[Mesa-dev] [PATCH v4 17/18] configure.ac: Only add default LLVM components if needed

[Emil Velikov]

On 16 October 2016 at 01:20, Tobias Droste <tdroste at gmx.de> wrote:
> LLVM components are only added when LLVM is needed.
> This means gallium adds this as soon as "--enable-gallium-llvm"
> is "yes" and radv + opencl add it explicitly.
>
> This slightly changes the "auto" value of "--enable-gallium-llvm":
> If no LLVM is installed, it is set to "no". If later drivers need
> this they get the error message that "--enable-gallium-llvm" is
> needed.
> This way if someone is only building softpipe he doesn't need to
> specify "--disable-gallium-llvm" and doesn't have to have LLVM
> installed.
>
> Signed-off-by: Tobias Droste <tdroste at gmx.de>
> ---
>  configure.ac | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/configure.ac b/configure.ac
> index bbc1cb5..9e7130ad 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -897,7 +897,11 @@ llvm_add_component() {
>      new_llvm_component=$1
>      driver_name=$2
>
> -    LLVM_COMPONENTS="$LLVM_COMPONENTS $new_llvm_component"
> +    if $LLVM_CONFIG --components | grep -iqw $new_llvm_component ; then
> +        LLVM_COMPONENTS="${LLVM_COMPONENTS} ${new_llvm_component}"
> +    else
> +        AC_MSG_ERROR([LLVM component '$new_llvm_component' not enabled in your LLVM build. Required by $driver_name.])
> +    fi
>  }
>
>  llvm_add_default_components() {
> @@ -980,8 +984,6 @@ llvm_set_environment_variables() {
>              LLVM_VERSION_INT=`echo $LLVM_VERSION | sed -e 's/\([[0-9]]\)\.\([[0-9]]\)/\10\2/g'`
>          fi
>
> -        llvm_add_default_components "gallium"
> -
>          DEFINES="${DEFINES} -DHAVE_LLVM=0x0$LLVM_VERSION_INT -DMESA_LLVM_VERSION_PATCH=$LLVM_VERSION_PATCH"
>          MESA_LLVM=1
>      else
> @@ -1007,6 +1009,7 @@ radeon_llvm_check() {
>
>      llvm_add_target $amdgpu_llvm_target_name $4
>
> +    llvm_add_default_components $4
>      llvm_add_component "bitreader" $4
>      llvm_add_component "ipo" $4
>
> @@ -2175,6 +2178,7 @@ if test "x$enable_opencl" = xyes; then
>
>      llvm_check_version_for "3" "6" "0" "opencl"
>
> +    llvm_add_default_components "opencl"
>      llvm_add_component "all-targets" "opencl"
>      llvm_add_component "linker" "opencl"
>      llvm_add_component "instrumentation" "opencl"
> @@ -2322,9 +2326,18 @@ if test -z "$with_gallium_drivers"; then
>  fi
>  if test "x$enable_gallium_llvm" = xauto; then
>      case "$host_cpu" in
> -    i*86|x86_64|amd64) enable_gallium_llvm=yes;;
> +    i*86|x86_64|amd64)
> +        if test "x$MESA_LLVM" = "x1"; then
> +            enable_gallium_llvm=yes
> +        else
> +            enable_gallium_llvm=no
> +        fi
This won't work as expected I'm afraid.

For example: if we've failed during the autodetection of llvm,
MESA_LLVM will be 0, thus instead of enabling enable_gallium_llvm [on
supported platforms] and error-ing out you'll get a silent disable.
The latter of which is not what the llvmpipe/r300 folk would
appreciate.

-Emil