Fix to issue #156: multithread end events (#198)

Author: asantagata

src/c/weaver/weave/perfflow_weave_common.cpp

@@ -153,8 +153,21 @@ bool weave_ns::WeaveCommon::insertAfter(Module &m, Function &f, StringRef &a,
     for (BasicBlock &bb : f)
     {
         Instruction *inst = bb.getTerminator();
+        bool valid = false;
         if (isa<ReturnInst>(inst) || isa<ResumeInst>(inst))
         {
+            valid = true;
+        } else if (isa<UnreachableInst>(inst)) {
+            if (auto *call = dyn_cast<CallInst>(inst->getPrevNode())) {
+                Function *callee = call->getCalledFunction();
+                if (callee && callee->getName() == "pthread_exit" || callee->getName() == "exit" || callee->getName() == "abort") {
+                    inst = inst->getPrevNode();
+                    valid = true;
+                }
+            }
+        }
+
+        if (valid) {
             IRBuilder<> builder(inst);
             Value *v1 = builder.CreateGlobalStringPtr(m.getName(), "str");
             Value *v2 = builder.CreateGlobalStringPtr(f.getName(), "str");