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      1 /* Vector API for GNU compiler.
      2    Copyright (C) 2004-2013 Free Software Foundation, Inc.
      3    Contributed by Nathan Sidwell <nathan (at) codesourcery.com>
      4    Re-implemented in C++ by Diego Novillo <dnovillo (at) google.com>
      5 
      6 This file is part of GCC.
      7 
      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
     11 version.
     12 
     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
     16 for more details.
     17 
     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/>.  */
     21 
     22 #ifndef GCC_VEC_H
     23 #define GCC_VEC_H
     24 
     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.
     29 
     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.  */
     35 #ifdef GENERATOR_FILE
     36 #define VEC_GC_ENABLED	0
     37 #else
     38 #define VEC_GC_ENABLED	1
     39 #endif	// GENERATOR_FILE
     40 
     41 #include "statistics.h"		// For CXX_MEM_STAT_INFO.
     42 
     43 #if VEC_GC_ENABLED
     44 #include "ggc.h"
     45 #else
     46 # ifndef GCC_GGC_H
     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);
     54 #  endif  // GCC_GGC_H
     55 #endif	// VEC_GC_ENABLED
     56 
     57 /* Templated vector type and associated interfaces.
     58 
     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.
     62 
     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.
     68 
     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.
     83 
     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.
     94 
     95    Vectors are template types with three arguments: the type of the
     96    elements in the vector, the allocation strategy, and the physical
     97    layout to use
     98 
     99    Four allocation strategies are supported:
    100 
    101 	- Heap: allocation is done using malloc/free.  This is the
    102 	  default allocation strategy.
    103 
    104   	- Stack: allocation is done using alloca.
    105 
    106   	- GC: allocation is done using ggc_alloc/ggc_free.
    107 
    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
    113 	  GC activities.
    114 
    115    Two physical layouts are supported:
    116 
    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).
    123 
    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
    129 	  need to relocate).
    130 
    131    The type, allocation and layout are specified when the vector is
    132    declared.
    133 
    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.
    138 
    139    Notes on the different layout strategies
    140 
    141    * Embeddable vectors (vec<T, A, vl_embed>)
    142 
    143      These vectors are suitable to be embedded in other data
    144      structures so that they can be pre-allocated in a contiguous
    145      memory block.
    146 
    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.
    153 
    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).
    157 
    158      Properties of embeddable vectors:
    159 
    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).
    168 
    169 
    170    * Space efficient vector (vec<T, A, vl_ptr>)
    171 
    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
    175      word of storage.
    176 
    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.
    181 
    182      Properties:
    183 
    184 	- The whole vector and control data are allocated in a single
    185 	  contiguous block.
    186   	- The whole vector may be re-allocated.
    187   	- Vector data may grow and shrink.
    188   	- Access and manipulation requires a pointer test and
    189 	  indirection.
    190   	- It requires 1 word of storage (prior to vector allocation).
    191 
    192    An example of their use would be,
    193 
    194    struct my_struct {
    195      // A space-efficient vector of tree pointers in GC memory.
    196      vec<tree, va_gc, vl_ptr> v;
    197    };
    198 
    199    struct my_struct *s;
    200 
    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 }
    205 */
    206 
    207 /* Support function for statistics.  */
    208 extern void dump_vec_loc_statistics (void);
    209 
    210 
    211 /* Control data for vectors.  This contains the number of allocated
    212    and used slots inside a vector.  */
    213 
    214 struct vec_prefix
    215 {
    216   /* FIXME - These fields should be private, but we need to cater to
    217 	     compilers that have stricter notions of PODness for types.  */
    218 
    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);
    223 
    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.
    227 
    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;
    231 
    232   /* The allocator types also need access to our internals.  */
    233   friend struct va_gc;
    234   friend struct va_gc_atomic;
    235   friend struct va_heap;
    236   friend struct va_stack;
    237 
    238   unsigned alloc_;
    239   unsigned num_;
    240 };
    241 
    242 template<typename, typename, typename> struct vec;
    243 
    244 /* Valid vector layouts
    245 
    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.  */
    249 struct vl_embed { };
    250 struct vl_ptr { };
    251 
    252 
    253 /* Types of supported allocations
    254 
    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.  */
    260 
    261 /* Allocator type for heap vectors.  */
    262 struct va_heap
    263 {
    264   /* Heap vectors are frequently regular instances, so use the vl_ptr
    265      layout for them.  */
    266   typedef vl_ptr default_layout;
    267 
    268   template<typename T>
    269   static void reserve (vec<T, va_heap, vl_embed> *&, unsigned, bool
    270 		       CXX_MEM_STAT_INFO);
    271 
    272   template<typename T>
    273   static void release (vec<T, va_heap, vl_embed> *&);
    274 };
    275 
    276 
    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.  */
    281 
    282 template<typename T>
    283 inline void
    284 va_heap::reserve (vec<T, va_heap, vl_embed> *&v, unsigned reserve, bool exact
    285 		  MEM_STAT_DECL)
    286 {
    287   unsigned alloc
