AttributeList.h revision 9864c7dc0232701b9cc6b3928a867c11c92564a5 
1//===--- AttributeList.h - Parsed attribute sets ----------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the AttributeList class, which is used to collect
11// parsed attributes.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_CLANG_SEMA_ATTRLIST_H
16#define LLVM_CLANG_SEMA_ATTRLIST_H
17
18#include "llvm/Support/Allocator.h"
19#include "llvm/ADT/SmallVector.h"
20#include "clang/Basic/SourceLocation.h"
21#include "clang/Basic/VersionTuple.h"
22#include <cassert>
23
24namespace clang {
25  class ASTContext;
26  class IdentifierInfo;
27  class Expr;
28
29/// \brief Represents information about a change in availability for
30/// an entity, which is part of the encoding of the 'availability'
31/// attribute.
32struct AvailabilityChange {
33  /// \brief The location of the keyword indicating the kind of change.
34  SourceLocation KeywordLoc;
35
36  /// \brief The version number at which the change occurred.
37  VersionTuple Version;
38
39  /// \brief The source range covering the version number.
40  SourceRange VersionRange;
41
42  /// \brief Determine whether this availability change is valid.
43  bool isValid() const { return !Version.empty(); }
44};
45
46/// AttributeList - Represents GCC's __attribute__ declaration. There are
47/// 4 forms of this construct...they are:
48///
49/// 1: __attribute__(( const )). ParmName/Args/NumArgs will all be unused.
50/// 2: __attribute__(( mode(byte) )). ParmName used, Args/NumArgs unused.
51/// 3: __attribute__(( format(printf, 1, 2) )). ParmName/Args/NumArgs all used.
52/// 4: __attribute__(( aligned(16) )). ParmName is unused, Args/Num used.
53///
54class AttributeList { // TODO: This should really be called ParsedAttribute
55private:
56  IdentifierInfo *AttrName;
57  IdentifierInfo *ScopeName;
58  IdentifierInfo *ParmName;
59  SourceLocation AttrLoc;
60  SourceLocation ScopeLoc;
61  SourceLocation ParmLoc;
62
63  /// The number of expression arguments this attribute has.
64  /// The expressions themselves are stored after the object.
65  unsigned NumArgs : 16;
66
67  /// True if Microsoft style: declspec(foo).
68  unsigned DeclspecAttribute : 1;
69
70  /// True if C++0x-style: [[foo]].
71  unsigned CXX0XAttribute : 1;
72
73  /// True if already diagnosed as invalid.
74  mutable unsigned Invalid : 1;
75
76  /// True if this has the extra information associated with an
77  /// availability attribute.
78  unsigned IsAvailability : 1;
79
80  unsigned AttrKind : 8;
81
82  /// \brief The location of the 'unavailable' keyword in an
83  /// availability attribute.
84  SourceLocation UnavailableLoc;
85
86  /// The next attribute in the current position.
87  AttributeList *NextInPosition;
88
89  /// The next attribute allocated in the current Pool.
90  AttributeList *NextInPool;
91
92  Expr **getArgsBuffer() {
93    return reinterpret_cast<Expr**>(this+1);
94  }
95  Expr * const *getArgsBuffer() const {
96    return reinterpret_cast<Expr* const *>(this+1);
97  }
98
99  enum AvailabilitySlot {
100    IntroducedSlot, DeprecatedSlot, ObsoletedSlot
101  };
102
103  AvailabilityChange &getAvailabilitySlot(AvailabilitySlot index) {
104    return reinterpret_cast<AvailabilityChange*>(this+1)[index];
105  }
106  const AvailabilityChange &getAvailabilitySlot(AvailabilitySlot index) const {
107    return reinterpret_cast<const AvailabilityChange*>(this+1)[index];
108  }
109
110  AttributeList(const AttributeList &); // DO NOT IMPLEMENT
111  void operator=(const AttributeList &); // DO NOT IMPLEMENT
112  void operator delete(void *); // DO NOT IMPLEMENT
113  ~AttributeList(); // DO NOT IMPLEMENT
114
115  size_t allocated_size() const;
116
117  AttributeList(IdentifierInfo *attrName, SourceLocation attrLoc,
118                IdentifierInfo *scopeName, SourceLocation scopeLoc,
119                IdentifierInfo *parmName, SourceLocation parmLoc,
120                Expr **args, unsigned numArgs,
121                bool declspec, bool cxx0x)
122    : AttrName(attrName), ScopeName(scopeName), ParmName(parmName),
123      AttrLoc(attrLoc), ScopeLoc(scopeLoc), ParmLoc(parmLoc),
124      NumArgs(numArgs),
125      DeclspecAttribute(declspec), CXX0XAttribute(cxx0x), Invalid(false),
126      IsAvailability(false), NextInPosition(0), NextInPool(0) {
127    if (numArgs) memcpy(getArgsBuffer(), args, numArgs * sizeof(Expr*));
128    AttrKind = getKind(getName());
129  }
130
131  AttributeList(IdentifierInfo *attrName, SourceLocation attrLoc,
132                IdentifierInfo *scopeName, SourceLocation scopeLoc,
133                IdentifierInfo *parmName, SourceLocation parmLoc,
134                const AvailabilityChange &introduced,
135                const AvailabilityChange &deprecated,
136                const AvailabilityChange &obsoleted,
137                SourceLocation unavailable,
138                bool declspec, bool cxx0x)
139    : AttrName(attrName), ScopeName(scopeName), ParmName(parmName),
140      AttrLoc(attrLoc), ScopeLoc(scopeLoc), ParmLoc(parmLoc),
141      NumArgs(0), DeclspecAttribute(declspec), CXX0XAttribute(cxx0x),
142      Invalid(false), IsAvailability(true), UnavailableLoc(unavailable),
143      NextInPosition(0), NextInPool(0) {
144    new (&getAvailabilitySlot(IntroducedSlot)) AvailabilityChange(introduced);
145    new (&getAvailabilitySlot(DeprecatedSlot)) AvailabilityChange(deprecated);
146    new (&getAvailabilitySlot(ObsoletedSlot)) AvailabilityChange(obsoleted);
147    AttrKind = getKind(getName());
148  }
149
150  friend class AttributePool;
151  friend class AttributeFactory;
152
153public:
154  enum Kind {             // Please keep this list alphabetized.
