Keep Lua class field lifetime semantics aligned with Jass (#1276)

Author: Frotty

.github/workflows/build.yml

@@ -11,27 +11,15 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  # Emit a wider matrix on master pushes (adds macOS), narrow on PRs (saves minutes)
-  setup:
-    runs-on: ubuntu-latest
-    outputs:
-      matrix: ${{ steps.set-matrix.outputs.matrix }}
-    steps:
-      - id: set-matrix
-        shell: bash
-        run: |
-          if [[ "${{ github.event_name }}" == "push" ]]; then
-            echo 'matrix={"include":[{"os":"ubuntu-latest"},{"os":"windows-latest"},{"os":"macos-latest"},{"os":"macos-15-intel"}]}' >> "$GITHUB_OUTPUT"
-          else
-            echo 'matrix={"include":[{"os":"ubuntu-latest"},{"os":"windows-latest"}]}' >> "$GITHUB_OUTPUT"
-          fi
-
+  # Master pushes exercise every supported host. Pull requests use one Linux job
+  # so that the normal feedback loop does not spend four runner-minutes on the
+  # same compiler test suite; the full host matrix still runs before release.
   build:
     name: Gradle build on ${{ matrix.os }}
-    needs: setup
     strategy:
       fail-fast: false
-      matrix: ${{ fromJson(needs.setup.outputs.matrix) }}
+      matrix:
+        os: ${{ fromJSON(github.event_name == 'push' && '["ubuntu-latest","windows-latest","macos-latest","macos-15-intel"]' || '["ubuntu-latest"]') }}
     runs-on: ${{ matrix.os }}
     permissions:
       checks: write
@@ -96,18 +84,28 @@ jobs:
       - name: Setup Gradle (cache)
         uses: gradle/actions/setup-gradle@v4
 
-      # ---- FAIL FAST: package first (so jlink issues show immediately) ----
+      # Packaging is a release artifact, not a pull-request gate. Keeping it on
+      # master avoids paying for a second full build on every PR update.
       - name: Package slim runtime (fail fast)
+        if: github.event_name == 'push'
         shell: bash
         run: ./gradlew packageSlimCompilerDist --no-daemon --stacktrace
 
       - name: Prepare bundled Lua runtime (Linux)
         if: runner.os == 'Linux'
         shell: bash
         run: |
-          if [[ -f src/test/resources/lua53 ]]; then
-            chmod +x src/test/resources/lua53
-          fi
+          set -euo pipefail
+          # Use Ubuntu's maintained Lua 5.3 build. The checked-in portable
+          # binary is linked against libreadline.so.6, which is absent from
+          # current runner images.
+          sudo apt-get update -qq
+          sudo apt-get install -y --no-install-recommends lua5.3
+          lua5.3 -e 'assert(_VERSION == "Lua 5.3")'
+          luac5.3 -v
+          # These binaries are tracked with mode 0644 for cross-platform
+          # checkouts; keep them usable as a fallback for local/older images.
+          chmod +x src/test/resources/lua53 src/test/resources/luac53
 
       - name: Install Lua compiler (macOS)
         if: runner.os == 'macOS'
@@ -119,14 +117,14 @@ jobs:
       - name: Run tests
         shell: bash
         run: |
-          if [[ "${{ runner.os }}" == "Linux" ]]; then
+          if [[ "${{ github.event_name }}" == "push" && "${{ runner.os }}" == "Linux" ]]; then
             ./gradlew test jacocoTestReport --no-daemon --stacktrace --quiet
           else
             ./gradlew test --no-daemon --stacktrace --quiet
           fi
 
       - name: Upload coverage to Coveralls
-        if: runner.os == 'Linux'
+        if: github.event_name == 'push' && runner.os == 'Linux'
         uses: coverallsapp/github-action@v2
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -157,6 +155,7 @@ jobs:
           retention-days: 14
 
       - name: Upload packaged artifact (per-OS)
+        if: github.event_name == 'push'
         uses: actions/upload-artifact@v4
         with:
           name: wurst-compiler-${{ matrix.os }}

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/translation/lua/translation/LuaTranslator.java

@@ -207,8 +207,9 @@ public LuaVariable initFor(ImClass a) {
      * per canonical IM field, indexed by that id; class descriptors remain static tables and are
      * reached through {@link #objectClass}. Allocation therefore creates no per-instance table.
      *
-     * <p>Destroy clears every field slot before putting the id on the free stack. As in the Jass
-     * backend, a stale reference aliases a later object after that id is recycled; before reuse its
+     * <p>Destroy only removes the live-object descriptor before putting the id on the free stack.
+     * Field storage intentionally retains its value, matching the Jass backend's array-backed
+     * fields. A stale reference aliases a later object after that id is recycled; before reuse its
      * descriptor is absent, so virtual dispatch fails and {@code instanceof} is false. Capturing
      * closures use the same representation and, like Jass closures, retain their id until destroyed.
      */
@@ -1031,12 +1032,6 @@ private void translateClass(ImClass c) {
         LuaFunction cleanup = luaClassCleanup.getFor(c);
         LuaVariable object = LuaAst.LuaVariable("object", LuaAst.LuaNoExpr());
         cleanup.getParams().add(object);
-        for (ImVar field : collectFieldsForAllocation(c)) {
-            cleanup.getBody().add(LuaAst.LuaAssignment(
-                LuaAst.LuaExprArrayAccess(LuaAst.LuaExprVarAccess(fieldStorage(field)),
-                    LuaAst.LuaExprlist(LuaAst.LuaExprVarAccess(object))),
-                LuaAst.LuaExprNull()));
-        }
         luaModel.add(cleanup);
         deferMainInit(LuaAst.LuaAssignment(
             LuaAst.LuaExprFieldAccess(LuaAst.LuaExprVarAccess(classVar), "__wurst_dealloc"),