Enhance struct Lisp_Subr to hold the alternative "BC_" function.scratch/accurate-warning-pos

Also fix a GC bug, where symbols with position were not being disabled.

* src/lisp.h (union Lisp_Function): New type.
(struct Lisp_Subr): Add fields normal_function, BC_function, and next.
(DEFUN): Setup all three function fields to the subr (BC_function is still a
dummy), set field next to NULL.

* src/alloc.c (Fgarbage_collect): Move the binding of
Qsymbols_with_pos_enabled to garbage_collect_1 so that it gets bound when GC
is invoked via garbage_collect.

* src/lread.c (subr_ptr, using_BC_subrs): New static variables.
(Fswitch_to_BC_subrs, Fswitch_to_normal_subrs): New defuns.
(defsubr): Chain new subr to previous using field next and variable subr_ptr.
(init_lread): Initialise subr_ptr to NULL.
(syms_of_lread): Create subrs Sswitch_to_BC_subrs and Sswitch_to_normal_subrs.

* src/pdumper.c (dump_subr): Enhance to dump struct Lisp_Subr's new fields.
Update the expected value of HASH_Lisp_Subr_xxxxxxxxxx.
(dump_vectorlike): Also dump PVEC_SYMBOL_WITH_POSes.

1 files changed, 15 insertions, 6 deletions

diff --git a/src/lisp.h b/src/lisp.h
index 3324dac98f6..a22043026ad 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2127,10 +2127,7 @@ CHAR_TABLE_SET (Lisp_Object ct, int idx, Lisp_Object val)
    It is generated by the DEFUN macro only.
    defsubr makes it into a Lisp object.  */
 
-struct Lisp_Subr
-  {
-    union vectorlike_header header;
-    union {
+union Lisp_Function {
       Lisp_Object (*a0) (void);
       Lisp_Object (*a1) (Lisp_Object);
       Lisp_Object (*a2) (Lisp_Object, Lisp_Object);
@@ -2142,10 +2139,18 @@ struct Lisp_Subr
       Lisp_Object (*a8) (Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object);
       Lisp_Object (*aUNEVALLED) (Lisp_Object args);
       Lisp_Object (*aMANY) (ptrdiff_t, Lisp_Object *);
-    } function;
+};
+
+struct Lisp_Subr
+  {
+    union vectorlike_header header;
+    union Lisp_Function function;
+    union Lisp_Function normal_function;
+    union Lisp_Function BC_function;
     short min_args, max_args;
     const char *symbol_name;
     const char *intspec;
+    union Aligned_Lisp_Subr *next;
     EMACS_INT doc;
   } GCALIGNED_STRUCT;
 union Aligned_Lisp_Subr
@@ -3162,7 +3167,11 @@ CHECK_INTEGER (Lisp_Object x)
   static union Aligned_Lisp_Subr sname =                                \
      {{{ PVEC_SUBR << PSEUDOVECTOR_AREA_BITS },                         \
        { .a ## maxargs = fnname },                                      \
-       minargs, maxargs, lname, intspec, 0}};                           \
+       { .a ## maxargs = fnname },                                      \
+       { .a ## maxargs = /* BC_ ##  */fnname },                               \
+       minargs, maxargs, lname, intspec,                                \
+       NULL,                                                            \
+       0}};                                                             \
    Lisp_Object fnname
 
 /* defsubr (Sname);