diff --git a/llvm/lib/Target/BPF/BPFISelLowering.h b/llvm/lib/Target/BPF/BPFISelLowering.h
--- a/llvm/lib/Target/BPF/BPFISelLowering.h
+++ b/llvm/lib/Target/BPF/BPFISelLowering.h
@@ -66,6 +66,8 @@
 
   MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override;
 
+  void finalizeLowering(MachineFunction &MF) const override;
+
 private:
   // Control Instruction Selection Features
   bool HasAlu32;
@@ -73,6 +75,11 @@
   bool HasJmpExt;
   bool HasMovsx;
 
+  mutable bool HasError = false;
+
+  void fail(const SDLoc &DL, SelectionDAG &DAG, const Twine &Msg,
+            SDValue Val) const;
+
   SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
diff --git a/llvm/lib/Target/BPF/BPFISelLowering.cpp b/llvm/lib/Target/BPF/BPFISelLowering.cpp
--- a/llvm/lib/Target/BPF/BPFISelLowering.cpp
+++ b/llvm/lib/Target/BPF/BPFISelLowering.cpp
@@ -35,22 +35,18 @@
   cl::Hidden, cl::init(false),
   cl::desc("Expand memcpy into load/store pairs in order"));
 
-static void fail(const SDLoc &DL, SelectionDAG &DAG, const Twine &Msg) {
-  MachineFunction &MF = DAG.getMachineFunction();
-  DAG.getContext()->diagnose(
-      DiagnosticInfoUnsupported(MF.getFunction(), Msg, DL.getDebugLoc()));
-}
-
-static void fail(const SDLoc &DL, SelectionDAG &DAG, const char *Msg,
-                 SDValue Val) {
-  MachineFunction &MF = DAG.getMachineFunction();
+void BPFTargetLowering::fail(const SDLoc &DL, SelectionDAG &DAG,
+                             const Twine &Msg, SDValue Val = {}) const {
+  HasError = true;
   std::string Str;
-  raw_string_ostream OS(Str);
-  OS << Msg;
-  Val->print(OS);
-  OS.flush();
-  DAG.getContext()->diagnose(
-      DiagnosticInfoUnsupported(MF.getFunction(), Str, DL.getDebugLoc()));
+  if (Val) {
+    raw_string_ostream OS(Str);
+    Val->print(OS);
+    OS << ' ';
+  }
+  MachineFunction &MF = DAG.getMachineFunction();
+  DAG.getContext()->diagnose(DiagnosticInfoUnsupported(
+      MF.getFunction(), Msg.concat(Str), DL.getDebugLoc()));
 }
 
 BPFTargetLowering::BPFTargetLowering(const TargetMachine &TM,
@@ -871,6 +867,13 @@
   return (getHasAlu32() && VT == MVT::i32) ? MVT::i32 : MVT::i64;
 }
 
+void BPFTargetLowering::finalizeLowering(MachineFunction &MF) const {
+  if (HasError) {
+    report_fatal_error("failed to generate BPF instructions, see diagnostics");
+  }
+  TargetLowering::finalizeLowering(MF);
+}
+
 bool BPFTargetLowering::isLegalAddressingMode(const DataLayout &DL,
                                               const AddrMode &AM, Type *Ty,
                                               unsigned AS,