    288     = vec_prefix::calculate_allocation (v ? &v->vecpfx_ : 0, reserve, exact);
    289   if (!alloc)
    290     {
    291       release (v);
    292       return;
    293     }
    294 
    295   if (GATHER_STATISTICS && v)
    296     v->vecpfx_.release_overhead ();
    297 
    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);
    302 
    303   if (GATHER_STATISTICS)
    304     v->vecpfx_.register_overhead (size FINAL_PASS_MEM_STAT);
    305 }
    306 
    307 
    308 /* Free the heap space allocated for vector V.  */
    309 
    310 template<typename T>
    311 void
    312 va_heap::release (vec<T, va_heap, vl_embed> *&v)
    313 {
    314   if (v == NULL)
    315     return;
    316 
    317   if (GATHER_STATISTICS)
    318     v->vecpfx_.release_overhead ();
    319   ::free (v);
    320   v = NULL;
    321 }
    322 
    323 
    324 /* Allocator type for GC vectors.  Notice that we need the structure
    325    declaration even if GC is not enabled.  */
    326 
    327 struct va_gc
    328 {
    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;
    334 
    335   template<typename T, typename A>
    336   static void reserve (vec<T, A, vl_embed> *&, unsigned, bool
    337 		       CXX_MEM_STAT_INFO);
    338 
    339   template<typename T, typename A>
    340   static void release (vec<T, A, vl_embed> *&v) { v = NULL; }
    341 };
    342 
    343 
    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.  */
    348 
    349 template<typename T, typename A>
    350 void
    351 va_gc::reserve (vec<T, A, vl_embed> *&v, unsigned reserve, bool exact
    352 		MEM_STAT_DECL)
    353 {
    354   unsigned alloc
    355     = vec_prefix::calculate_allocation (v ? &v->vecpfx_ : 0, reserve, exact);
    356   if (!alloc)
    357     {
    358       ::ggc_free (v);
    359       v = NULL;
    360       return;
    361     }
    362 
    363   /* Calculate the amount of space we want.  */
    364   size_t size = vec<T, A, vl_embed>::embedded_size (alloc);
    365 
    366   /* Ask the allocator how much space it will really give us.  */
    367   size = ::ggc_round_alloc_size (size);
    368 
    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;
    373 
    374   /* And finally, recalculate the amount of space we ask for.  */
    375   size = vec_offset + alloc * elt_size;
    376 
    377   unsigned nelem = v ? v->length () : 0;
    378   v = static_cast <vec<T, A, vl_embed> *> (::ggc_realloc_stat (v, size
    379 							       PASS_MEM_STAT));
    380   v->embedded_init (alloc, nelem);
    381 }
    382 
    383 
    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
    388 {
    389 };
    390 
    391 
    392 /* Allocator type for stack vectors.  */
    393 struct va_stack
    394 {
    395   /* Use vl_ptr as the default layout for stack vectors.  */
    396   typedef vl_ptr default_layout;
    397 
    398   template<typename T>
    399   static void alloc (vec<T, va_stack, vl_ptr>&, unsigned,
    400 		     vec<T, va_stack, vl_embed> *);
    401 
    402   template <typename T>
    403   static void reserve (vec<T, va_stack, vl_embed> *&, unsigned, bool
    404 		       CXX_MEM_STAT_INFO);
    405 
    406   template <typename T>
    407   static void release (vec<T, va_stack, vl_embed> *&);
    408 };
    409 
    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);
    414 
    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.  */
    418 
    419 template<typename T>
    420 void
    421 va_stack::alloc (vec<T, va_stack, vl_ptr> &v, unsigned nelems,
    422 		 vec<T, va_stack, vl_embed> *space)
    423 {
    424   v.vec_ = space;
    425   register_stack_vec (static_cast<void *> (v.vec_));
    426   v.vec_->embedded_init (nelems, 0);
    427 }
    428 
    429 
    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.  */
    435 
    436 template<typename T>
    437 void
    438 va_stack::reserve (vec<T, va_stack, vl_embed> *&v, unsigned nelems, bool exact
    439 		   MEM_STAT_DECL)
    440 {
    441   int ix = stack_vec_register_index (static_cast<void *> (v));
    442   if (ix >= 0)
    443     unregister_stack_vec (ix);
    444   else
    445     {
    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);
    449       return;
    450     }
    451 
    452   /* Move VEC_ to the heap.  */
    453   nelems += v->vecpfx_.num_;
    454   vec<T, va_stack, vl_embed> *oldvec = v;
    455   v = NULL;
    456   va_heap::reserve (reinterpret_cast<vec<T, va_heap, vl_embed> *&>(v), nelems,
    457 		    exact PASS_MEM_STAT);
    458   if (v && oldvec)
    459     {
    460       v->vecpfx_.num_ = oldvec->length ();
    461       memcpy (v->vecdata_,
    462 	      oldvec->vecdata_,
    463 	      oldvec->length () * sizeof (T));
    464     }
    465 }
    466 
    467 
    468 /* Free a vector allocated on the stack.  Don't actually free it if we
    469    find it in the hash table.  */
    470 
    471 template<typename T>
    472 void
    473 va_stack::release (vec<T, va_stack, vl_embed> *&v)
    474 {
    475   if (v == NULL)
    476     return;
    477 
    478   int ix = stack_vec_register_index (static_cast<void *> (v));
    479   if (ix >= 0)
    480     {
    481       unregister_stack_vec (ix);
    482       v = NULL;
    483     }
    484   else
    485     {
    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));
    489     }
    490 }
    491 
    492 
    493 /* Generic vector template.  Default values for A and L indicate the
    494    most commonly used strategies.
    495 
    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
    499 	   themselves.
    500 
    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).  */
    504 template<typename T,
    505          typename A = va_heap,
    506          typename L = typename A::default_layout>
    507 struct GTY((user)) vec
    508 {
    509 };
    510 
    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.  */
    515 struct vnull
    516 {
    517   template <typename T, typename A, typename L>
    518   operator vec<T, A, L> () { return vec<T, A, L>(); }
    519 };
    520 extern vnull vNULL;
    521 
    522 
    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.
    526 
    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.
