sb-cltl2::macroexpand-all doesn't track the lexenv properly

[Attila Lendvai]

on 1.0.39.4

see the pasted form below (the macro is expanded twice, although that's not illegal in itself).

the lexenv passed to the macrolet does not contain the tags of the tagbody, nor the blocks, and a throughout test would probably uncover other missing things.

(sb-cltl2::macroexpand-all
       '(BLOCK B1
         (TAGBODY
          T1
            (PROGN)
          T2
            (BLOCK B2
              (MACROLET ((INJECTOR-MACRO2131 (&ENVIRONMENT ENV)
                           (print env)
                           (VALUES)))
                (INJECTOR-MACRO2131))))))

will print this:

#S(SB-KERNEL:LEXENV
   :FUNS ((INJECTOR-MACRO2131 SB-SYS:MACRO . #) (#:G4 SB-SYS:MACRO . #) (#:G4 SB-SYS:MACRO . #))
   :VARS NIL
   :BLOCKS NIL
   :TAGS NIL
   :TYPE-RESTRICTIONS NIL
   :LAMBDA NIL
   :CLEANUP NIL
   :HANDLED-CONDITIONS NIL
   :DISABLED-PACKAGE-LOCKS NIL
   :%POLICY ((COMPILATION-SPEED . 1) (DEBUG . 3) (SB-EXT:INHIBIT-WARNINGS . 1) (SAFETY . 1) (SPACE . 1) (SPEED . 1))
   :USER-DATA NIL)
#S(SB-KERNEL:LEXENV
   :FUNS ((#:G4 SB-SYS:MACRO . #) (INJECTOR-MACRO2131 SB-SYS:MACRO . #) (#:G4 SB-SYS:MACRO . #) (#:G4 SB-SYS:MACRO . #))
   :VARS NIL
   :BLOCKS NIL
   :TAGS NIL
   :TYPE-RESTRICTIONS NIL
   :LAMBDA NIL
   :CLEANUP NIL
   :HANDLED-CONDITIONS NIL
   :DISABLED-PACKAGE-LOCKS NIL
   :%POLICY ((COMPILATION-SPEED . 1) (DEBUG . 3) (SB-EXT:INHIBIT-WARNINGS . 1) (SAFETY . 1) (SPACE . 1) (SPEED . 1))
   :USER-DATA NIL)

[Nikodemus Siivola (nikodemus)]

This is clearly suboptimal, but given that there's no supported way (via sb-cltl2) to access block and tag names, non-critical.

The issue is with SB-WALKER not adding block and tag names into the environment in the first place.

[Michael Raskin (nh6dwy2v2wew)]

It looks like environments with blocks are fragile outside the expansion extent, it may create additional problems for a code walker.

For example,
(macrolet ((f (&environment e) (format t "~s~%" e) `(quote ,e))) (block a (f)))
prints the environment during the expansion, but then errors while trying to print the returned environment.

[Douglas Katzman (dougk)]

"... while trying to print the returned environment." - DON'T DO THAT.

See http://www.lispworks.com/documentation/HyperSpec/Issues/iss229_w.htm which discusses whether environments have indefinite or dynamic extent.
Our environments have dynamic extent, so of course you can't print them after return from the form that tried to capture one indefinitely.