[PATCH v2 0/4] Some fixes for debug files and sysroots

[John Baldwin <jhb at FreeBSD dot org>]

Relative to the first series:

1) I combined the duplicate checks for "are we in a sysroot" in the
   first patch as as suggested by Simon.

2) I dropped the second patch (trim trailing '/' from sysroot).

3) Patches 2 and 3 are a different take on solving the issue when the
   sysroot ends in '/'.  Patch 2 adds a 'child_path' function to
   determine if a child path is a child of a parent (requiring the child
   to have at least one component "below" the parent).  It also returns
   a pointer to the first component below the parent (but after the
   directory separator).  Patch 3 uses child_path in
   find_separate_debug_file which fixes it in the case that the sysroot
   ends in a /.

4) The 4th patch is a new patch for a different issue I ran into while
   testing this some more today.  The paths to object files are always
   canonical paths with symlinks resolved.  If the sysroot entered by
   the user is a path containing symlinks, the filename_ncmp will
   never match.  To handle sysroot paths that traverse symlinks,
   use gdb_realpath to generate a canonical sysroot path and use that
   instead of gdb_sysroot with child_path.

As an aside, it's not clear to me when one should use gdb_realpath
instead of lrealpath.  gdb_realpath seems more widespread and also
returns an RAII-friendly type, so I used that.

John Baldwin (4):
  Look for separate debug files in debug directories under a sysroot.
  Add a new function child_path.
  Use child_path to determine if an object file is under a sysroot.
  Try to use the canonical version of a sysroot for debug file links.

 gdb/ChangeLog                        | 23 ++++++++++
 gdb/Makefile.in                      |  1 +
 gdb/common/pathstuff.c               | 52 ++++++++++++++++++++++
 gdb/common/pathstuff.h               |  6 +++
 gdb/symfile.c                        | 36 +++++++++++++---
 gdb/unittests/child-path-selftests.c | 64 ++++++++++++++++++++++++++++
 6 files changed, 175 insertions(+), 7 deletions(-)
 create mode 100644 gdb/unittests/child-path-selftests.c

-- 
2.19.2