+namespace {
+ /// ReduceCrashingGlobalVariables - This works by removing the global
+ /// variable's initializer and seeing if the program still crashes. If it
+ /// does, then we keep that program and try again.
+ ///
+ class ReduceCrashingGlobalVariables : public ListReducer<GlobalVariable*> {
+ BugDriver &BD;
+ bool (*TestFn)(const BugDriver &, Module *);
+ public:
+ ReduceCrashingGlobalVariables(BugDriver &bd,
+ bool (*testFn)(const BugDriver &, Module *))
+ : BD(bd), TestFn(testFn) {}
+
+ virtual TestResult doTest(std::vector<GlobalVariable*> &Prefix,
+ std::vector<GlobalVariable*> &Kept,
+ std::string &Error) {
+ if (!Kept.empty() && TestGlobalVariables(Kept))
+ return KeepSuffix;
+ if (!Prefix.empty() && TestGlobalVariables(Prefix))
+ return KeepPrefix;
+ return NoFailure;
+ }
+
+ bool TestGlobalVariables(std::vector<GlobalVariable*> &GVs);
+ };
+}
+
+bool
+ReduceCrashingGlobalVariables::TestGlobalVariables(
+ std::vector<GlobalVariable*> &GVs) {
+ // Clone the program to try hacking it apart...
+ ValueToValueMapTy VMap;
+ Module *M = CloneModule(BD.getProgram(), VMap);
+
+ // Convert list to set for fast lookup...
+ std::set<GlobalVariable*> GVSet;
+
+ for (unsigned i = 0, e = GVs.size(); i != e; ++i) {
+ GlobalVariable* CMGV = cast<GlobalVariable>(VMap[GVs[i]]);
+ assert(CMGV && "Global Variable not in module?!");
+ GVSet.insert(CMGV);
+ }
+
+ outs() << "Checking for crash with only these global variables: ";
+ PrintGlobalVariableList(GVs);
+ outs() << ": ";
+
+ // Loop over and delete any global variables which we aren't supposed to be
+ // playing with...
+ for (Module::global_iterator I = M->global_begin(), E = M->global_end();
+ I != E; ++I)
+ if (I->hasInitializer() && !GVSet.count(I)) {
+ I->setInitializer(0);
+ I->setLinkage(GlobalValue::ExternalLinkage);
+ }
+
+ // Try running the hacked up program...
+ if (TestFn(BD, M)) {
+ BD.setNewProgram(M); // It crashed, keep the trimmed version...
+
+ // Make sure to use global variable pointers that point into the now-current
+ // module.
+ GVs.assign(GVSet.begin(), GVSet.end());
+ return true;
+ }
+
+ delete M;
+ return false;
+}
+