It should be possible to be much more specific (overflow, division
by zero, etc.) and of course the "How can this be?" should be fixable.
-147:
- (reported by Alexey Dejneka sbcl-devel 2002-01-28)
- Compiling a file containing
- (deftype digit () '(member #\1))
- (defun parse-num (string ind)
- (flet ((digs ()
- (let (old-index)
- (if (and (< ind ind)
- (typep (char string ind) 'digit))
- nil))))))
- in sbcl-0.7.1 causes the compiler to fail with
- internal error, failed AVER: "(= (LENGTH (BLOCK-SUCC CALL-BLOCK)) 1)"
- This problem seems to have been introduced by the sbcl-0.pre7.* compiler
- changes, since 0.pre7.73 and 0.6.13 don't suffer from it. A related
- test case is
- (defun parse-num (index)
- (let (num x)
- (flet ((digs ()
- (setq num index))
- (z ()
- (let ()
- (setq x nil))))
- (when (and (digs) (digs)) x))))
- In sbcl-0.7.1, this second test case failed with the same
- internal error, failed AVER: "(= (LENGTH (BLOCK-SUCC CALL-BLOCK)) 1)"
- After the APD patches in sbcl-0.7.1.2 (new consistency check in
- TARGET-IF-DESIRABLE, plus a fix in meta-vmdef.lisp to keep the
- new consistency check from failing routinely) this second test case
- failed in FIND-IN-PHYSENV instead. Fixes in sbcl-0.7.1.3 (not
- closing over unreferenced variables) made this second test case
- compile without error, but the original test case still fails.
-
- Another way to get rid of the DEFTYPE without changing the symptom
- of the bug is
- (defvar *ch*)
- (defun parse-num (string ind)
- (flet ((digs ()
- (let ()
- (if (and (< ind ind)
- (sb-int:memq *ch* '(#\1)))
- nil))))))
- In sbcl-0.7.1.3, this fails with
- internal error, failed AVER: "(= (LENGTH (BLOCK-SUCC CALL-BLOCK)) 1)"
- The problem occurs while the inline expansion of MEMQ,
- #<LAMBDA :%DEBUG-NAME "varargs entry point for SB-C::.ANONYMOUS.">
- is being LET-converted after having its second REF deleted, leaving
- it with only one entry in LEAF-REFS.
-
148:
In sbcl-0.7.1.3 on x86, COMPILE-FILE on the file
(in-package :cl-user)