Never return an empty reference from MCInstReference::get

Author: atrosinenko

bolt/lib/Core/MCInstUtils.cpp

@@ -39,18 +39,19 @@ class mapped_mcinst_iterator
 MCInstReference MCInstReference::get(const MCInst &Inst,
                                      const BinaryFunction &BF) {
   if (BF.hasCFG()) {
-    for (BinaryBasicBlock &BB : BF)
+    for (BinaryBasicBlock &BB : BF) {
       for (MCInst &MI : BB)
         if (&MI == &Inst)
           return MCInstReference(BB, Inst);
-    return {};
+    }
+    llvm_unreachable("Inst is not contained in BF");
   }
 
   for (auto I = BF.instrs().begin(), E = BF.instrs().end(); I != E; ++I) {
     if (&I->second == &Inst)
       return MCInstReference(BF, I);
   }
-  return {};
+  llvm_unreachable("Inst is not contained in BF");
 }
 
 uint64_t MCInstReference::computeAddress(const MCCodeEmitter *Emitter) const {

bolt/lib/Passes/PAuthGadgetScanner.cpp

@@ -531,11 +531,8 @@ class SrcSafetyAnalysis {
     const SrcState &S = getStateBefore(Inst);
 
     std::vector<MCInstReference> Result;
-    for (const MCInst *Inst : lastWritingInsts(S, ClobberedReg)) {
-      MCInstReference Ref = MCInstReference::get(*Inst, BF);
-      assert(!Ref.empty() && "Expected Inst to be found");
-      Result.push_back(Ref);
-    }
+    for (const MCInst *Inst : lastWritingInsts(S, ClobberedReg))
+      Result.push_back(MCInstReference::get(*Inst, BF));
     return Result;
   }
 };
@@ -1103,11 +1100,8 @@ class DstSafetyAnalysis {
     const DstState &S = getStateAfter(Inst);
 
     std::vector<MCInstReference> Result;
-    for (const MCInst *Inst : firstLeakingInsts(S, LeakedReg)) {
-      MCInstReference Ref = MCInstReference::get(*Inst, BF);
-      assert(!Ref.empty() && "Expected Inst to be found");
-      Result.push_back(Ref);
-    }
+    for (const MCInst *Inst : firstLeakingInsts(S, LeakedReg))
+      Result.push_back(MCInstReference::get(*Inst, BF));
     return Result;
   }
 };