[wasm] Add meson build option

Autotools support missing.

meson.build

@@ -114,6 +114,7 @@ glib_dep = dependency('glib-2.0', required: get_option('glib'))
 gobject_dep = dependency('gobject-2.0', required: get_option('gobject'))
 graphite2_dep = dependency('graphite2', required: get_option('graphite2'))
 graphite_dep = dependency('graphite2', required: get_option('graphite'))
+wasm_dep = cpp.find_library('iwasm', required: get_option('wasm'))
 
 if meson.version().version_compare('>=0.60.0')
   # pkg-config: icu-uc, cmake: ICU but with components
@@ -229,7 +230,9 @@ if chafa_dep.found()
   conf.set('HAVE_CHAFA', 1)
 endif
 
-conf.set('HAVE_WASM', 1)
+if wasm_dep.found()
+  conf.set('HAVE_WASM', 1)
+endif
 
 if graphite2_dep.found() or graphite_dep.found()
   conf.set('HAVE_GRAPHITE2', 1)

meson_options.txt

@@ -21,6 +21,8 @@ option('directwrite', type: 'feature', value: 'disabled',
   description: 'Enable DirectWrite shaper backend on Windows (experimental)')
 option('coretext', type: 'feature', value: 'disabled',
   description: 'Enable CoreText shaper backend on macOS')
+option('wasm', type: 'feature', value: 'disabled',
+  description: 'Enable WebAssembly shaper backend')
 
 # Common feature options
 option('tests', type: 'feature', value: 'enabled', yield: true,

src/hb-wasm-shape.cc

@@ -28,6 +28,25 @@
 
 #ifdef HAVE_WASM
 
+#include <wasm_c_api.h>
+
+#define own // wasm-micro-runtime wasm-c-api/hello.c example has this; no idea why :))
+
+static wasm_store_t *
+get_wasm_store ()
+{
+
+  static wasm_store_t *store;
+  if (!store)
+  {
+    static wasm_engine_t *engine = wasm_engine_new();
+    store = wasm_store_new (engine);
+  }
+
+  return store;
+}
+
+
 /*
  * shaper face data
  */
@@ -36,30 +55,50 @@
 
 struct hb_wasm_face_data_t {
   hb_blob_t *blob;
+  wasm_module_t *mod;
 };
 
 hb_wasm_face_data_t *
 _hb_wasm_shaper_face_data_create (hb_face_t *face)
 {
-  hb_blob_t *wasm_blob = hb_face_reference_table (face, HB_WASM_TAG_WASM);
-  if (!hb_blob_get_length (wasm_blob))
-  {
-    hb_blob_destroy (wasm_blob);
-    return nullptr;
-  }
+  hb_blob_t *wasm_blob = nullptr;
+  own wasm_module_t *wasm_module = nullptr;
+  hb_wasm_face_data_t *data = nullptr;
 
-  hb_wasm_face_data_t *data = (hb_wasm_face_data_t *) hb_calloc (1, sizeof (hb_wasm_face_data_t));
+  wasm_blob = hb_face_reference_table (face, HB_WASM_TAG_WASM);
+  unsigned length = hb_blob_get_length (wasm_blob);
+  if (!length)
+    goto fail;
+
+  wasm_byte_vec_t binary;
+  wasm_byte_vec_new_uninitialized (&binary, length);
+  memcpy (binary.data, hb_blob_get_data (wasm_blob, nullptr), length);
+  wasm_module = wasm_module_new (get_wasm_store (), &binary);
+  if (!wasm_module)
+    goto fail;
+  wasm_byte_vec_delete(&binary);
+
+  data = (hb_wasm_face_data_t *) hb_calloc (1, sizeof (hb_wasm_face_data_t));
   if (unlikely (!data))
-    return nullptr;
+    goto fail;
 
   data->blob = wasm_blob;
+  data->mod = wasm_module;
 
   return data;
+
+fail:
+  if (wasm_module)
+    wasm_module_delete (wasm_module);
+  hb_blob_destroy (wasm_blob);
+  hb_free (data);
+  return nullptr;
 }
 
 void
 _hb_wasm_shaper_face_data_destroy (hb_wasm_face_data_t *data)
 {
+  wasm_module_delete (data->mod);
   hb_blob_destroy (data->blob);
   hb_free (data);
 }

src/meson.build

@@ -256,7 +256,6 @@ hb_base_sources = files(
   'hb-unicode.hh',
   'hb-utf.hh',
   'hb-vector.hh',
-  'hb-wasm-shape.cc',
   'hb.hh',
 )
 
@@ -325,6 +324,9 @@ hb_glib_headers = files('hb-glib.h')
 hb_graphite2_sources = files('hb-graphite2.cc')
 hb_graphite2_headers = files('hb-graphite2.h')
 
+hb_wasm_sources = files('hb-wasm-shape.cc')
+hb_wasm_headers = files()
+
 # System-dependent sources and headers
 
 hb_coretext_sources = files('hb-coretext.cc')
@@ -460,6 +462,12 @@ if conf.get('HAVE_GRAPHITE2', 0) == 1
   harfbuzz_deps += [graphite2_dep, graphite_dep]
 endif
 
+if conf.get('HAVE_WASM', 0) == 1
+  hb_sources += hb_wasm_sources
+  hb_headers += hb_wasm_headers
+  harfbuzz_deps += wasm_dep
+endif
+
 if conf.get('HAVE_UNISCRIBE', 0) == 1
   hb_sources += hb_uniscribe_sources
   hb_headers += hb_uniscribe_headers