Re: [PING**3] [PATCH] Force use of absolute path names for gcov

[Nathan Sidwell <nathan at acm dot org>]

On 06/01/2017 03:24 PM, Bernd Edlinger wrote:

> This is a gcc option that converts relative
> path names to absolute ones, so that gcov can
> properly merge the line numbers in projects
> where different relative path names may refer
> to the same source file.

Thanks.  From reading the patch though, I didn't grok that intent.  The 
patch itself suggests gcov simply fails with relative paths and 
directories.  What you're really trying to do is find the canonical 
path, which happens to be absolute.  But you're not doing that either -- 
you're concatenating the relative path to cwd.  How is that helping? Is 
it when you have a mixture of absolute and relative paths?

Some other cases:
1) 'bob/../foo.c' and 'baz/../foo.c'?
2) 'bob/foo.c' and 'baz/foo.c' where baz is a symlink to bob?
3) combinations of #2 and #3 such that textual elision of .. gets you to 
a different place than resolving symlinks.

Given all that complexity, wouldn't it be better to tell gcov where 
relative paths should start?  (perhaps encoding in the file?).  It does 
need access to the source directories.

note libiberty has lrealpath to do (much of?) what you want.

nathan

--
Nathan Sidwell