3 files changed, 14 insertions, 5 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
index a3ea96b72ba..f3a3cbdbc74 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
@@ -36,9 +36,9 @@ void DwarfFile::emitStringOffsetsTableHeader(MCSection *Section) {
   // FIXME: DWARF64
   // We are emitting the header for a contribution to the string offsets
   // table. The header consists of an entry with the contribution's
-  // size (not including the size of the header), the DWARF version and
+  // size (not including the size of the length field), the DWARF version and
   // 2 bytes of padding.
-  Asm->emitInt32(StrPool.size() * EntrySize);
+  Asm->emitInt32(StrPool.size() * EntrySize + 4);
   Asm->emitInt16(Asm->getDwarfVersion());
   Asm->emitInt16(0);
   // Define the symbol that marks the start of the contribution. It is
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 6fbe55bbdc7..8488fe8ced7 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -172,7 +172,11 @@ static void dumpDWARFv5StringOffsetsSection(
       OS << (ContributionHeader - Offset) << "\n";
     }
     OS << format("0x%8.8x: ", (uint32_t)ContributionHeader);
-    OS << "Contribution size = " << Contribution->Size
+    // In DWARF v5 the contribution size in the descriptor does not equal
+    // the originally encoded length (it does not contain the length of the
+    // version field and the padding, a total of 4 bytes). Add them back in
+    // for reporting.
+    OS << "Contribution size = " << (Contribution->Size + (Version < 5 ? 0 : 4))
        << ", Format = " << (Format == DWARF32 ? "DWARF32" : "DWARF64")
        << ", Version = " << Version << "\n";
 
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
index d54275d302f..2d456b4b530 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -517,7 +517,9 @@ parseDWARF64StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
   uint64_t Size = DA.getU64(&Offset);
   uint8_t Version = DA.getU16(&Offset);
   (void)DA.getU16(&Offset); // padding
-  return StrOffsetsContributionDescriptor(Offset, Size, Version, DWARF64);
+  // The encoded length includes the 2-byte version field and the 2-byte
+  // padding, so we need to subtract them out when we populate the descriptor.
+  return StrOffsetsContributionDescriptor(Offset, Size - 4, Version, DWARF64);
   //return Optional<StrOffsetsContributionDescriptor>(Descriptor);
 }
 
@@ -532,7 +534,10 @@ parseDWARF32StringOffsetsTableHeader(DWARFDataExtractor &DA, uint32_t Offset) {
     return Optional<StrOffsetsContributionDescriptor>();
   uint8_t Version = DA.getU16(&Offset);
   (void)DA.getU16(&Offset); // padding
-  return StrOffsetsContributionDescriptor(Offset, ContributionSize, Version, DWARF32);
+  // The encoded length includes the 2-byte version field and the 2-byte
+  // padding, so we need to subtract them out when we populate the descriptor.
+  return StrOffsetsContributionDescriptor(Offset, ContributionSize - 4, Version,
+                                          DWARF32);
   //return Optional<StrOffsetsContributionDescriptor>(Descriptor);
 }