This file is indexed.

/usr/include/llvm-3.9/llvm/IR/GlobalValue.h is in llvm-3.9-dev 1:3.9.1-19ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
//===-- llvm/GlobalValue.h - Class to represent a global value --*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a common base class of all globally definable objects.  As such,
// it is subclassed by GlobalVariable, GlobalAlias and by Function.  This is
// used because you can do certain things with these global objects that you
// can't do to anything else.  For example, use the address of one as a
// constant.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_GLOBALVALUE_H
#define LLVM_IR_GLOBALVALUE_H

#include "llvm/IR/Constant.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/Support/MD5.h"
#include <system_error>

namespace llvm {

class Comdat;
class PointerType;
class Module;

namespace Intrinsic {
  enum ID : unsigned;
}

class GlobalValue : public Constant {
  GlobalValue(const GlobalValue &) = delete;
public:
  /// @brief An enumeration for the kinds of linkage for global values.
  enum LinkageTypes {
    ExternalLinkage = 0,///< Externally visible function
    AvailableExternallyLinkage, ///< Available for inspection, not emission.
    LinkOnceAnyLinkage, ///< Keep one copy of function when linking (inline)
    LinkOnceODRLinkage, ///< Same, but only replaced by something equivalent.
    WeakAnyLinkage,     ///< Keep one copy of named function when linking (weak)
    WeakODRLinkage,     ///< Same, but only replaced by something equivalent.
    AppendingLinkage,   ///< Special purpose, only applies to global arrays
    InternalLinkage,    ///< Rename collisions when linking (static functions).
    PrivateLinkage,     ///< Like Internal, but omit from symbol table.
    ExternalWeakLinkage,///< ExternalWeak linkage description.
    CommonLinkage       ///< Tentative definitions.
  };

  /// @brief An enumeration for the kinds of visibility of global values.
  enum VisibilityTypes {
    DefaultVisibility = 0,  ///< The GV is visible
    HiddenVisibility,       ///< The GV is hidden
    ProtectedVisibility     ///< The GV is protected
  };

  /// @brief Storage classes of global values for PE targets.
  enum DLLStorageClassTypes {
    DefaultStorageClass   = 0,
    DLLImportStorageClass = 1, ///< Function to be imported from DLL
    DLLExportStorageClass = 2  ///< Function to be accessible from DLL.
  };

protected:
  GlobalValue(Type *Ty, ValueTy VTy, Use *Ops, unsigned NumOps,
              LinkageTypes Linkage, const Twine &Name, unsigned AddressSpace)
      : Constant(PointerType::get(Ty, AddressSpace), VTy, Ops, NumOps),
        ValueType(Ty), Linkage(Linkage), Visibility(DefaultVisibility),
        UnnamedAddrVal(unsigned(UnnamedAddr::None)),
        DllStorageClass(DefaultStorageClass), ThreadLocal(NotThreadLocal),
        IntID((Intrinsic::ID)0U), Parent(nullptr) {
    setName(Name);
  }

  Type *ValueType;
  // All bitfields use unsigned as the underlying type so that MSVC will pack
  // them.
  unsigned Linkage : 4;       // The linkage of this global
  unsigned Visibility : 2;    // The visibility style of this global
  unsigned UnnamedAddrVal : 2; // This value's address is not significant
  unsigned DllStorageClass : 2; // DLL storage class

  unsigned ThreadLocal : 3; // Is this symbol "Thread Local", if so, what is
                            // the desired model?
  static const unsigned GlobalValueSubClassDataBits = 19;

private:
  // Give subclasses access to what otherwise would be wasted padding.
  // (19 + 4 + 2 + 2 + 2 + 3) == 32.
  unsigned SubClassData : GlobalValueSubClassDataBits;

  friend class Constant;
  void destroyConstantImpl();
  Value *handleOperandChangeImpl(Value *From, Value *To);

