scanner: disable printing for WASM

WASM builds does not expose symbols for printing. As such, settle for
simply crashing.

Also add WASM build step to CI to verify that it can be built.

.github/workflows/ci.yml

@@ -93,12 +93,34 @@ jobs:
         with:
           command: build
 
+  wasm:
+    needs: [generate]
+    runs-on: ubuntu-latest
+    name: Run WASM test build
+    steps:
+      - uses: actions/checkout@v4
+      - name: Download generated parser
+        uses: actions/download-artifact@v4
+        with:
+          name: parser
+          path: src/
+      - name: Setup NodeJS
+        uses: actions/setup-node@v4
+        with:
+          cache: "npm"
+          node-version: "20"
+      - name: Install dependencies
+        run: npm ci
+      - name: Run test build
+        run: npx tree-sitter build --wasm
+
   success:
     needs:
       - compare-parser
       - generate
       - tests
       - rust
+      - wasm
     if: always()
     runs-on: ubuntu-latest
     name: "All checks passed"

.gitignore

@@ -15,3 +15,4 @@ target/
 *.so
 *.pc
 *.a
+*.wasm

src/scanner.c

@@ -47,13 +47,21 @@ static bool debug_mode = false; /* NOLINT(*-global-variables) */
 static const bool debug_mode = false;
 #endif
 
-#define RUNTIME_ASSERT(cond)                                            \
-  if (!(cond)) {                                                        \
-    (void)fprintf(                                                      \
-        stderr, "lex_nim: %s():%d: Assertion `%s' failed.\n", __func__, \
-        __LINE__, #cond);                                               \
-    abort();                                                            \
-  }
+#ifndef __wasm__
+#  define RUNTIME_ASSERT(cond)                                            \
+    if (!(cond)) {                                                        \
+      (void)fprintf(                                                      \
+          stderr, "lex_nim: %s():%d: Assertion `%s' failed.\n", __func__, \
+          __LINE__, #cond);                                               \
+      abort();                                                            \
+    }
+#else
+// WASM doesn't have printing enabled
+#  define RUNTIME_ASSERT(cond) \
+    if (!(cond)) {             \
+      abort();                 \
+    }
+#endif
 
 #define MIN(left, right) ((left) > (right) ? (right) : (left))
 #define MAX(left, right) ((left) < (right) ? (right) : (left))