missing FILE symbol for .(s|S) files

[rnagy]

Summary

Hello

When compiling .(s|S) files with clang, a FILE symbol is missing from the object
file, unless explicitly setting one with the .file directive. Not using the integrated as, also fixes the issue:

$ clang -g bzero.S a.c && readelf -Ws a.out | grep FILE

33: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS a.c

$ clang -no-integrated-as -g bzero.S a.c && readelf -Ws a.out | grep FILE

31: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS bzero.S
33: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS a.c

$ gcc -g bzero.S a.c && readelf -Ws a.out | grep FILE

31: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS bzero.S
33: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS a.c

This seems like a bug and the FILE symbol should be added with the integrated
as as well.

The patch that I've attached works for me and generates the
proper file directive.

https://bugs.llvm.org/show_bug.cgi?id=34019

Thank you!

[niravd]

This looks good. Can you convert your example into a test case?

[rnagy]

In D44633#1041943, @niravd wrote:

This looks good. Can you convert your example into a test case?

I will try. I am not really familiar with the codebase.

[niravd]

Robert, it looks like the state of the assembler file handling has shifted. Is the underlying issue still valid?

lib/MC/MCParser/AsmParser.cpp

   AsmCond StartingCondState = TheCondState;
   SmallVector<AsmRewrite, 4> AsmStrRewrites;
 
+  StringRef Filename = getContext().getMainFileName();
+
   // If we are generating dwarf for assembly source files save the initial text
   // section and generate a .file directive.
   if (getContext().getGenDwarfForAssembly()) {

     assert(InsertResult && ".text section should not have debug info yet");
     (void)InsertResult;
     getContext().setGenDwarfFileNumber(getStreamer().EmitDwarfFileDirective(
-        0, StringRef(), getContext().getMainFileName()));
+        0, StringRef(), Filename));
   }
 
+  if (!Filename.empty() && (Filename.compare(StringRef("-")) != 0))
+    Out.EmitFileDirective(Filename);
+
   // While we have input, parse each statement.
   while (Lexer.isNot(AsmToken::Eof)) {
     ParseStatementInfo Info(&AsmStrRewrites);