feature detection versus feature selection

[Arnaldo Carvalho de Melo]

Hey guys,

	Now we have this output when building tools with the feature
detection mechanisms in tools/build/:

Auto-detecting system features:
...                         dwarf: [ on  ]
...            dwarf_getlocations: [ OFF ]
...                         glibc: [ on  ]
...                          gtk2: [ on  ]
...                      libaudit: [ on  ]
...                        libbfd: [ on  ]
...                        libelf: [ on  ]
...                       libnuma: [ on  ]
...        numa_num_possible_cpus: [ OFF ]
...                       libperl: [ on  ]
...                     libpython: [ on  ]
...                      libslang: [ on  ]
...                     libcrypto: [ on  ]
...                     libunwind: [ on  ]
...            libdw-dwarf-unwind: [ OFF ]
...                          zlib: [ on  ]
...                          lzma: [ on  ]
...                     get_cpuid: [ on  ]
...                           bpf: [ on  ]


	What I miss is a way to have another column that would state if
the user had used, say, NO_LIBELF to disable libelf...

	Jiri, is there already some file where we have the list of
manually disabled features? Or do you have something like that in mind?
.config files?

- Arnaldo