implement version: latest for gcc, intel and lfortran, fixes #136 and #33 (#137)

Implementation of version: latest parsing, fixes #136 and #33

version: latest is now default for gcc and lfortran installations (since they use package managers) while also defaults to the latest "known" version for intel if explicitly specified in the workflow, e.g.

  - uses: fortran-lang/setup-fortran@v1
     with:
       compiler: intel
       version: latest

If the version option is not explicitly specified, the updated defaults are now:

gcc: latest
lfortran: latest
intel-classic: 2023.2.0 (pinned)
intel: 2025.0 (pinned)
nvidia-hpc: 25.1 (pinned)

The main changes to the logic are:

    install_gcc_brew: Uses brew install gcc without version pinning for version: latest
    install_gcc_apt: Installs gcc gfortran g++ without version pinning for version: latest
    install_gcc_choco: Install unpinned gcc via choco install for version: latest
    install_intel_apt: Installs last known version of Intel packages when version: latest, but only if version: latest explicitly specified
    install_lfortran_*: All platforms install unpinned lfortran when latest

Note that the Cache key in action.yml uses ${{ inputs.version || 'latest' }} instead of just ${{ inputs.version }}. This ensures that when no version is specified, it defaults to 'latest' in the cache key. This should prevent cache conflicts between different "latest" installs.

Author: danieljprice

action.yml

@@ -44,7 +44,7 @@ runs:
       uses: actions/cache/restore@v3
       with:
         path: ${{ env.ONEAPI_ROOT }}
-        key: ${{ runner.os }}-${{ inputs.compiler }}-${{ inputs.version }}-${{ steps.get-date.outputs.date }}
+        key: ${{ runner.os }}-${{ inputs.compiler }}-${{ inputs.version || 'latest' }}-${{ steps.get-date.outputs.date }}
 
     # Use micromamba for lfortran install on mac. Check if micromamba already
     # exists, only install it if needed. If we install it, clean it up after.
@@ -88,7 +88,7 @@ runs:
       uses: actions/cache/save@v3
       with:
         path: ${{ env.ONEAPI_ROOT }}
-        key: ${{ runner.os }}-${{ inputs.compiler }}-${{ inputs.version }}-${{ steps.get-date.outputs.date }}
+        key: ${{ runner.os }}-${{ inputs.compiler }}-${{ inputs.version || 'latest' }}-${{ steps.get-date.outputs.date }}
     - name: Activate oneAPI
       if: runner.os == 'Windows' && contains(inputs.compiler, 'intel')
       shell: cmd

main.sh

@@ -13,7 +13,7 @@ source ./setup-fortran.sh
 
 case $compiler in
   gcc)
-    version=${VERSION:-13}
+    version=${VERSION:-latest}
     install_gcc $platform
     ;;
   intel-classic)
@@ -29,7 +29,7 @@ case $compiler in
     install_nvidiahpc $platform
     ;;
   lfortran)
-    version=${VERSION:-0.45.0}
+    version=${VERSION:-latest}
     install_lfortran $platform
     ;;
   *)

setup-fortran.sh

@@ -27,49 +27,61 @@ install_environment_modules_apt() {
 
 install_gcc_brew()
 {
-  brew install --force gcc@${version}
+  if [[ "$version" == "latest" ]]; then
+    brew install --force gcc
+    # detect installed version using homebrew
+    gcc_version=$(brew list --versions gcc | grep -o '[0-9]\+' | head -1)
+  else
+    brew install --force gcc@${version}
+    gcc_version=$version
+  fi
 
   # make an unversioned symlink
   os_ver=$(sw_vers -productVersion | cut -d'.' -f1)
   if (( "$os_ver" > 13 )); then
     # default homebrew bin dir changed with macos 14
-    ln -fs /opt/homebrew/bin/gfortran-${version} /usr/local/bin/gfortran
-    ln -fs /opt/homebrew/bin/gcc-${version} /usr/local/bin/gcc
-    ln -fs /opt/homebrew/bin/g++-${version} /usr/local/bin/g++
+    bindir=/opt/homebrew/bin
   else
-    ln -fs /usr/local/bin/gfortran-${version} /usr/local/bin/gfortran
-    ln -fs /usr/local/bin/gcc-${version} /usr/local/bin/gcc
-    ln -fs /usr/local/bin/g++-${version} /usr/local/bin/g++
+    bindir=/usr/local/bin
   fi
+
+  ln -fs ${bindir}/gfortran-${gcc_version} /usr/local/bin/gfortran
+  ln -fs ${bindir}/gcc-${gcc_version} /usr/local/bin/gcc
+  ln -fs ${bindir}/g++-${gcc_version} /usr/local/bin/g++
 }
 
 install_gcc_apt()
 {
-  # Check whether the system gcc version is the version we are after.
-  cur=$(apt show gcc | grep "Version" | cut -d':' -f3 | cut -d'-' -f1)
-  maj=$(echo $cur | cut -d'.' -f1)
-  needs_install=1
-  if [ "$maj" == "$version" ]; then
-    # Check whether that version is installed.
-    if apt list --installed gcc-${version} | grep -q "gcc-${version}/"; then
-      echo "GCC $version already installed"
-      needs_install=0
-    fi
-  else
-    # Install the PPA for installing other versions of gcc.
-    sudo add-apt-repository --yes ppa:ubuntu-toolchain-r/test
+  if [ "$version" == "latest" ]; then
     sudo apt-get update
-  fi
+    sudo apt-get install -y gcc gfortran g++
+  else
+    # Check whether the system gcc version is the version we are after.
+    cur=$(apt show gcc | grep "Version" | cut -d':' -f3 | cut -d'-' -f1)
+    maj=$(echo $cur | cut -d'.' -f1)
+    needs_install=1
+    if [ "$maj" == "$version" ]; then
+      # Check whether that version is installed.
+      if apt list --installed gcc-${version} | grep -q "gcc-${version}/"; then
+        echo "GCC $version already installed"
+        needs_install=0
+      fi
+    else
+      # Install the PPA for installing other versions of gcc.
+      sudo add-apt-repository --yes ppa:ubuntu-toolchain-r/test
+      sudo apt-get update
+    fi
 
