+namespace {
+// Reduce the list of Named Metadata nodes. We keep this as a list of
+// names to avoid having to convert back and forth every time.
+class ReduceCrashingNamedMD : public ListReducer<std::string> {
+ BugDriver &BD;
+ bool (*TestFn)(const BugDriver &, Module *);
+
+public:
+ ReduceCrashingNamedMD(BugDriver &bd,
+ bool (*testFn)(const BugDriver &, Module *))
+ : BD(bd), TestFn(testFn) {}
+
+ TestResult doTest(std::vector<std::string> &Prefix,
+ std::vector<std::string> &Kept,
+ std::string &Error) override {
+ if (!Kept.empty() && TestNamedMDs(Kept))
+ return KeepSuffix;
+ if (!Prefix.empty() && TestNamedMDs(Prefix))
+ return KeepPrefix;
+ return NoFailure;
+ }
+
+ bool TestNamedMDs(std::vector<std::string> &NamedMDs);
+};
+}
+
+bool ReduceCrashingNamedMD::TestNamedMDs(std::vector<std::string> &NamedMDs) {
+
+ ValueToValueMapTy VMap;
+ Module *M = CloneModule(BD.getProgram(), VMap).release();
+
+ outs() << "Checking for crash with only these named metadata nodes:";
+ unsigned NumPrint = std::min<size_t>(NamedMDs.size(), 10);
+ for (unsigned i = 0, e = NumPrint; i != e; ++i)
+ outs() << " " << NamedMDs[i];
+ if (NumPrint < NamedMDs.size())
+ outs() << "... <" << NamedMDs.size() << " total>";
+ outs() << ": ";
+
+ // Make a StringMap for faster lookup
+ StringSet<> Names;
+ for (const std::string &Name : NamedMDs)
+ Names.insert(Name);
+
+ // First collect all the metadata to delete in a vector, then
+ // delete them all at once to avoid invalidating the iterator
+ std::vector<NamedMDNode *> ToDelete;
+ ToDelete.reserve(M->named_metadata_size() - Names.size());
+ for (auto &NamedMD : M->named_metadata())
+ if (!Names.count(NamedMD.getName()))
+ ToDelete.push_back(&NamedMD);
+
+ for (auto *NamedMD : ToDelete)
+ NamedMD->eraseFromParent();
+
+ // Verify that this is still valid.
+ legacy::PassManager Passes;
+ Passes.add(createVerifierPass());
+ Passes.run(*M);
+
+ // Try running on the hacked up program...
+ if (TestFn(BD, M)) {
+ BD.setNewProgram(M); // It crashed, keep the trimmed version...
+ return true;
+ }
+ delete M; // It didn't crash, try something else.
+ return false;
+}
+
+namespace {
+// Reduce the list of operands to named metadata nodes
+class ReduceCrashingNamedMDOps : public ListReducer<const MDNode *> {
+ BugDriver &BD;
+ bool (*TestFn)(const BugDriver &, Module *);
+
+public:
+ ReduceCrashingNamedMDOps(BugDriver &bd,
+ bool (*testFn)(const BugDriver &, Module *))
+ : BD(bd), TestFn(testFn) {}
+
+ TestResult doTest(std::vector<const MDNode *> &Prefix,
+ std::vector<const MDNode *> &Kept,
+ std::string &Error) override {
+ if (!Kept.empty() && TestNamedMDOps(Kept))
+ return KeepSuffix;
+ if (!Prefix.empty() && TestNamedMDOps(Prefix))
+ return KeepPrefix;
+ return NoFailure;
+ }
+
+ bool TestNamedMDOps(std::vector<const MDNode *> &NamedMDOps);
+};
+}
+
+bool ReduceCrashingNamedMDOps::TestNamedMDOps(
+ std::vector<const MDNode *> &NamedMDOps) {
+ // Convert list to set for fast lookup...
+ SmallPtrSet<const MDNode *, 64> OldMDNodeOps;
+ for (unsigned i = 0, e = NamedMDOps.size(); i != e; ++i) {
+ OldMDNodeOps.insert(NamedMDOps[i]);
+ }
+
+ outs() << "Checking for crash with only " << OldMDNodeOps.size();
+ if (OldMDNodeOps.size() == 1)
+ outs() << " named metadata operand: ";
+ else
+ outs() << " named metadata operands: ";
+
+ ValueToValueMapTy VMap;
+ Module *M = CloneModule(BD.getProgram(), VMap).release();
+
+ // This is a little wasteful. In the future it might be good if we could have
+ // these dropped during cloning.
+ for (auto &NamedMD : BD.getProgram()->named_metadata()) {
+ // Drop the old one and create a new one
+ M->eraseNamedMetadata(M->getNamedMetadata(NamedMD.getName()));
+ NamedMDNode *NewNamedMDNode =
+ M->getOrInsertNamedMetadata(NamedMD.getName());
+ for (MDNode *op : NamedMD.operands())
+ if (OldMDNodeOps.count(op))
+ NewNamedMDNode->addOperand(cast<MDNode>(MapMetadata(op, VMap)));
+ }
+
+ // Verify that this is still valid.
+ legacy::PassManager Passes;
+ Passes.add(createVerifierPass());
+ Passes.run(*M);
+
+ // Try running on the hacked up program...
+ if (TestFn(BD, M)) {
+ // Make sure to use instruction pointers that point into the now-current
+ // module, and that they don't include any deleted blocks.
+ NamedMDOps.clear();
+ for (const MDNode *Node : OldMDNodeOps)
+ NamedMDOps.push_back(cast<MDNode>(VMap.MD()[Node].get()));
+
+ BD.setNewProgram(M); // It crashed, keep the trimmed version...
+ return true;
+ }
+ delete M; // It didn't crash, try something else.
+ return false;
+}
+