summaryrefslogtreecommitdiff
path: root/include/llvm/IR/Module.h
blob: 4bfa9e68aa897f9f02b8b9fec67c592f8bcf1fdd (plain)
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
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
//===-- llvm/Module.h - C++ class to represent a VM module ------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// @file
/// Module.h This file contains the declarations for the Module class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_MODULE_H
#define LLVM_IR_MODULE_H

#include "llvm/ADT/OwningPtr.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Metadata.h"
#include "llvm/Support/CBindingWrapping.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/system_error.h"

namespace llvm {

class FunctionType;
class GVMaterializer;
class LLVMContext;
class StructType;
template<typename T> struct DenseMapInfo;
template<typename KeyT, typename ValueT, typename KeyInfoT> class DenseMap;

template<> struct ilist_traits<Function>
  : public SymbolTableListTraits<Function, Module> {

  // createSentinel is used to get hold of the node that marks the end of the
  // list... (same trick used here as in ilist_traits<Instruction>)
  Function *createSentinel() const {
    return static_cast<Function*>(&Sentinel);
  }
  static void destroySentinel(Function*) {}

  Function *provideInitialHead() const { return createSentinel(); }
  Function *ensureHead(Function*) const { return createSentinel(); }
  static void noteHead(Function*, Function*) {}

private:
  mutable ilist_node<Function> Sentinel;
};

template<> struct ilist_traits<GlobalVariable>
  : public SymbolTableListTraits<GlobalVariable, Module> {
  // createSentinel is used to create a node that marks the end of the list.
  GlobalVariable *createSentinel() const {
    return static_cast<GlobalVariable*>(&Sentinel);
  }
  static void destroySentinel(GlobalVariable*) {}

  GlobalVariable *provideInitialHead() const { return createSentinel(); }
  GlobalVariable *ensureHead(GlobalVariable*) const { return createSentinel(); }
  static void noteHead(GlobalVariable*, GlobalVariable*) {}
private:
  mutable ilist_node<GlobalVariable> Sentinel;
};

template<> struct ilist_traits<GlobalAlias>
  : public SymbolTableListTraits<GlobalAlias, Module> {
  // createSentinel is used to create a node that marks the end of the list.
  GlobalAlias *createSentinel() const {
    return static_cast<GlobalAlias*>(&Sentinel);
  }
  static void destroySentinel(GlobalAlias*) {}

  GlobalAlias *provideInitialHead() const { return createSentinel(); }
  GlobalAlias *ensureHead(GlobalAlias*) const { return createSentinel(); }
  static void noteHead(GlobalAlias*, GlobalAlias*) {}
private:
  mutable ilist_node<GlobalAlias> Sentinel;
};

template<> struct ilist_traits<NamedMDNode>
  : public ilist_default_traits<NamedMDNode> {
  // createSentinel is used to get hold of a node that marks the end of
  // the list...
  NamedMDNode *createSentinel() const {
    return static_cast<NamedMDNode*>(&Sentinel);
  }
  static void destroySentinel(NamedMDNode*) {}

  NamedMDNode *provideInitialHead() const { return createSentinel(); }
  NamedMDNode *ensureHead(NamedMDNode*) const { return createSentinel(); }
  static void noteHead(NamedMDNode*, NamedMDNode*) {}
  void addNodeToList(NamedMDNode *) {}
  void removeNodeFromList(NamedMDNode *) {}
private:
  mutable ilist_node<NamedMDNode> Sentinel;
};

/// A Module instance is used to store all the information related to an
/// LLVM module. Modules are the top level container of all other LLVM
/// Intermediate Representation (IR) objects. Each module directly contains a
/// list of globals variables, a list of functions, a list of libraries (or
/// other modules) this module depends on, a symbol table, and various data
/// about the target's characteristics.
///
/// A module maintains a GlobalValRefMap object that is used to hold all
/// constant references to global variables in the module.  When a global
/// variable is destroyed, it should have no entries in the GlobalValueRefMap.
/// @brief The main container class for the LLVM Intermediate Representation.
class Module {
/// @name Types And Enumerations
/// @{
public:
  /// The type for the list of global variables.
  typedef iplist<GlobalVariable> GlobalListType;
  /// The type for the list of functions.
  typedef iplist<Function> FunctionListType;
  /// The type for the list of aliases.
  typedef iplist<GlobalAlias> AliasListType;
  /// The type for the list of named metadata.
  typedef ilist<NamedMDNode> NamedMDListType;

  /// The Global Variable iterator.
  typedef GlobalListType::iterator                      global_iterator;
  /// The Global Variable constant iterator.
  typedef GlobalListType::const_iterator          const_global_iterator;

