Revert "Reapply "[DWARFv5] Emit file 0 to the line table.""

This reverts commit r328676.

Commit r328676 broke the -no-integrated-as flag necessary to build Linux kernel with Clang:

$ cat t.c
void foo() {}
$ clang -no-integrated-as   -c  t.c -g
/tmp/t-dcdec5.s: Assembler messages:
/tmp/t-dcdec5.s:8: Error: file number less than one
clang-7.0: error: assembler command failed with exit code 1 (use -v to see invocation)

llvm-svn: 328699

1 files changed, 7 insertions, 11 deletions

diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 8de6579fe3f..3042f9964ff 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -3276,8 +3276,8 @@ bool AsmParser::parseDirectiveFile(SMLoc DirectiveLoc) {
     FileNumber = getTok().getIntVal();
     Lex();
 
-    if (FileNumber < 0)
-      return TokError("negative file number");
+    if (FileNumber < 1)
+      return TokError("file number less than one");
   }
 
   std::string Path = getTok().getString();
@@ -3356,15 +3356,11 @@ bool AsmParser::parseDirectiveFile(SMLoc DirectiveLoc) {
       memcpy(SourceBuf, SourceString.data(), SourceString.size());
       Source = StringRef(SourceBuf, SourceString.size());
     }
-    if (FileNumber == 0)
-      getStreamer().emitDwarfFile0Directive(Directory, Filename, CKMem, Source);
-    else {
-      Expected<unsigned> FileNumOrErr = getStreamer().tryEmitDwarfFileDirective(
-          FileNumber, Directory, Filename, CKMem, Source);
-      if (!FileNumOrErr)
-        return Error(DirectiveLoc, toString(FileNumOrErr.takeError()));
-      FileNumber = FileNumOrErr.get();
-    }
+    Expected<unsigned> FileNumOrErr = getStreamer().tryEmitDwarfFileDirective(
+        FileNumber, Directory, Filename, CKMem, Source);
+    if (!FileNumOrErr)
+      return Error(DirectiveLoc, toString(FileNumOrErr.takeError()));
+    FileNumber = FileNumOrErr.get();
   }
 
   return false;