155    AT_address_space,
156    AT_alias,
157    AT_aligned,
158    AT_always_inline,
159    AT_analyzer_noreturn,
160    AT_annotate,
161    AT_availability,      // Clang-specific
162    AT_base_check,
163    AT_blocks,
164    AT_carries_dependency,
165    AT_cdecl,
166    AT_cf_consumed,             // Clang-specific.
167    AT_cf_returns_autoreleased, // Clang-specific.
168    AT_cf_returns_not_retained, // Clang-specific.
169    AT_cf_returns_retained,     // Clang-specific.
170    AT_cleanup,
171    AT_common,
172    AT_const,
173    AT_constant,
174    AT_constructor,
175    AT_deprecated,
176    AT_destructor,
177    AT_device,
178    AT_dllexport,
179    AT_dllimport,
180    AT_ext_vector_type,
181    AT_fastcall,
182    AT_format,
183    AT_format_arg,
184    AT_global,
185    AT_gnu_inline,
186    AT_host,
187    AT_IBAction,          // Clang-specific.
188    AT_IBOutlet,          // Clang-specific.
189    AT_IBOutletCollection, // Clang-specific.
190    AT_init_priority,
191    AT_launch_bounds,
192    AT_malloc,
193    AT_may_alias,
194    AT_mode,
195    AT_MsStruct,
196    AT_naked,
197    AT_neon_polyvector_type,    // Clang-specific.
198    AT_neon_vector_type,        // Clang-specific.
199    AT_no_instrument_function,
200    AT_nocommon,
201    AT_nodebug,
202    AT_noinline,
203    AT_nonnull,
204    AT_noreturn,
205    AT_nothrow,
206    AT_ns_consumed,             // Clang-specific.
207    AT_ns_consumes_self,        // Clang-specific.
208    AT_ns_returns_autoreleased, // Clang-specific.
209    AT_ns_returns_not_retained, // Clang-specific.
210    AT_ns_returns_retained,     // Clang-specific.
211    AT_nsobject,
212    AT_objc_exception,
213    AT_objc_gc,
214    AT_objc_method_family,
215    AT_objc_ownership,          // Clang-specific.
216    AT_objc_precise_lifetime,   // Clang-specific.
217    AT_opencl_image_access,     // OpenCL-specific.
218    AT_opencl_kernel_function,  // OpenCL-specific.
219    AT_overloadable,       // Clang-specific.
220    AT_ownership_holds,    // Clang-specific.
221    AT_ownership_returns,  // Clang-specific.
222    AT_ownership_takes,    // Clang-specific.
223    AT_packed,
224    AT_pascal,
225    AT_pcs,  // ARM specific
226    AT_pure,
227    AT_regparm,
228    AT_reqd_wg_size,
229    AT_section,
230    AT_sentinel,
231    AT_shared,
232    AT_stdcall,
233    AT_thiscall,
234    AT_transparent_union,
235    AT_unavailable,
236    AT_unused,
237    AT_used,
238    AT_uuid,
239    AT_vecreturn,     // PS3 PPU-specific.
240    AT_vector_size,
241    AT_visibility,
242    AT_warn_unused_result,
243    AT_weak,
244    AT_weak_import,
245    AT_weakref,
246    IgnoredAttribute,
247    UnknownAttribute
248  };
249
250  IdentifierInfo *getName() const { return AttrName; }
251  SourceLocation getLoc() const { return AttrLoc; }
252
253  bool hasScope() const { return ScopeName; }
254  IdentifierInfo *getScopeName() const { return ScopeName; }
255  SourceLocation getScopeLoc() const { return ScopeLoc; }
256
257  IdentifierInfo *getParameterName() const { return ParmName; }
258  SourceLocation getParameterLoc() const { return ParmLoc; }
259
