AttributeList.h revision 742352a3984aeef9ecf911be23e673e97b34595f 
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    AT_arc_weakref_unavailable,
247    IgnoredAttribute,
248    UnknownAttribute
249  };
250
251  IdentifierInfo *getName() const { return AttrName; }
252  SourceLocation getLoc() const { return AttrLoc; }
253
254  bool hasScope() const { return ScopeName; }
255  IdentifierInfo *getScopeName() const { return ScopeName; }
256  SourceLocation getScopeLoc() const { return ScopeLoc; }
257
258  IdentifierInfo *getParameterName() const { return ParmName; }
259  SourceLocation getParameterLoc() const { return ParmLoc; }
260
261  bool isDeclspecAttribute() const { return DeclspecAttribute; }
262  bool isCXX0XAttribute() const { return CXX0XAttribute; }
263
264  bool isInvalid() const { return Invalid; }
265  void setInvalid(bool b = true) const { Invalid = b; }
266
267  Kind getKind() const { return Kind(AttrKind); }
268  static Kind getKind(const IdentifierInfo *Name);
269
270  AttributeList *getNext() const { return NextInPosition; }
271  void setNext(AttributeList *N) { NextInPosition = N; }
272
273  /// getNumArgs - Return the number of actual arguments to this attribute.
274  unsigned getNumArgs() const { return NumArgs; }
275
276  /// hasParameterOrArguments - Return true if this attribute has a parameter,
277  /// or has a non empty argument expression list.
278  bool hasParameterOrArguments() const { return ParmName || NumArgs; }
279
280  /// getArg - Return the specified argument.
281  Expr *getArg(unsigned Arg) const {
282    assert(Arg < NumArgs && "Arg access out of range!");
283    return getArgsBuffer()[Arg];
284  }
285
286  class arg_iterator {
287    Expr * const *X;
288    unsigned Idx;
289  public:
290    arg_iterator(Expr * const *x, unsigned idx) : X(x), Idx(idx) {}
291
292    arg_iterator& operator++() {
293      ++Idx;
294      return *this;
295    }
296
297    bool operator==(const arg_iterator& I) const {
298      assert (X == I.X &&
299              "compared arg_iterators are for different argument lists");
300      return Idx == I.Idx;
301    }
302
303    bool operator!=(const arg_iterator& I) const {
304      return !operator==(I);
305    }
306
307    Expr* operator*() const {
308      return X[Idx];
309    }
310
311    unsigned getArgNum() const {
312      return Idx+1;
313    }
314  };
315
316  arg_iterator arg_begin() const {
317    return arg_iterator(getArgsBuffer(), 0);
318  }
319
320  arg_iterator arg_end() const {
321    return arg_iterator(getArgsBuffer(), NumArgs);
322  }
323
324  const AvailabilityChange &getAvailabilityIntroduced() const {
325    assert(getKind() == AT_availability && "Not an availability attribute");
326    return getAvailabilitySlot(IntroducedSlot);
327  }
328
329  const AvailabilityChange &getAvailabilityDeprecated() const {
330    assert(getKind() == AT_availability && "Not an availability attribute");
331    return getAvailabilitySlot(DeprecatedSlot);
332  }
333
334  const AvailabilityChange &getAvailabilityObsoleted() const {
335    assert(getKind() == AT_availability && "Not an availability attribute");
336    return getAvailabilitySlot(ObsoletedSlot);
337  }
338
339  SourceLocation getUnavailableLoc() const {
340    assert(getKind() == AT_availability && "Not an availability attribute");
341    return UnavailableLoc;
342  }
343};
344
345/// A factory, from which one makes pools, from which one creates
346/// individual attributes which are deallocated with the pool.
347///
348/// Note that it's tolerably cheap to create and destroy one of
349/// these as long as you don't actually allocate anything in it.
350class AttributeFactory {
351public:
352  enum {
353    /// The required allocation size of an availability attribute,
354    /// which we want to ensure is a multiple of sizeof(void*).
355    AvailabilityAllocSize =
356      sizeof(AttributeList)
357      + ((3 * sizeof(AvailabilityChange) + sizeof(void*) - 1)
358         / sizeof(void*) * sizeof(void*))
359  };
360
361private:
362  enum {
363    /// The number of free lists we want to be sure to support
364    /// inline.  This is just enough that availability attributes
365    /// don't surpass it.  It's actually very unlikely we'll see an
366    /// attribute that needs more than that; on x86-64 you'd need 10
367    /// expression arguments, and on i386 you'd need 19.