  /// The Function iterators.
  typedef FunctionListType::iterator                           iterator;
  /// The Function constant iterator
  typedef FunctionListType::const_iterator               const_iterator;

  /// The Global Alias iterators.
  typedef AliasListType::iterator                        alias_iterator;
  /// The Global Alias constant iterator
  typedef AliasListType::const_iterator            const_alias_iterator;

  /// The named metadata iterators.
  typedef NamedMDListType::iterator             named_metadata_iterator;
  /// The named metadata constant interators.
  typedef NamedMDListType::const_iterator const_named_metadata_iterator;

  /// This enumeration defines the supported behaviors of module flags.
  enum ModFlagBehavior {
    /// Emits an error if two values disagree, otherwise the resulting value is
    /// that of the operands.
    Error = 1,

    /// Emits a warning if two values disagree. The result value will be the
    /// operand for the flag from the first module being linked.
    Warning = 2,

    /// Adds a requirement that another module flag be present and have a
    /// specified value after linking is performed. The value must be a metadata
    /// pair, where the first element of the pair is the ID of the module flag
    /// to be restricted, and the second element of the pair is the value the
    /// module flag should be restricted to. This behavior can be used to
    /// restrict the allowable results (via triggering of an error) of linking
    /// IDs with the **Override** behavior.
    Require = 3,

    /// Uses the specified value, regardless of the behavior or value of the
    /// other module. If both modules specify **Override**, but the values
    /// differ, an error will be emitted.
    Override = 4,

    /// Appends the two values, which are required to be metadata nodes.
    Append = 5,

    /// Appends the two values, which are required to be metadata
    /// nodes. However, duplicate entries in the second list are dropped
    /// during the append operation.
    AppendUnique = 6
  };

  struct ModuleFlagEntry {
    ModFlagBehavior Behavior;
    MDString *Key;
    Value *Val;
    ModuleFlagEntry(ModFlagBehavior B, MDString *K, Value *V)
      : Behavior(B), Key(K), Val(V) {}
  };

/// @}
/// @name Member Variables
/// @{
private:
  LLVMContext &Context;           ///< The LLVMContext from which types and
                                  ///< constants are allocated.
  GlobalListType GlobalList;      ///< The Global Variables in the module
  FunctionListType FunctionList;  ///< The Functions in the module
  AliasListType AliasList;        ///< The Aliases in the module
  NamedMDListType NamedMDList;    ///< The named metadata in the module
  std::string GlobalScopeAsm;     ///< Inline Asm at global scope.
  ValueSymbolTable *ValSymTab;    ///< Symbol table for values
  OwningPtr<GVMaterializer> Materializer;  ///< Used to materialize GlobalValues
  std::string ModuleID;           ///< Human readable identifier for the module
  std::string TargetTriple;       ///< Platform target triple Module compiled on
  std::string DataLayout;         ///< Target data description
  void *NamedMDSymTab;            ///< NamedMDNode names.

  friend class Constant;

/// @}
/// @name Constructors
/// @{
public:
  /// The Module constructor. Note that there is no default constructor. You
  /// must provide a name for the module upon construction.
  explicit Module(StringRef ModuleID, LLVMContext& C);
  /// The module destructor. This will dropAllReferences.
  ~Module();

/// @}
/// @name Module Level Accessors
/// @{

  /// Get the module identifier which is, essentially, the name of the module.
  /// @returns the module identifier as a string
  const std::string &getModuleIdentifier() const { return ModuleID; }

  /// Get the data layout string for the module's target platform.  This encodes
  /// the type sizes and alignments expected by this module.
  /// @returns the data layout as a string
  const std::string &getDataLayout() const { return DataLayout; }

  /// Get the target triple which is a string describing the target host.
  /// @returns a string containing the target triple.
  const std::string &getTargetTriple() const { return TargetTriple; }

  /// Get the global data context.
  /// @returns LLVMContext - a container for LLVM's global information
  LLVMContext &getContext() const { return Context; }

  /// Get any module-scope inline assembly blocks.
  /// @returns a string containing the module-scope inline assembly blocks.
  const std::string &getModuleInlineAsm() const { return GlobalScopeAsm; }

/// @}
/// @name Module Level Mutators
/// @{

  /// Set the module identifier.
  void setModuleIdentifier(StringRef ID) { ModuleID = ID; }

  /// Set the data layout
  void setDataLayout(StringRef DL) { DataLayout = DL; }

  /// Set the target triple.
  void setTargetTriple(StringRef T) { TargetTriple = T; }

