wanted: different docs for same function under different names

[Nikodemus Siivola]

Consider:

 (setf (symbol-function 'foo) #'car)
 (setf (symbol-function 'bar) #'car)

 (setf (documentation 'foo 'function) "Returns the thing.")
 (setf (documentation 'bar 'function) "Names of the thang.")

The (SETF DOCUMENTATION) should not set the documentation slot of the function, but rather store the documentation under the given name.

Regression since 1.0.29.24 when we added proper documentation for anonymous functions.

[Stas Boukarev (stassats)]

Is this related to https://bugs.launchpad.net/sbcl/+bug/565737 ?

[Nikodemus Siivola (nikodemus)]

In 1.0.43.63.

[Stas Boukarev (stassats)]

This only solves the problem with SBCL code, which only uses (setf ([f]documentation 'structure-accessor 'function) "...")

But since structures share the same closure for accessors, setting documentation of #'structure-accessor will mess it up. It's not used this way in the sources of SBCL, but external libraries do that (cxml, for example). So it's sufficient just to load a library with a single (setf documentation) on a structure accessor to mess up all other accessor docstrings throughout SBCL.

[Stas Boukarev (stassats)]

Note that (setf fdocumentation) is susceptible to this problem when called on symbols. Although it can be easily fixed in the same manner as (setf documentation), I see no point in doing so, since it will be messed up by external libraries anyway.

[Nikodemus Siivola (nikodemus)]

You're right, we need to either store docs for closures in a weak hash-table, or add a slot to closure objects.

[Stas Boukarev (stassats)]

That was fixed some time ago.