  /// Returns true if the definition of this global may be replaced by a
  /// differently optimized variant of the same source level function at link
  /// time.
  bool mayBeDerefined() const {
    switch (getLinkage()) {
    case WeakODRLinkage:
    case LinkOnceODRLinkage:
    case AvailableExternallyLinkage:
      return true;

    case WeakAnyLinkage:
    case LinkOnceAnyLinkage:
    case CommonLinkage:
    case ExternalWeakLinkage:
    case ExternalLinkage:
    case AppendingLinkage:
    case InternalLinkage:
    case PrivateLinkage:
      return isInterposable();
    }

    llvm_unreachable("Fully covered switch above!");
  }

protected:
  /// \brief The intrinsic ID for this subclass (which must be a Function).
  ///
  /// This member is defined by this class, but not used for anything.
  /// Subclasses can use it to store their intrinsic ID, if they have one.
  ///
  /// This is stored here to save space in Function on 64-bit hosts.
  Intrinsic::ID IntID;

  unsigned getGlobalValueSubClassData() const {
    return SubClassData;
  }
  void setGlobalValueSubClassData(unsigned V) {
    assert(V < (1 << GlobalValueSubClassDataBits) && "It will not fit");
    SubClassData = V;
  }

  Module *Parent;             // The containing module.
public:
  enum ThreadLocalMode {
    NotThreadLocal = 0,
    GeneralDynamicTLSModel,
    LocalDynamicTLSModel,
    InitialExecTLSModel,
    LocalExecTLSModel
  };

  ~GlobalValue() override {
    removeDeadConstantUsers();   // remove any dead constants using this.
  }

  unsigned getAlignment() const;

  enum class UnnamedAddr {
    None,
    Local,
    Global,
  };

  bool hasGlobalUnnamedAddr() const {
    return getUnnamedAddr() == UnnamedAddr::Global;
  }

  /// Returns true if this value's address is not significant in this module.
  /// This attribute is intended to be used only by the code generator and LTO
  /// to allow the linker to decide whether the global needs to be in the symbol
  /// table. It should probably not be used in optimizations, as the value may
  /// have uses outside the module; use hasGlobalUnnamedAddr() instead.
  bool hasAtLeastLocalUnnamedAddr() const {
    return getUnnamedAddr() != UnnamedAddr::None;
  }

  UnnamedAddr getUnnamedAddr() const {
    return UnnamedAddr(UnnamedAddrVal);
  }
  void setUnnamedAddr(UnnamedAddr Val) { UnnamedAddrVal = unsigned(Val); }

  static UnnamedAddr getMinUnnamedAddr(UnnamedAddr A, UnnamedAddr B) {
    if (A == UnnamedAddr::None || B == UnnamedAddr::None)
      return UnnamedAddr::None;
    if (A == UnnamedAddr::Local || B == UnnamedAddr::Local)
      return UnnamedAddr::Local;
    return UnnamedAddr::Global;
  }

  bool hasComdat() const { return getComdat() != nullptr; }
  Comdat *getComdat();
  const Comdat *getComdat() const {
    return const_cast<GlobalValue *>(this)->getComdat();
  }

  VisibilityTypes getVisibility() const { return VisibilityTypes(Visibility); }
  bool hasDefaultVisibility() const { return Visibility == DefaultVisibility; }
  bool hasHiddenVisibility() const { return Visibility == HiddenVisibility; }
  bool hasProtectedVisibility() const {
    return Visibility == ProtectedVisibility;
  }
  void setVisibility(VisibilityTypes V) {
    assert((!hasLocalLinkage() || V == DefaultVisibility) &&
           "local linkage requires default visibility");
    Visibility = V;
  }

  /// If the value is "Thread Local", its value isn't shared by the threads.
  bool isThreadLocal() const { return getThreadLocalMode() != NotThreadLocal; }
  void setThreadLocal(bool Val) {
    setThreadLocalMode(Val ? GeneralDynamicTLSModel : NotThreadLocal);
  }
  void setThreadLocalMode(ThreadLocalMode Val) {
    assert(Val == NotThreadLocal || getValueID() != Value::FunctionVal);
    ThreadLocal = Val;
  }
  ThreadLocalMode getThreadLocalMode() const {
    return static_cast<ThreadLocalMode>(ThreadLocal);
  }