  /// Set the module-scope inline assembly blocks.
  void setModuleInlineAsm(StringRef Asm) {
    GlobalScopeAsm = Asm;
    if (!GlobalScopeAsm.empty() &&
        GlobalScopeAsm[GlobalScopeAsm.size()-1] != '\n')
      GlobalScopeAsm += '\n';
  }

  /// Append to the module-scope inline assembly blocks, automatically inserting
  /// a separating newline if necessary.
  void appendModuleInlineAsm(StringRef Asm) {
    GlobalScopeAsm += Asm;
    if (!GlobalScopeAsm.empty() &&
        GlobalScopeAsm[GlobalScopeAsm.size()-1] != '\n')
      GlobalScopeAsm += '\n';
  }

/// @}
/// @name Generic Value Accessors
/// @{

  /// getNamedValue - Return the global value in the module with
  /// the specified name, of arbitrary type.  This method returns null
  /// if a global with the specified name is not found.
  GlobalValue *getNamedValue(StringRef Name) const;

  /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
  /// This ID is uniqued across modules in the current LLVMContext.
  unsigned getMDKindID(StringRef Name) const;

  /// getMDKindNames - Populate client supplied SmallVector with the name for
  /// custom metadata IDs registered in this LLVMContext.
  void getMDKindNames(SmallVectorImpl<StringRef> &Result) const;

  
  typedef DenseMap<StructType*, unsigned, DenseMapInfo<StructType*> >
                   NumeredTypesMapTy;

  /// getTypeByName - Return the type with the specified name, or null if there
  /// is none by that name.
  StructType *getTypeByName(StringRef Name) const;

/// @}
/// @name Function Accessors
/// @{

  /// getOrInsertFunction - Look up the specified function in the module symbol
  /// table.  Four possibilities:
  ///   1. If it does not exist, add a prototype for the function and return it.
  ///   2. If it exists, and has a local linkage, the existing function is
  ///      renamed and a new one is inserted.
  ///   3. Otherwise, if the existing function has the correct prototype, return
  ///      the existing function.
  ///   4. Finally, the function exists but has the wrong prototype: return the
  ///      function with a constantexpr cast to the right prototype.
  Constant *getOrInsertFunction(StringRef Name, FunctionType *T,
                                AttributeSet AttributeList);

  Constant *getOrInsertFunction(StringRef Name, FunctionType *T);

  /// getOrInsertFunction - Look up the specified function in the module symbol
  /// table.  If it does not exist, add a prototype for the function and return
  /// it.  This function guarantees to return a constant of pointer to the
  /// specified function type or a ConstantExpr BitCast of that type if the
  /// named function has a different type.  This version of the method takes a
  /// null terminated list of function arguments, which makes it easier for
  /// clients to use.
  Constant *getOrInsertFunction(StringRef Name,
                                AttributeSet AttributeList,
                                Type *RetTy, ...)  END_WITH_NULL;

  /// getOrInsertFunction - Same as above, but without the attributes.
  Constant *getOrInsertFunction(StringRef Name, Type *RetTy, ...)
    END_WITH_NULL;

  /// getFunction - Look up the specified function in the module symbol table.
  /// If it does not exist, return null.
  Function *getFunction(StringRef Name) const;

/// @}
/// @name Global Variable Accessors
/// @{

  /// getGlobalVariable - Look up the specified global variable in the module
  /// symbol table.  If it does not exist, return null. If AllowInternal is set
  /// to true, this function will return types that have InternalLinkage. By
  /// default, these types are not returned.
  const GlobalVariable *getGlobalVariable(StringRef Name,
                                          bool AllowInternal = false) const {
    return const_cast<Module *>(this)->getGlobalVariable(Name, AllowInternal);
  }

  GlobalVariable *getGlobalVariable(StringRef Name, bool AllowInternal = false);

  /// getNamedGlobal - Return the global variable in the module with the
  /// specified name, of arbitrary type.  This method returns null if a global
  /// with the specified name is not found.
  GlobalVariable *getNamedGlobal(StringRef Name) {
    return getGlobalVariable(Name, true);
  }
  const GlobalVariable *getNamedGlobal(StringRef Name) const {
    return const_cast<Module *>(this)->getNamedGlobal(Name);
  }

  /// getOrInsertGlobal - Look up the specified global in the module symbol
  /// table.
  ///   1. If it does not exist, add a declaration of the global and return it.
  ///   2. Else, the global exists but has the wrong type: return the function
  ///      with a constantexpr cast to the right type.
  ///   3. Finally, if the existing global is the correct declaration, return
  ///      the existing global.
  Constant *getOrInsertGlobal(StringRef Name, Type *Ty);

