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 IR library.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/IR/Module.h"
15#include "SymbolTableListTraitsImpl.h"
16#include "llvm/ADT/DenseSet.h"
17#include "llvm/ADT/STLExtras.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/ADT/StringExtras.h"
20#include "llvm/GVMaterializer.h"
21#include "llvm/IR/Constants.h"
22#include "llvm/IR/DerivedTypes.h"
23#include "llvm/IR/InstrTypes.h"
24#include "llvm/IR/LLVMContext.h"
25#include "llvm/Support/LeakDetector.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  NamedMDList.clear();
59  delete ValSymTab;
60  delete static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab);
61}
62
63/// Target endian information.
64Module::Endianness Module::getEndianness() const {
65  StringRef temp = DataLayout;
66  Module::Endianness ret = AnyEndianness;
67
68  while (!temp.empty()) {
69    std::pair<StringRef, StringRef> P = getToken(temp, "-");
70
71    StringRef token = P.first;
72    temp = P.second;
73
74    if (token[0] == 'e') {
75      ret = LittleEndian;
76    } else if (token[0] == 'E') {
77      ret = BigEndian;
78    }
79  }
80
81  return ret;
82}
83
84/// Target Pointer Size information.
85Module::PointerSize Module::getPointerSize() const {
86  StringRef temp = DataLayout;
87  Module::PointerSize ret = AnyPointerSize;
88
89  while (!temp.empty()) {
90    std::pair<StringRef, StringRef> TmpP = getToken(temp, "-");
91    temp = TmpP.second;
92    TmpP = getToken(TmpP.first, ":");
93    StringRef token = TmpP.second, signalToken = TmpP.first;
94
95    if (signalToken[0] == 'p') {
96      int size = 0;
97      getToken(token, ":").first.getAsInteger(10, size);
98      if (size == 32)
99        ret = Pointer32;
100      else if (size == 64)
101        ret = Pointer64;
102    }
103  }
104
105  return ret;
106}
107
108/// getNamedValue - Return the first global value in the module with
109/// the specified name, of arbitrary type.  This method returns null
110/// if a global with the specified name is not found.
111GlobalValue *Module::getNamedValue(StringRef Name) const {
112  return cast_or_null<GlobalValue>(getValueSymbolTable().lookup(Name));
113}
114
115/// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
116/// This ID is uniqued across modules in the current LLVMContext.
117unsigned Module::getMDKindID(StringRef Name) const {
118  return Context.getMDKindID(Name);
119}
120
121/// getMDKindNames - Populate client supplied SmallVector with the name for
122/// custom metadata IDs registered in this LLVMContext.   ID #0 is not used,
123/// so it is filled in as an empty string.
124void Module::getMDKindNames(SmallVectorImpl<StringRef> &Result) const {
125  return Context.getMDKindNames(Result);
126}
127
128
129//===----------------------------------------------------------------------===//
130// Methods for easy access to the functions in the module.
131//
132
133// getOrInsertFunction - Look up the specified function in the module symbol
134// table.  If it does not exist, add a prototype for the function and return
135// it.  This is nice because it allows most passes to get away with not handling
136// the symbol table directly for this common task.
137//
138Constant *Module::getOrInsertFunction(StringRef Name,
139                                      FunctionType *Ty,
140                                      AttributeSet AttributeList) {
141  // See if we have a definition for the specified function already.
142  GlobalValue *F = getNamedValue(Name);
143  if (F == 0) {
144    // Nope, add it
145    Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage, Name);
146    if (!New->isIntrinsic())       // Intrinsics get attrs set on construction
147      New->setAttributes(AttributeList);
148    FunctionList.push_back(New);
149    return New;                    // Return the new prototype.
150  }
151
152  // Okay, the function exists.  Does it have externally visible linkage?
153  if (F->hasLocalLinkage()) {
154    // Clear the function's name.
155    F->setName("");
156    // Retry, now there won't be a conflict.
157    Constant *NewF = getOrInsertFunction(Name, Ty);
158    F->setName(Name);
159    return NewF;
160  }
161
162  // If the function exists but has the wrong type, return a bitcast to the
163  // right type.
164  if (F->getType() != PointerType::getUnqual(Ty))
165    return ConstantExpr::getBitCast(F, PointerType::getUnqual(Ty));
166
167  // Otherwise, we just found the existing function or a prototype.
168  return F;
169}
170
171Constant *Module::getOrInsertTargetIntrinsic(StringRef Name,
172                                             FunctionType *Ty,
173                                             AttributeSet AttributeList) {
174  // See if we have a definition for the specified function already.
175  GlobalValue *F = getNamedValue(Name);
176  if (F == 0) {
177    // Nope, add it
178    Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage, Name);
179    New->setAttributes(AttributeList);
180    FunctionList.push_back(New);
181    return New; // Return the new prototype.
182  }
183
184  // Otherwise, we just found the existing function or a prototype.
185  return F;
186}
187
188Constant *Module::getOrInsertFunction(StringRef Name,
189                                      FunctionType *Ty) {
190  return getOrInsertFunction(Name, Ty, AttributeSet());
191}
192
193// getOrInsertFunction - Look up the specified function in the module symbol
194// table.  If it does not exist, add a prototype for the function and return it.