  DLLStorageClassTypes getDLLStorageClass() const {
    return DLLStorageClassTypes(DllStorageClass);
  }
  bool hasDLLImportStorageClass() const {
    return DllStorageClass == DLLImportStorageClass;
  }
  bool hasDLLExportStorageClass() const {
    return DllStorageClass == DLLExportStorageClass;
  }
  void setDLLStorageClass(DLLStorageClassTypes C) { DllStorageClass = C; }

  bool hasSection() const { return !getSection().empty(); }
  StringRef getSection() const;

  /// Global values are always pointers.
  PointerType *getType() const { return cast<PointerType>(User::getType()); }

  Type *getValueType() const { return ValueType; }

  static LinkageTypes getLinkOnceLinkage(bool ODR) {
    return ODR ? LinkOnceODRLinkage : LinkOnceAnyLinkage;
  }
  static LinkageTypes getWeakLinkage(bool ODR) {
    return ODR ? WeakODRLinkage : WeakAnyLinkage;
  }

  static bool isExternalLinkage(LinkageTypes Linkage) {
    return Linkage == ExternalLinkage;
  }
  static bool isAvailableExternallyLinkage(LinkageTypes Linkage) {
    return Linkage == AvailableExternallyLinkage;
  }
  static bool isLinkOnceODRLinkage(LinkageTypes Linkage) {
    return Linkage == LinkOnceODRLinkage;
  }
  static bool isLinkOnceLinkage(LinkageTypes Linkage) {
    return Linkage == LinkOnceAnyLinkage || Linkage == LinkOnceODRLinkage;
  }
  static bool isWeakAnyLinkage(LinkageTypes Linkage) {
    return Linkage == WeakAnyLinkage;
  }
  static bool isWeakODRLinkage(LinkageTypes Linkage) {
    return Linkage == WeakODRLinkage;
  }
  static bool isWeakLinkage(LinkageTypes Linkage) {
    return isWeakAnyLinkage(Linkage) || isWeakODRLinkage(Linkage);
  }
  static bool isAppendingLinkage(LinkageTypes Linkage) {
    return Linkage == AppendingLinkage;
  }
  static bool isInternalLinkage(LinkageTypes Linkage) {
    return Linkage == InternalLinkage;
  }
  static bool isPrivateLinkage(LinkageTypes Linkage) {
    return Linkage == PrivateLinkage;
  }
  static bool isLocalLinkage(LinkageTypes Linkage) {
    return isInternalLinkage(Linkage) || isPrivateLinkage(Linkage);
  }
  static bool isExternalWeakLinkage(LinkageTypes Linkage) {
    return Linkage == ExternalWeakLinkage;
  }
  static bool isCommonLinkage(LinkageTypes Linkage) {
    return Linkage == CommonLinkage;
  }
  static bool isValidDeclarationLinkage(LinkageTypes Linkage) {
    return isExternalWeakLinkage(Linkage) || isExternalLinkage(Linkage);
  }

  /// Whether the definition of this global may be replaced by something
  /// non-equivalent at link time. For example, if a function has weak linkage
  /// then the code defining it may be replaced by different code.
  static bool isInterposableLinkage(LinkageTypes Linkage) {
    switch (Linkage) {
    case WeakAnyLinkage:
    case LinkOnceAnyLinkage:
    case CommonLinkage:
    case ExternalWeakLinkage:
      return true;

    case AvailableExternallyLinkage:
    case LinkOnceODRLinkage:
    case WeakODRLinkage:
    // The above three cannot be overridden but can be de-refined.

    case ExternalLinkage:
    case AppendingLinkage:
    case InternalLinkage:
    case PrivateLinkage:
      return false;
    }
    llvm_unreachable("Fully covered switch above!");
  }

  /// Whether the definition of this global may be discarded if it is not used
  /// in its compilation unit.
  static bool isDiscardableIfUnused(LinkageTypes Linkage) {
    return isLinkOnceLinkage(Linkage) || isLocalLinkage(Linkage) ||
           isAvailableExternallyLinkage(Linkage);
  }