/// @}
/// @name Global Alias Accessors
/// @{

  /// getNamedAlias - Return the global alias in the module with the
  /// specified name, of arbitrary type.  This method returns null if a global
  /// with the specified name is not found.
  GlobalAlias *getNamedAlias(StringRef Name) const;

/// @}
/// @name Named Metadata Accessors
/// @{

  /// getNamedMetadata - Return the first NamedMDNode in the module with the
  /// specified name. This method returns null if a NamedMDNode with the
  /// specified name is not found.
  NamedMDNode *getNamedMetadata(const Twine &Name) const;

  /// getOrInsertNamedMetadata - Return the named MDNode in the module
  /// with the specified name. This method returns a new NamedMDNode if a
  /// NamedMDNode with the specified name is not found.
  NamedMDNode *getOrInsertNamedMetadata(StringRef Name);

  /// eraseNamedMetadata - Remove the given NamedMDNode from this module
  /// and delete it.
  void eraseNamedMetadata(NamedMDNode *NMD);

/// @}
/// @name Module Flags Accessors
/// @{

  /// getModuleFlagsMetadata - Returns the module flags in the provided vector.
  void getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> &Flags) const;

  /// Return the corresponding value if Key appears in module flags, otherwise
  /// return null.
  Value *getModuleFlag(StringRef Key) const;

  /// getModuleFlagsMetadata - Returns the NamedMDNode in the module that
  /// represents module-level flags. This method returns null if there are no
  /// module-level flags.
  NamedMDNode *getModuleFlagsMetadata() const;

  /// getOrInsertModuleFlagsMetadata - Returns the NamedMDNode in the module
  /// that represents module-level flags. If module-level flags aren't found,
  /// it creates the named metadata that contains them.
  NamedMDNode *getOrInsertModuleFlagsMetadata();

  /// addModuleFlag - Add a module-level flag to the module-level flags
  /// metadata. It will create the module-level flags named metadata if it
  /// doesn't already exist.
  void addModuleFlag(ModFlagBehavior Behavior, StringRef Key, Value *Val);
  void addModuleFlag(ModFlagBehavior Behavior, StringRef Key, uint32_t Val);
  void addModuleFlag(MDNode *Node);

/// @}
/// @name Materialization
/// @{

  /// setMaterializer - Sets the GVMaterializer to GVM.  This module must not
  /// yet have a Materializer.  To reset the materializer for a module that
  /// already has one, call MaterializeAllPermanently first.  Destroying this
  /// module will destroy its materializer without materializing any more
  /// GlobalValues.  Without destroying the Module, there is no way to detach or
  /// destroy a materializer without materializing all the GVs it controls, to
  /// avoid leaving orphan unmaterialized GVs.
  void setMaterializer(GVMaterializer *GVM);
  /// getMaterializer - Retrieves the GVMaterializer, if any, for this Module.
  GVMaterializer *getMaterializer() const { return Materializer.get(); }

  /// isMaterializable - True if the definition of GV has yet to be materialized
  /// from the GVMaterializer.
  bool isMaterializable(const GlobalValue *GV) const;
  /// isDematerializable - Returns true if this GV was loaded from this Module's
  /// GVMaterializer and the GVMaterializer knows how to dematerialize the GV.
  bool isDematerializable(const GlobalValue *GV) const;

  /// Materialize - Make sure the 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.
  bool Materialize(GlobalValue *GV, std::string *ErrInfo = 0);
  /// Dematerialize - If the GlobalValue is read in, and if the GVMaterializer
  /// supports it, release the memory for the function, and set it up to be
  /// materialized lazily.  If !isDematerializable(), this method is a noop.
  void Dematerialize(GlobalValue *GV);

  /// Make sure all GlobalValues in this Module are fully read.
  error_code materializeAll();

  /// MaterializeAllPermanently - Make sure all GlobalValues in this Module are
  /// fully read and clear the Materializer.  If the module is corrupt, this
  /// returns true, fills in the optional string with information about the
  /// problem, and DOES NOT clear the old Materializer.  If successful, this
  /// returns false.
  bool MaterializeAllPermanently(std::string *ErrInfo = 0);

/// @}
/// @name Direct access to the globals list, functions list, and symbol table
/// @{