    533 
    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).
    537 
    538    Properties:
    539 
    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).  */
    548 
    549 template<typename T, typename A>
    550 struct GTY((user)) vec<T, A, vl_embed>
    551 {
    552 public:
    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);
    560   T &last (void);
    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;
    565   void splice (vec &);
    566   void splice (vec *src);
    567   T *quick_push (const T &);
    568   T &pop (void);
    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);
    580 
    581   /* vec class can access our internal data and functions.  */
    582   template <typename, typename, typename> friend struct vec;
    583 
    584   /* The allocator types also need access to our internals.  */
    585   friend struct va_gc;
    586   friend struct va_gc_atomic;
    587   friend struct va_heap;
    588   friend struct va_stack;
    589 
    590   /* FIXME - These fields should be private, but we need to cater to
    591 	     compilers that have stricter notions of PODness for types.  */
    592   vec_prefix vecpfx_;
    593   T vecdata_[1];
    594 };
    595 
    596 
    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:
    600 
    601 	1- The pointer may be NULL (e.g., before initial allocation).
    602 
    603   	2- When the vector needs to grow, it must be reallocated, so
    604   	   the pointer will change its value.
    605 
    606    Because of limitations with the current GC machinery, all vectors
    607    in GC memory *must* be pointers.  */
    608 
    609 
    610 /* If V contains no room for NELEMS elements, return false. Otherwise,
    611    return true.  */
    612 template<typename T, typename A>
    613 inline bool
    614 vec_safe_space (const vec<T, A, vl_embed> *v, unsigned nelems)
    615 {
    616   return v ? v->space (nelems) : nelems == 0;
    617 }
    618 
    619 
    620 /* If V is NULL, return 0.  Otherwise, return V->length().  */
    621 template<typename T, typename A>
    622 inline unsigned
    623 vec_safe_length (const vec<T, A, vl_embed> *v)
    624 {
    625   return v ? v->length () : 0;
    626 }
    627 
    628 
    629 /* If V is NULL, return NULL.  Otherwise, return V->address().  */
    630 template<typename T, typename A>
    631 inline T *
    632 vec_safe_address (vec<T, A, vl_embed> *v)
    633 {
    634   return v ? v->address () : NULL;
    635 }
    636 
    637 
    638 /* If V is NULL, return true.  Otherwise, return V->is_empty().  */
    639 template<typename T, typename A>
    640 inline bool
    641 vec_safe_is_empty (vec<T, A, vl_embed> *v)
    642 {
    643   return v ? v->is_empty () : true;
    644 }
    645 
    646 
    647 /* If V does not have space for NELEMS elements, call
    648    V->reserve(NELEMS, EXACT).  */
    649 template<typename T, typename A>
    650 inline bool
    651 vec_safe_reserve (vec<T, A, vl_embed> *&v, unsigned nelems, bool exact = false
    652 		  CXX_MEM_STAT_INFO)
    653 {
    654   bool extend = nelems ? !vec_safe_space (v, nelems) : false;
    655   if (extend)
    656     A::reserve (v, nelems, exact PASS_MEM_STAT);
    657   return extend;
    658 }
    659 
    660 template<typename T, typename A>
    661 inline bool
    662 vec_safe_reserve_exact (vec<T, A, vl_embed> *&v, unsigned nelems
    663 			CXX_MEM_STAT_INFO)
    664 {
    665   return vec_safe_reserve (v, nelems, true PASS_MEM_STAT);
    666 }
    667 
    668 
    669 /* Allocate GC memory for V with space for NELEMS slots.  If NELEMS
    670    is 0, V is initialized to NULL.  */
    671 
    672 template<typename T, typename A>
    673 inline void
    674 vec_alloc (vec<T, A, vl_embed> *&v, unsigned nelems CXX_MEM_STAT_INFO)
    675 {
    676   v = NULL;
    677   vec_safe_reserve (v, nelems, false PASS_MEM_STAT);
    678 }
    679 
    680 
    681 /* Free the GC memory allocated by vector V and set it to NULL.  */
    682 
    683 template<typename T, typename A>
    684 inline void
    685 vec_free (vec<T, A, vl_embed> *&v)
    686 {
    687   A::release (v);
    688 }
    689 
    690 
    691 /* Grow V to length LEN.  Allocate it, if necessary.  */
    692 template<typename T, typename A>
    693 inline void
    694 vec_safe_grow (vec<T, A, vl_embed> *&v, unsigned len CXX_MEM_STAT_INFO)
    695 {
    696   unsigned oldlen = vec_safe_length (v);
    697   gcc_checking_assert (len >= oldlen);
    698   vec_safe_reserve_exact (v, len - oldlen PASS_MEM_STAT);
    699   v->quick_grow (len);
    700 }
    701 
    702 
    703 /* If V is NULL, allocate it.  Call V->safe_grow_cleared(LEN).  */
    704 template<typename T, typename A>
    705 inline void
    706 vec_safe_grow_cleared (vec<T, A, vl_embed> *&v, unsigned len CXX_MEM_STAT_INFO)
    707 {
    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));
    711 }
    712 
    713 
    714 /* If V is NULL return false, otherwise return V->iterate(IX, PTR).  */
