X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/sod/blobdiff_plain/e895be217c3be6769708da17c9ae87cb22db040e..refs/heads/mdw/progfmt:/src/method-proto.lisp

diff --git a/src/method-proto.lisp b/src/method-proto.lisp
index e72044e..0a20f39 100644
--- a/src/method-proto.lisp
+++ b/src/method-proto.lisp
@@ -347,6 +347,15 @@ (defgeneric simple-method-body (method codegen target)
 
 (definst convert-to-ilayout (stream :export t)
     (%class chain-head %expr)
+  "Expression to convert EXPR to point to its enclosing `ilayout'.
+
+   Given a pointer EXPR which points into a direct instance of CLASS,
+   specifically to the `ichain' whose head class is CHAIN-HEAD, evaluate the
+   base address of the enclosing `ilayout' structure.
+
+   The output looks like:
+
+	SOD_ILAYOUT(CLASS, NICK, EXPR)"
   (format stream "SOD_ILAYOUT(~@<~A, ~_~A, ~_~A~:>)"
 	  class (sod-class-nickname chain-head) expr))