Bootstrap the cxx frontend in the CI.

.github/workflows/ci.yml

@@ -31,6 +31,11 @@ jobs:
         run: |
           ctest --output-on-failure
 
+      - name: the cxx frontend
+        run: |
+          npm ci --ignore-scripts
+          node scripts/bootstrap.js --cxx=build/src/frontend/cxx --syntax-only
+
   build-linux-mlir:
     runs-on: ubuntu-26.04
 
@@ -39,10 +44,11 @@ jobs:
 
       - name: Install LLVM and MLIR deps
         run: |
-          sudo apt-get install -y libmlir-22-dev mlir-22-tools
+          sudo apt-get install -y libmlir-22-dev mlir-22-tools liblld-22-dev
 
       - name: Install unit tests requirements
         run: |
+          npm ci --ignore-scripts
           pipx install uv
           uv sync
 
@@ -61,6 +67,10 @@ jobs:
         run: |
           ctest --output-on-failure
 
+      - name: Bootstrap the cxx frontend
+        run: |
+          node scripts/bootstrap.js --cxx=build/src/frontend/cxx
+
   build-windows:
     runs-on: windows-latest
 

packages/cxx-gen-ast/README.md

@@ -2,18 +2,13 @@
 
 Source-driven compiler code generation and read-only JavaScript reflection.
 
-`npm run cxx-gen-ast` refreshes `semantic-model.json` from the built JavaScript
-frontend and then generates AST support and semantic wrappers from it, so a
-change to a declaration in `src/parser/cxx/` reaches the generated code in one
-step. The snapshot is generated, not checked in: when the frontend has not been
-built the generator reuses the snapshot it finds and says so, and fails with
-what to build when there is none. `--no-refresh` keeps it on purpose.
-`npm run cxx-gen-model` uses the same snapshot for persistence. Neither command
-extracts declarations from `ast.h`.
+`npm run cxx-gen-ast` refreshes the semantic model, the AST supporting code, and the TypeScript API.
 
-`npm run cxx-dump-model` prints the model, `--write` refreshes the snapshot
-alone, and `--check` verifies it is current.
+`npm run cxx-dump-model` prints the model, `--write` refreshes the snapshot, and `--check` verifies it is current.
 
-See [the semantic API design](../../docs/design/semantic-api.md) for build
-steps, ownership, and coverage. Run generator tests with
-`npm test -w @robertoraggi/cxx-gen-ast`.
+The cxx-gen-ast requires cxx-frontend, it is a bit of a circular dependency, build it with:
+
+```bash
+npm ci
+npm run build:cxx-frontend
+```

scripts/bootstrap.js

@@ -96,7 +96,6 @@ const cxx = argv.cxx ? path.resolve(String(argv.cxx)) : await which("cxx");
 
 const compileFlags = [
   `-std=${std}`,
-  "-c",
   opt,
   ...includePaths.flatMap((dir) => ["-I", dir]),
   "-D_WASI_EMULATED_MMAN",
@@ -151,9 +150,13 @@ async function compile(sources) {
   }
 
   await runPool(sources, async (source) => {
-    const output = syntaxOnly ? "/dev/null" : objectFileFor(source);
     try {
-      await $`${cxx} ${compileFlags} ${source} -o ${output}`;
+      if (syntaxOnly) {
+        await $`${cxx} -fsyntax-only ${compileFlags} ${source}`;
+      } else {
+        const output = objectFileFor(source);
+        await $`${cxx} -c ${compileFlags} ${source} -o ${output}`;
+      }
       echo(chalk.green(`[${++done}/${sources.length}] compiled ${source}`));
     } catch (error) {
       ++done;