    715 template<typename T, typename A>
    716 inline bool
    717 vec_safe_iterate (const vec<T, A, vl_embed> *v, unsigned ix, T **ptr)
    718 {
    719   if (v)
    720     return v->iterate (ix, ptr);
    721   else
    722     {
    723       *ptr = 0;
    724       return false;
    725     }
    726 }
    727 
    728 template<typename T, typename A>
    729 inline bool
    730 vec_safe_iterate (const vec<T, A, vl_embed> *v, unsigned ix, T *ptr)
    731 {
    732   if (v)
    733     return v->iterate (ix, ptr);
    734   else
    735     {
    736       *ptr = 0;
    737       return false;
    738     }
    739 }
    740 
    741 
    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>
    745 inline T *
    746 vec_safe_push (vec<T, A, vl_embed> *&v, const T &obj CXX_MEM_STAT_INFO)
    747 {
    748   vec_safe_reserve (v, 1, false PASS_MEM_STAT);
    749   return v->quick_push (obj);
    750 }
    751 
    752 
    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>
    756 inline void
    757 vec_safe_insert (vec<T, A, vl_embed> *&v, unsigned ix, const T &obj
    758 		 CXX_MEM_STAT_INFO)
    759 {
    760   vec_safe_reserve (v, 1, false PASS_MEM_STAT);
    761   v->quick_insert (ix, obj);
    762 }
    763 
    764 
    765 /* If V is NULL, do nothing.  Otherwise, call V->truncate(SIZE).  */
    766 template<typename T, typename A>
    767 inline void
    768 vec_safe_truncate (vec<T, A, vl_embed> *v, unsigned size)
    769 {
    770   if (v)
    771     v->truncate (size);
    772 }
    773 
    774 
    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)
    779 {
    780   return src ? src->copy () : NULL;
    781 }
    782 
    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>
    786 inline void
    787 vec_safe_splice (vec<T, A, vl_embed> *&dst, vec<T, A, vl_embed> *src
    788 		 CXX_MEM_STAT_INFO)
    789 {
    790   unsigned src_len = vec_safe_length (src);
    791   if (src_len)
    792     {
    793       vec_safe_reserve_exact (dst, vec_safe_length (dst) + src_len
    794 			      PASS_MEM_STAT);
    795       dst->splice (*src);
    796     }
    797 }
    798 
    799 
    800 /* Index into vector.  Return the IX'th element.  IX must be in the
    801    domain of the vector.  */
    802 
    803 template<typename T, typename A>
    804 inline const T &
    805 vec<T, A, vl_embed>::operator[] (unsigned ix) const
    806 {
    807   gcc_checking_assert (ix < vecpfx_.num_);
    808   return vecdata_[ix];
    809 }
    810 
    811 template<typename T, typename A>
    812 inline T &
    813 vec<T, A, vl_embed>::operator[] (unsigned ix)
    814 {
    815   gcc_checking_assert (ix < vecpfx_.num_);
    816   return vecdata_[ix];
    817 }
    818 
    819 
    820 /* Get the final element of the vector, which must not be empty.  */
    821 
    822 template<typename T, typename A>
    823 inline T &
    824 vec<T, A, vl_embed>::last (void)
    825 {
    826   gcc_checking_assert (vecpfx_.num_ > 0);
    827   return (*this)[vecpfx_.num_ - 1];
    828 }
    829 
    830 
    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
    835    will.  */
    836 
    837 template<typename T, typename A>
    838 inline bool
    839 vec<T, A, vl_embed>::space (unsigned nelems) const
    840 {
    841   return vecpfx_.alloc_ - vecpfx_.num_ >= nelems;
    842 }
    843 
    844 
    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
    847    vector as follows,
    848 
    849      for (ix = 0; vec<T, A>::iterate(v, ix, &ptr); ix++)
    850        continue;  */
    851 
    852 template<typename T, typename A>
    853 inline bool
    854 vec<T, A, vl_embed>::iterate (unsigned ix, T *ptr) const
    855 {
    856   if (ix < vecpfx_.num_)
    857     {
    858       *ptr = vecdata_[ix];
    859       return true;
    860     }
    861   else
    862     {
    863       *ptr = 0;
    864       return false;
    865     }
    866 }
    867 
    868 
    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,
    872 
    873      for (ix = 0; v->iterate(ix, &ptr); ix++)
    874        continue;
    875 
    876    This variant is for vectors of objects.  */
    877 
    878 template<typename T, typename A>
    879 inline bool
    880 vec<T, A, vl_embed>::iterate (unsigned ix, T **ptr) const
    881 {
    882   if (ix < vecpfx_.num_)
    883     {
    884       *ptr = CONST_CAST (T *, &vecdata_[ix]);
    885       return true;
    886     }
    887   else
    888     {
    889       *ptr = 0;
    890       return false;
    891     }
    892 }
    893 
    894 
    895 /* Return a pointer to a copy of this vector.  */
    896 
    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
    900 {
    901   vec<T, A, vl_embed> *new_vec = NULL;
    902   unsigned len = length ();
    903   if (len)
    904     {
    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);
    908     }
    909   return new_vec;
    910 }
    911 
    912 
    913 /* Copy the elements from SRC to the end of this vector as if by memcpy.
