diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h
@@ -80,7 +80,7 @@
                uint64_t *offset_ptr, DWARFSectionKind SectionKind);
   // For units in DWARF Package File, remember the index entry and update
   // the abbreviation offset read by extract().
-  bool applyIndexEntry(const DWARFUnitIndex::Entry *Entry);
+  Error applyIndexEntry(const DWARFUnitIndex::Entry *Entry);
   uint64_t getOffset() const { return Offset; }
   const dwarf::FormParams &getFormParams() const { return FormParams; }
   uint16_t getVersion() const { return FormParams.Version; }
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -95,8 +95,12 @@
         if (!IndexEntry)
           IndexEntry = Index.getFromOffset(Header.getOffset());
       }
-      if (IndexEntry && !Header.applyIndexEntry(IndexEntry))
-        return nullptr;
+      if (IndexEntry) {
+        if (Error Err = Header.applyIndexEntry(IndexEntry)) {
+          Context.getWarningHandler()(std::move(Err));
+          return nullptr;
+        }
+      }
       std::unique_ptr<DWARFUnit> U;
       if (Header.isTypeUnit())
         U = std::make_unique<DWARFTypeUnit>(Context, InfoSection, Header, DA,
@@ -345,21 +349,33 @@
   return true;
 }
 
-bool DWARFUnitHeader::applyIndexEntry(const DWARFUnitIndex::Entry *Entry) {
+Error DWARFUnitHeader::applyIndexEntry(const DWARFUnitIndex::Entry *Entry) {
   assert(Entry);
   assert(!IndexEntry);
-  IndexEntry = Entry;
   if (AbbrOffset)
-    return false;
-  auto *UnitContrib = IndexEntry->getContribution();
+    return createStringError(
+        errc::invalid_argument,
+        "DWARF package unit at offset 0x%8.8" PRIx64
+        " has a non-zero abbreviation offset prior to applying an index entry",
+        Offset);
+
+  auto *UnitContrib = Entry->getContribution();
   if (!UnitContrib ||
       UnitContrib->getLength() != (getLength() + getUnitLengthFieldByteSize()))
-    return false;
-  auto *AbbrEntry = IndexEntry->getContribution(DW_SECT_ABBREV);
+    return createStringError(errc::invalid_argument,
+                             "DWARF package unit at offset 0x%8.8" PRIx64
+                             " has an inconsistent unit index",
+                             Offset);
+
+  auto *AbbrEntry = Entry->getContribution(DW_SECT_ABBREV);
   if (!AbbrEntry)
-    return false;
+    return createStringError(errc::invalid_argument,
+                             "DWARF package unit at offset 0x%8.8" PRIx64
+                             " is missing an abbreviation column",
+                             Offset);
   AbbrOffset = AbbrEntry->getOffset();
-  return true;
+  IndexEntry = Entry;
+  return Error::success();
 }
 
 Error DWARFUnit::extractRangeList(uint64_t RangeListOffset,