Add default version aliases for ubuntu and fedora

This means you can just do:

 $ make kernel@ppc64le@ubuntu

or

 $ make kernel@ppc64le@fedora

To use the image with the latest version.

Author: mpe

build/Makefile

@@ -1,11 +1,15 @@
 all: help
 
-FEDORA_DISTROS := fedora@35 fedora@34 fedora@33 fedora@31
-UBUNTU_DISTROS := ubuntu@21.10 ubuntu@21.04 ubuntu@20.04 ubuntu@18.04 ubuntu@16.04
+export FEDORA_LATEST := 35
+export UBUNTU_LATEST := 21.10
+
+FEDORA_DISTROS := fedora@${FEDORA_LATEST} fedora@34 fedora@33 fedora@31 fedora
+UBUNTU_DISTROS := ubuntu@${UBUNTU_LATEST} ubuntu@21.04 ubuntu@20.04 ubuntu@18.04 ubuntu@16.04 ubuntu)
 KORG_DISTROS := korg@11.1.0 korg@10.3.0 korg@9.3.0 korg@8.1.0 korg@5.5.0
 ALL_DISTROS := ${UBUNTU_DISTROS} ${KORG_DISTROS} ${FEDORA_DISTROS}
-DOCS_DISTRO := docs@21.10
-X86_DISTRO := ubuntu@21.10
+DOCS_DISTRO := docs@${UBUNTU_LATEST}
+X86_DISTRO := ubuntu@${UBUNTU_LATEST}
+ALIAS_DISTROS := ubuntu fedora
 SUBARCHES := ppc64le ppc64 ppc
 
 VERSION:
@@ -34,7 +38,7 @@ kernel@${1}@${2}: image@${1}@${2}
 clean-kernel@${1}@${2}:
 	@./scripts/clean.sh $$@
 
-KERNEL += kernel@${1}@${2}
+KERNEL += $(if $(filter-out ${ALIAS_DISTROS},${2}), kernel@${1}@${2})
 endef
 
 define SELFTESTS_TEMPLATE =
@@ -44,8 +48,8 @@ ppctests@${1}@${2} selftests@${1}@${2}: image@${1}@${2}
 clean-selftests@${1}@${2}:
 	@./scripts/clean.sh $$@
 
-PPCTESTS += ppctests@${1}@${2}
-SELFTESTS += selftests@${1}@${2}
+PPCTESTS += $(if $(filter-out ${ALIAS_DISTROS},${2}), ppctests@${1}@${2})
+SELFTESTS += $(if $(filter-out ${ALIAS_DISTROS},${2}), selftests@${1}@${2})
 endef
 
 define PERF_TEMPLATE =
@@ -55,7 +59,7 @@ perf@${1}@${2}: image@${1}@${2}
 clean-perf@${1}@${2}:
 	@./scripts/clean.sh $$@
 
-PERF += perf@${1}@${2}
+PERF += $(if $(filter-out ${ALIAS_DISTROS},${2}), perf@${1}@${2})
 endef
 
 define DOCS_TEMPLATE =

build/scripts/build.sh

@@ -17,8 +17,6 @@ script_base="$(realpath "$dir")"
 
 IFS=@ read -r task subarch distro version <<< "$1"
 
-image="docker.io/linuxppc/build:$distro-$version"
-
 SRC="${SRC/#\~/$HOME}"
 SRC=$(realpath "$SRC")
 
@@ -148,6 +146,13 @@ fi
 
 cmd+="$PODMAN_OPTS "
 
+if [[ -z "$version" ]]; then
+    # NB, after we passed $version to get_output_dir()
+    version=$(get_default_version $distro)
+fi
+
+image="docker.io/linuxppc/build:$distro-$version"
+
 cmd+="$image "
 cmd+="/bin/container-build.sh $task"
 

build/scripts/image.sh

@@ -11,6 +11,10 @@ script_base="$(realpath "$dir")"
 
 IFS=@ read -r task subarch distro version <<< "$1"
 
+if [[ -z "$version" ]]; then
+    version=$(get_default_version $distro)
+fi
+
 image="docker.io/linuxppc/build:$distro-$version"
 
 if [[ "$task" == "image" ]]; then

build/scripts/lib.sh

@@ -27,15 +27,19 @@ function get_output_dir()
     local clang="$8"
     local d
 
-    if [[ -z "$script_base" || -z "$subarch" || -z "$distro" || -z "$version" ]]; then
+    if [[ -z "$script_base" || -z "$subarch" || -z "$distro" ]]; then
         echo "Error: not enough arguments to get_output_dir()" >&2
         return 1
     fi
 
     if [[ -n "$CI_OUTPUT" ]]; then
-        d="$CI_OUTPUT/$subarch@$distro@$version"
+        d="$CI_OUTPUT/$subarch@$distro"
     else
-        d="$script_base/../output/$subarch@$distro@$version"
+        d="$script_base/../output/$subarch@$distro"
+    fi
+
+    if [[ -n "$version" ]]; then
+        d="$d@$version"
     fi
 
     case "$task" in
@@ -72,6 +76,26 @@ function get_output_dir()
     return 0
 }
 
+function get_default_version()
+{
+    local distro="$1"
+    local latest
+
+    case "$distro" in
+        ubuntu) latest="$UBUNTU_LATEST" ;;
+        fedora) latest="$FEDORA_LATEST" ;;
+    esac
+
+    if [[ -z "$latest" ]]; then
+        echo "Error: No default version for $distro" >&2
+        return 1
+    fi
+
+    echo "$latest"
+
+    return 0
+}
+
 podman --version > /dev/null
 if [[ $? -eq 0 ]]; then
     DOCKER="podman"