1//===-- Module.cpp - Implement the Module class ---------------------------===//
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 implements the Module class for the VMCore library.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Module.h"
15#include "llvm/InstrTypes.h"
16#include "llvm/Constants.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/GVMaterializer.h"
19#include "llvm/LLVMContext.h"
20#include "llvm/ADT/DenseSet.h"
21#include "llvm/ADT/SmallString.h"
22#include "llvm/ADT/STLExtras.h"
23#include "llvm/ADT/StringExtras.h"
24#include "llvm/Support/LeakDetector.h"
25#include "SymbolTableListTraitsImpl.h"
26#include <algorithm>
27#include <cstdarg>
28#include <cstdlib>
29using namespace llvm;
30
31//===----------------------------------------------------------------------===//
32// Methods to implement the globals and functions lists.
33//
34
35// Explicit instantiations of SymbolTableListTraits since some of the methods
36// are not in the public header file.
37template class llvm::SymbolTableListTraits<Function, Module>;
38template class llvm::SymbolTableListTraits<GlobalVariable, Module>;
39template class llvm::SymbolTableListTraits<GlobalAlias, Module>;
40
41//===----------------------------------------------------------------------===//
42// Primitive Module methods.
43//
44
45Module::Module(StringRef MID, LLVMContext& C)
46  : Context(C), Materializer(NULL), ModuleID(MID) {
47  ValSymTab = new ValueSymbolTable();
48  NamedMDSymTab = new StringMap<NamedMDNode *>();
49  Context.addModule(this);
50}
51
52Module::~Module() {
53  Context.removeModule(this);
54  dropAllReferences();
55  GlobalList.clear();
56  FunctionList.clear();
57  AliasList.clear();
58  LibraryList.clear();
59  NamedMDList.clear();
60  delete ValSymTab;
61  delete static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab);
62}
63
64/// Target endian information.
65Module::Endianness Module::getEndianness() const {
66  StringRef temp = DataLayout;
67  Module::Endianness ret = AnyEndianness;
68
69  while (!temp.empty()) {
70    std::pair<StringRef, StringRef> P = getToken(temp, "-");
71
72    StringRef token = P.first;
73    temp = P.second;
74
75    if (token[0] == 'e') {
76      ret = LittleEndian;
77    } else if (token[0] == 'E') {
78      ret = BigEndian;
79    }
80  }
81
82  return ret;
83}
84
85/// Target Pointer Size information.
86Module::PointerSize Module::getPointerSize() const {
87  StringRef temp = DataLayout;
88  Module::PointerSize ret = AnyPointerSize;
89
90  while (!temp.empty()) {
91    std::pair<StringRef, StringRef> TmpP = getToken(temp, "-");
92    temp = TmpP.second;
93    TmpP = getToken(TmpP.first, ":");
94    StringRef token = TmpP.second, signalToken = TmpP.first;
95
96    if (signalToken[0] == 'p') {
97      int size = 0;
98      getToken(token, ":").first.getAsInteger(10, size);
99      if (size == 32)
100        ret = Pointer32;
101      else if (size == 64)
102        ret = Pointer64;
103    }
104  }
105
106  return ret;
107}
108
109/// getNamedValue - Return the first global value in the module with
110/// the specified name, of arbitrary type.  This method returns null
111/// if a global with the specified name is not found.
112GlobalValue *Module::getNamedValue(StringRef Name) const {
113  return cast_or_null<GlobalValue>(getValueSymbolTable().lookup(Name));
114}
115
116/// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
117/// This ID is uniqued across modules in the current LLVMContext.
118unsigned Module::getMDKindID(StringRef Name) const {
119  return Context.getMDKindID(Name);
120}
121
122/// getMDKindNames - Populate client supplied SmallVector with the name for
123/// custom metadata IDs registered in this LLVMContext.   ID #0 is not used,
124/// so it is filled in as an empty string.
125void Module::getMDKindNames(SmallVectorImpl<StringRef> &Result) const {
126  return Context.getMDKindNames(Result);
127}
128
129
130//===----------------------------------------------------------------------===//
131// Methods for easy access to the functions in the module.
132//
133
134// getOrInsertFunction - Look up the specified function in the module symbol
135// table.  If it does not exist, add a prototype for the function and return
136// it.  This is nice because it allows most passes to get away with not handling
137// the symbol table directly for this common task.