368    InlineFreeListsCapacity =
369      1 + (AvailabilityAllocSize - sizeof(AttributeList)) / sizeof(void*)
370  };
371
372  llvm::BumpPtrAllocator Alloc;
373
374  /// Free lists.  The index is determined by the following formula:
375  ///   (size - sizeof(AttributeList)) / sizeof(void*)
376  llvm::SmallVector<AttributeList*, InlineFreeListsCapacity> FreeLists;
377
378  // The following are the private interface used by AttributePool.
379  friend class AttributePool;
380
381  /// Allocate an attribute of the given size.
382  void *allocate(size_t size);
383
384  /// Reclaim all the attributes in the given pool chain, which is
385  /// non-empty.  Note that the current implementation is safe
386  /// against reclaiming things which were not actually allocated
387  /// with the allocator, although of course it's important to make
388  /// sure that their allocator lives at least as long as this one.
389  void reclaimPool(AttributeList *head);
390
391public:
392  AttributeFactory();
393  ~AttributeFactory();
394};
395
396class AttributePool {
397  AttributeFactory &Factory;
398  AttributeList *Head;
399
400  void *allocate(size_t size) {
401    return Factory.allocate(size);
402  }
403
404  AttributeList *add(AttributeList *attr) {
405    // We don't care about the order of the pool.
406    attr->NextInPool = Head;
407    Head = attr;
408    return attr;
409  }
410
411  void takePool(AttributeList *pool);
412
413public:
414  /// Create a new pool for a factory.
415  AttributePool(AttributeFactory &factory) : Factory(factory), Head(0) {}
416
417  /// Move the given pool's allocations to this pool.
418  AttributePool(AttributePool &pool) : Factory(pool.Factory), Head(pool.Head) {
419    pool.Head = 0;
420  }
421
422  AttributeFactory &getFactory() const { return Factory; }
423
424  void clear() {
425    if (Head) {
426      Factory.reclaimPool(Head);
427      Head = 0;
428    }
429  }
430
431  /// Take the given pool's allocations and add them to this pool.
432  void takeAllFrom(AttributePool &pool) {
433    if (pool.Head) {
434      takePool(pool.Head);
435      pool.Head = 0;
436    }
437  }
438
439  ~AttributePool() {
440    if (Head) Factory.reclaimPool(Head);
441  }
442
443  AttributeList *create(IdentifierInfo *attrName, SourceLocation attrLoc,
444                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
445                        IdentifierInfo *parmName, SourceLocation parmLoc,
446                        Expr **args, unsigned numArgs,
447                        bool declspec = false, bool cxx0x = false) {
448    void *memory = allocate(sizeof(AttributeList)
449                            + numArgs * sizeof(Expr*));
450    return add(new (memory) AttributeList(attrName, attrLoc,
451                                          scopeName, scopeLoc,
452                                          parmName, parmLoc,
453                                          args, numArgs,
454                                          declspec, cxx0x));
455  }
456
457  AttributeList *create(IdentifierInfo *attrName, SourceLocation attrLoc,
458                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
459                        IdentifierInfo *parmName, SourceLocation parmLoc,
460                        const AvailabilityChange &introduced,
461                        const AvailabilityChange &deprecated,
462                        const AvailabilityChange &obsoleted,
463                        SourceLocation unavailable,
464                        bool declspec = false, bool cxx0x = false) {
465    void *memory = allocate(AttributeFactory::AvailabilityAllocSize);
466    return add(new (memory) AttributeList(attrName, attrLoc,
467                                          scopeName, scopeLoc,
468                                          parmName, parmLoc,
469                                          introduced, deprecated, obsoleted,
470                                          unavailable,
471                                          declspec, cxx0x));
472  }
473
474  AttributeList *createIntegerAttribute(ASTContext &C, IdentifierInfo *Name,
475                                        SourceLocation TokLoc, int Arg);
476};
477
478/// addAttributeLists - Add two AttributeLists together
479/// The right-hand list is appended to the left-hand list, if any
480/// A pointer to the joined list is returned.
481/// Note: the lists are not left unmodified.