195// This version of the method takes a null terminated list of function
196// arguments, which makes it easier for clients to use.
197//
198Constant *Module::getOrInsertFunction(StringRef Name,
199                                      AttributeSet AttributeList,
200                                      Type *RetTy, ...) {
201  va_list Args;
202  va_start(Args, RetTy);
203
204  // Build the list of argument types...
205  std::vector<Type*> ArgTys;
206  while (Type *ArgTy = va_arg(Args, Type*))
207    ArgTys.push_back(ArgTy);
208
209  va_end(Args);
210
211  // Build the function type and chain to the other getOrInsertFunction...
212  return getOrInsertFunction(Name,
213                             FunctionType::get(RetTy, ArgTys, false),
214                             AttributeList);
215}
216
217Constant *Module::getOrInsertFunction(StringRef Name,
218                                      Type *RetTy, ...) {
219  va_list Args;
220  va_start(Args, RetTy);
221
222  // Build the list of argument types...
223  std::vector<Type*> ArgTys;
224  while (Type *ArgTy = va_arg(Args, Type*))
225    ArgTys.push_back(ArgTy);
226
227  va_end(Args);
228
229  // Build the function type and chain to the other getOrInsertFunction...
230  return getOrInsertFunction(Name,
231                             FunctionType::get(RetTy, ArgTys, false),
232                             AttributeSet());
233}
234
235// getFunction - Look up the specified function in the module symbol table.
236// If it does not exist, return null.
237//
238Function *Module::getFunction(StringRef Name) const {
239  return dyn_cast_or_null<Function>(getNamedValue(Name));
240}
241
242//===----------------------------------------------------------------------===//
243// Methods for easy access to the global variables in the module.
244//
245
246/// getGlobalVariable - Look up the specified global variable in the module
247/// symbol table.  If it does not exist, return null.  The type argument
248/// should be the underlying type of the global, i.e., it should not have
249/// the top-level PointerType, which represents the address of the global.
250/// If AllowLocal is set to true, this function will return types that
251/// have an local. By default, these types are not returned.
252///
253GlobalVariable *Module::getGlobalVariable(StringRef Name,
254                                          bool AllowLocal) const {
255  if (GlobalVariable *Result =
256      dyn_cast_or_null<GlobalVariable>(getNamedValue(Name)))
257    if (AllowLocal || !Result->hasLocalLinkage())
258      return Result;
259  return 0;
260}
261
262/// getOrInsertGlobal - Look up the specified global in the module symbol table.
263///   1. If it does not exist, add a declaration of the global and return it.
264///   2. Else, the global exists but has the wrong type: return the function
265///      with a constantexpr cast to the right type.
266///   3. Finally, if the existing global is the correct delclaration, return the
267///      existing global.
268Constant *Module::getOrInsertGlobal(StringRef Name, Type *Ty) {
269  // See if we have a definition for the specified global already.
270  GlobalVariable *GV = dyn_cast_or_null<GlobalVariable>(getNamedValue(Name));
271  if (GV == 0) {
272    // Nope, add it
273    GlobalVariable *New =
274      new GlobalVariable(*this, Ty, false, GlobalVariable::ExternalLinkage,
275                         0, Name);
276     return New;                    // Return the new declaration.
277  }
278
279  // If the variable exists but has the wrong type, return a bitcast to the
280  // right type.
281  if (GV->getType() != PointerType::getUnqual(Ty))
282    return ConstantExpr::getBitCast(GV, PointerType::getUnqual(Ty));
283
284  // Otherwise, we just found the existing function or a prototype.
285  return GV;
286}
287
288//===----------------------------------------------------------------------===//
289// Methods for easy access to the global variables in the module.
290//
291
292// getNamedAlias - Look up the specified global in the module symbol table.
293// If it does not exist, return null.
294//
295GlobalAlias *Module::getNamedAlias(StringRef Name) const {
296  return dyn_cast_or_null<GlobalAlias>(getNamedValue(Name));
297}
298
299/// getNamedMetadata - Return the first NamedMDNode in the module with the
300/// specified name. This method returns null if a NamedMDNode with the
301/// specified name is not found.
302NamedMDNode *Module::getNamedMetadata(const Twine &Name) const {
303  SmallString<256> NameData;
304  StringRef NameRef = Name.toStringRef(NameData);
305  return static_cast<StringMap<NamedMDNode*> *>(NamedMDSymTab)->lookup(NameRef);
306}
307
308/// getOrInsertNamedMetadata - Return the first named MDNode in the module
309/// with the specified name. This method returns a new NamedMDNode if a
310/// NamedMDNode with the specified name is not found.
311NamedMDNode *Module::getOrInsertNamedMetadata(StringRef Name) {
312  NamedMDNode *&NMD =
313    (*static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab))[Name];
314  if (!NMD) {
315    NMD = new NamedMDNode(Name);
316    NMD->setParent(this);
317    NamedMDList.push_back(NMD);
318  }
319  return NMD;
320}
321
322/// eraseNamedMetadata - Remove the given NamedMDNode from this module and
323/// delete it.
