+
+/// categorizeModuleFlagNodes -
+bool ModuleLinker::
+categorizeModuleFlagNodes(const NamedMDNode *ModFlags,
+ DenseMap<MDString*, MDNode*> &ErrorNode,
+ DenseMap<MDString*, MDNode*> &WarningNode,
+ DenseMap<MDString*, MDNode*> &OverrideNode,
+ DenseMap<MDString*,
+ SmallSetVector<MDNode*, 8> > &RequireNodes,
+ SmallSetVector<MDString*, 16> &SeenIDs) {
+ bool HasErr = false;
+
+ for (unsigned I = 0, E = ModFlags->getNumOperands(); I != E; ++I) {
+ MDNode *Op = ModFlags->getOperand(I);
+ assert(Op->getNumOperands() == 3 && "Invalid module flag metadata!");
+ assert(isa<ConstantInt>(Op->getOperand(0)) &&
+ "Module flag's first operand must be an integer!");
+ assert(isa<MDString>(Op->getOperand(1)) &&
+ "Module flag's second operand must be an MDString!");
+
+ ConstantInt *Behavior = cast<ConstantInt>(Op->getOperand(0));
+ MDString *ID = cast<MDString>(Op->getOperand(1));
+ Value *Val = Op->getOperand(2);
+ switch (Behavior->getZExtValue()) {
+ default:
+ assert(false && "Invalid behavior in module flag metadata!");
+ break;
+ case Module::Error: {
+ MDNode *&ErrNode = ErrorNode[ID];
+ if (!ErrNode) ErrNode = Op;
+ if (ErrNode->getOperand(2) != Val)
+ HasErr = emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting values");
+ break;
+ }
+ case Module::Warning: {
+ MDNode *&WarnNode = WarningNode[ID];
+ if (!WarnNode) WarnNode = Op;
+ if (WarnNode->getOperand(2) != Val)
+ errs() << "WARNING: linking module flags '" << ID->getString()
+ << "': IDs have conflicting values";
+ break;
+ }
+ case Module::Require: RequireNodes[ID].insert(Op); break;
+ case Module::Override: {
+ MDNode *&OvrNode = OverrideNode[ID];
+ if (!OvrNode) OvrNode = Op;
+ if (OvrNode->getOperand(2) != Val)
+ HasErr = emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting override values");
+ break;
+ }
+ }
+
+ SeenIDs.insert(ID);
+ }
+
+ return HasErr;
+}
+
+/// linkModuleFlagsMetadata - Merge the linker flags in Src into the Dest
+/// module.
+bool ModuleLinker::linkModuleFlagsMetadata() {
+ const NamedMDNode *SrcModFlags = SrcM->getModuleFlagsMetadata();
+ if (!SrcModFlags) return false;
+
+ NamedMDNode *DstModFlags = DstM->getOrInsertModuleFlagsMetadata();
+
+ // If the destination module doesn't have module flags yet, then just copy
+ // over the source module's flags.
+ if (DstModFlags->getNumOperands() == 0) {
+ for (unsigned I = 0, E = SrcModFlags->getNumOperands(); I != E; ++I)
+ DstModFlags->addOperand(SrcModFlags->getOperand(I));
+
+ return false;
+ }
+
+ bool HasErr = false;
+
+ // Otherwise, we have to merge them based on their behaviors. First,
+ // categorize all of the nodes in the modules' module flags. If an error or
+ // warning occurs, then emit the appropriate message(s).
+ DenseMap<MDString*, MDNode*> ErrorNode;
+ DenseMap<MDString*, MDNode*> WarningNode;
+ DenseMap<MDString*, MDNode*> OverrideNode;
+ DenseMap<MDString*, SmallSetVector<MDNode*, 8> > RequireNodes;
+ SmallSetVector<MDString*, 16> SeenIDs;
+
+ HasErr |= categorizeModuleFlagNodes(SrcModFlags, ErrorNode, WarningNode,
+ OverrideNode, RequireNodes, SeenIDs);
+ HasErr |= categorizeModuleFlagNodes(DstModFlags, ErrorNode, WarningNode,
+ OverrideNode, RequireNodes, SeenIDs);
+
+ // Check that there isn't both an error and warning node for a flag.
+ for (SmallSetVector<MDString*, 16>::iterator
+ I = SeenIDs.begin(), E = SeenIDs.end(); I != E; ++I) {
+ MDString *ID = *I;
+ if (ErrorNode[ID] && WarningNode[ID])
+ HasErr = emitError("linking module flags '" + ID->getString() +
+ "': IDs have conflicting behaviors");
+ }
+
+ // Early exit if we had an error.
+ if (HasErr) return true;
+
+ // Get the destination's module flags ready for new operands.
+ DstModFlags->dropAllReferences();
+
+ // Add all of the module flags to the destination module.
+ DenseMap<MDString*, SmallVector<MDNode*, 4> > AddedNodes;
+ for (SmallSetVector<MDString*, 16>::iterator
+ I = SeenIDs.begin(), E = SeenIDs.end(); I != E; ++I) {
+ MDString *ID = *I;
+ if (OverrideNode[ID]) {
+ DstModFlags->addOperand(OverrideNode[ID]);
+ AddedNodes[ID].push_back(OverrideNode[ID]);
+ } else if (ErrorNode[ID]) {
+ DstModFlags->addOperand(ErrorNode[ID]);
+ AddedNodes[ID].push_back(ErrorNode[ID]);
+ } else if (WarningNode[ID]) {
+ DstModFlags->addOperand(WarningNode[ID]);
+ AddedNodes[ID].push_back(WarningNode[ID]);
+ }
+
+ for (SmallSetVector<MDNode*, 8>::iterator
+ II = RequireNodes[ID].begin(), IE = RequireNodes[ID].end();
+ II != IE; ++II)
+ DstModFlags->addOperand(*II);
+ }
+
+ // Now check that all of the requirements have been satisfied.
+ for (SmallSetVector<MDString*, 16>::iterator
+ I = SeenIDs.begin(), E = SeenIDs.end(); I != E; ++I) {
+ MDString *ID = *I;
+ SmallSetVector<MDNode*, 8> &Set = RequireNodes[ID];
+
+ for (SmallSetVector<MDNode*, 8>::iterator
+ II = Set.begin(), IE = Set.end(); II != IE; ++II) {
+ MDNode *Node = *II;
+ assert(isa<MDNode>(Node->getOperand(2)) &&
+ "Module flag's third operand must be an MDNode!");
+ MDNode *Val = cast<MDNode>(Node->getOperand(2));
+
+ MDString *ReqID = cast<MDString>(Val->getOperand(0));
+ Value *ReqVal = Val->getOperand(1);
+
+ bool HasValue = false;
+ for (SmallVectorImpl<MDNode*>::iterator
+ RI = AddedNodes[ReqID].begin(), RE = AddedNodes[ReqID].end();
+ RI != RE; ++RI) {
+ MDNode *ReqNode = *RI;
+ if (ReqNode->getOperand(2) == ReqVal) {
+ HasValue = true;
+ break;
+ }
+ }
+
+ if (!HasValue)
+ HasErr = emitError("linking module flags '" + ReqID->getString() +
+ "': does not have the required value");
+ }
+ }
+
+ return HasErr;
+}