crosstool-ng/config/libc/newlib.in

# 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.

source "config/versions/newlib.in"

# 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.

config LIBC_NEWLIB_IO_C99FMT
    bool
    prompt "Enable IOs on C99 formats"
    help
      Enable support for IOs on C99 formats.

config LIBC_NEWLIB_IO_LL
    bool
    prompt "Enable IOs on long long"
    help
      Enable support for IOs on long long integers.

config LIBC_NEWLIB_IO_FLOAT
    bool
    prompt "Enable IOs on floats and doubles"
    help
      Enable support for IOs on floating point
      values (float and double).

config LIBC_NEWLIB_IO_LDBL
    bool
    prompt "Enable IOs on long doubles"
    depends on LIBC_NEWLIB_IO_FLOAT
    help
      Enable support for IOs on long doubles.

config LIBC_NEWLIB_IO_POS_ARGS
    bool
    prompt "Enable printf-family positional arg support"
    help
        Enable printf-family positional arg support.

config LIBC_NEWLIB_FVWRITE_IN_STREAMIO
    bool
    prompt "Vector buffer mechanism to support stream IO buffering"
    default y
    help
        NEWLIB implements the vector buffer mechanism to support stream IO
        buffering required by C standard.  This feature is possibly
        unnecessary for embedded systems which won't change file buffering
        with functions like `setbuf' or `setvbuf'.  The buffering mechanism
        still acts as default for STDIN/STDOUT/STDERR even if this option
        is specified.

config LIBC_NEWLIB_UNBUF_STREAM_OPT
    bool
    prompt "Optimize fprintf to unbuffered unix file"
    default y
    help
        NEWLIB does optimization when `fprintf to write only unbuffered unix
        file'.  It creates a temorary buffer to do the optimization that
        increases stack consumption by about `BUFSIZ' bytes. Disabling this option
        disables the optimization and saves size of text and stack.

config LIBC_NEWLIB_FSEEK_OPTIMIZATION
    bool
    prompt "Fseek optimisation"
    default y
    help
        Disabling fseek optimisation can decrease code size.

config LIBC_NEWLIB_DISABLE_SUPPLIED_SYSCALLS
    bool
    prompt "Disable the syscalls supplied with newlib"
    help
      Disable the syscalls that come with newlib. You
      will have to implement your own _sbrk, _read,
      _write... If you plan to port newlib to a new
      platform/board, say Yes.

config LIBC_NEWLIB_REGISTER_FINI
    bool
    prompt "Enable finalization function registration using atexit"
    help
        Enable finalization function registration using atexit.

config LIBC_NEWLIB_ATEXIT_DYNAMIC_ALLOC
    bool
    prompt "Enable dynamic allocation of atexit entries"
    default y
    help
        Enable dynamic allocation of atexit entries.

config LIBC_NEWLIB_GLOBAL_ATEXIT
    bool
    prompt "Enable atexit data structure as global variable"
    help
        Enable atexit data structure as global variable.  By doing so it is
        move out of _reent structure, and can be garbage collected if atexit
        is not referenced.

config LIBC_NEWLIB_LITE_EXIT
    bool
    prompt "Enable lite exit"
    help
        Enable lite exit, a size-reduced implementation of exit that doesn't
        invoke clean-up functions such as _fini or global destructors.

config LIBC_NEWLIB_REENT_SMALL
    bool
    prompt "Enable small reentrant struct support"
    help
        Enable small reentrant struct support.

config LIBC_NEWLIB_MULTITHREAD
    bool
    prompt "Enable support for multiple threads"
    default y
    help
        Enable support for multiple threads.

config LIBC_NEWLIB_EXTRA_SECTIONS
    bool
    prompt "Place each function & data element in their own section"
    help
        Place each function & data symbol in their own section. This allows
        the linker to garbage collect unused symbols at link time.

config LIBC_NEWLIB_WIDE_ORIENT
    bool
    prompt "Allow wide C99 stream orientation"
    default y
    help
        C99 states that each stream has an orientation, wide or byte.  This
        feature is possibly unnecessary for embedded systems which only do
        byte input/output operations on stream. Disabling this feature can
        decrease code size.

config LIBC_NEWLIB_ENABLE_TARGET_OPTSPACE
    bool
    prompt "Optimize newlib for size"
    default y
    help
      Pass --enable-target-optspace to newlib configure.

      This will compile newlib with -Os.

config LIBC_NEWLIB_LTO
    bool
    prompt "Enable Link Time Optimization"
    depends on CC_GCC_USE_LTO
    help
      Builds the libraries with -flto to enable more aggressive link time
      optimization. You will need to add -flto-partition=one to your
      application's link line to keep the RETURN assembler macro together
      with it's consumers.

config LIBC_NEWLIB_NANO_MALLOC
    bool
    prompt "Enable Nano Malloc"
    depends on NEWLIB_HAS_NANO_MALLOC
    help
      NEWLIB has two implementations of malloc family's functions, one in
      `mallocr.c' and the other one in `nano-mallocr.c'.  This options
      enables the nano-malloc implementation, which is for small systems
      with very limited memory.  Note that this implementation does not
      support `--enable-malloc-debugging' any more.

config LIBC_NEWLIB_NANO_FORMATTED_IO
    bool
    prompt "Enable Nano Formatted I/O"
    depends on NEWLIB_HAS_NANO_FORMATTED_IO
    help
      This builds NEWLIB with a special implementation of formatted I/O
      functions, designed to lower the size of application on small systems
      with size constraint issues.  This option does not affect wide-char
      formatted I/O functions.

config LIBC_NEWLIB_EXTRA_CONFIG_ARRAY
    string
    prompt "Extra config for newlib"
    default ""
    help
      Extra flags to pass onto ./configure when configuring the newlib.