    914    The vector must have sufficient headroom available.  */
    915 
    916 template<typename T, typename A>
    917 inline void
    918 vec<T, A, vl_embed>::splice (vec<T, A, vl_embed> &src)
    919 {
    920   unsigned len = src.length();
    921   if (len)
    922     {
    923       gcc_checking_assert (space (len));
    924       memcpy (address() + length(), src.address(), len * sizeof (T));
    925       vecpfx_.num_ += len;
    926     }
    927 }
    928 
    929 template<typename T, typename A>
    930 inline void
    931 vec<T, A, vl_embed>::splice (vec<T, A, vl_embed> *src)
    932 {
    933   if (src)
    934     splice (*src);
    935 }
    936 
    937 
    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.  */
    941 
    942 template<typename T, typename A>
    943 inline T *
    944 vec<T, A, vl_embed>::quick_push (const T &obj)
    945 {
    946   gcc_checking_assert (space (1));
    947   T *slot = &vecdata_[vecpfx_.num_++];
    948   *slot = obj;
    949   return slot;
    950 }
    951 
    952 
    953 /* Pop and return the last element off the end of the vector.  */
    954 
    955 template<typename T, typename A>
    956 inline T &
    957 vec<T, A, vl_embed>::pop (void)
    958 {
    959   gcc_checking_assert (length () > 0);
    960   return vecdata_[--vecpfx_.num_];
    961 }
    962 
    963 
    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.  */
    966 
    967 template<typename T, typename A>
    968 inline void
    969 vec<T, A, vl_embed>::truncate (unsigned size)
    970 {
    971   gcc_checking_assert (length () >= size);
    972   vecpfx_.num_ = size;
    973 }
    974 
    975 
    976 /* Insert an element, OBJ, at the IXth position of this vector.  There
    977    must be sufficient space.  */
    978 
    979 template<typename T, typename A>
    980 inline void
    981 vec<T, A, vl_embed>::quick_insert (unsigned ix, const T &obj)
    982 {
    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));
    987   *slot = obj;
    988 }
    989 
    990 
    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
    993    memmove.  */
    994 
    995 template<typename T, typename A>
    996 inline void
    997 vec<T, A, vl_embed>::ordered_remove (unsigned ix)
    998 {
    999   gcc_checking_assert (ix < length());
   1000   T *slot = &vecdata_[ix];
   1001   memmove (slot, slot + 1, (--vecpfx_.num_ - ix) * sizeof (T));
   1002 }
   1003 
   1004 
   1005 /* Remove an element from the IXth position of this vector.  Ordering of
   1006    remaining elements is destroyed.  This is an O(1) operation.  */
   1007 
   1008 template<typename T, typename A>
   1009 inline void
   1010 vec<T, A, vl_embed>::unordered_remove (unsigned ix)
   1011 {
   1012   gcc_checking_assert (ix < length());
   1013   vecdata_[ix] = vecdata_[--vecpfx_.num_];
   1014 }
   1015 
   1016 
   1017 /* Remove LEN elements starting at the IXth.  Ordering is retained.
   1018    This is an O(N) operation due to memmove.  */
   1019 
   1020 template<typename T, typename A>
   1021 inline void
   1022 vec<T, A, vl_embed>::block_remove (unsigned ix, unsigned len)
   1023 {
   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));
   1028 }
   1029 
   1030 
   1031 /* Sort the contents of this vector with qsort.  CMP is the comparison
   1032    function to pass to qsort.  */
   1033 
   1034 template<typename T, typename A>
   1035 inline void
   1036 vec<T, A, vl_embed>::qsort (int (*cmp) (const void *, const void *))
   1037 {
   1038   ::qsort (address(), length(), sizeof (T), cmp);
   1039 }
   1040 
   1041 
   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
   1045    than the second.  */
   1046 
   1047 template<typename T, typename A>
   1048 unsigned
   1049 vec<T, A, vl_embed>::lower_bound (T obj, bool (*lessthan)(const T &, const T &))
   1050   const
   1051 {
   1052   unsigned int len = length ();
   1053   unsigned int half, middle;
   1054   unsigned int first = 0;
   1055   while (len > 0)
   1056     {
   1057       half = len / 2;
   1058       middle = first;
   1059       middle += half;
   1060       T middle_elem = (*this)[middle];
   1061       if (lessthan (middle_elem, obj))
   1062 	{
   1063 	  first = middle;
   1064 	  ++first;
   1065 	  len = len - half - 1;
   1066 	}
   1067       else
   1068 	len = half;
   1069     }
   1070   return first;
   1071 }
   1072 
   1073 
   1074 /* Return the number of bytes needed to embed an instance of an
   1075    embeddable vec inside another data structure.
