create initial dart ffigen hooks

PiperOrigin-RevId: 492528444

upb/port/def.inc

@@ -86,7 +86,14 @@
 
 #define UPB_MAPTYPE_STRING 0
 
-/* UPB_INLINE: inline if possible, emit standalone code if required. */
+// UPB_EXPORT: always generate a public symbol.
+#if defined(__GNUC__) || defined(__clang__)
+#define UPB_EXPORT __attribute__((visibility("default"))) __attribute__((used))
+#else
+#define UPB_EXPORT
+#endif
+
+// UPB_INLINE: inline if possible, emit standalone code if required.
 #ifdef __cplusplus
 #define UPB_INLINE inline
 #elif defined (__GNUC__) || defined(__clang__)
@@ -95,6 +102,14 @@
 #define UPB_INLINE static
 #endif
 
+#ifdef UPB_BUILD_API
+#define UPB_API UPB_EXPORT
+#define UPB_API_INLINE UPB_EXPORT
+#else
+#define UPB_API
+#define UPB_API_INLINE UPB_INLINE
+#endif
+
 #define UPB_MALLOC_ALIGN 8
 #define UPB_ALIGN_UP(size, align) (((size) + (align) - 1) / (align) * (align))
 #define UPB_ALIGN_DOWN(size, align) ((size) / (align) * (align))

upb/port/undef.inc

@@ -32,7 +32,10 @@
 #undef UPB_READ_ONEOF
 #undef UPB_WRITE_ONEOF
 #undef UPB_MAPTYPE_STRING
+#undef UPB_EXPORT
 #undef UPB_INLINE
+#undef UPB_API
+#undef UPB_API_INLINE
 #undef UPB_ALIGN_UP
 #undef UPB_ALIGN_DOWN
 #undef UPB_ALIGN_MALLOC

upbc/BUILD

@@ -67,6 +67,21 @@ upb_proto_reflection_library(
     deps = ["@com_google_protobuf//:compiler_plugin_proto"],
 )
 
+cc_binary(
+    name = "upbc_so",
+    srcs = ["upbc_so.c"],
+    copts = UPB_DEFAULT_COPTS,
+    linkshared = 1,
+    linkstatic = 1,
+    visibility = ["//visibility:public"],
+    deps = [
+        "//:mem",
+        "//:message",
+        "//:mini_table",
+        "//upbc:upbdev",
+    ],
+)
+
 cc_library(
     name = "common",
     srcs = [

upbc/upbc_so.c

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2009-2022, Google LLC
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Google LLC nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// This disables inlining and forces all public functions to be exported to the
+// linker. It is used to generate bindings for FFIs from other languages.
+#define UPB_BUILD_API
+
+#include "upb/mem/arena.h"
+#include "upb/message/message.h"
+#include "upb/mini_table/decode.h"
+#include "upbc/upbdev.h"