138//
139Constant *Module::getOrInsertFunction(StringRef Name,
140                                      FunctionType *Ty,
141                                      AttrListPtr AttributeList) {
142  // See if we have a definition for the specified function already.
143  GlobalValue *F = getNamedValue(Name);
144  if (F == 0) {
145    // Nope, add it
146    Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage, Name);
147    if (!New->isIntrinsic())       // Intrinsics get attrs set on construction
148      New->setAttributes(AttributeList);
149    FunctionList.push_back(New);
150    return New;                    // Return the new prototype.
151  }
152
153  // Okay, the function exists.  Does it have externally visible linkage?
154  if (F->hasLocalLinkage()) {
155    // Clear the function's name.
156    F->setName("");
157    // Retry, now there won't be a conflict.
158    Constant *NewF = getOrInsertFunction(Name, Ty);
159    F->setName(Name);
160    return NewF;
161  }
162
163  // If the function exists but has the wrong type, return a bitcast to the
164  // right type.
165  if (F->getType() != PointerType::getUnqual(Ty))
166    return ConstantExpr::getBitCast(F, PointerType::getUnqual(Ty));
167
168  // Otherwise, we just found the existing function or a prototype.
169  return F;
170}
171
172Constant *Module::getOrInsertTargetIntrinsic(StringRef Name,
173                                             FunctionType *Ty,
174                                             AttrListPtr AttributeList) {
175  // See if we have a definition for the specified function already.
176  GlobalValue *F = getNamedValue(Name);
177  if (F == 0) {
178    // Nope, add it
179    Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage, Name);
180    New->setAttributes(AttributeList);
181    FunctionList.push_back(New);
182    return New; // Return the new prototype.
183  }
184
185  // Otherwise, we just found the existing function or a prototype.
186  return F;
187}
188
189Constant *Module::getOrInsertFunction(StringRef Name,
190                                      FunctionType *Ty) {
191  AttrListPtr AttributeList = AttrListPtr::get((AttributeWithIndex *)0, 0);
192  return getOrInsertFunction(Name, Ty, AttributeList);
193}
194
195// getOrInsertFunction - Look up the specified function in the module symbol
196// table.  If it does not exist, add a prototype for the function and return it.
197// This version of the method takes a null terminated list of function
198// arguments, which makes it easier for clients to use.
199//
200Constant *Module::getOrInsertFunction(StringRef Name,
201                                      AttrListPtr AttributeList,
202                                      Type *RetTy, ...) {
203  va_list Args;
204  va_start(Args, RetTy);
205
206  // Build the list of argument types...
207  std::vector<Type*> ArgTys;
208  while (Type *ArgTy = va_arg(Args, Type*))
209    ArgTys.push_back(ArgTy);
210
211  va_end(Args);
212
213  // Build the function type and chain to the other getOrInsertFunction...
214  return getOrInsertFunction(Name,
215                             FunctionType::get(RetTy, ArgTys, false),
216                             AttributeList);
217}
218
219Constant *Module::getOrInsertFunction(StringRef Name,
220                                      Type *RetTy, ...) {
221  va_list Args;
222  va_start(Args, RetTy);
223
224  // Build the list of argument types...
225  std::vector<Type*> ArgTys;
226  while (Type *ArgTy = va_arg(Args, Type*))
227    ArgTys.push_back(ArgTy);
228
229  va_end(Args);
230
231  // Build the function type and chain to the other getOrInsertFunction...
232  return getOrInsertFunction(Name,
233                             FunctionType::get(RetTy, ArgTys, false),
234                             AttrListPtr::get((AttributeWithIndex *)0, 0));
235}
236
237// getFunction - Look up the specified function in the module symbol table.
238// If it does not exist, return null.
239//
240Function *Module::getFunction(StringRef Name) const {
241  return dyn_cast_or_null<Function>(getNamedValue(Name));
242}
243
244//===----------------------------------------------------------------------===//
245// Methods for easy access to the global variables in the module.
246//
247
248/// getGlobalVariable - Look up the specified global variable in the module
249/// symbol table.  If it does not exist, return null.  The type argument
250/// should be the underlying type of the global, i.e., it should not have
251/// the top-level PointerType, which represents the address of the global.
252/// If AllowLocal is set to true, this function will return types that
253/// have an local. By default, these types are not returned.