324void Module::eraseNamedMetadata(NamedMDNode *NMD) {
325  static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab)->erase(NMD->getName());
326  NamedMDList.erase(NMD);
327}
328
329/// getModuleFlagsMetadata - Returns the module flags in the provided vector.
330void Module::
331getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> &Flags) const {
332  const NamedMDNode *ModFlags = getModuleFlagsMetadata();
333  if (!ModFlags) return;
334
335  for (unsigned i = 0, e = ModFlags->getNumOperands(); i != e; ++i) {
336    MDNode *Flag = ModFlags->getOperand(i);
337    ConstantInt *Behavior = cast<ConstantInt>(Flag->getOperand(0));
338    MDString *Key = cast<MDString>(Flag->getOperand(1));
339    Value *Val = Flag->getOperand(2);
340    Flags.push_back(ModuleFlagEntry(ModFlagBehavior(Behavior->getZExtValue()),
341                                    Key, Val));
342  }
343}
344
345/// getModuleFlagsMetadata - Returns the NamedMDNode in the module that
346/// represents module-level flags. This method returns null if there are no
347/// module-level flags.
348NamedMDNode *Module::getModuleFlagsMetadata() const {
349  return getNamedMetadata("llvm.module.flags");
350}
351
352/// getOrInsertModuleFlagsMetadata - Returns the NamedMDNode in the module that
353/// represents module-level flags. If module-level flags aren't found, it
354/// creates the named metadata that contains them.
355NamedMDNode *Module::getOrInsertModuleFlagsMetadata() {
356  return getOrInsertNamedMetadata("llvm.module.flags");
357}
358
359/// addModuleFlag - Add a module-level flag to the module-level flags
360/// metadata. It will create the module-level flags named metadata if it doesn't
361/// already exist.
362void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
363                           Value *Val) {
364  Type *Int32Ty = Type::getInt32Ty(Context);
365  Value *Ops[3] = {
366    ConstantInt::get(Int32Ty, Behavior), MDString::get(Context, Key), Val
367  };
368  getOrInsertModuleFlagsMetadata()->addOperand(MDNode::get(Context, Ops));
369}
370void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
371                           uint32_t Val) {
372  Type *Int32Ty = Type::getInt32Ty(Context);
373  addModuleFlag(Behavior, Key, ConstantInt::get(Int32Ty, Val));
374}
375void Module::addModuleFlag(MDNode *Node) {
376  assert(Node->getNumOperands() == 3 &&
377         "Invalid number of operands for module flag!");
378  assert(isa<ConstantInt>(Node->getOperand(0)) &&
379         isa<MDString>(Node->getOperand(1)) &&
380         "Invalid operand types for module flag!");
381  getOrInsertModuleFlagsMetadata()->addOperand(Node);
382}
383
384//===----------------------------------------------------------------------===//
385// Methods to control the materialization of GlobalValues in the Module.
386//
387void Module::setMaterializer(GVMaterializer *GVM) {
388  assert(!Materializer &&
389         "Module already has a GVMaterializer.  Call MaterializeAllPermanently"
390         " to clear it out before setting another one.");
391  Materializer.reset(GVM);
392}
393
394bool Module::isMaterializable(const GlobalValue *GV) const {
395  if (Materializer)
396    return Materializer->isMaterializable(GV);
397  return false;
398}
399
400bool Module::isDematerializable(const GlobalValue *GV) const {
401  if (Materializer)
402    return Materializer->isDematerializable(GV);
403  return false;
404}
405
406bool Module::Materialize(GlobalValue *GV, std::string *ErrInfo) {
407  if (Materializer)
408    return Materializer->Materialize(GV, ErrInfo);
409  return false;
410}
411
412void Module::Dematerialize(GlobalValue *GV) {
413  if (Materializer)
414    return Materializer->Dematerialize(GV);
415}
416
417bool Module::MaterializeAll(std::string *ErrInfo) {
418  if (!Materializer)
419    return false;
420  return Materializer->MaterializeModule(this, ErrInfo);
421}
422
423bool Module::MaterializeAllPermanently(std::string *ErrInfo) {
424  if (MaterializeAll(ErrInfo))
425    return true;
426  Materializer.reset();
427  return false;
428}
429
430//===----------------------------------------------------------------------===//
431// Other module related stuff.
432//
433
434
435// dropAllReferences() - This function causes all the subelements to "let go"
436// of all references that they are maintaining.  This allows one to 'delete' a
437// whole module at a time, even though there may be circular references... first
438// all references are dropped, and all use counts go to zero.  Then everything
439// is deleted for real.  Note that no operations are valid on an object that
440// has "dropped all references", except operator delete.
441//
442void Module::dropAllReferences() {
443  for(Module::iterator I = begin(), E = end(); I != E; ++I)
444    I->dropAllReferences();
445
446  for(Module::global_iterator I = global_begin(), E = global_end(); I != E; ++I)
447    I->dropAllReferences();
448
449  for(Module::alias_iterator I = alias_begin(), E = alias_end(); I != E; ++I)
450    I->dropAllReferences();
451}
452