260  bool isDeclspecAttribute() const { return DeclspecAttribute; }
261  bool isCXX0XAttribute() const { return CXX0XAttribute; }
262
263  bool isInvalid() const { return Invalid; }
264  void setInvalid(bool b = true) const { Invalid = b; }
265
266  Kind getKind() const { return Kind(AttrKind); }
267  static Kind getKind(const IdentifierInfo *Name);
268
269  AttributeList *getNext() const { return NextInPosition; }
270  void setNext(AttributeList *N) { NextInPosition = N; }
271
272  /// getNumArgs - Return the number of actual arguments to this attribute.
273  unsigned getNumArgs() const { return NumArgs; }
274
275  /// hasParameterOrArguments - Return true if this attribute has a parameter,
276  /// or has a non empty argument expression list.
277  bool hasParameterOrArguments() const { return ParmName || NumArgs; }
278
279  /// getArg - Return the specified argument.
280  Expr *getArg(unsigned Arg) const {
281    assert(Arg < NumArgs && "Arg access out of range!");
282    return getArgsBuffer()[Arg];
283  }
284
285  class arg_iterator {
286    Expr * const *X;
287    unsigned Idx;
288  public:
289    arg_iterator(Expr * const *x, unsigned idx) : X(x), Idx(idx) {}
290
291    arg_iterator& operator++() {
292      ++Idx;
293      return *this;
294    }
295
296    bool operator==(const arg_iterator& I) const {
297      assert (X == I.X &&
298              "compared arg_iterators are for different argument lists");
299      return Idx == I.Idx;
300    }
301
302    bool operator!=(const arg_iterator& I) const {
303      return !operator==(I);
304    }
305
306    Expr* operator*() const {
307      return X[Idx];
308    }
309
310    unsigned getArgNum() const {
311      return Idx+1;
312    }
313  };
314
315  arg_iterator arg_begin() const {
316    return arg_iterator(getArgsBuffer(), 0);
317  }
318
319  arg_iterator arg_end() const {
320    return arg_iterator(getArgsBuffer(), NumArgs);
321  }
322
323  const AvailabilityChange &getAvailabilityIntroduced() const {
324    assert(getKind() == AT_availability && "Not an availability attribute");
325    return getAvailabilitySlot(IntroducedSlot);
326  }
327
328  const AvailabilityChange &getAvailabilityDeprecated() const {
329    assert(getKind() == AT_availability && "Not an availability attribute");
330    return getAvailabilitySlot(DeprecatedSlot);
331  }
332
333  const AvailabilityChange &getAvailabilityObsoleted() const {
334    assert(getKind() == AT_availability && "Not an availability attribute");
335    return getAvailabilitySlot(ObsoletedSlot);
336  }
337
338  SourceLocation getUnavailableLoc() const {
339    assert(getKind() == AT_availability && "Not an availability attribute");
340    return UnavailableLoc;
341  }
342};
343
344/// A factory, from which one makes pools, from which one creates
345/// individual attributes which are deallocated with the pool.
346///
347/// Note that it's tolerably cheap to create and destroy one of
348/// these as long as you don't actually allocate anything in it.
349class AttributeFactory {
350public:
351  enum {
352    /// The required allocation size of an availability attribute,
353    /// which we want to ensure is a multiple of sizeof(void*).
