dbStatic: Allow empty recordtype bodies in DBD files

A record type with an empty body is a declaration. The IOC will
accept one of these in a DBD file as long as it has already
loaded the full record type definition.
This will allow device support to provide a DBD file that declares
each record type it uses before giving the related device() entry.
Later commits will explain why.

src/ioc/dbStatic/dbLexRoutines.c

@@ -62,6 +62,7 @@ static void dbMenuChoice(char *name,char *value);
 static void dbMenuBody(void);
 
 static void dbRecordtypeHead(char *name);
+static void dbRecordtypeEmpty(void);
 static void dbRecordtypeBody(void);
 static void dbRecordtypeFieldHead(char *name,char *type);
 static void dbRecordtypeFieldItem(char *name,char *value);
@@ -607,6 +608,23 @@ static void dbRecordtypeCdef(char *text) {
     return;
 }
 
+static void dbRecordtypeEmpty(void)
+{
+    tempListNode *ptempListNode;
+    dbRecordType *pdbRecordType;
+
+    if (duplicate) {
+        duplicate = FALSE;
+	return;
+    }
+
+    ptempListNode = (tempListNode *)ellFirst(&tempList);
+    pdbRecordType = ptempListNode->item;
+    epicsPrintf("Declaration of recordtype(%s) preceeded full definition.\n",
+        pdbRecordType->name);
+    yyerrorAbort(NULL);
+}
+
 static void dbRecordtypeBody(void)
 {
     dbRecordType		*pdbRecordType;

src/ioc/dbStatic/dbYacc.y

@@ -100,7 +100,12 @@ recordtype_head: '(' tokenSTRING ')'
 	dbRecordtypeHead($2); dbmfFree($2);
 };
 
-recordtype_body: '{' recordtype_field_list '}'
+recordtype_body: '{' '}'
+{
+	if(dbStaticDebug>2) printf("empty recordtype_body\n");
+	dbRecordtypeEmpty();
+}
+	| '{' recordtype_field_list '}'
 {
 	if(dbStaticDebug>2) printf("recordtype_body\n");
 	dbRecordtypeBody();
@@ -215,14 +220,14 @@ record_head: '(' tokenSTRING ',' tokenSTRING ')'
 	dbRecordHead($2,$4,0); dbmfFree($2); dbmfFree($4);
 };
 
-record_body: /*Null*/
+record_body: /* empty */
 {
 	if(dbStaticDebug>2) printf("null record_body\n");
 	dbRecordBody();
 }
 	| '{' '}'
 {
-	if(dbStaticDebug>2) printf("record_body - no fields\n");
+	if(dbStaticDebug>2) printf("empty record_body\n");
 	dbRecordBody();
 }
         | '{' record_field_list '}'