[llvm] r205286 - DebugInfo: Emit relocation to debug_line section when emitting asm for asm

[Eric Christopher]

On Tue, Apr 1, 2014 at 12:35 AM, David Blaikie <dblaikie at gmail.com> wrote:
> Author: dblaikie
> Date: Tue Apr  1 02:35:52 2014
> New Revision: 205286
>
> URL: http://llvm.org/viewvc/llvm-project?rev=205286&view=rev
> Log:
> DebugInfo: Emit relocation to debug_line section when emitting asm for asm
>
> I don't think this is reachable by any frontend (why would you transform
> asm to asm+debug info?) but it helps tidy up some of this code, avoid
> the weird special case of "emit the first CU, store the label, then emit
> the rest" in MCDwarfLineTable::Emit by instead having the
> DWARF-for-assembly case use the same codepath as DwarfDebug.cpp, by
> registering the label of the debug_line section, thus causing it to be
> emitted. (with a special case in asm output to just emit the label since
> asm output uses the .loc directives, etc, rather than the debug_loc
> directly)
>

Looks very nice, thanks.

>    // Check to see there are no empty DwarfFile slots.
> -  const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles =
> -      getContext().getMCDwarfFiles();
> -  for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
> -    if (MCDwarfFiles[i].Name.empty())
> -      TokError("unassigned file number: " + Twine(i) + " for .file directives");
> +  const auto &LineTables = getContext().getMCDwarfLineTables();
> +  if (!LineTables.empty()) {
> +    unsigned Index = 0;
> +    for (const auto &File : LineTables.begin()->second.getMCDwarfFiles()) {
> +      if (File.Name.empty() && Index != 0)
> +        TokError("unassigned file number: " + Twine(Index) +
> +                 " for .file directives");
> +      ++Index;
> +    }
>    }

Might be silly, but update the comment to reflect that we're also
looking for invalid ones? Not that you changed anything here, but ...

-eric