Use this to iterate over the
1396 elements of a vector as follows,
1398 for (ix = 0; v->iterate(ix, &ptr); ix++)
1401 This variant is for vectors of objects. */
1403 template<typename T, typename A>
1405 vec<T, A, vl_ptr>::iterate (unsigned ix, T **ptr) const
1408 return vec_->iterate (ix, ptr);
1417 /* Convenience macro for forward iteration. */
1418 #define FOR_EACH_VEC_ELT(V, I, P) \
1419 for (I = 0; (V).iterate ((I), &(P)); ++(I))
1421 #define FOR_EACH_VEC_SAFE_ELT(V, I, P) \
1422 for (I = 0; vec_safe_iterate ((V), (I), &(P)); ++(I))
1424 /* Likewise, but start from FROM rather than 0. */
1425 #define FOR_EACH_VEC_ELT_FROM(V, I, P, FROM) \
1426 for (I = (FROM); (V).iterate ((I), &(P)); ++(I))
1428 /* Convenience macro for reverse iteration. */
1429 #define FOR_EACH_VEC_ELT_REVERSE(V, I, P) \
1430 for (I = (V).length () - 1; \
1431 (V).iterate ((I), &(P)); \
1434 #define FOR_EACH_VEC_SAFE_ELT_REVERSE(V, I, P) \
1435 for (I = vec_safe_length (V) - 1; \
1436 vec_safe_iterate ((V), (I), &(P)); \
1440 /* Return a copy of this vector. */
1442 template<typename T, typename A>
1443 inline vec<T, A, vl_ptr>
1444 vec<T, A, vl_ptr>::copy (ALONE_MEM_STAT_DECL) const
1446 vec<T, A, vl_ptr> new_vec = vNULL;
1448 new_vec.vec_ = vec_->copy ();
1453 /* Ensure that the vector has at least RESERVE slots available (if
1454 EXACT is false), or exactly RESERVE slots available (if EXACT is
1457 This may create additional headroom if EXACT is false.
1459 Note that this can cause the embedded vector to be reallocated.
1460 Returns true iff reallocation actually occurred. */
1462 template<typename T, typename A>
1464 vec<T, A, vl_ptr>::reserve (unsigned nelems, bool exact MEM_STAT_DECL)
1466 bool extend = nelems ? !space (nelems) : false;
1468 A::reserve (vec_, nelems, exact PASS_MEM_STAT);
1473 /* Ensure that this vector has exactly NELEMS slots available. This
1474 will not create additional headroom. Note this can cause the
1475 embedded vector to be reallocated. Returns true iff reallocation
1476 actually occurred. */
1478 template<typename T, typename A>
1480 vec<T, A, vl_ptr>::reserve_exact (unsigned nelems MEM_STAT_DECL)
1482 return reserve (nelems, true PASS_MEM_STAT);
1486 /* Create the internal vector and reserve NELEMS for it. This is
1487 exactly like vec::reserve, but the internal vector is
1488 unconditionally allocated from scratch. The old one, if it
1489 existed, is lost. */
1491 template<typename T, typename A>
1493 vec<T, A, vl_ptr>::create (unsigned nelems MEM_STAT_DECL)
1497 reserve_exact (nelems PASS_MEM_STAT);
1501 /* Free the memory occupied by the embedded vector. */
1503 template<typename T, typename A>
1505 vec<T, A, vl_ptr>::release (void)
1512 /* Copy the elements from SRC to the end of this vector as if by memcpy.
1513 SRC and this vector must be allocated with the same memory
1514 allocation mechanism. This vector is assumed to have sufficient
1515 headroom available. */
1517 template<typename T, typename A>
1519 vec<T, A, vl_ptr>::splice (vec<T, A, vl_ptr> &src)
1522 vec_->splice (*(src.vec_));
1526 /* Copy the elements in SRC to the end of this vector as if by memcpy.
