[wasm-api] Try to add face_reference_table

src/hb-wasm-api-face.hh

@@ -0,0 +1,51 @@
+/*
+ * Copyright © 2023  Behdad Esfahbod
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#ifndef HB_WASM_FACE_HH
+#define HB_WASM_FACE_HH
+
+#include <hb-wasm-api.hh>
+
+namespace hb {
+namespace wasm {
+
+
+void
+face_reference_table (HB_WASM_EXEC_ENV_COMPOUND
+		      face_t faceref,
+		      tag_t table_tag)
+{
+  HB_RETURN_TYPE (blob_t, blob);
+
+  HB_REF2OBJ (face);
+  if (unlikely (!face))
+    return;
+
+  blob.length = 1;
+}
+
+
+}}
+
+#endif /* HB_WASM_FACE_HH */

src/hb-wasm-api-list.hh

@@ -45,6 +45,9 @@ debugprint (HB_WASM_EXEC_ENV
 static NativeSymbol _hb_wasm_native_symbols[] =
 {
 
+  /* face */
+  NATIVE_SYMBOL ("(iii)",	face_reference_table),
+
   /* font */
   NATIVE_SYMBOL ("(i)i",	font_get_face),
 

src/hb-wasm-api.cc

@@ -27,12 +27,10 @@
 #define module_inst wasm_runtime_get_module_inst (exec_env)
 
 
+#include "hb-wasm-api-face.hh"
 #include "hb-wasm-api-font.hh"
 
 
 #undef module_inst
-#undef HB_WASM_EXEC_ENV
-#undef HB_REF2OBJ
-#undef HB_OBJ2REF
 
 hb_user_data_key_t _hb_wasm_ref_type_key = {};

src/hb-wasm-api.h

@@ -46,14 +46,20 @@
 HB_WASM_BEGIN_DECLS
 
 #ifndef HB_WASM_API
-#define HB_WASM_API(x) x
+#define HB_WASM_API(ret_t, name) ret_t name
+#endif
+#ifndef HB_WASM_API_COMPOUND /* compound return type */
+#define HB_WASM_API_COMPOUND(ret_t, name) HB_WASM_API(ret_t, name)
 #endif
 #ifndef HB_WASM_INTERFACE
-#define HB_WASM_INTERFACE(x) x
+#define HB_WASM_INTERFACE(ret_t, name) ret_t name
 #endif
 #ifndef HB_WASM_EXEC_ENV
 #define HB_WASM_EXEC_ENV
 #endif
+#ifndef HB_WASM_EXEC_ENV_COMPOUND
+#define HB_WASM_EXEC_ENV_COMPOUND HB_WASM_EXEC_ENV
+#endif
 
 
 #ifndef bool_t
@@ -62,24 +68,41 @@ HB_WASM_BEGIN_DECLS
 #ifndef ref_t
 #define ref_t uint32_t
 #endif
+#ifndef ptr_t
+#define ptr_t uint32_t
+#endif
+
+typedef uint32_t tag_t;
+#define TAG(c1,c2,c3,c4) ((tag_t)((((uint32_t)(c1)&0xFF)<<24)|(((uint32_t)(c2)&0xFF)<<16)|(((uint32_t)(c3)&0xFF)<<8)|((uint32_t)(c4)&0xFF)))
+
 typedef ref_t face_t;
 typedef ref_t font_t;
 typedef ref_t buffer_t;
 
+typedef struct {
+  ref_t data;
+  uint32_t length;
+} blob_t;
+
+
+/* face */
+
+HB_WASM_API_COMPOUND (blob_t, face_reference_table) (HB_WASM_EXEC_ENV_COMPOUND
+						     face_t faceref,
+						     tag_t table_tag);
+
 
 /* font */
 
-face_t
+HB_WASM_API (face_t, font_get_face) (HB_WASM_EXEC_ENV
-HB_WASM_API (font_get_face) (HB_WASM_EXEC_ENV
+				     font_t fontref);
-			     font_t);
 
 
 /* shape interface */
 
-bool_t
+HB_WASM_INTERFACE (bool_t, shape) (HB_WASM_EXEC_ENV
-HB_WASM_INTERFACE (shape) (HB_WASM_EXEC_ENV
+				   font_t fontref,
-			   font_t,
+				   buffer_t bufferref);
-			   buffer_t);
 
 
 HB_WASM_END_DECLS

src/hb-wasm-api.hh

@@ -29,11 +29,14 @@
 
 #include <wasm_export.h>
 
-#define HB_WASM_API(x) HB_INTERNAL x
 #define HB_WASM_BEGIN_DECLS namespace hb { namespace wasm {
 #define HB_WASM_END_DECLS }}
 
+#define HB_WASM_API(ret_t, name) HB_INTERNAL ret_t name
+#define HB_WASM_API_COMPOUND(ret_t, name) HB_INTERNAL void name
+
 #define HB_WASM_EXEC_ENV wasm_exec_env_t exec_env,
+#define HB_WASM_EXEC_ENV_COMPOUND wasm_exec_env_t exec_env, ptr_t retptr,
 
 #include "hb-wasm-api.h"
 
@@ -63,7 +66,6 @@ HB_INTERNAL extern hb_user_data_key_t _hb_wasm_ref_type_key;
 		  (void *) hb_wasm_ref_type_##obj)) \
       obj = nullptr; \
   } HB_STMT_END
-
 #define HB_OBJ2REF(obj) \
   uint32_t obj##ref = nullref; \
   HB_STMT_START { \
@@ -73,5 +75,18 @@ HB_INTERNAL extern hb_user_data_key_t _hb_wasm_ref_type_key;
     (void) wasm_externref_obj2ref (module_inst, obj, &obj##ref); \
   } HB_STMT_END
 
+#define HB_RETURN_TYPE(type, name) \
+  type *_name_ptr = nullptr; \
+  { \
+    if (likely (wasm_runtime_validate_app_addr (module_inst, \
+						retptr, sizeof (type)))) \
+    { \
+      _name_ptr = (type *) wasm_runtime_addr_app_to_native (module_inst, retptr); \
+      if (unlikely (!_name_ptr)) \
+	return; \
+    } \
+  } \
+  type &name = *_name_ptr
+
 
 #endif /* HB_WASM_API_HH */