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

1 files changed, 2 insertions, 3 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;