[2/5] libc/musl: Add options for optimization

This commit adds configuration knobs for optimizing musl-libc.

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
---
 config/libc/musl.in.2      | 32 ++++++++++++++++++++++++++++++++
 scripts/build/libc/musl.sh | 14 +++++++++++++-
 2 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 config/libc/musl.in.2

Bryan, All,

On 2014-09-04 13:56 -0700, Bryan Hundven spake thusly:
> This commit adds configuration knobs for optimizing musl-libc.
> 
> Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
> ---
>  config/libc/musl.in.2      | 32 ++++++++++++++++++++++++++++++++
>  scripts/build/libc/musl.sh | 14 +++++++++++++-
>  2 files changed, 45 insertions(+), 1 deletion(-)
>  create mode 100644 config/libc/musl.in.2
> 
> diff --git a/config/libc/musl.in.2 b/config/libc/musl.in.2
> new file mode 100644
> index 0000000..42f45e1
> --- /dev/null
> +++ b/config/libc/musl.in.2
> @@ -0,0 +1,32 @@
> +# musl second-part option
> +
> +choice
> +    prompt "How to optimize musl-libc"
> +    default LIBC_MUSL_OPTIMIZE_AUTO
> +
> +config LIBC_MUSL_OPTIMIZE_NONE
> +    bool
> +    prompt "Do not optimize musl-libc"
> +    help
> +      This option sets `--optimize=no'
> +
> +config LIBC_MUSL_OPTIMIZE_AUTO
> +    bool
> +    prompt "Optimize musl-libc based CFLAGS passed"

Wrong prompt (as already seen on IRC).

> +    help
> +      This option allows musl-libc's ./configure script to automatically
> +      set the optimization.
> +
> +config LIBC_MUSL_OPTIMIZE_SPEED
> +    bool
> +    prompt "Optimize musl-libc for speed"
> +    help
> +      This option sets `--optimize=yes'

"Speed" vs. "yes"  <-- correct?

> +config LIBC_MUSL_OPTIMIZE_SIZE
> +    bool
> +    prompt "Optimize musl-libc for size"
> +    help
> +      This option sets `--optimize=size'
> +
> +endchoice

What about adding:

    config LIBC_MUSL_OPTIMIZE
        string
        default "no"   if LIBC_MUSL_OPTIMIZE_NONE
        default "auto" if LIBC_MUSL_OPTIMIZE_AUTO
        default "yes"  if LIBC_MUSL_OPTIMIZE_SPEED
        default "size" if LIBC_MUSL_OPTIMIZE_SIZE

And then...  [1]

> diff --git a/scripts/build/libc/musl.sh b/scripts/build/libc/musl.sh
> index 6dbf657..bd7ae2a 100644
> --- a/scripts/build/libc/musl.sh
> +++ b/scripts/build/libc/musl.sh
> @@ -37,6 +37,7 @@ do_libc_check_config() {
>  do_libc_configure() {
>      CT_DoLog EXTRA "Configuring C library"
>      local -a extra_cflags
> +    local -a extra_conf

extra_config  [0]

>      # From buildroot:
>      # gcc constant folding bug with weak aliases workaround
> @@ -45,6 +46,16 @@ do_libc_configure() {
>          extra_cflags+=("-fno-toplevel-reorder")
>      fi
>  
> +    if [ "${CT_LIBC_MUSL_OPTIMIZE_NONE}" = "y" ]; then
> +        extra_conf+=("--optimize=no")
> +    elif [ "${CT_LIBC_MUSL_OPTIMIZE_AUTO}" = "y" ]; then
> +        extra_conf+=("--optimize=auto")
> +    elif [ "${CT_LIBC_MUSL_OPTIMIZE_SPEED}" = "y" ]; then
> +        extra_conf+=("--optimize=yes")
> +    elif [ "${CT_LIBC_MUSL_OPTIMIZE_SIZE}" = "y" ]; then
> +        extra_conf+=("--optimize=size")
> +    fi

[1] use it here instead of all the if-else blocks:
    extra_config+=( "--optimize=${CT_LIBC_MUSL_OPTIMIZE}" )

>      # NOTE: musl handles the build/host/target a little bit differently
>      # then one would expect:
>      #   build   : not used
> @@ -56,7 +67,8 @@ do_libc_configure() {
>      ./configure                     \
>          --host="${CT_TARGET}"       \
>          --target="${CT_TARGET}"     \
> -        --prefix="/usr"
> +        --prefix="/usr"             \
> +        "${extra_config[@]}"

[0] Because that's what you're using here (and we are using everywhere
else, too.)

Regards,
Yann E. MORIN.

>  }
>  
>  do_libc_start_files() {
> -- 
> 2.1.0
>