   1076 
   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
   1079    final member):
   1080 
   1081    size_t vec<T, A, vl_embed>::embedded_size (unsigned alloc);
   1082    void v->embedded_init(unsigned alloc, unsigned num);
   1083 
   1084    These allow the caller to perform the memory allocation.  */
   1085 
   1086 template<typename T, typename A>
   1087 inline size_t
   1088 vec<T, A, vl_embed>::embedded_size (unsigned alloc)
   1089 {
   1090   typedef vec<T, A, vl_embed> vec_embedded;
   1091   return offsetof (vec_embedded, vecdata_) + alloc * sizeof (T);
   1092 }
   1093 
   1094 
   1095 /* Initialize the vector to contain room for ALLOC elements and
   1096    NUM active elements.  */
   1097 
   1098 template<typename T, typename A>
   1099 inline void
   1100 vec<T, A, vl_embed>::embedded_init (unsigned alloc, unsigned num)
   1101 {
   1102   vecpfx_.alloc_ = alloc;
   1103   vecpfx_.num_ = num;
   1104 }
   1105 
   1106 
   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.  */
   1109 
   1110 template<typename T, typename A>
   1111 inline void
   1112 vec<T, A, vl_embed>::quick_grow (unsigned len)
   1113 {
   1114   gcc_checking_assert (length () <= len && len <= vecpfx_.alloc_);
   1115   vecpfx_.num_ = len;
   1116 }
   1117 
   1118 
   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.  */
   1121 
   1122 template<typename T, typename A>
   1123 inline void
   1124 vec<T, A, vl_embed>::quick_grow_cleared (unsigned len)
   1125 {
   1126   unsigned oldlen = length ();
   1127   quick_grow (len);
   1128   memset (&(address()[oldlen]), 0, sizeof (T) * (len - oldlen));
   1129 }
   1130 
   1131 
   1132 /* Garbage collection support for vec<T, A, vl_embed>.  */
   1133 
   1134 template<typename T>
   1135 void
   1136 gt_ggc_mx (vec<T, va_gc> *v)
   1137 {
   1138   extern void gt_ggc_mx (T &);
   1139   for (unsigned i = 0; i < v->length (); i++)
   1140     gt_ggc_mx ((*v)[i]);
   1141 }
   1142 
   1143 template<typename T>
   1144 void
   1145 gt_ggc_mx (vec<T, va_gc_atomic, vl_embed> *v ATTRIBUTE_UNUSED)
   1146 {
   1147   /* Nothing to do.  Vectors of atomic types wrt GC do not need to
   1148      be traversed.  */
   1149 }
   1150 
   1151 
   1152 /* PCH support for vec<T, A, vl_embed>.  */
   1153 
   1154 template<typename T, typename A>
   1155 void
   1156 gt_pch_nx (vec<T, A, vl_embed> *v)
   1157 {
   1158   extern void gt_pch_nx (T &);
   1159   for (unsigned i = 0; i < v->length (); i++)
   1160     gt_pch_nx ((*v)[i]);
   1161 }
   1162 
   1163 template<typename T, typename A>
   1164 void
   1165 gt_pch_nx (vec<T *, A, vl_embed> *v, gt_pointer_operator op, void *cookie)
   1166 {
   1167   for (unsigned i = 0; i < v->length (); i++)
   1168     op (&((*v)[i]), cookie);
   1169 }
   1170 
   1171 template<typename T, typename A>
   1172 void
   1173 gt_pch_nx (vec<T, A, vl_embed> *v, gt_pointer_operator op, void *cookie)
   1174 {
   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);
   1178 }
   1179 
   1180 
   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.
   1185 
   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.
   1190 
   1191    Properties:
   1192 
   1193 	- The whole vector and control data are allocated in a single
   1194 	  contiguous block.
   1195   	- The whole vector may be re-allocated.
   1196   	- Vector data may grow and shrink.
   1197   	- Access and manipulation requires a pointer test and
   1198 	  indirection.
   1199 	- It requires 1 word of storage (prior to vector allocation).
   1200 
   1201 
   1202    Limitations:
   1203 
   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.  */
   1208 
   1209 template<typename T, typename A>
   1210 struct vec<T, A, vl_ptr>
   1211 {
   1212 public:
   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);
   1217 
   1218   /* Vector operations.  */
   1219   bool exists (void) const
   1220   { return vec_ != NULL; }
   1221 
   1222   bool is_empty (void) const
   1223   { return vec_ ? vec_->is_empty() : true; }
   1224 
   1225   unsigned length (void) const
   1226   { return vec_ ? vec_->length() : 0; }
   1227 
   1228   T *address (void)
   1229   { return vec_ ? vec_->vecdata_ : NULL; }
   1230 
   1231   const T *address (void) const
   1232   { return vec_ ? vec_->vecdata_ : NULL; }
   1233 
   1234   const T &operator[] (unsigned ix) const
   1235   { return (*vec_)[ix]; }
   1236 
   1237   bool operator!=(const vec &other) const
   1238   { return !(*this == other); }
   1239 
   1240   bool operator==(const vec &other) const
   1241   { return address() == other.address(); }
   1242 
   1243   T &operator[] (unsigned ix)
   1244   { return (*vec_)[ix]; }
   1245 
   1246   T &last (void)
   1247   { return vec_->last(); }
   1248 
   1249   bool space (int nelems) const
   1250   { return vec_ ? vec_->space (nelems) : nelems == 0; }
   1251 
   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);
   1261   T &pop (void);
   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;
   1274 
   1275   template<typename T1>
   1276   friend void va_stack::alloc(vec<T1, va_stack, vl_ptr>&, unsigned,
   1277 			      vec<T1, va_stack, vl_embed> *);
   1278 
   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_;
   1282 };
   1283 
   1284 
   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.  */
   1288 
   1289 template<typename T>
   1290 struct vec<T, va_gc, vl_ptr>
   1291 {
   1292 };
   1293 
   1294 
   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.  */
   1298 
   1299 template<typename T>
   1300 inline void
   1301 vec_alloc (vec<T> *&v, unsigned nelems CXX_MEM_STAT_INFO)
   1302 {
   1303   v = new vec<T>;
   1304   v->create (nelems PASS_MEM_STAT);
   1305 }
   1306 
   1307 
   1308 /* Conditionally allocate heap memory for VEC and its internal vector.  */
   1309 
   1310 template<typename T>
   1311 inline void
   1312 vec_check_alloc (vec<T, va_heap> *&vec, unsigned nelems CXX_MEM_STAT_INFO)
   1313 {
   1314   if (!vec)
   1315     vec_alloc (vec, nelems PASS_MEM_STAT);
   1316 }
   1317 
   1318 
   1319 /* Free the heap memory allocated by vector V and set it to NULL.  */
   1320 
   1321 template<typename T>
   1322 inline void
   1323 vec_free (vec<T> *&v)
   1324 {
   1325   if (v == NULL)
   1326     return;
   1327 
   1328   v->release ();
   1329   delete v;
   1330   v = NULL;
   1331 }
   1332 
   1333 
   1334 /* Allocate a new stack vector with space for exactly NELEMS objects.
   1335    If NELEMS is zero, NO vector is created.
   1336 
   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.
