Stubbed out a few more methods in _msg and _context.

upb_context.c

@@ -30,6 +30,7 @@ bool upb_context_init(struct upb_context *c)
 void upb_context_free(struct upb_context *c)
 {
   upb_strtable_free(&c->symtab);
+  for(size_t i = 0; i < c->fd_len; i++) free(c->fd[i]);
 }
 
 struct upb_symtab_entry *upb_context_lookup(struct upb_context *c,
@@ -215,7 +216,7 @@ bool upb_context_addfd(struct upb_context *c,
         else
           continue;  /* No resolving necessary. */
         if(!ref.msg) goto error;
-        upb_msg_ref(m, f, &ref);
+        upb_msg_ref(m, f, ref);
       }
     }
   }
@@ -227,5 +228,14 @@ bool upb_context_addfd(struct upb_context *c,
   return true;
 
 error:
+  /* TODO */
   return false;
 }
+
+bool upb_context_parsefd(struct upb_context *c, struct upb_string *fd_str) {
+  google_protobuf_FileDescriptorProto *fd = upb_msg_parse(c->fd_msg, fd_str);
+  if(!fd) return false;
+  if(!upb_context_addfd(c, fd)) return false;
+  c->fd[c->fd_len++] = fd;  /* Need to keep a ref since we own it. */
+  return true;
+}

upb_context.h

@@ -2,9 +2,10 @@
  * upb - a minimalist implementation of protocol buffers.
  *
  * A context represents a namespace of proto definitions, sort of like an
- * interpreter's symbol table.  It is mostly empty when first constructed.
- * Clients add definitions to the context by supplying unserialized or
- * serialized descriptors (as defined in descriptor.proto).
+ * interpreter's symbol table.  It is empty when first constructed, with the
+ * exception of built-in types (those defined in descriptor.proto).  Clients
+ * add definitions to the context by supplying unserialized or serialized
+ * descriptors (as defined in descriptor.proto).
  *
  * Copyright (c) 2009 Joshua Haberman.  See LICENSE for details.
  */
@@ -27,6 +28,12 @@ struct upb_symtab_entry {
 
 struct upb_context {
   struct upb_strtable symtab;
+  struct upb_msg *fd_msg;  /* This is in symtab also, kept here for convenience. */
+
+  /* A list of the FileDescriptorProtos we own (from having parsed them
+   * ourselves) and must free on destruction. */
+  size_t fd_size, fd_len;
+  google_protobuf_FileDescriptorProto **fd;
 };
 
 /* Initializes and frees a upb_context, respectively.  Newly initialized
@@ -72,20 +79,9 @@ struct upb_symtab_entry *upb_context_lookup(struct upb_context *c,
 bool upb_context_addfd(struct upb_context *c,
                        google_protobuf_FileDescriptorProto *fd);
 
-/* Adds the serialized FileDescriptorSet proto contained in fdss to the context,
- * and adds symbol table entries for all the objects defined therein.  onredef
- * controls the behavior in the case the fds attempts to define a type that is
- * already defined.
- *
- * Returns true if the protobuf in fds was parsed successfully and all
- * references were successfully resolved.  If false is returned, the context is
- * unmodified.  */
-bool upb_context_parsefds(struct upb_context *c, struct upb_string *fds,
-                          int onredef);
-
-/* Like the previous, but for a single FileDescriptorProto instead of a set. */
-bool upb_context_parsefd(struct upb_context *c, struct upb_string *fds,
-                         int onredef);
+/* Like the previous, but takes a serialized FileDescriptorProto and parses
+ * it before adding to the context. */
+bool upb_context_parsefd(struct upb_context *c, struct upb_string *fd);
 
 #ifdef __cplusplus
 }  /* extern "C" */

upb_msg.h

@@ -107,6 +107,13 @@ INLINE struct upb_msg_field *upb_get_msg_field(
 bool upb_msg_init(struct upb_msg *m, struct google_protobuf_DescriptorProto *d);
 void upb_msg_free(struct upb_msg *m);
 
+/* Clients use this function on a previously initialized upb_msg to resolve the
+ * "ref" field in the upb_msg_field and upb_abbrev_msg_field.  Since messages
+ * can refer to each other in mutually-recursive ways, this step must be
+ * separated from initialization.  The function is necessary because there are
+ * multiple internal maps in which the ref appears. */
+void upb_msg_ref(struct upb_msg *m, struct upb_msg_field *f, union upb_symbol_ref ref);
+
 /* While these are written to be as fast as possible, it will still be faster
  * to cache the results of this lookup if possible.  These return NULL if no
  * such field is found. */
@@ -272,6 +279,13 @@ INLINE void upb_msg_clear(void *s, struct upb_msg *m)
   memset(s, 0, m->set_flags_bytes);
 }
 
+/* Serialization/Deserialization.  ********************************************/
+
+/* Parses the string data in s according to the message description in m.
+ * Returns a newly allocated message which is now owned by the caller, or
+ * NULL if there was an error parsing the string. */
+void *upb_msg_parse(struct upb_msg *m, struct upb_string *s);
+
 #ifdef __cplusplus
 }  /* extern "C" */
 #endif