[tables] Redefine methods for accessing linker tables

Intel's C compiler (icc) chokes on the zero-length arrays that we
currently use as part of the mechanism for accessing linker table
entries.  Abstract away the zero-length arrays, to make a port to icc
easier.

Introduce macros such as for_each_table_entry() to simplify the common
case of iterating over all entries in a linker table.

Represent table names as #defined string constants rather than
unquoted literals; this avoids visual confusion between table names
and C variable or type names, and also allows us to force a
compilation error in the event of incorrect table names.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/include/gpxe/open.h b/src/include/gpxe/open.h
index 81d5fc246..69a8b3f44 100644
--- a/src/include/gpxe/open.h
+++ b/src/include/gpxe/open.h
@@ -58,8 +58,11 @@ struct uri_opener {
 	int ( * open ) ( struct xfer_interface *xfer, struct uri *uri );
 };
 
+/** URI opener table */
+#define URI_OPENERS "uri_openers"
+
 /** Register a URI opener */
-#define __uri_opener __table ( struct uri_opener, uri_openers, 01 )
+#define __uri_opener __table ( struct uri_opener, URI_OPENERS, 01 )
 
 /** A socket opener */
 struct socket_opener {
@@ -78,8 +81,11 @@ struct socket_opener {
 			 struct sockaddr *local );
 };
 
+/** Socket opener table */
+#define SOCKET_OPENERS "socket_openers"
+
 /** Register a socket opener */
-#define __socket_opener __table ( struct socket_opener, socket_openers, 01 )
+#define __socket_opener __table ( struct socket_opener, SOCKET_OPENERS, 01 )
 
 extern int xfer_open_uri ( struct xfer_interface *xfer, struct uri *uri );
 extern int xfer_open_uri_string ( struct xfer_interface *xfer,