-  if [ "${needs_install}" == "1" ]; then
-    sudo apt-get install -y gcc-${version} gfortran-${version} g++-${version}
-  fi
+    if [ "${needs_install}" == "1" ]; then
+      sudo apt-get install -y gcc-${version} gfortran-${version} g++-${version}
+    fi
 
-  sudo update-alternatives \
-    --install /usr/bin/gcc gcc /usr/bin/gcc-${version} 100 \
-    --slave /usr/bin/gfortran gfortran /usr/bin/gfortran-${version} \
-    --slave /usr/bin/gcov gcov /usr/bin/gcov-${version} \
-    --slave /usr/bin/g++ g++ /usr/bin/g++-${version}
+    sudo update-alternatives \
+      --install /usr/bin/gcc gcc /usr/bin/gcc-${version} 100 \
+      --slave /usr/bin/gfortran gfortran /usr/bin/gfortran-${version} \
+      --slave /usr/bin/gcov gcov /usr/bin/gcov-${version} \
+      --slave /usr/bin/g++ g++ /usr/bin/g++-${version}
+  fi
 }
 
 install_gcc_choco()
@@ -88,8 +100,12 @@ install_gcc_choco()
     mv /c/mingw64 "$RUNNER_TEMP/"
     # ...and install selected version
     case $version in
-      13)
-        choco install mingw --version 13.2.0 --force
+      latest|13)
+        if [ "$version" == "latest" ]; then
+          choco install mingw --force
+        else
+          choco install mingw --version 13.2.0 --force
+        fi
         # mingw 13 on Windows doesn't create shims (http://disq.us/p/2w5c5tj)
         # so hide Strawberry compilers and manually add mingw bin dir to PATH
         mkdir "$RUNNER_TEMP/strawberry"
@@ -114,7 +130,7 @@ install_gcc_choco()
         choco install mingw --version 8.5.0 --force
         ;;
       *)
-        echo "Unsupported version: $version (choose 8-13)"
+        echo "Unsupported version: $version (choose 8-13 or latest)"
         exit 1
         ;;
     esac
@@ -345,7 +361,9 @@ install_intel_apt()
 {
   local version=$1
   local classic=$2
-  intel_version_map_l $version $classic
+  if [ "$version" != "latest" ]; then
+    intel_version_map_l $version $classic
+  fi
 
   require_fetch
   local _KEY="GPG-PUB-KEY-INTEL-SW-PRODUCTS.PUB"
@@ -356,17 +374,23 @@ install_intel_apt()
     | sudo tee /etc/apt/sources.list.d/oneAPI.list
   sudo apt-get update
 
-  # c/cpp compiler package names changed with 2024+
-  case $version in
-    2024* | 2025*)
-      sudo apt-get install -y \
-        intel-oneapi-compiler-{fortran,dpcpp-cpp}-$version
-      ;;
-    *)
-      sudo apt-get install -y \
-        intel-oneapi-compiler-{fortran,dpcpp-cpp-and-cpp-classic}-$version
-      ;;
-  esac
+  if [ "$version" == "latest" ]; then
+    sudo apt-get install -y \
+      intel-oneapi-compiler-fortran \
+      intel-oneapi-compiler-dpcpp-cpp
+  else
+    # c/cpp compiler package names changed with 2024+
+    case $version in
+      2024* | 2025*)
+        sudo apt-get install -y \
+          intel-oneapi-compiler-{fortran,dpcpp-cpp}-$version
+        ;;
+      *)
+        sudo apt-get install -y \
+          intel-oneapi-compiler-{fortran,dpcpp-cpp-and-cpp-classic}-$version
+        ;;
+    esac
+  fi
 
   source /opt/intel/oneapi/setvars.sh
   export_intel_vars
@@ -623,7 +647,11 @@ install_lfortran_l()
   export CC="gcc"
   export CXX="g++"
   export CONDA=conda
-  $CONDA install -c conda-forge -n base -y lfortran=$version
+  if [ "$version" == "latest" ]; then
+    $CONDA install -c conda-forge -n base -y lfortran
+  else
+    $CONDA install -c conda-forge -n base -y lfortran=$version
+  fi
 }
 
 install_lfortran_w()
@@ -632,7 +660,11 @@ install_lfortran_w()
   export CC="cl"
   export CXX="cl"
   export CONDA=$CONDA\\Scripts\\conda  # https://github.com/actions/runner-images/blob/main/images/windows/Windows2022-Readme.md#environment-variables
-  $CONDA install -c conda-forge -n base -y lfortran=$version
+  if [ "$version" == "latest" ]; then
+    $CONDA install -c conda-forge -n base -y lfortran
+  else
+    $CONDA install -c conda-forge -n base -y lfortran=$version
+  fi
 }
 
 install_lfortran_m()
@@ -642,7 +674,11 @@ install_lfortran_m()
   export CXX="g++"
   export CONDA_ROOT_PREFIX=$MAMBA_ROOT_PREFIX
   export CONDA=micromamba
-  $CONDA install -c conda-forge -n base -y lfortran=$version
+  if [ "$version" == "latest" ]; then
+    $CONDA install -c conda-forge -n base -y lfortran
+  else
+    $CONDA install -c conda-forge -n base -y lfortran=$version
+  fi
 }
 
 install_lfortran()