   1340 
   1341    Usage notes:
   1342 
   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
   1345      vec<T, A> instance.
   1346 
   1347    * This allocator must always be a macro:
   1348 
   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.
   1356 
   1357      Important limitations of stack vectors:
   1358 
   1359      - Only the initial allocation will be made using alloca, so pass
   1360        a reasonable estimate that doesn't use too much stack space;
   1361        don't pass zero.
   1362 
   1363      - Don't return a stack-allocated vector from the function which
   1364        allocated it.  */
   1365 
   1366 #define vec_stack_alloc(T,V,N)						\
   1367   do {									\
   1368     typedef vec<T, va_stack, vl_embed> stackv;				\
   1369     va_stack::alloc (V, N, XALLOCAVAR (stackv, stackv::embedded_size (N)));\
   1370   } while (0)
   1371 
   1372 
   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
   1375    vector as follows,
   1376 
   1377      for (ix = 0; v.iterate(ix, &ptr); ix++)
   1378        continue;  */
   1379 
   1380 template<typename T, typename A>
   1381 inline bool
   1382 vec<T, A, vl_ptr>::iterate (unsigned ix, T *ptr) const
   1383 {
   1384   if (vec_)
   1385     return vec_->iterate (ix, ptr);
   1386   else
   1387     {
   1388       *ptr = 0;
   1389       return false;
   1390     }
   1391 }
   1392 
   1393 
   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,
   1397 
   1398      for (ix = 0; v->iterate(ix, &ptr); ix++)
   1399        continue;
   1400 
   1401    This variant is for vectors of objects.  */
   1402 
   1403 template<typename T, typename A>
   1404 inline bool
   1405 vec<T, A, vl_ptr>::iterate (unsigned ix, T **ptr) const
   1406 {
   1407   if (vec_)
   1408     return vec_->iterate (ix, ptr);
   1409   else
   1410     {
   1411       *ptr = 0;
   1412       return false;
   1413     }
   1414 }
   1415 
   1416 
   1417 /* Convenience macro for forward iteration.  */
   1418 #define FOR_EACH_VEC_ELT(V, I, P)			\
   1419   for (I = 0; (V).iterate ((I), &(P)); ++(I))
   1420 
   1421 #define FOR_EACH_VEC_SAFE_ELT(V, I, P)			\
   1422   for (I = 0; vec_safe_iterate ((V), (I), &(P)); ++(I))
   1423 
   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))
   1427 
   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));				\
   1432        (I)--)
   1433 
   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));	\
   1437        (I)--)
   1438 
   1439 
   1440 /* Return a copy of this vector.  */
   1441 
   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
   1445 {
   1446   vec<T, A, vl_ptr> new_vec = vNULL;
   1447   if (length ())
   1448     new_vec.vec_ = vec_->copy ();
   1449   return new_vec;
   1450 }
   1451 
   1452 
   1453 /* Ensure that the vector has at least RESERVE slots available (if
   1454    EXACT is false), or exactly RESERVE slots available (if EXACT is
   1455    true).
   1456 
   1457    This may create additional headroom if EXACT is false.
   1458 
   1459    Note that this can cause the embedded vector to be reallocated.
   1460    Returns true iff reallocation actually occurred.  */
   1461 
   1462 template<typename T, typename A>
   1463 inline bool
   1464 vec<T, A, vl_ptr>::reserve (unsigned nelems, bool exact MEM_STAT_DECL)
   1465 {
   1466   bool extend = nelems ? !space (nelems) : false;
   1467   if (extend)
   1468     A::reserve (vec_, nelems, exact PASS_MEM_STAT);
   1469   return extend;
   1470 }
   1471 
   1472 
   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.  */
   1477 
   1478 template<typename T, typename A>
   1479 inline bool
   1480 vec<T, A, vl_ptr>::reserve_exact (unsigned nelems MEM_STAT_DECL)
   1481 {
   1482   return reserve (nelems, true PASS_MEM_STAT);
   1483 }
   1484 
   1485 
   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.  */
   1490 
   1491 template<typename T, typename A>
   1492 inline void
   1493 vec<T, A, vl_ptr>::create (unsigned nelems MEM_STAT_DECL)
   1494 {
   1495   vec_ = NULL;
   1496   if (nelems > 0)
   1497     reserve_exact (nelems PASS_MEM_STAT);
   1498 }
   1499 
   1500 
   1501 /* Free the memory occupied by the embedded vector.  */
   1502 
   1503 template<typename T, typename A>
   1504 inline void
   1505 vec<T, A, vl_ptr>::release (void)
   1506 {
   1507   if (vec_)
   1508     A::release (vec_);
   1509 }
   1510 
   1511 
   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.  */
   1516 
   1517 template<typename T, typename A>
   1518 inline void
   1519 vec<T, A, vl_ptr>::splice (vec<T, A, vl_ptr> &src)
   1520 {
   1521   if (src.vec_)
   1522     vec_->splice (*(src.vec_));
   1523 }
   1524 
   1525 
   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
   1529    as needed.  */
   1530 
   1531 template<typename T, typename A>
   1532 inline void
   1533 vec<T, A, vl_ptr>::safe_splice (vec<T, A, vl_ptr> &src MEM_STAT_DECL)
   1534 {
   1535   if (src.length())
   1536     {
   1537       reserve_exact (src.length());
   1538       splice (src);
   1539     }
   1540 }
   1541 
   1542 
