We currently have DWARF that has a DW_AT_comp_dir that is set to "./" followed 
by any number of extra '/' characters. I would like to have this path 
normalized as we parse the DWARF so we don't end up with line tables with a 
variety of ".//+" prefixes on each source file.

While looking to solve this issue, I took a look at the functionality that is 
in FileSpec right now. In:

void FileSpec::SetFile(llvm::StringRef pathname, bool resolve, PathSyntax 
syntax);


This function always calls a cheaper normalize function:

namespace {
  void Normalize(llvm::SmallVectorImpl<char> &path, FileSpec::PathSyntax 
syntax);
}

This function does nothing for posix paths, but switches backward slashes to 
forward slashes. 

We have a FileSpec function named FileSpec::GetNormalizedPath() which will do 
much more path normalization on a path by removing redundant "." and ".." and 
"//". 

I can fix my DWARF issue in a few ways:
1 - fix FileSpec::SetFile() to still call ::Normalize() but have it do more 
work and have it normalize out the and redundant or relative path info
2 - call FileSpec::GetNormalizedPath() on each comp dir before using it to 
actually normalize it

The main question is: do we want paths floating around LLDB that aren't 
normalized? It seems like having a mixture of theses path will lead to issues 
in LLDB so I would vote for solution #1.

Also, looking at the tests for normalizing paths I found the following pairs of 
pre-normalized and post-normalization paths for posix:

      {"//", "//"},
      {"//net", "//net"},

Why wouldn't we reduce "//" to just "/" for posix? And why wouldn't we reduce 
"//net" to "/net"?

Also I found:

      {"./foo", "foo"},

Do we prefer to not have "./foo" to stay as "./foo"? Seems like if users know 
that their debug info has line table entries that are "./foo/foo.c" that they 
might type this in:

(lldb) b ./foo/foo.c:12

But this will fail since it might not match the "foo/foo.c:12" that might 
result from path normalization. We don't normalize right now so it doesn't 
matter and things would match, but part of my fix is normalizing a path in the 
DWARF that is currently ".////////foo/foo.c" down to either "./foo/foo.c" or 
"foo/foo.c" so it will matter depending on what we decide here. 

Any input would be appreciated.

Greg Clayton

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