354    AvailabilityAllocSize =
355      sizeof(AttributeList)
356      + ((3 * sizeof(AvailabilityChange) + sizeof(void*) - 1)
357         / sizeof(void*) * sizeof(void*))
358  };
359
360private:
361  enum {
362    /// The number of free lists we want to be sure to support
363    /// inline.  This is just enough that availability attributes
364    /// don't surpass it.  It's actually very unlikely we'll see an
365    /// attribute that needs more than that; on x86-64 you'd need 10
366    /// expression arguments, and on i386 you'd need 19.
367    InlineFreeListsCapacity =
368      1 + (AvailabilityAllocSize - sizeof(AttributeList)) / sizeof(void*)
369  };
370
371  llvm::BumpPtrAllocator Alloc;
372
373  /// Free lists.  The index is determined by the following formula:
374  ///   (size - sizeof(AttributeList)) / sizeof(void*)
375  llvm::SmallVector<AttributeList*, InlineFreeListsCapacity> FreeLists;
376
377  // The following are the private interface used by AttributePool.
378  friend class AttributePool;
379
380  /// Allocate an attribute of the given size.
381  void *allocate(size_t size);
382
383  /// Reclaim all the attributes in the given pool chain, which is
384  /// non-empty.  Note that the current implementation is safe
385  /// against reclaiming things which were not actually allocated
386  /// with the allocator, although of course it's important to make
387  /// sure that their allocator lives at least as long as this one.
388  void reclaimPool(AttributeList *head);
389
390public:
391  AttributeFactory();
392  ~AttributeFactory();
393};
394
395class AttributePool {
396  AttributeFactory &Factory;
397  AttributeList *Head;
398
399  void *allocate(size_t size) {
400    return Factory.allocate(size);
401  }
402
403  AttributeList *add(AttributeList *attr) {
404    // We don't care about the order of the pool.
405    attr->NextInPool = Head;
406    Head = attr;
407    return attr;
408  }
409
410  void takePool(AttributeList *pool);
411
412public:
413  /// Create a new pool for a factory.
414  AttributePool(AttributeFactory &factory) : Factory(factory), Head(0) {}
415
416  /// Move the given pool's allocations to this pool.
417  AttributePool(AttributePool &pool) : Factory(pool.Factory), Head(pool.Head) {
418    pool.Head = 0;
419  }
420
421  AttributeFactory &getFactory() const { return Factory; }
422
423  void clear() {
424    if (Head) {
425      Factory.reclaimPool(Head);
426      Head = 0;
427    }
428  }
429
430  /// Take the given pool's allocations and add them to this pool.
431  void takeAllFrom(AttributePool &pool) {
432    if (pool.Head) {
433      takePool(pool.Head);
434      pool.Head = 0;
435    }
436  }
437
438  ~AttributePool() {
439    if (Head) Factory.reclaimPool(Head);
440  }
441
442  AttributeList *create(IdentifierInfo *attrName, SourceLocation attrLoc,
443                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
444                        IdentifierInfo *parmName, SourceLocation parmLoc,
445                        Expr **args, unsigned numArgs,
446                        bool declspec = false, bool cxx0x = false) {
447    void *memory = allocate(sizeof(AttributeList)
448                            + numArgs * sizeof(Expr*));
449    return add(new (memory) AttributeList(attrName, attrLoc,
450                                          scopeName, scopeLoc,
451                                          parmName, parmLoc,
452                                          args, numArgs,
453                                          declspec, cxx0x));
454  }
455
456  AttributeList *create(IdentifierInfo *attrName, SourceLocation attrLoc,
457                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
458                        IdentifierInfo *parmName, SourceLocation parmLoc,
459                        const AvailabilityChange &introduced,
460                        const AvailabilityChange &deprecated,
461                        const AvailabilityChange &obsoleted,
462                        SourceLocation unavailable,
463                        bool declspec = false, bool cxx0x = false) {
464    void *memory = allocate(AttributeFactory::AvailabilityAllocSize);
465    return add(new (memory) AttributeList(attrName, attrLoc,
466                                          scopeName, scopeLoc,
467                                          parmName, parmLoc,
468                                          introduced, deprecated, obsoleted,
469                                          unavailable,
470                                          declspec, cxx0x));
471  }
472
473  AttributeList *createIntegerAttribute(ASTContext &C, IdentifierInfo *Name,
474                                        SourceLocation TokLoc, int Arg);
475};
476
477/// addAttributeLists - Add two AttributeLists together
478/// The right-hand list is appended to the left-hand list, if any
479/// A pointer to the joined list is returned.
