ci: add offline c++ lifter syntax checking

.github/workflows/opam.yml

@@ -3,9 +3,9 @@ name: Build with opam
 on:
   push:
     branches: [ partial_eval ]
-    paths: [ '*.opam', '.github/**' ]
+    paths: [ '*.opam', '.github/workflows/opam.yml' ]
   pull_request:
-    paths: [ '*.opam', '.github/**' ]
+    paths: [ '*.opam', '.github/workflows/opam.yml' ]
   workflow_dispatch:
 
 # only run one instance of this action at a time.

.github/workflows/test.yml

@@ -58,3 +58,26 @@ jobs:
     - run: dune build offlineASL -j4
 
     - run: dune build @offline-coverage -j4
+
+  offline-cpp:
+    runs-on: ubuntu-24.04
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - uses: cachix/install-nix-action@v25
+    - run: echo 'preparing nix shell environment'
+
+    - uses: actions/setup-python@v5
+      with:
+        python-version: '3.11'
+
+    - run: python -m pip install 'meson~=1.4.0' 'ninja'
+
+    - run: dune build --profile release
+    - run: echo ':gen A64 .* cpp' | OCAMLRUNPARAM=b dune exec asli
+
+    - run: LLVM_CONFIG=$(which llvm-config-17) offlineASL-cpp/check.py
+
+    - name: 'syntax check generated C++ lifter'
+      run: meson compile -C offlineASL-cpp/build

offlineASL-cpp/subprojects/aslp-lifter-llvm/meson.build

@@ -3,7 +3,7 @@ project('aslp-lifter-llvm', 'cpp',
   default_options : [ 'warning_level=3', 'cpp_std=c++20' ])
 
 version = meson.project_version()
-llvm_dep = dependency('llvm', version: ['>=17', '<18'])
+llvm_dep = dependency('llvm', version: ['>=16', '<18'])
 empty_dep = dependency('', required: false)
 
 lifter_dep = dependency('aslp-lifter', version: version, fallback: ['aslp-lifter', 'gen_dep'])