  /// Whether the definition of this global may be replaced at link time.  NB:
  /// Using this method outside of the code generators is almost always a
  /// mistake: when working at the IR level use isInterposable instead as it
  /// knows about ODR semantics.
  static bool isWeakForLinker(LinkageTypes Linkage)  {
    return Linkage == WeakAnyLinkage || Linkage == WeakODRLinkage ||
           Linkage == LinkOnceAnyLinkage || Linkage == LinkOnceODRLinkage ||
           Linkage == CommonLinkage || Linkage == ExternalWeakLinkage;
  }

  /// Return true if the currently visible definition of this global (if any) is
  /// exactly the definition we will see at runtime.
  ///
  /// Non-exact linkage types inhibits most non-inlining IPO, since a
  /// differently optimized variant of the same function can have different
  /// observable or undefined behavior than in the variant currently visible.
  /// For instance, we could have started with
  ///
  ///   void foo(int *v) {
  ///     int t = 5 / v[0];
  ///     (void) t;
  ///   }
  ///
  /// and "refined" it to
  ///
  ///   void foo(int *v) { }
  ///
  /// However, we cannot infer readnone for `foo`, since that would justify
  /// DSE'ing a store to `v[0]` across a call to `foo`, which can cause
  /// undefined behavior if the linker replaces the actual call destination with
  /// the unoptimized `foo`.
  ///
  /// Inlining is okay across non-exact linkage types as long as they're not
  /// interposable (see \c isInterposable), since in such cases the currently
  /// visible variant is *a* correct implementation of the original source
  /// function; it just isn't the *only* correct implementation.
  bool isDefinitionExact() const {
    return !mayBeDerefined();
  }

  /// Return true if this global has an exact defintion.
  bool hasExactDefinition() const {
    // While this computes exactly the same thing as
    // isStrongDefinitionForLinker, the intended uses are different.  This
    // function is intended to help decide if specific inter-procedural
    // transforms are correct, while isStrongDefinitionForLinker's intended use
    // is in low level code generation.
    return !isDeclaration() && isDefinitionExact();
  }

  /// Return true if this global's definition can be substituted with an
  /// *arbitrary* definition at link time.  We cannot do any IPO or inlinining
  /// across interposable call edges, since the callee can be replaced with
  /// something arbitrary at link time.
  bool isInterposable() const { return isInterposableLinkage(getLinkage()); }

  bool hasExternalLinkage() const { return isExternalLinkage(getLinkage()); }
  bool hasAvailableExternallyLinkage() const {
    return isAvailableExternallyLinkage(getLinkage());
  }
  bool hasLinkOnceLinkage() const { return isLinkOnceLinkage(getLinkage()); }
  bool hasLinkOnceODRLinkage() const {
    return isLinkOnceODRLinkage(getLinkage());
  }
  bool hasWeakLinkage() const { return isWeakLinkage(getLinkage()); }
  bool hasWeakAnyLinkage() const { return isWeakAnyLinkage(getLinkage()); }
  bool hasWeakODRLinkage() const { return isWeakODRLinkage(getLinkage()); }
  bool hasAppendingLinkage() const { return isAppendingLinkage(getLinkage()); }
  bool hasInternalLinkage() const { return isInternalLinkage(getLinkage()); }
  bool hasPrivateLinkage() const { return isPrivateLinkage(getLinkage()); }
  bool hasLocalLinkage() const { return isLocalLinkage(getLinkage()); }
  bool hasExternalWeakLinkage() const {
    return isExternalWeakLinkage(getLinkage());
  }
  bool hasCommonLinkage() const { return isCommonLinkage(getLinkage()); }
  bool hasValidDeclarationLinkage() const {
    return isValidDeclarationLinkage(getLinkage());
  }

  void setLinkage(LinkageTypes LT) {
    if (isLocalLinkage(LT))
      Visibility = DefaultVisibility;
    Linkage = LT;
  }
  LinkageTypes getLinkage() const { return LinkageTypes(Linkage); }

  bool isDiscardableIfUnused() const {
    return isDiscardableIfUnused(getLinkage());
  }

  bool isWeakForLinker() const { return isWeakForLinker(getLinkage()); }

  /// Copy all additional attributes (those not needed to create a GlobalValue)
  /// from the GlobalValue Src to this one.
  virtual void copyAttributesFrom(const GlobalValue *Src);