254///
255GlobalVariable *Module::getGlobalVariable(StringRef Name,
256                                          bool AllowLocal) const {
257  if (GlobalVariable *Result =
258      dyn_cast_or_null<GlobalVariable>(getNamedValue(Name)))
259    if (AllowLocal || !Result->hasLocalLinkage())
260      return Result;
261  return 0;
262}
263
264/// getOrInsertGlobal - Look up the specified global in the module symbol table.
265///   1. If it does not exist, add a declaration of the global and return it.
266///   2. Else, the global exists but has the wrong type: return the function
267///      with a constantexpr cast to the right type.
268///   3. Finally, if the existing global is the correct delclaration, return the
269///      existing global.
270Constant *Module::getOrInsertGlobal(StringRef Name, Type *Ty) {
271  // See if we have a definition for the specified global already.
272  GlobalVariable *GV = dyn_cast_or_null<GlobalVariable>(getNamedValue(Name));
273  if (GV == 0) {
274    // Nope, add it
275    GlobalVariable *New =
276      new GlobalVariable(*this, Ty, false, GlobalVariable::ExternalLinkage,
277                         0, Name);
278     return New;                    // Return the new declaration.
279  }
280
281  // If the variable exists but has the wrong type, return a bitcast to the
282  // right type.
283  if (GV->getType() != PointerType::getUnqual(Ty))
284    return ConstantExpr::getBitCast(GV, PointerType::getUnqual(Ty));
285
286  // Otherwise, we just found the existing function or a prototype.
287  return GV;
288}
289
290//===----------------------------------------------------------------------===//
291// Methods for easy access to the global variables in the module.
292//
293
294// getNamedAlias - Look up the specified global in the module symbol table.
295// If it does not exist, return null.
296//
297GlobalAlias *Module::getNamedAlias(StringRef Name) const {
298  return dyn_cast_or_null<GlobalAlias>(getNamedValue(Name));
299}
300
301/// getNamedMetadata - Return the first NamedMDNode in the module with the
302/// specified name. This method returns null if a NamedMDNode with the
303/// specified name is not found.
304NamedMDNode *Module::getNamedMetadata(const Twine &Name) const {
305  SmallString<256> NameData;
306  StringRef NameRef = Name.toStringRef(NameData);
307  return static_cast<StringMap<NamedMDNode*> *>(NamedMDSymTab)->lookup(NameRef);
308}
309
310/// getOrInsertNamedMetadata - Return the first named MDNode in the module
311/// with the specified name. This method returns a new NamedMDNode if a
312/// NamedMDNode with the specified name is not found.
313NamedMDNode *Module::getOrInsertNamedMetadata(StringRef Name) {
314  NamedMDNode *&NMD =
315    (*static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab))[Name];
316  if (!NMD) {
317    NMD = new NamedMDNode(Name);
318    NMD->setParent(this);
319    NamedMDList.push_back(NMD);
320  }
321  return NMD;
322}
323
324/// eraseNamedMetadata - Remove the given NamedMDNode from this module and
325/// delete it.
326void Module::eraseNamedMetadata(NamedMDNode *NMD) {
327  static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab)->erase(NMD->getName());
328  NamedMDList.erase(NMD);
329}
330
331/// getModuleFlagsMetadata - Returns the module flags in the provided vector.
332void Module::
333getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> &Flags) const {
334  const NamedMDNode *ModFlags = getModuleFlagsMetadata();
335  if (!ModFlags) return;
336
337  for (unsigned i = 0, e = ModFlags->getNumOperands(); i != e; ++i) {
338    MDNode *Flag = ModFlags->getOperand(i);
339    ConstantInt *Behavior = cast<ConstantInt>(Flag->getOperand(0));
340    MDString *Key = cast<MDString>(Flag->getOperand(1));
341    Value *Val = Flag->getOperand(2);
342    Flags.push_back(ModuleFlagEntry(ModFlagBehavior(Behavior->getZExtValue()),
343                                    Key, Val));
344  }
345}
346
347/// getModuleFlagsMetadata - Returns the NamedMDNode in the module that
348/// represents module-level flags. This method returns null if there are no
349/// module-level flags.
350NamedMDNode *Module::getModuleFlagsMetadata() const {
351  return getNamedMetadata("llvm.module.flags");
352}
353
354/// getOrInsertModuleFlagsMetadata - Returns the NamedMDNode in the module that
355/// represents module-level flags. If module-level flags aren't found, it
356/// creates the named metadata that contains them.
