Moved iobuf.h assertions outside the static inline functions, so that

the assert message's file and line number gives some clue as to the
real location of the problem.

Added similar assertions to list.h.

src/include/gpxe/iobuf.h

 static inline void * iob_reserve ( struct io_buffer *iobuf, size_t len ) {
 	iobuf->data += len;
 	iobuf->tail += len;
-	assert ( iobuf->tail <= iobuf->end );
 	return iobuf->data;
 }
+#define iob_reserve( iobuf, len ) ( {			\
+	void *__result;					\
+	__result = iob_reserve ( (iobuf), (len) );	\
+	assert ( (iobuf)->tail <= (iobuf)->end );	\
+	__result; } )
 
 /**
  * Add data to start of I/O buffer
  */
 static inline void * iob_push ( struct io_buffer *iobuf, size_t len ) {
 	iobuf->data -= len;
-	assert ( iobuf->data >= iobuf->head );
 	return iobuf->data;
 }
+#define iob_push( iobuf, len ) ( {			\
+	void *__result;					\
+	__result = iob_push ( (iobuf), (len) );		\
+	assert ( (iobuf)->data >= (iobuf)->head );	\
+	__result; } )
 
 /**
  * Remove data from start of I/O buffer
 	assert ( iobuf->data <= iobuf->tail );
 	return iobuf->data;
 }
+#define iob_pull( iobuf, len ) ( {			\
+	void *__result;					\
+	__result = iob_pull ( (iobuf), (len) );		\
+	assert ( (iobuf)->data <= (iobuf)->tail );	\
+	__result; } )
 
 /**
  * Add data to end of I/O buffer
 static inline void * iob_put ( struct io_buffer *iobuf, size_t len ) {
 	void *old_tail = iobuf->tail;
 	iobuf->tail += len;
-	assert ( iobuf->tail <= iobuf->end );
 	return old_tail;
 }
+#define iob_put( iobuf, len ) ( {			\
+	void *__result;					\
+	__result = iob_put ( (iobuf), (len) );		\
+	assert ( (iobuf)->tail <= (iobuf)->end );	\
+	__result; } )
 
 /**
  * Remove data from end of I/O buffer
  */
 static inline void iob_unput ( struct io_buffer *iobuf, size_t len ) {
 	iobuf->tail -= len;
-	assert ( iobuf->tail >= iobuf->data );
 }
+#define iob_unput( iobuf, len ) do {			\
+	iob_unput ( (iobuf), (len) );			\
+	assert ( (iobuf)->tail >= (iobuf)->data );	\
+	} while ( 0 )
 
 /**
  * Empty an I/O buffer

src/include/gpxe/list.h

  */
 
 #include <stddef.h>
+#include <assert.h>
 
 /*
  * Simple doubly linked list implementation.
 static inline void list_add ( struct list_head *new, struct list_head *head ) {
 	__list_add ( new, head, head->next );
 }
+#define list_add( new, head ) do {			\
+	assert ( (head)->next->prev == (head) );	\
+	assert ( (head)->prev->next == (head) );	\
+	list_add ( (new), (head) );			\
+	} while ( 0 )
 
 /**
  * Add a new entry to the tail of a list
 				   struct list_head *head ) {
 	__list_add ( new, head->prev, head );
 }
+#define list_add_tail( new, head ) do {			\
+	assert ( (head)->next->prev == (head) );	\
+	assert ( (head)->prev->next == (head) );	\
+	list_add_tail ( (new), (head) );		\
+	} while ( 0 )
 
 /*
  * Delete a list entry by making the prev/next entries
 static inline void list_del ( struct list_head *entry ) {
 	__list_del ( entry->prev, entry->next );
 }
+#define list_del( entry ) do {				\
+	assert ( (entry)->prev != NULL );		\
+	assert ( (entry)->next != NULL );		\
+	assert ( (entry)->next->prev == (entry) );	\
+	assert ( (entry)->prev->next == (entry) );	\
+	list_del ( (entry) );				\
+	} while ( 0 )
 
 /**
  * Test whether a list is empty