  /// Get the Module's list of global variables (constant).
  const GlobalListType   &getGlobalList() const       { return GlobalList; }
  /// Get the Module's list of global variables.
  GlobalListType         &getGlobalList()             { return GlobalList; }
  static iplist<GlobalVariable> Module::*getSublistAccess(GlobalVariable*) {
    return &Module::GlobalList;
  }
  /// Get the Module's list of functions (constant).
  const FunctionListType &getFunctionList() const     { return FunctionList; }
  /// Get the Module's list of functions.
  FunctionListType       &getFunctionList()           { return FunctionList; }
  static iplist<Function> Module::*getSublistAccess(Function*) {
    return &Module::FunctionList;
  }
  /// Get the Module's list of aliases (constant).
  const AliasListType    &getAliasList() const        { return AliasList; }
  /// Get the Module's list of aliases.
  AliasListType          &getAliasList()              { return AliasList; }
  static iplist<GlobalAlias> Module::*getSublistAccess(GlobalAlias*) {
    return &Module::AliasList;
  }
  /// Get the Module's list of named metadata (constant).
  const NamedMDListType  &getNamedMDList() const      { return NamedMDList; }
  /// Get the Module's list of named metadata.
  NamedMDListType        &getNamedMDList()            { return NamedMDList; }
  static ilist<NamedMDNode> Module::*getSublistAccess(NamedMDNode*) {
    return &Module::NamedMDList;
  }
  /// Get the symbol table of global variable and function identifiers
  const ValueSymbolTable &getValueSymbolTable() const { return *ValSymTab; }
  /// Get the Module's symbol table of global variable and function identifiers.
  ValueSymbolTable       &getValueSymbolTable()       { return *ValSymTab; }

/// @}
/// @name Global Variable Iteration
/// @{

  global_iterator       global_begin()       { return GlobalList.begin(); }
  const_global_iterator global_begin() const { return GlobalList.begin(); }
  global_iterator       global_end  ()       { return GlobalList.end(); }
  const_global_iterator global_end  () const { return GlobalList.end(); }
  bool                  global_empty() const { return GlobalList.empty(); }

/// @}
/// @name Function Iteration
/// @{

  iterator                begin()       { return FunctionList.begin(); }
  const_iterator          begin() const { return FunctionList.begin(); }
  iterator                end  ()       { return FunctionList.end();   }
  const_iterator          end  () const { return FunctionList.end();   }
  size_t                  size() const  { return FunctionList.size(); }
  bool                    empty() const { return FunctionList.empty(); }

/// @}
/// @name Alias Iteration
/// @{

  alias_iterator       alias_begin()            { return AliasList.begin(); }
  const_alias_iterator alias_begin() const      { return AliasList.begin(); }
  alias_iterator       alias_end  ()            { return AliasList.end();   }
  const_alias_iterator alias_end  () const      { return AliasList.end();   }
  size_t               alias_size () const      { return AliasList.size();  }
  bool                 alias_empty() const      { return AliasList.empty(); }


/// @}
/// @name Named Metadata Iteration
/// @{

  named_metadata_iterator named_metadata_begin() { return NamedMDList.begin(); }
  const_named_metadata_iterator named_metadata_begin() const {
    return NamedMDList.begin();
  }

  named_metadata_iterator named_metadata_end() { return NamedMDList.end(); }
  const_named_metadata_iterator named_metadata_end() const {
    return NamedMDList.end();
  }

  size_t named_metadata_size() const { return NamedMDList.size();  }
  bool named_metadata_empty() const { return NamedMDList.empty(); }


/// @}
/// @name Utility functions for printing and dumping Module objects
/// @{

  /// Print the module to an output stream with an optional
  /// AssemblyAnnotationWriter.
  void print(raw_ostream &OS, AssemblyAnnotationWriter *AAW) const;

  /// Dump the module to stderr (for debugging).
  void dump() const;
  
  /// This function causes all the subinstructions to "let go" of all references
  /// that they are maintaining.  This allows one to 'delete' a whole class at
  /// a time, even though there may be circular references... first all
  /// references are dropped, and all use counts go to zero.  Then everything
  /// is delete'd for real.  Note that no operations are valid on an object
  /// that has "dropped all references", except operator delete.
  void dropAllReferences();
/// @}
};

/// An raw_ostream inserter for modules.
inline raw_ostream &operator<<(raw_ostream &O, const Module &M) {
  M.print(O, 0);
  return O;
}

// Create wrappers for C Binding types (see CBindingWrapping.h).
DEFINE_SIMPLE_CONVERSION_FUNCTIONS(Module, LLVMModuleRef)

/* LLVMModuleProviderRef exists for historical reasons, but now just holds a
 * Module.
 */
inline Module *unwrap(LLVMModuleProviderRef MP) {
  return reinterpret_cast<Module*>(MP);
}
  
} // End llvm namespace

#endif