1527 SRC and this vector must be allocated with the same mechanism.
1528 If there is not enough headroom in this vector, it will be reallocated
1531 template<typename T, typename A>
1533 vec<T, A, vl_ptr>::safe_splice (vec<T, A, vl_ptr> &src MEM_STAT_DECL)
1537 reserve_exact (src.length());
1543 /* Push OBJ (a new element) onto the end of the vector. There must be
1544 sufficient space in the vector. Return a pointer to the slot
1545 where OBJ was inserted. */
1547 template<typename T, typename A>
1549 vec<T, A, vl_ptr>::quick_push (const T &obj)
1551 return vec_->quick_push (obj);
1555 /* Push a new element OBJ onto the end of this vector. Reallocates
1556 the embedded vector, if needed. Return a pointer to the slot where
1557 OBJ was inserted. */
1559 template<typename T, typename A>
1561 vec<T, A, vl_ptr>::safe_push (const T &obj MEM_STAT_DECL)
1563 reserve (1, false PASS_MEM_STAT);
1564 return quick_push (obj);
1568 /* Pop and return the last element off the end of the vector. */
1570 template<typename T, typename A>
1572 vec<T, A, vl_ptr>::pop (void)
1574 return vec_->pop ();
1578 /* Set the length of the vector to LEN. The new length must be less
1579 than or equal to the current length. This is an O(1) operation. */
1581 template<typename T, typename A>
1583 vec<T, A, vl_ptr>::truncate (unsigned size)
1586 vec_->truncate (size);
1588 gcc_checking_assert (size == 0);
1592 /* Grow the vector to a specific length. LEN must be as long or
1593 longer than the current length. The new elements are
1594 uninitialized. Reallocate the internal vector, if needed. */
1596 template<typename T, typename A>
1598 vec<T, A, vl_ptr>::safe_grow (unsigned len MEM_STAT_DECL)
1600 unsigned oldlen = length ();
1601 gcc_checking_assert (oldlen <= len);
1602 reserve_exact (len - oldlen PASS_MEM_STAT);
1603 vec_->quick_grow (len);
1607 /* Grow the embedded vector to a specific length. LEN must be as
1608 long or longer than the current length. The new elements are
1609 initialized to zero. Reallocate the internal vector, if needed. */
1611 template<typename T, typename A>
1613 vec<T, A, vl_ptr>::safe_grow_cleared (unsigned len MEM_STAT_DECL)
1615 unsigned oldlen = length ();
1616 safe_grow (len PASS_MEM_STAT);
1617 memset (&(address()[oldlen]), 0, sizeof (T) * (len - oldlen));
1621 /* Same as vec::safe_grow but without reallocation of the internal vector.
1622 If the vector cannot be extended, a runtime assertion will be triggered. */
1624 template<typename T, typename A>
1626 vec<T, A, vl_ptr>::quick_grow (unsigned len)
1628 gcc_checking_assert (vec_);
1629 vec_->quick_grow (len);
1633 /* Same as vec::quick_grow_cleared but without reallocation of the
1634 internal vector. If the vector cannot be extended, a runtime
1635 assertion will be triggered. */
1637 template<typename T, typename A>
1639 vec<T, A, vl_ptr>::quick_grow_cleared (unsigned len)
1641 gcc_checking_assert (vec_);
1642 vec_->quick_grow_cleared (len);
1646 /* Insert an element, OBJ, at the IXth position of this vector. There
1647 must be sufficient space. */
1649 template<typename T, typename A>
1651 vec<T, A, vl_ptr>::quick_insert (unsigned ix, const T &obj)
1653 vec_->quick_insert (ix, obj);
1657 /* Insert an element, OBJ, at the IXth position of the vector.
1658 Reallocate the embedded vector, if necessary. */
1660 template<typename T, typename A>
1662 vec<T, A, vl_ptr>::safe_insert (unsigned ix, const T &obj MEM_STAT_DECL)
1664 reserve (1, false PASS_MEM_STAT);
1665 quick_insert (ix, obj);
1669 /* Remove an element from the IXth position of this vector. Ordering of
1670 remaining elements is preserved. This is an O(N) operation due to
1673 template<typename T, typename A>
1675 vec<T, A, vl_ptr>::ordered_remove (unsigned ix)
1677 vec_->ordered_remove (ix);
1681 /* Remove an element from the IXth position of this vector. Ordering
1682 of remaining elements is destroyed. This is an O(1) operation. */
1684 template<typename T, typename A>
1686 vec<T, A, vl_ptr>::unordered_remove (unsigned ix)
1688 vec_->unordered_remove (ix);
1692 /* Remove LEN elements starting at the IXth. Ordering is retained.
1693 This is an O(N) operation due to memmove. */
1695 template<typename T, typename A>
1697 vec<T, A, vl_ptr>::block_remove (unsigned ix, unsigned len)
1699 vec_->block_remove (ix, len);
1703 /* Sort the contents of this vector with qsort. CMP is the comparison
1704 function to pass to qsort. */
1706 template<typename T, typename A>
1708 vec<T, A, vl_ptr>::qsort (int (*cmp) (const void *, const void *))
1715 /* Find and return the first position in which OBJ could be inserted
1716 without changing the ordering of this vector. LESSTHAN is a
1717 function that returns true if the first argument is strictly less
1720 template<typename T, typename A>
1722 vec<T, A, vl_ptr>::lower_bound (T obj, bool (*lessthan)(const T &, const T &))
1725 return vec_ ? vec_->lower_bound (obj, lessthan) : 0;
1728 #if (GCC_VERSION >= 3000)
1729 # pragma GCC poison vec_ vecpfx_ vecdata_