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: http://www.bell-labs.com/project/nmake/newsletters/issue021.html
What do you need exactly that -iquote or any of the -i* options provide? Or even what this patch should provide: http://gcc.gnu.org/ml/gcc-patches/2006-03/msg01197.html 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 ***