482inline AttributeList *addAttributeLists(AttributeList *Left,
483                                        AttributeList *Right) {
484  if (!Left)
485    return Right;
486
487  AttributeList *next = Left, *prev;
488  do {
489    prev = next;
490    next = next->getNext();
491  } while (next);
492  prev->setNext(Right);
493  return Left;
494}
495
496/// CXX0XAttributeList - A wrapper around a C++0x attribute list.
497/// Stores, in addition to the list proper, whether or not an actual list was
498/// (as opposed to an empty list, which may be ill-formed in some places) and
499/// the source range of the list.
500struct CXX0XAttributeList {
501  AttributeList *AttrList;
502  SourceRange Range;
503  bool HasAttr;
504  CXX0XAttributeList (AttributeList *attrList, SourceRange range, bool hasAttr)
505    : AttrList(attrList), Range(range), HasAttr (hasAttr) {
506  }
507  CXX0XAttributeList ()
508    : AttrList(0), Range(), HasAttr(false) {
509  }
510};
511
512/// ParsedAttributes - A collection of parsed attributes.  Currently
513/// we don't differentiate between the various attribute syntaxes,
514/// which is basically silly.
515///
516/// Right now this is a very lightweight container, but the expectation
517/// is that this will become significantly more serious.
518class ParsedAttributes {
519public:
520  ParsedAttributes(AttributeFactory &factory)
521    : pool(factory), list(0) {
522  }
523
524  ParsedAttributes(ParsedAttributes &attrs)
525    : pool(attrs.pool), list(attrs.list) {
526    attrs.list = 0;
527  }
528
529  AttributePool &getPool() const { return pool; }
530
531  bool empty() const { return list == 0; }
532
533  void add(AttributeList *newAttr) {
534    assert(newAttr);
535    assert(newAttr->getNext() == 0);
536    newAttr->setNext(list);
537    list = newAttr;
538  }
539
540  void addAll(AttributeList *newList) {
541    if (!newList) return;
542
543    AttributeList *lastInNewList = newList;
544    while (AttributeList *next = lastInNewList->getNext())
545      lastInNewList = next;
546
547    lastInNewList->setNext(list);
548    list = newList;
549  }
550
551  void set(AttributeList *newList) {
552    list = newList;
553  }
554
555  void takeAllFrom(ParsedAttributes &attrs) {
556    addAll(attrs.list);
557    attrs.list = 0;
558    pool.takeAllFrom(attrs.pool);
559  }
560
561  void clear() { list = 0; pool.clear(); }
562  AttributeList *getList() const { return list; }
563
564  /// Returns a reference to the attribute list.  Try not to introduce
565  /// dependencies on this method, it may not be long-lived.
566  AttributeList *&getListRef() { return list; }
567
568
569  AttributeList *addNew(IdentifierInfo *attrName, SourceLocation attrLoc,
570                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
571                        IdentifierInfo *parmName, SourceLocation parmLoc,
572                        Expr **args, unsigned numArgs,
573                        bool declspec = false, bool cxx0x = false) {
574    AttributeList *attr =
575      pool.create(attrName, attrLoc, scopeName, scopeLoc, parmName, parmLoc,
576                  args, numArgs, declspec, cxx0x);
577    add(attr);
578    return attr;
579  }
580
581  AttributeList *addNew(IdentifierInfo *attrName, SourceLocation attrLoc,
582                        IdentifierInfo *scopeName, SourceLocation scopeLoc,
583                        IdentifierInfo *parmName, SourceLocation parmLoc,
584                        const AvailabilityChange &introduced,
585                        const AvailabilityChange &deprecated,
586                        const AvailabilityChange &obsoleted,
587                        SourceLocation unavailable,
588                        bool declspec = false, bool cxx0x = false) {
589    AttributeList *attr =
590      pool.create(attrName, attrLoc, scopeName, scopeLoc, parmName, parmLoc,
591                  introduced, deprecated, obsoleted, unavailable,
592                  declspec, cxx0x);
593    add(attr);
594    return attr;
595  }
596
597  AttributeList *addNewInteger(ASTContext &C, IdentifierInfo *name,
598                               SourceLocation loc, int arg) {
599    AttributeList *attr =
600      pool.createIntegerAttribute(C, name, loc, arg);
601    add(attr);
602    return attr;
603  }
604
605
606private:
607  mutable AttributePool pool;
608  AttributeList *list;
609};
610
611}  // end namespace clang
612
613#endif
614