357NamedMDNode *Module::getOrInsertModuleFlagsMetadata() {
358  return getOrInsertNamedMetadata("llvm.module.flags");
359}
360
361/// addModuleFlag - Add a module-level flag to the module-level flags
362/// metadata. It will create the module-level flags named metadata if it doesn't
363/// already exist.
364void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
365                           Value *Val) {
366  Type *Int32Ty = Type::getInt32Ty(Context);
367  Value *Ops[3] = {
368    ConstantInt::get(Int32Ty, Behavior), MDString::get(Context, Key), Val
369  };
370  getOrInsertModuleFlagsMetadata()->addOperand(MDNode::get(Context, Ops));
371}
372void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
373                           uint32_t Val) {
374  Type *Int32Ty = Type::getInt32Ty(Context);
375  addModuleFlag(Behavior, Key, ConstantInt::get(Int32Ty, Val));
376}
377void Module::addModuleFlag(MDNode *Node) {
378  assert(Node->getNumOperands() == 3 &&
379         "Invalid number of operands for module flag!");
380  assert(isa<ConstantInt>(Node->getOperand(0)) &&
381         isa<MDString>(Node->getOperand(1)) &&
382         "Invalid operand types for module flag!");
383  getOrInsertModuleFlagsMetadata()->addOperand(Node);
384}
385
386//===----------------------------------------------------------------------===//
387// Methods to control the materialization of GlobalValues in the Module.
388//
389void Module::setMaterializer(GVMaterializer *GVM) {
390  assert(!Materializer &&
391         "Module already has a GVMaterializer.  Call MaterializeAllPermanently"
392         " to clear it out before setting another one.");
393  Materializer.reset(GVM);
394}
395
396bool Module::isMaterializable(const GlobalValue *GV) const {
397  if (Materializer)
398    return Materializer->isMaterializable(GV);
399  return false;
400}
401
402bool Module::isDematerializable(const GlobalValue *GV) const {
403  if (Materializer)
404    return Materializer->isDematerializable(GV);
405  return false;
406}
407
408bool Module::Materialize(GlobalValue *GV, std::string *ErrInfo) {
409  if (Materializer)
410    return Materializer->Materialize(GV, ErrInfo);
411  return false;
412}
413
414void Module::Dematerialize(GlobalValue *GV) {
415  if (Materializer)
416    return Materializer->Dematerialize(GV);
417}
418
419bool Module::MaterializeAll(std::string *ErrInfo) {
420  if (!Materializer)
421    return false;
422  return Materializer->MaterializeModule(this, ErrInfo);
423}
424
425bool Module::MaterializeAllPermanently(std::string *ErrInfo) {
426  if (MaterializeAll(ErrInfo))
427    return true;
428  Materializer.reset();
429  return false;
430}
431
432//===----------------------------------------------------------------------===//
433// Other module related stuff.
434//
435
436
437// dropAllReferences() - This function causes all the subelements to "let go"
438// of all references that they are maintaining.  This allows one to 'delete' a
439// whole module at a time, even though there may be circular references... first
440// all references are dropped, and all use counts go to zero.  Then everything
441// is deleted for real.  Note that no operations are valid on an object that
442// has "dropped all references", except operator delete.
443//
444void Module::dropAllReferences() {
445  for(Module::iterator I = begin(), E = end(); I != E; ++I)
446    I->dropAllReferences();
447
448  for(Module::global_iterator I = global_begin(), E = global_end(); I != E; ++I)
449    I->dropAllReferences();
450
451  for(Module::alias_iterator I = alias_begin(), E = alias_end(); I != E; ++I)
452    I->dropAllReferences();
453}
454
455void Module::addLibrary(StringRef Lib) {
456  for (Module::lib_iterator I = lib_begin(), E = lib_end(); I != E; ++I)
457    if (*I == Lib)
458      return;
459  LibraryList.push_back(Lib);
460}
461
462void Module::removeLibrary(StringRef Lib) {
463  LibraryListType::iterator I = LibraryList.begin();
464  LibraryListType::iterator E = LibraryList.end();
465  for (;I != E; ++I)
466    if (*I == Lib) {
467      LibraryList.erase(I);
468      return;
469    }
470}
471
472//===----------------------------------------------------------------------===//
473// Type finding functionality.
474//===----------------------------------------------------------------------===//
475
476namespace {
477  /// TypeFinder - Walk over a module, identifying all of the types that are
478  /// used by the module.
