[ccache] ccache direct mode

[Anders Björklund]

vijay nag wrote:

> The documentation under direct mode suggest that it works by hashing
> the contents of include files, but it is not clear if it hashes the
> contents of every included file in BFS or DFS inclusion order ?

The files are indexed in the order the compiler (preprocessor) says.
You can check the order by running gcc -c yourself with the -H flag.

Or you can dump the .manifest file afterwards, using --dump-manifest.
Normally it is very top-to-bottom, which corresponds to a DFS order ?

/Anders