1 files changed, 32 insertions, 14 deletions

diff --git a/contrib/llvm-project/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/contrib/llvm-project/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index 0a9a80688a41..910e97489dbb 100644
--- a/contrib/llvm-project/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/contrib/llvm-project/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -22,7 +22,6 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/ADT/ilist_iterator.h"
-#include "llvm/ADT/iterator_range.h"
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/Bitcode/LLVMBitCodes.h"
@@ -555,12 +554,12 @@ class MetadataLoader::MetadataLoaderImpl {
         if (!CU)
           continue;
 
-        if (auto *RawImported = CU->getRawImportedEntities()) {
+        if (CU->getRawImportedEntities()) {
           // Collect a set of imported entities to be moved.
           SetVector<Metadata *> EntitiesToRemove;
           for (Metadata *Op : CU->getImportedEntities()->operands()) {
             auto *IE = cast<DIImportedEntity>(Op);
-            if (auto *S = dyn_cast_or_null<DILocalScope>(IE->getScope())) {
+            if (dyn_cast_or_null<DILocalScope>(IE->getScope())) {
               EntitiesToRemove.insert(IE);
             }
           }
@@ -705,10 +704,11 @@ class MetadataLoader::MetadataLoaderImpl {
     return Error::success();
   }
 
-  void upgradeDebugInfo() {
+  void upgradeDebugInfo(bool ModuleLevel) {
     upgradeCUSubprograms();
     upgradeCUVariables();
-    upgradeCULocals();
+    if (ModuleLevel)
+      upgradeCULocals();
   }
 
   void callMDTypeCallback(Metadata **Val, unsigned TypeID);
@@ -1085,7 +1085,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) {
       // Reading the named metadata created forward references and/or
       // placeholders, that we flush here.
       resolveForwardRefsAndPlaceholders(Placeholders);
-      upgradeDebugInfo();
+      upgradeDebugInfo(ModuleLevel);
       // Return at the beginning of the block, since it is easy to skip it
       // entirely from there.
       Stream.ReadBlockEnd(); // Pop the abbrev block context.
@@ -1116,7 +1116,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseMetadata(bool ModuleLevel) {
       return error("Malformed block");
     case BitstreamEntry::EndBlock:
       resolveForwardRefsAndPlaceholders(Placeholders);
-      upgradeDebugInfo();
+      upgradeDebugInfo(ModuleLevel);
       return Error::success();
     case BitstreamEntry::Record:
       // The interesting case.
@@ -1213,6 +1213,26 @@ void MetadataLoader::MetadataLoaderImpl::resolveForwardRefsAndPlaceholders(
   Placeholders.flush(MetadataList);
 }
 
+static Value *getValueFwdRef(BitcodeReaderValueList &ValueList, unsigned Idx,
+                             Type *Ty, unsigned TyID) {
+  Value *V = ValueList.getValueFwdRef(Idx, Ty, TyID,
+                                      /*ConstExprInsertBB*/ nullptr);
+  if (V)
+    return V;
+
+  // This is a reference to a no longer supported constant expression.
+  // Pretend that the constant was deleted, which will replace metadata
+  // references with undef.
+  // TODO: This is a rather indirect check. It would be more elegant to use
+  // a separate ErrorInfo for constant materialization failure and thread
+  // the error reporting through getValueFwdRef().
+  if (Idx < ValueList.size() && ValueList[Idx] &&
+      ValueList[Idx]->getType() == Ty)
+    return UndefValue::get(Ty);
+
+  return nullptr;
+}
+
 Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     SmallVectorImpl<uint64_t> &Record, unsigned Code,
     PlaceholderQueue &Placeholders, StringRef Blob, unsigned &NextMetadataNo) {
@@ -1315,7 +1335,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
 
     unsigned TyID = Record[0];
     Type *Ty = Callbacks.GetTypeByID(TyID);
-    if (Ty->isMetadataTy() || Ty->isVoidTy()) {
+    if (!Ty || Ty->isMetadataTy() || Ty->isVoidTy()) {
       dropRecord();
       break;
     }
@@ -1344,8 +1364,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
       if (Ty->isMetadataTy())
         Elts.push_back(getMD(Record[i + 1]));
       else if (!Ty->isVoidTy()) {
-        Value *V = ValueList.getValueFwdRef(Record[i + 1], Ty, TyID,
-                                            /*ConstExprInsertBB*/ nullptr);
+        Value *V = getValueFwdRef(ValueList, Record[i + 1], Ty, TyID);
         if (!V)
           return error("Invalid value reference from old metadata");
         Metadata *MD = ValueAsMetadata::get(V);
@@ -1366,11 +1385,10 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
 
     unsigned TyID = Record[0];
     Type *Ty = Callbacks.GetTypeByID(TyID);
-    if (Ty->isMetadataTy() || Ty->isVoidTy())
+    if (!Ty || Ty->isMetadataTy() || Ty->isVoidTy())
       return error("Invalid record");
 
-    Value *V = ValueList.getValueFwdRef(Record[1], Ty, TyID,
-                                        /*ConstExprInsertBB*/ nullptr);
+    Value *V = getValueFwdRef(ValueList, Record[1], Ty, TyID);
     if (!V)
       return error("Invalid value reference from metadata");
 
@@ -1615,7 +1633,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
         // DICompositeType flag specifying whether template parameters are
         // required on declarations of this type.
         StringRef NameStr = Name->getString();
-        if (!NameStr.contains('<') || NameStr.startswith("_STN|"))
+        if (!NameStr.contains('<') || NameStr.starts_with("_STN|"))
           TemplateParams = getMDOrNull(Record[14]);
       }
     } else {