Revert "[llvm] Reapply "Prevent duplicate files in debug line header in dwarf 5.""

This reverts commit rL357020.

The commit broke the test llvm/test/tools/llvm-objdump/embedded-source.test
on some builds including clang-ppc64be-linux-multistage,
clang-s390x-linux, clang-with-lto-ubuntu, clang-x64-windows-msvc,
llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast (and others).

llvm-svn: 357026

2 files changed, 2 insertions, 14 deletions

diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 348436f4bd0..49fad131a2c 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -603,8 +603,7 @@ Expected<unsigned> MCContext::getDwarfFile(StringRef Directory,
                                            MD5::MD5Result *Checksum,
                                            Optional<StringRef> Source,
                                            unsigned CUID) {
-  MCDwarfLineTable &Table =
-      MCDwarfLineTablesCUMap.emplace(CUID, DwarfVersion).first->second;
+  MCDwarfLineTable &Table = MCDwarfLineTablesCUMap[CUID];
   return Table.tryGetFile(Directory, FileName, Checksum, Source, FileNumber);
 }
 
@@ -613,7 +612,7 @@ Expected<unsigned> MCContext::getDwarfFile(StringRef Directory,
 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
   const MCDwarfLineTable &LineTable = getMCDwarfLineTable(CUID);
   if (FileNumber == 0)
-    return getDwarfVersion() >= 5;
+    return getDwarfVersion() >= 5 && LineTable.hasRootFile();
   if (FileNumber >= LineTable.getMCDwarfFiles().size())
     return false;
 
diff --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index 73b4d4bcd19..83b6b4f1aa3 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -542,15 +542,6 @@ Expected<unsigned> MCDwarfLineTable::tryGetFile(StringRef &Directory,
   return Header.tryGetFile(Directory, FileName, Checksum, Source, FileNumber);
 }
 
-bool isRootFile(const MCDwarfFile &RootFile, StringRef &Directory,
-                StringRef &FileName, MD5::MD5Result *Checksum) {
-  if (RootFile.Name.empty() || RootFile.Name != FileName.data())
-    return false;
-  if (!RootFile.Checksum)
-    return !Checksum;
-  return *RootFile.Checksum == *Checksum;
-}
-
 Expected<unsigned>
 MCDwarfLineTableHeader::tryGetFile(StringRef &Directory,
                                    StringRef &FileName,
@@ -570,8 +561,6 @@ MCDwarfLineTableHeader::tryGetFile(StringRef &Directory,
     trackMD5Usage(Checksum);
     HasSource = (Source != None);
   }
-  if (isRootFile(RootFile, Directory, FileName, Checksum) && DwarfVersion >= 5)
-    return 0;
   if (FileNumber == 0) {
     // File numbers start with 1 and/or after any file numbers
     // allocated by inline-assembler .file directives.