+
+
+KNOWN BUGS RELATED TO THE IR1 INTERPRETER
+
+(Note: At some point, the pure interpreter (actually a semi-pure
+interpreter aka "the IR1 interpreter") will probably go away, replaced
+by constructs like
+ (DEFUN EVAL (X) (FUNCALL (COMPILE NIL (LAMBDA ..)))))
+and at that time these bugs should either go away automatically or
+become more tractable to fix. Until then, they'll probably remain,
+since some of them aren't considered urgent, and the rest are too hard
+to fix as long as so many special cases remain. After the IR1
+interpreter goes away is also the preferred time to start
+systematically exterminating cases where debugging functionality
+(backtrace, breakpoint, etc.) breaks down, since getting rid of the
+IR1 interpreter will reduce the number of special cases we need to
+support.)
+
+IR1-1:
+ The FUNCTION special operator doesn't check properly whether its
+ argument is a function name. E.g. (FUNCTION (X Y)) returns a value
+ instead of failing with an error. (Later attempting to funcall the
+ value does cause an error.)
+
+IR1-2:
+ COMPILED-FUNCTION-P bogusly reports T for interpreted functions:
+ * (DEFUN FOO (X) (- 12 X))
+ FOO
+ * (COMPILED-FUNCTION-P #'FOO)
+ T
+
+IR1-3:
+ Executing
+ (DEFVAR *SUPPRESS-P* T)
+ (EVAL '(UNLESS *SUPPRESS-P*
+ (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
+ (FORMAT T "surprise!"))))
+ prints "surprise!". Probably the entire EVAL-WHEN mechanism ought to be
+ rewritten from scratch to conform to the ANSI definition, abandoning
+ the *ALREADY-EVALED-THIS* hack which is used in sbcl-0.6.8.9 (and
+ in the original CMU CL source, too). This should be easier to do --
+ though still nontrivial -- once the various IR1 interpreter special
+ cases are gone.
+
+IR1-3a:
+ EVAL-WHEN's idea of what's a toplevel form is even more screwed up
+ than the example in IR1-3 would suggest, since COMPILE-FILE and
+ COMPILE both print both "right now!" messages when compiling the
+ following code,
+ (LAMBDA (X)
+ (COND (X
+ (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
+ (PRINT "yes! right now!"))
+ "yes!")
+ (T
+ (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
+ (PRINT "no! right now!"))
+ "no!")))
+ and while EVAL doesn't print the "right now!" messages, the first
+ FUNCALL on the value returned by EVAL causes both of them to be printed.