480/// Note: the lists are not left unmodified.
481inline AttributeList *addAttributeLists(AttributeList *Left,
482                                        AttributeList *Right) {
483  if (!Left)
484    return Right;
485
486  AttributeList *next = Left, *prev;
487  do {
488    prev = next;
489    next = next->getNext();
490  } while (next);
491  prev->setNext(Right);
492  return Left;
493}
494
495/// CXX0XAttributeList - A wrapper around a C++0x attribute list.
496/// Stores, in addition to the list proper, whether or not an actual list was
497/// (as opposed to an empty list, which may be ill-formed in some places) and
498/// the source range of the list.
499struct CXX0XAttributeList {
500  AttributeList *AttrList;
501  SourceRange Range;
502  bool HasAttr;
503  CXX0XAttributeList (AttributeList *attrList, SourceRange range, bool hasAttr)
504    : AttrList(attrList), Range(range), HasAttr (hasAttr) {
505  }
506  CXX0XAttributeList ()
507    : AttrList(0), Range(), HasAttr(false) {
508  }
509};
510
511/// ParsedAttributes - A collection of parsed attributes.  Currently
512/// we don't differentiate between the various attribute syntaxes,
513/// which is basically silly.
514///
515/// Right now this is a very lightweight container, but the expectation
516/// is that this will become significantly more serious.
517class ParsedAttributes {
518public:
519  ParsedAttributes(AttributeFactory &factory)
520    : pool(factory), list(0) {
521  }
522
523  ParsedAttributes(ParsedAttributes &attrs)
524    : pool(attrs.pool), list(attrs.list) {
525    attrs.list = 0;
526  }
527
528  AttributePool &getPool() const { return pool; }
529
530  bool empty() const { return list == 0; }
531
532  void add(AttributeList *newAttr) {
533    assert(newAttr);
534    assert(newAttr->getNext() == 0);
535    newAttr->setNext(list);
536    list = newAttr;
537  }
538
539  void addAll(AttributeList *newList) {
540    if (!newList) return;
541
542    AttributeList *lastInNewList = newList;
543    while (AttributeList *next = lastInNewList->getNext())
544      lastInNewList = next;
545
546    lastInNewList->setNext(list);
547    list = newList;
548  }
549
550  void set(AttributeList *newList) {
551    list = newList;
552  }
553
554  void takeAllFrom(ParsedAttributes &attrs) {
555    addAll(attrs.list);
556    attrs.list = 0;
557    pool.takeAllFrom(attrs.pool);
558  }
559
560  void clear() { list = 0; pool.clear(); }
561  AttributeList *getList() const { return list; }
562
563  /// Returns a reference to the attribute list.  Try not to introduce
564  /// dependencies on this method, it may not be long-lived.
565  AttributeList *&getListRef() { return list; }
566
567
568  AttributeList *addNew(IdentifierInfo *attrName, SourceLocation attrLoc,
569                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
570                        IdentifierInfo *parmName, SourceLocation parmLoc,
571                        Expr **args, unsigned numArgs,
572                        bool declspec = false, bool cxx0x = false) {
573    AttributeList *attr =
574      pool.create(attrName, attrLoc, scopeName, scopeLoc, parmName, parmLoc,
575                  args, numArgs, declspec, cxx0x);
576    add(attr);
577    return attr;
578  }
579
580  AttributeList *addNew(IdentifierInfo *attrName, SourceLocation attrLoc,
581                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
582                        IdentifierInfo *parmName, SourceLocation parmLoc,
583                        const AvailabilityChange &introduced,
584                        const AvailabilityChange &deprecated,
585                        const AvailabilityChange &obsoleted,
586                        SourceLocation unavailable,
587                        bool declspec = false, bool cxx0x = false) {
588    AttributeList *attr =
589      pool.create(attrName, attrLoc, scopeName, scopeLoc, parmName, parmLoc,
590                  introduced, deprecated, obsoleted, unavailable,
591                  declspec, cxx0x);
592    add(attr);
593    return attr;
594  }
595
596  AttributeList *addNewInteger(ASTContext &C, IdentifierInfo *name,
597                               SourceLocation loc, int arg) {
598    AttributeList *attr =
599      pool.createIntegerAttribute(C, name, loc, arg);
600    add(attr);
601    return attr;
602  }
603
604
605private:
606  mutable AttributePool pool;
607  AttributeList *list;
608};
609
610}  // end namespace clang
611
612#endif
613