Bad calls to exported SB-KERNEL functions may cause compiler failures

[Paul F. Dietz]

I don't know if you consider this a valid bug, but there are calls to these sorts of functions in user code in quicklisp. Mark "Won't fix" on this if you think it's not a real issue.

(lambda () (sb-kernel:%array-displaced-p "Not a kno"))

==>

Unhandled memory fault at #x60.
   [Condition of type SB-SYS:MEMORY-FAULT-ERROR]
[...]
  0: [error printing frame]
  1: [error printing frame]
  2: ((FLET SB-C::CLOSURE-NEEDING-IR1-ENVIRONMENT-FROM-NODE :IN SB-C::CONSTANT-FOLD-CALL))
  3: (SB-C::%WITH-IR1-ENVIRONMENT-FROM-NODE #<SB-C::COMBINATION :FUN #<SB-C::REF :LEAF #<SB-C::GLOBAL-VAR :%SOURCE-NAME SB-KERNEL:%ARRAY-DISPLACED-P :TYPE #1=#<SB-KERNEL:FUN-TYPE #> :DEFINED-TYPE #1# :WHE..
  4: (SB-C::CONSTANT-FOLD-CALL #<SB-C::COMBINATION :FUN #<SB-C::REF :LEAF #<SB-C::GLOBAL-VAR :%SOURCE-NAME SB-KERNEL:%ARRAY-DISPLACED-P :TYPE #1=#<SB-KERNEL:FUN-TYPE #> :DEFINED-TYPE #1# :WHERE-FROM :DECL..
  5: (SB-C::IR1-OPTIMIZE-COMBINATION #<SB-C::COMBINATION :FUN #<SB-C::REF :LEAF #<SB-C::GLOBAL-VAR :%SOURCE-NAME SB-KERNEL:%ARRAY-DISPLACED-P :TYPE #1=#<SB-KERNEL:FUN-TYPE #> :DEFINED-TYPE #1# :WHERE-FROM..
[...]

[Stas Boukarev (stassats)]

That sequence will never be produce by SBCL for safe code.

[Paul F. Dietz (paul-f-dietz)]

I understand, but calls to SB-KERNEL:%... functions do appear fairly often in user code in quicklisp. Examples attached. So it's not just internally generated calls produced by the compiler itself.

[Stas Boukarev (stassats)]

Using such functions voids any warranty.