defclass allows invalid slot options

[Wayne Rittimann, Jr.]

CL-USER> (defclass ttt () ((s :initargs (:s))))
#<STANDARD-CLASS COMMON-LISP-USER::TTT>

Note the usage of :initargS instead of :initarg.

CL-USER> (make-instance 'ttt :s 0)
; Debugger entered on #<SB-PCL::INITARG-ERROR {1006F869C3}>

The ANSI standard states that "It is required that all implementations signal an error of type program-error if they observe a class option or slot option that is not implemented locally."

It seems that the slot options are not checked until a call to make-instance for standard-direct-slot-definition. I think any option that is also an :initarg for a slot in that class is erroneously allowed.

 1: ((:METHOD MAKE-INSTANCE (CLASS)) #<STANDARD-CLASS SB-MOP:STANDARD-DIRECT-SLOT-DEFINITION> :CLASS #<STANDARD-CLASS COMMON-LISP-USER::TTT> :NAME S :READERS NIL :WRITERS NIL :INITARGS NIL SB-PCL::SOURCE ..
      Locals:
        CLASS = #<STANDARD-CLASS SB-MOP:STANDARD-DIRECT-SLOT-DEFINITION>
        SB-PCL::INITARGS = (:CLASS #<STANDARD-CLASS COMMON-LISP-USER::TTT> :NAME S :READERS NIL ...)

#<CONS {1007569867}>
--------------------
A proper list:
0: :CLASS
1: #<STANDARD-CLASS COMMON-LISP-USER::TTT>
2: :NAME
3: S
4: :READERS
5: NIL
6: :WRITERS
7: NIL
8: :INITARGS
9: NIL
10: SB-PCL::SOURCE
11: #S(SB-C:DEFINITION-SOURCE-LOCATION :NAMESTRING NIL :INDICES 0)
12: :READERS
13: (S)
14: :INITARGS
15: (:S)

I'll admit to being rather inexperienced with Common Lisp and CLOS. In fact it may be the only reason I noticed this. I mistakenly used :initargs instead of :initarg and it took me a while to figure out why I could not make a new instance.

Environment Info
----------------

$ sbcl --version
SBCL 2.0.6
$ uname -a
Darwin Waynes-MacBook-Pro-2.local 18.7.0 Darwin Kernel Version 18.7.0: Mon Apr 27 20:09:39 PDT 2020; root:xnu-4903.278.35~1/RELEASE_X86_64 x86_64
CL-USER> *FEATURES*
(:SLYNK :CL-JSON-DOUBLE-FLOAT-IS-SUBSUMED :CL-JSON-SINGLE-FLOAT-IS-SUBSUMED
 :CL-JSON-CLOS :CL-JSON :FLEXI-STREAMS :CHUNGA CHIPZ-SYSTEM:GRAY-STREAMS
 :CL-PPCRE :SBCL-DEBUG-PRINT-VARIABLE-ALIST :OSICAT-FD-STREAMS :21BIT-CHARS
 :BORDEAUX-THREADS CFFI-FEATURES:FLAT-NAMESPACE CFFI-FEATURES:X86-64
 CFFI-FEATURES:UNIX CFFI-FEATURES:DARWIN :CFFI CFFI-SYS::FLAT-NAMESPACE
 :SPLIT-SEQUENCE ALEXANDRIA::SEQUENCE-EMPTYP :THREAD-SUPPORT :SWANK :QUICKLISP
 :ASDF3.3 :ASDF3.2 :ASDF3.1 :ASDF3 :ASDF2 :ASDF :OS-MACOSX :OS-UNIX
 :NON-BASE-CHARS-EXIST-P :ASDF-UNICODE :X86-64 :GENCGC :64-BIT :ANSI-CL :BSD
 :COMMON-LISP :DARWIN :IEEE-FLOATING-POINT :LITTLE-ENDIAN :MACH-O
 :PACKAGE-LOCAL-NICKNAMES :SB-CORE-COMPRESSION :SB-LDB :SB-PACKAGE-LOCKS
 :SB-THREAD :SB-UNICODE :SBCL :UNIX)