CI: Test GitHub Actions support

.github/workflows/main.yml

@@ -0,0 +1,47 @@
+# https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions
+
+name: Main
+on:
+  - push # branch or tag
+
+jobs:
+  linux:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - job_name: ubuntu-x86_64 (testsuite)
+            target: x86_64-linux-gnu
+          - job_name: ubuntu-x86_64 (unittests)
+            target: x86_64-linux-gnu
+          - job_name: ubuntu-arm
+            target: arm-linux-gnueabi
+          #- job_name: ubuntu-armhf
+          #  target: arm-linux-gnueabihf
+          - job_name: ubuntu-aarch64
+            target: aarch64-linux-gnu
+          - job_name: ubuntu-mips
+            target: mips-linux-gnu
+          - job_name: ubuntu-mips64el
+            target: mips64el-linux-gnuabi64
+          - job_name: ubuntu-mipsel
+            target: mipsel-linux-gnu
+    name: ${{ matrix.job_name }}
+    runs-on: ubuntu-22.04
+    env:
+      GCC_CI_TARGET: ${{ matrix.target }}
+      GCC_CI_BOOTSTRAP: ${{ matrix.bootstrap || false }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 10
+      - name: Install dependencies
+        run: ./buildci.sh installdeps
+      - name: Configure gdc
+        run: ./buildci.sh configure
+      - name: Build gdc
+        run: ./buildci.sh build
+      - name: Run testsuite
+        run: ${{ contains(matrix.job_name, 'testsuite') && './buildci.sh testsuite' || 'echo disabled' }}
+      - name: Run unittests
+        run: ${{ contains(matrix.job_name, 'unittests') && './buildci.sh unittests' || 'echo disabled' }}

buildci.sh

@@ -1,20 +1,16 @@
 #!/bin/bash
-# This script is intended to be ran on SemaphoreCI or Buildkite platform.
-# Following environmental variables are assumed to be exported on SemaphoreCI.
+# This script is intended to be ran on platform on GitHub Action
+# Other CI platforms in this script are legacy and only kept around to keep
+# the modularity of this script in check.
 #
-# - SEMAPHORE_PROJECT_DIR
-# - SEMAPHORE_CACHE_DIR
+# Following environmental variables are assume to be exported on GitHub Actions.
 #
-# See https://semaphoreci.com/docs/available-environment-variables.html
+# - RUNNER_TOOL_CACHE
+# - RUNNER_OS
+# - GCC_CI_TARGET
+# - GCC_CI_BOOTSTRAP
 #
-# Following environmental variables are assumed to be exported on Buildkite.
-#
-# - BUILDKITE_CACHE_DIR
-# - BUILDKITE_OS
-# - BUILDKITE_TARGET
-# - BUILDKITE_BOOTSTRAP
-#
-# See https://buildkite.com/docs/builds/environment-variables
+# See https://docs.github.com/en/actions/learn-github-actions/variables#default-environment-variables
 #
 ## Top-level build system configration.
 gcc_prereqs="gmp-6.1.0.tar.bz2 mpfr-3.1.6.tar.bz2 mpc-1.0.3.tar.gz isl-0.18.tar.bz2"
@@ -127,6 +123,21 @@ environment() {
         build_target_canonical=${build_host_canonical}
         make_flags="-j$(nproc)"
         build_bootstrap="disable"
+    elif [ "${CI}" = "true" ]; then
+        export CC="gcc"
+        export CXX="g++"
+        export GDC="gdc"
+        gcc_prereqs=""
+        project_dir=${PWD}
+        cache_dir=${RUNNER_TOOL_CACHE}
+        log_dir=${PWD}/logs
+        mkdir -p ${log_dir}
+        make_flags="-j$(nproc)"
+        build_host=$($CC -dumpmachine)
+        build_host_canonical=$(${project_dir}/config.sub ${build_host})
+        build_target=${GCC_CI_TARGET}
+        build_target_canonical=$(${project_dir}/config.sub ${build_target})
+        build_bootstrap=${GCC_CI_BOOTSTRAP}
     else
         echo "Unhandled CI environment"
         exit 1
@@ -296,6 +307,36 @@ installdeps() {
             echo "Unhandled CI environment"
             exit 1
         fi
+    elif [ "${CI}" = "true" ]; then
+        if [ "${RUNNER_OS}" = "Linux" ]; then
+            case ${GCC_CI_TARGET} in
+                arm*-*-*eabi)
+                    install_packages="binutils-arm-linux-gnueabi libc6-dev-armel-cross"
+                    ;;
+                aarch64-*-*)
+                    install_packages="binutils-aarch64-linux-gnu libc6-dev-arm64-cross"
+                    ;;
+                mips-*-*)
+                    install_packages="binutils-mips-linux-gnu libc6-dev-mips-cross"
+                    ;;
+		mips64el-*-*)
+                    install_packages="binutils-mips64el-linux-gnuabi64 libc6-dev-mips64el-cross"
+                    ;;
+                mipsel-*-*)
+                    install_packages="binutils-mipsel-linux-gnu libc6-dev-mipsel-cross"
+                    ;;
+                *)
+                    install_packages="binutils libc6-dev"
+                    ;;
+            esac
+            sudo apt-get update -qq
+            sudo apt-get install -qq gcc g++ gdc ${install_packages} \
+                autogen autoconf automake dejagnu patch \
+                libcurl4-gnutls-dev libgmp-dev libisl-dev libmpc-dev libmpfr-dev || exit 1
+        else
+            echo "Unhandled CI environment"
+            exit 1
+        fi
     else
         echo "Unhandled CI environment"
         exit 1