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>
29 using 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.
37 template class llvm::SymbolTableListTraits<Function, Module>;
38 template class llvm::SymbolTableListTraits<GlobalVariable, Module>;
39 template class llvm::SymbolTableListTraits<GlobalAlias, Module>;
40
41 //===----------------------------------------------------------------------===//
42 // Primitive Module methods.
43 //
44
Module(StringRef MID,LLVMContext & C)45 Module::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
~Module()52 Module::~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.
getEndianness() const65 Module::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.
getPointerSize() const86 Module::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.
getNamedValue(StringRef Name) const112 GlobalValue *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.
getMDKindID(StringRef Name) const118 unsigned 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.
getMDKindNames(SmallVectorImpl<StringRef> & Result) const125 void 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 //
getOrInsertFunction(StringRef Name,FunctionType * Ty,AttrListPtr AttributeList)139 Constant *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
getOrInsertTargetIntrinsic(StringRef Name,FunctionType * Ty,AttrListPtr AttributeList)172 Constant *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
getOrInsertFunction(StringRef Name,FunctionType * Ty)189 Constant *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 //
getOrInsertFunction(StringRef Name,AttrListPtr AttributeList,Type * RetTy,...)200 Constant *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
getOrInsertFunction(StringRef Name,Type * RetTy,...)219 Constant *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 //
getFunction(StringRef Name) const240 Function *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 ///
getGlobalVariable(StringRef Name,bool AllowLocal) const255 GlobalVariable *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.
getOrInsertGlobal(StringRef Name,Type * Ty)270 Constant *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 //
getNamedAlias(StringRef Name) const297 GlobalAlias *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.
getNamedMetadata(const Twine & Name) const304 NamedMDNode *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.
getOrInsertNamedMetadata(StringRef Name)313 NamedMDNode *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.
eraseNamedMetadata(NamedMDNode * NMD)326 void 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.
332 void Module::
getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> & Flags) const333 getModuleFlagsMetadata(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.
getModuleFlagsMetadata() const350 NamedMDNode *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.
getOrInsertModuleFlagsMetadata()357 NamedMDNode *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.
addModuleFlag(ModFlagBehavior Behavior,StringRef Key,Value * Val)364 void 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 }
addModuleFlag(ModFlagBehavior Behavior,StringRef Key,uint32_t Val)372 void 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 }
addModuleFlag(MDNode * Node)377 void 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 //
setMaterializer(GVMaterializer * GVM)389 void 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
isMaterializable(const GlobalValue * GV) const396 bool Module::isMaterializable(const GlobalValue *GV) const {
397 if (Materializer)
398 return Materializer->isMaterializable(GV);
399 return false;
400 }
401
isDematerializable(const GlobalValue * GV) const402 bool Module::isDematerializable(const GlobalValue *GV) const {
403 if (Materializer)
404 return Materializer->isDematerializable(GV);
405 return false;
406 }
407
Materialize(GlobalValue * GV,std::string * ErrInfo)408 bool Module::Materialize(GlobalValue *GV, std::string *ErrInfo) {
409 if (Materializer)
410 return Materializer->Materialize(GV, ErrInfo);
411 return false;
412 }
413
Dematerialize(GlobalValue * GV)414 void Module::Dematerialize(GlobalValue *GV) {
415 if (Materializer)
416 return Materializer->Dematerialize(GV);
417 }
418
MaterializeAll(std::string * ErrInfo)419 bool Module::MaterializeAll(std::string *ErrInfo) {
420 if (!Materializer)
421 return false;
422 return Materializer->MaterializeModule(this, ErrInfo);
423 }
424
MaterializeAllPermanently(std::string * ErrInfo)425 bool 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 //
dropAllReferences()444 void 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
addLibrary(StringRef Lib)455 void 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
removeLibrary(StringRef Lib)462 void 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
476 namespace {
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:
TypeFinder(std::vector<StructType * > & structTypes)487 TypeFinder(std::vector<StructType*> &structTypes)
488 : StructTypes(structTypes) {}
489
run(const Module & M)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:
incorporateType(Type * Ty)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.
incorporateValue(const Value * V)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
incorporateMDNode(const MDNode * V)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
findUsedStructTypes(std::vector<StructType * > & StructTypes) const593 void Module::findUsedStructTypes(std::vector<StructType*> &StructTypes) const {
594 TypeFinder(StructTypes).run(*this);
595 }
596