479  class TypeFinder {
480    // To avoid walking constant expressions multiple times and other IR
481    // objects, we keep several helper maps.
482    DenseSet<const Value*> VisitedConstants;
483    DenseSet<Type*> VisitedTypes;
484
485    std::vector<StructType*> &StructTypes;
486  public:
487    TypeFinder(std::vector<StructType*> &structTypes)
488      : StructTypes(structTypes) {}
489
490    void run(const Module &M) {
491      // Get types from global variables.
492      for (Module::const_global_iterator I = M.global_begin(),
493           E = M.global_end(); I != E; ++I) {
494        incorporateType(I->getType());
495        if (I->hasInitializer())
496          incorporateValue(I->getInitializer());
497      }
498
499      // Get types from aliases.
500      for (Module::const_alias_iterator I = M.alias_begin(),
501           E = M.alias_end(); I != E; ++I) {
502        incorporateType(I->getType());
503        if (const Value *Aliasee = I->getAliasee())
504          incorporateValue(Aliasee);
505      }
506
507      SmallVector<std::pair<unsigned, MDNode*>, 4> MDForInst;
508
509      // Get types from functions.
510      for (Module::const_iterator FI = M.begin(), E = M.end(); FI != E; ++FI) {
511        incorporateType(FI->getType());
512
513        for (Function::const_iterator BB = FI->begin(), E = FI->end();
514             BB != E;++BB)
515          for (BasicBlock::const_iterator II = BB->begin(),
516               E = BB->end(); II != E; ++II) {
517            const Instruction &I = *II;
518            // Incorporate the type of the instruction and all its operands.
519            incorporateType(I.getType());
520            for (User::const_op_iterator OI = I.op_begin(), OE = I.op_end();
521                 OI != OE; ++OI)
522              incorporateValue(*OI);
523
524            // Incorporate types hiding in metadata.
525            I.getAllMetadataOtherThanDebugLoc(MDForInst);
526            for (unsigned i = 0, e = MDForInst.size(); i != e; ++i)
527              incorporateMDNode(MDForInst[i].second);
528            MDForInst.clear();
529          }
530      }
531
532      for (Module::const_named_metadata_iterator I = M.named_metadata_begin(),
533           E = M.named_metadata_end(); I != E; ++I) {
534        const NamedMDNode *NMD = I;
535        for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
536          incorporateMDNode(NMD->getOperand(i));
537      }
538    }
539
540  private:
541    void incorporateType(Type *Ty) {
542      // Check to see if we're already visited this type.
543      if (!VisitedTypes.insert(Ty).second)
544        return;
545
546      // If this is a structure or opaque type, add a name for the type.
547      if (StructType *STy = dyn_cast<StructType>(Ty))
548        StructTypes.push_back(STy);
549
550      // Recursively walk all contained types.
551      for (Type::subtype_iterator I = Ty->subtype_begin(),
552           E = Ty->subtype_end(); I != E; ++I)
553        incorporateType(*I);
554    }
555
556    /// incorporateValue - This method is used to walk operand lists finding
557    /// types hiding in constant expressions and other operands that won't be
558    /// walked in other ways.  GlobalValues, basic blocks, instructions, and
559    /// inst operands are all explicitly enumerated.
560    void incorporateValue(const Value *V) {
561      if (const MDNode *M = dyn_cast<MDNode>(V))
562        return incorporateMDNode(M);
563      if (!isa<Constant>(V) || isa<GlobalValue>(V)) return;
564
565      // Already visited?
566      if (!VisitedConstants.insert(V).second)
567        return;
568
569      // Check this type.
570      incorporateType(V->getType());
571
572      // Look in operands for types.
573      const User *U = cast<User>(V);
574      for (Constant::const_op_iterator I = U->op_begin(),
575           E = U->op_end(); I != E;++I)
576        incorporateValue(*I);
577    }
578
579    void incorporateMDNode(const MDNode *V) {
580
581      // Already visited?
582      if (!VisitedConstants.insert(V).second)
583        return;
584
585      // Look in operands for types.
586      for (unsigned i = 0, e = V->getNumOperands(); i != e; ++i)
587        if (Value *Op = V->getOperand(i))
588          incorporateValue(Op);
589    }
590  };
591} // end anonymous namespace
592
593void Module::findUsedStructTypes(std::vector<StructType*> &StructTypes) const {
594  TypeFinder(StructTypes).run(*this);
595}
596