+//===----------------------------------------------------------------------===//
+// Type finding functionality.
+//===----------------------------------------------------------------------===//
+
+namespace {
+ /// TypeFinder - Walk over a module, identifying all of the types that are
+ /// used by the module.
+ class TypeFinder {
+ // To avoid walking constant expressions multiple times and other IR
+ // objects, we keep several helper maps.
+ DenseSet<const Value*> VisitedConstants;
+ DenseSet<Type*> VisitedTypes;
+
+ std::vector<StructType*> &StructTypes;
+ public:
+ TypeFinder(std::vector<StructType*> &structTypes)
+ : StructTypes(structTypes) {}
+
+ void run(const Module &M) {
+ // Get types from global variables.
+ for (Module::const_global_iterator I = M.global_begin(),
+ E = M.global_end(); I != E; ++I) {
+ incorporateType(I->getType());
+ if (I->hasInitializer())
+ incorporateValue(I->getInitializer());
+ }
+
+ // Get types from aliases.
+ for (Module::const_alias_iterator I = M.alias_begin(),
+ E = M.alias_end(); I != E; ++I) {
+ incorporateType(I->getType());
+ if (const Value *Aliasee = I->getAliasee())
+ incorporateValue(Aliasee);
+ }
+
+ SmallVector<std::pair<unsigned, MDNode*>, 4> MDForInst;
+
+ // Get types from functions.
+ for (Module::const_iterator FI = M.begin(), E = M.end(); FI != E; ++FI) {
+ incorporateType(FI->getType());
+
+ for (Function::const_iterator BB = FI->begin(), E = FI->end();
+ BB != E;++BB)
+ for (BasicBlock::const_iterator II = BB->begin(),
+ E = BB->end(); II != E; ++II) {
+ const Instruction &I = *II;
+ // Incorporate the type of the instruction and all its operands.
+ incorporateType(I.getType());
+ for (User::const_op_iterator OI = I.op_begin(), OE = I.op_end();
+ OI != OE; ++OI)
+ incorporateValue(*OI);
+
+ // Incorporate types hiding in metadata.
+ I.getAllMetadataOtherThanDebugLoc(MDForInst);
+ for (unsigned i = 0, e = MDForInst.size(); i != e; ++i)
+ incorporateMDNode(MDForInst[i].second);
+ MDForInst.clear();
+ }
+ }
+
+ for (Module::const_named_metadata_iterator I = M.named_metadata_begin(),
+ E = M.named_metadata_end(); I != E; ++I) {
+ const NamedMDNode *NMD = I;
+ for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
+ incorporateMDNode(NMD->getOperand(i));
+ }
+ }
+
+ private:
+ void incorporateType(Type *Ty) {
+ // Check to see if we're already visited this type.
+ if (!VisitedTypes.insert(Ty).second)
+ return;
+
+ // If this is a structure or opaque type, add a name for the type.
+ if (StructType *STy = dyn_cast<StructType>(Ty))
+ StructTypes.push_back(STy);
+
+ // Recursively walk all contained types.
+ for (Type::subtype_iterator I = Ty->subtype_begin(),
+ E = Ty->subtype_end(); I != E; ++I)
+ incorporateType(*I);
+ }
+
+ /// incorporateValue - This method is used to walk operand lists finding
+ /// types hiding in constant expressions and other operands that won't be
+ /// walked in other ways. GlobalValues, basic blocks, instructions, and
+ /// inst operands are all explicitly enumerated.
+ void incorporateValue(const Value *V) {
+ if (const MDNode *M = dyn_cast<MDNode>(V))
+ return incorporateMDNode(M);
+ if (!isa<Constant>(V) || isa<GlobalValue>(V)) return;
+
+ // Already visited?
+ if (!VisitedConstants.insert(V).second)
+ return;
+
+ // Check this type.
+ incorporateType(V->getType());
+
+ // Look in operands for types.
+ const User *U = cast<User>(V);
+ for (Constant::const_op_iterator I = U->op_begin(),
+ E = U->op_end(); I != E;++I)
+ incorporateValue(*I);
+ }
+
+ void incorporateMDNode(const MDNode *V) {
+
+ // Already visited?
+ if (!VisitedConstants.insert(V).second)
+ return;
+
+ // Look in operands for types.
+ for (unsigned i = 0, e = V->getNumOperands(); i != e; ++i)
+ if (Value *Op = V->getOperand(i))
+ incorporateValue(Op);
+ }
+ };
+} // end anonymous namespace
+
+void Module::findUsedStructTypes(std::vector<StructType*> &StructTypes) const {
+ TypeFinder(StructTypes).run(*this);
+}