Fix PR23045.

Keep a note in the materializer that we are stripping debug info so that
user doing a lazy read of the module don't hit outdated formats.

Thanks to Duncan for suggesting the fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233603 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -16,6 +16,7 @@
 #include "llvm/Bitcode/LLVMBitCodes.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/DiagnosticPrinter.h"
@@ -218,6 +219,8 @@ class BitcodeReader : public GVMaterializer {
   /// True if any Metadata block has been materialized.
   bool IsMetadataMaterialized;
 
+  bool StripDebugInfo = false;
+
 public:
   std::error_code Error(BitcodeError E, const Twine &Message);
   std::error_code Error(BitcodeError E);
@@ -255,6 +258,8 @@ public:
   /// Materialize any deferred Metadata block.
   std::error_code materializeMetadata() override;
 
+  void setStripDebugInfo() override;
+
 private:
   std::vector<StructType *> IdentifiedStructTypes;
   StructType *createIdentifiedStructType(LLVMContext &Context, StringRef Name);
@@ -2609,6 +2614,10 @@ std::error_code BitcodeReader::materializeMetadata() {
   return std::error_code();
 }
 
+void BitcodeReader::setStripDebugInfo() {
+  StripDebugInfo = true;
+}
+
 /// RememberAndSkipFunctionBody - When we see the block for a function body,
 /// remember where it is and then skip it.  This lets us lazily deserialize the
 /// functions.
@@ -4305,6 +4314,9 @@ std::error_code BitcodeReader::materialize(GlobalValue *GV) {
     return EC;
   F->setIsMaterializable(false);
 
+  if (StripDebugInfo)
+    stripDebugInfo(*F);
+
   // Upgrade any old intrinsic calls in the function.
   for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
        E = UpgradedIntrinsics.end(); I != E; ++I) {