Compiler features for dependency data generation

[matheusmoreira]

What compilers feature dependency data generation? How best to use them?

[matheusmoreira]

Both gcc and clang support dependency data generation. Their options are apparently compatible. The parameters -M -MF $dependency -MT $target are appropriate: the library is likely to benefit from recompilation when linux headers are updated and since these compilers simplify the target's path it needs to be set explicitly in order to be compatible with the prefixed path method.

Since support for other compilers is a possibility, generating dependency data as a side effect of compilation might be problematic. Perhaps there is a way to avoid generating rules for dependency files in case an unsupported compiler is chosen. The alternative would be separate rules and recipes for these dependency files and it would require either gcc or clang even if they are not the selected compilers.