CWG2588 friend declarations and module linkage

Author: burblebee

source/basic.tex

@@ -2746,6 +2746,24 @@
 has its linkage determined as follows:
 \begin{itemize}
 \item
+\indextext{friend function!linkage of}%
+if the entity is a function or function template
+first declared in a friend declaration and
+that declaration is a definition and
+the enclosing class is defined within an \grammarterm{export-declaration},
+the name has the same linkage, if any,
+as the name of the enclosing class\iref{class.friend};
+\item
+otherwise,
+\indextext{friend function!linkage of}%
+if the entity is a function or function template
+declared in a friend declaration and
+a corresponding non-friend declaration is reachable,
+%FIXME: Which declaration is "that prior declaration"?
+%FIXME: "prior" with respect to what? And what about dependent lookup?
+the name has the linkage determined from that prior declaration,
+\item
+otherwise,
 if the enclosing namespace has internal linkage,
 the name has internal linkage;
 \item

source/classes.tex

@@ -4857,12 +4857,6 @@
 \end{codeblock}
 \end{example}
 
-\pnum
-\indextext{friend function!linkage of}%
-A function first declared in a friend declaration
-has the linkage of the namespace of which it is a member\iref{basic.link}.
-Otherwise, the function retains its previous linkage\iref{dcl.stc}.
-
 \pnum
 \indextext{declaration!overloaded name and \tcode{friend}}%
 \begin{note}