Except silentoldconfig, valid_stdin is 1, so check_stdin() is no-op.
oldconfig and silentoldconfig work almost in the same way except that
the latter generates additional files under include/. Both ask users
for input for new symbols.
I do not know why only silentoldconfig requires stdio be tty.
$ rm -f .config; touch .config
$ yes "" | make oldconfig > stdout
$ rm -f .config; touch .config
$ yes "" | make silentoldconfig > stdout
make[1]: *** [silentoldconfig] Error 1
make: *** [silentoldconfig] Error 2
$ tail -n 4 stdout
Console input/output is redirected. Run 'make oldconfig' to update configuration.
scripts/kconfig/Makefile:40: recipe for target 'silentoldconfig' failed
Makefile:507: recipe for target 'silentoldconfig' failed
Redirection is useful, for example, for testing where we want to give
particular key inputs from a test file, then check the result.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
d2a04648a5