kconfig: Add "def_string", "def_int" and "def_hex"

Kconfig has offered "def_bool" and "def_tristate" as a shorthand for a
type definition plus a default since before the git era, but has never
offered the equivalent for the other three types. Conor Dooley ran into
this gap[1] when fixing a symbol that had been given the wrong type:

  Unfortunately, there is no such thing as "def_string", but in this
  case we can use "default" to propagate the value of ...

Nothing in the grammar requires the restriction. The rule that consumes
a default is already type agnostic. Add the three missing types. No
changes are needed to existing diagnostics. E.g. declaring a symbol
"bool" and then assigning it with "def_string" still reports

  warning: ignoring type redefinition of 'CONFLICT' from 'bool' to 'string'

Added tests for the types.

Build tested ARCH=x86_64 with GCC 16.2.0. Tests pass with "make testconfig".

Link: https://lore.kernel.org/all/20230111104848.2088516-1-conor.dooley@microchip.com/ [1]
Assisted-by: LLM
Signed-off-by: Kees Cook <kees@kernel.org>
Tested-by: Julian Braha <julianbraha@gmail.com>
Reviewed-by: Julian Braha <julianbraha@gmail.com>
Link: https://patch.msgid.link/20260919005929.4077729-1-kees@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

0 files changed, 0 insertions, 0 deletions