The -I option inhibits the use of the current file directory as the first search directory for #include "file". This is important for software development which uses partially populated source trees for which the build "looks through" other trees to find the missing pieces.
Without -I- gcc should offer something like the IBM xlc -qidirfirst option:
Specifies the search order for files included with
the '#include' <file_name> directive. Use
-qidirfirst with the -I option. If -qidirfirst is
specified, the directories specified by the
-I<directory> option are searched before the
directory where the current file resides. The
default is -qnoidirfirst.
This is all we need, but over the last 10 years we have instead pushed vendors to support the -I- option. It is sadly ironic that gcc deprecates it.
My employer does not use `nmake', but `nmake' has noticed this too:
What do you need exactly that -iquote or any of the -i* options provide?
Or even what this patch should provide:
That adds an option to do what exactly -I- did except for not change the behavior of -I* after -I-.
If that patch does the trick for you, then this is a dup of bug 19541.
The patch for bug 19541 should resolve this, thanks!
*** This bug has been marked as a duplicate of 19541 ***