[Chicken-janitors] Re: #531: "Snowdigest" egg causes stack overflow error in tests with experimental

[Chicken Trac]

#531: "Snowdigest" egg causes stack overflow error in tests with experimental
-----------------------------+----------------------------------------------
  Reporter:  sjamaan         |       Owner:  felix         
      Type:  defect          |      Status:  closed        
  Priority:  critical        |   Milestone:  4.7.0         
 Component:  core libraries  |     Version:  4.6.x         
Resolution:  fixed           |    Keywords:  stack overflow
-----------------------------+----------------------------------------------
Changes (by felix):

  * status:  new => closed
  * resolution:  => fixed


Comment:

 The problem appears to be that the internal calculation-routines in
 snowdigest are optimized into non-CPS "direct" calls (this code is very
 tight and does lots of fixnum-arithmetic). It is also recursive, so,
 depending on initial stack size, it may happen that the recursive direct-
 style part is running while the stack is already relatively near to the
 limit (i.e. shortly before CPS-code would trigger a minor GC). I have
 raised the size of the "reserve" area on the stack for this situation (it
 was 4096 bytes before, now it's 64k).

 There also was a problem with garbage bits in character values for which
 the internal comparison routines didn't work correctly.

 See "experimental" branch for the fix. The char-comparison change will
 only propagate by compiling the compiler with itself and then rebuilding.

-- 
Ticket URL: <http://bugs.call-cc.org/ticket/531#comment:1>
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