  /// If special LLVM prefix that is used to inform the asm printer to not emit
  /// usual symbol prefix before the symbol name is used then return linkage
  /// name after skipping this special LLVM prefix.
  static StringRef getRealLinkageName(StringRef Name) {
    if (!Name.empty() && Name[0] == '\1')
      return Name.substr(1);
    return Name;
  }

  /// Return the modified name for a global value suitable to be
  /// used as the key for a global lookup (e.g. profile or ThinLTO).
  /// The value's original name is \c Name and has linkage of type
  /// \c Linkage. The value is defined in module \c FileName.
  static std::string getGlobalIdentifier(StringRef Name,
                                         GlobalValue::LinkageTypes Linkage,
                                         StringRef FileName);

  /// Return the modified name for this global value suitable to be
  /// used as the key for a global lookup (e.g. profile or ThinLTO).
  std::string getGlobalIdentifier() const;

  /// Declare a type to represent a global unique identifier for a global value.
  /// This is a 64 bits hash that is used by PGO and ThinLTO to have a compact
  /// unique way to identify a symbol.
  using GUID = uint64_t;

  /// Return a 64-bit global unique ID constructed from global value name
  /// (i.e. returned by getGlobalIdentifier()).
  static GUID getGUID(StringRef GlobalName) { return MD5Hash(GlobalName); }

  /// Return a 64-bit global unique ID constructed from global value name
  /// (i.e. returned by getGlobalIdentifier()).
  GUID getGUID() const { return getGUID(getGlobalIdentifier()); }

  /// @name Materialization
  /// Materialization is used to construct functions only as they're needed.
  /// This
  /// is useful to reduce memory usage in LLVM or parsing work done by the
  /// BitcodeReader to load the Module.
  /// @{

  /// If this function's Module is being lazily streamed in functions from disk
  /// or some other source, this method can be used to check to see if the
  /// function has been read in yet or not.
  bool isMaterializable() const;

  /// Make sure this GlobalValue is fully read. If the module is corrupt, this
  /// returns true and fills in the optional string with information about the
  /// problem.  If successful, this returns false.
  std::error_code materialize();

/// @}

  /// Return true if the primary definition of this global value is outside of
  /// the current translation unit.
  bool isDeclaration() const;

  bool isDeclarationForLinker() const {
    if (hasAvailableExternallyLinkage())
      return true;

    return isDeclaration();
  }

  /// Returns true if this global's definition will be the one chosen by the
  /// linker.
  ///
  /// NB! Ideally this should not be used at the IR level at all.  If you're
  /// interested in optimization constraints implied by the linker's ability to
  /// choose an implementation, prefer using \c hasExactDefinition.
  bool isStrongDefinitionForLinker() const {
    return !(isDeclarationForLinker() || isWeakForLinker());
  }

  // Returns true if the alignment of the value can be unilaterally
  // increased.
  bool canIncreaseAlignment() const;

  /// This method unlinks 'this' from the containing module, but does not delete
  /// it.
  virtual void removeFromParent() = 0;

  /// This method unlinks 'this' from the containing module and deletes it.
  virtual void eraseFromParent() = 0;

  /// Get the module that this global value is contained inside of...
  Module *getParent() { return Parent; }
  const Module *getParent() const { return Parent; }

  // Methods for support type inquiry through isa, cast, and dyn_cast:
  static bool classof(const Value *V) {
    return V->getValueID() == Value::FunctionVal ||
           V->getValueID() == Value::GlobalVariableVal ||
           V->getValueID() == Value::GlobalAliasVal ||
           V->getValueID() == Value::GlobalIFuncVal;
  }
};

} // End llvm namespace

#endif