SCM_DEBUG fix: Don't apply SCM_CAR to non-pairs when walking argument

lists in method cache matching.

* libguile/goops.c (scm_mcache_lookup_cmethod): Don't apply SCM_CAR to
  non-pairs when walking argument lists in method cache matching.
  Don't check for CLASSP or symbol in the car slot, since the end of
  the specifier list is a non-pair.  Update comments to reflect new
  structure of method cache entry.
* module/oops/goops/dispatch.scm: Update comments here too.

diff --git a/libguile/goops.c b/libguile/goops.c
index 33e1c6e..e3f403d 100644 (file)
--- a/libguile/goops.c
+++ b/libguile/goops.c
@@ -1779,12 +1779,12 @@ SCM_GLOBAL_SYMBOL (scm_sym_args, "args");
  *
  * Format #1:
  * (SCM_IM_DISPATCH ARGS N-SPECIALIZED
- *   #((TYPE1 ... ENV FORMALS FORM ...) ...)
+ *   #((TYPE1 ... . CMETHOD) ...)
  *   GF)
  *
  * Format #2:
  * (SCM_IM_HASH_DISPATCH ARGS N-SPECIALIZED HASHSET MASK
- *   #((TYPE1 ... ENV FORMALS FORM ...) ...)
+ *   #((TYPE1 ... CMETHOD) ...)
  *   GF)
  *
  * ARGS is either a list of expressions, in which case they
@@ -1795,9 +1795,6 @@ SCM_GLOBAL_SYMBOL (scm_sym_args, "args");
  * SCM_IM_DISPATCH expressions in generic functions always
  * have ARGS = the symbol `args' or the iloc #@0-0.
  *
- * Need FORMALS in order to support varying arity.  This
- * also avoids the need for renaming of bindings.
- *
  * We should probably not complicate this mechanism by
  * introducing "optimizations" for getters and setters or
  * primitive methods.  Getters and setter will normally be
@@ -1853,19 +1850,18 @@ scm_mcache_lookup_cmethod (SCM cache, SCM args)
       long j = n;
       z = SCM_SIMPLE_VECTOR_REF (methods, i);
       ls = args; /* list of arguments */
-      if (!scm_is_null (ls))
+      /* More arguments than specifiers => z = CMETHOD, not a pair.
+       * Fewer arguments than specifiers => CAR != CLASS or `no-method'.  */
+      if (!scm_is_null (ls) && scm_is_pair (z))
        do
          {
-           /* More arguments than specifiers => CLASS != ENV */
            if (! scm_is_eq (scm_class_of (SCM_CAR (ls)), SCM_CAR (z)))
              goto next_method;
            ls = SCM_CDR (ls);
            z = SCM_CDR (z);
          }
-       while (j-- && !scm_is_null (ls));
-      /* Fewer arguments than specifiers => CAR != CLASS or `no-method' */
-      if (!scm_is_pair (z)
-          || (!SCM_CLASSP (SCM_CAR (z)) && !scm_is_symbol (SCM_CAR (z))))
+       while (j-- && !scm_is_null (ls) && scm_is_pair (z));
+      if (!scm_is_pair (z))
        return z;
     next_method:
       i = (i + 1) & mask;

diff --git a/module/oop/goops/dispatch.scm b/module/oop/goops/dispatch.scm
index 88abf80..6a450c1 100644 (file)
--- a/module/oop/goops/dispatch.scm
+++ b/module/oop/goops/dispatch.scm
@@ -53,9 +53,9 @@
 ;;; Method cache
 ;;;
 
-;; (#@dispatch args N-SPECIALIZED #((TYPE1 ... ENV FORMALS FORM1 ...) ...) GF)
+;; (#@dispatch args N-SPECIALIZED #((TYPE1 ... . CMETHOD) ...) GF)
 ;; (#@dispatch args N-SPECIALIZED HASHSET MASK
-;;             #((TYPE1 ... ENV FORMALS FORM1 ...) ...)
+;;             #((TYPE1 ... . CMETHOD) ...)
 ;;             GF)
 
 ;;; Representation