Документация на синтаксис .in (autoconf template?)

# newlib options

## depends on BARE_METAL
## select LIBC_SUPPORT_THREADS_NONE
## select CC_CORE_PASSES_NEEDED if CANADIAN
## select CC_CORE_PASS_2_NEEDED if ! CANADIAN

## help Newlib is a C library intended for use on embedded systems. It is a
## help conglomeration of several library parts, all under free software
## help licenses that make them easily usable on embedded products. Newlib
## help is only available in source form. It can be compiled for a wide
## help array of processors, and will usually work on any architecture with
## help the addition of a few low-level routines.

# maybe older versions of newlib will support it too, but this
# needs to be checked
config NEWLIB_CXA_ATEXIT
    def_bool y
    depends on NEWLIB_2_0_or_later
    select LIBC_PROVIDES_CXA_ATEXIT

config NEWLIB_HAS_NANO_MALLOC
    def_bool y
    depends on NEWLIB_2_1_or_later

config NEWLIB_HAS_NANO_FORMATTED_IO
    def_bool y
    depends on NEWLIB_2_2_or_later

config LIBC_NEWLIB_TARGET_CFLAGS
    string
    prompt "Target CFLAGS for newlib"
    default ""
    help
      Used to add specific options when compiling the target libraries
      (eg. -ffunction-sections -fdata-sections), which can't be defined
      in global TARGET_CFLAGS, because they shall be not used for the
      gcc target libraries.
      Note:  Both TARGET_CFLAGS and LIBC_NEWLIB_TARGET_CFLAGS are used
             to compile the libraries.

      Leave blank if you don't know better.