   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.  */
   1546 
   1547 template<typename T, typename A>
   1548 inline T *
   1549 vec<T, A, vl_ptr>::quick_push (const T &obj)
   1550 {
   1551   return vec_->quick_push (obj);
   1552 }
   1553 
   1554 
   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.  */
   1558 
   1559 template<typename T, typename A>
   1560 inline T *
   1561 vec<T, A, vl_ptr>::safe_push (const T &obj MEM_STAT_DECL)
   1562 {
   1563   reserve (1, false PASS_MEM_STAT);
   1564   return quick_push (obj);
   1565 }
   1566 
   1567 
   1568 /* Pop and return the last element off the end of the vector.  */
   1569 
   1570 template<typename T, typename A>
   1571 inline T &
   1572 vec<T, A, vl_ptr>::pop (void)
   1573 {
   1574   return vec_->pop ();
   1575 }
   1576 
   1577 
   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.  */
   1580 
   1581 template<typename T, typename A>
   1582 inline void
   1583 vec<T, A, vl_ptr>::truncate (unsigned size)
   1584 {
   1585   if (vec_)
   1586     vec_->truncate (size);
   1587   else
   1588     gcc_checking_assert (size == 0);
   1589 }
   1590 
   1591 
   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.  */
   1595 
   1596 template<typename T, typename A>
   1597 inline void
   1598 vec<T, A, vl_ptr>::safe_grow (unsigned len MEM_STAT_DECL)
   1599 {
   1600   unsigned oldlen = length ();
   1601   gcc_checking_assert (oldlen <= len);
   1602   reserve_exact (len - oldlen PASS_MEM_STAT);
   1603   vec_->quick_grow (len);
   1604 }
   1605 
   1606 
   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.  */
   1610 
   1611 template<typename T, typename A>
   1612 inline void
   1613 vec<T, A, vl_ptr>::safe_grow_cleared (unsigned len MEM_STAT_DECL)
   1614 {
   1615   unsigned oldlen = length ();
   1616   safe_grow (len PASS_MEM_STAT);
   1617   memset (&(address()[oldlen]), 0, sizeof (T) * (len - oldlen));
   1618 }
   1619 
   1620 
   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.  */
   1623 
   1624 template<typename T, typename A>
   1625 inline void
   1626 vec<T, A, vl_ptr>::quick_grow (unsigned len)
   1627 {
   1628   gcc_checking_assert (vec_);
   1629   vec_->quick_grow (len);
   1630 }
   1631 
   1632 
   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.  */
   1636 
   1637 template<typename T, typename A>
   1638 inline void
   1639 vec<T, A, vl_ptr>::quick_grow_cleared (unsigned len)
   1640 {
   1641   gcc_checking_assert (vec_);
   1642   vec_->quick_grow_cleared (len);
   1643 }
   1644 
   1645 
   1646 /* Insert an element, OBJ, at the IXth position of this vector.  There
   1647    must be sufficient space.  */
   1648 
   1649 template<typename T, typename A>
   1650 inline void
   1651 vec<T, A, vl_ptr>::quick_insert (unsigned ix, const T &obj)
   1652 {
   1653   vec_->quick_insert (ix, obj);
   1654 }
   1655 
   1656 
   1657 /* Insert an element, OBJ, at the IXth position of the vector.
   1658    Reallocate the embedded vector, if necessary.  */
   1659 
   1660 template<typename T, typename A>
   1661 inline void
   1662 vec<T, A, vl_ptr>::safe_insert (unsigned ix, const T &obj MEM_STAT_DECL)
   1663 {
   1664   reserve (1, false PASS_MEM_STAT);
   1665   quick_insert (ix, obj);
   1666 }
   1667 
   1668 
   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
   1671    a memmove.  */
   1672 
   1673 template<typename T, typename A>
   1674 inline void
   1675 vec<T, A, vl_ptr>::ordered_remove (unsigned ix)
   1676 {
   1677   vec_->ordered_remove (ix);
   1678 }
   1679 
   1680 
   1681 /* Remove an element from the IXth position of this vector.  Ordering
   1682    of remaining elements is destroyed.  This is an O(1) operation.  */
   1683 
   1684 template<typename T, typename A>
   1685 inline void
   1686 vec<T, A, vl_ptr>::unordered_remove (unsigned ix)
   1687 {
   1688   vec_->unordered_remove (ix);
   1689 }
   1690 
   1691 
   1692 /* Remove LEN elements starting at the IXth.  Ordering is retained.
   1693    This is an O(N) operation due to memmove.  */
   1694 
   1695 template<typename T, typename A>
   1696 inline void
   1697 vec<T, A, vl_ptr>::block_remove (unsigned ix, unsigned len)
   1698 {
   1699   vec_->block_remove (ix, len);
   1700 }
   1701 
   1702 
   1703 /* Sort the contents of this vector with qsort.  CMP is the comparison
   1704    function to pass to qsort.  */
   1705 
   1706 template<typename T, typename A>
   1707 inline void
   1708 vec<T, A, vl_ptr>::qsort (int (*cmp) (const void *, const void *))
   1709 {
   1710   if (vec_)
   1711     vec_->qsort (cmp);
   1712 }
   1713 
   1714 
   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
   1718    than the second.  */
   1719 
   1720 template<typename T, typename A>
   1721 inline unsigned
   1722 vec<T, A, vl_ptr>::lower_bound (T obj, bool (*lessthan)(const T &, const T &))
   1723     const
   1724 {
   1725   return vec_ ? vec_->lower_bound (obj, lessthan) : 0;
   1726 }
   1727 
   1728 #if (GCC_VERSION >= 3000)
   1729 # pragma GCC poison vec_ vecpfx_ vecdata_
   1730 #endif
   1731 
   1732 #endif // GCC_VEC_H
   1733