Fix mis-declarations of non-const functions

Problem for mpz_get_d_rounded reported by Helmut Eller in:
https://lists.gnu.org/r/emacs-devel/2025-11/msg00795.html
* lib-src/make-docfile.c (DEFUN_pure): New constant.
(write_globals, scan_c_stream): Support "attributes: pure".
* src/bignum.h (mpz_get_d_rounded):
* src/data.c (Fsymbolp, Fmodule_function_p, Fintegerp, Fnumberp):
* src/lisp.h (bignum_to_double, bignum_to_intmax)
(bignum_to_uintmax, bignum_bufsize):
Now pure, not const, since they depend on current state.
For example, Fsymbolp now inspects symbols_with_pos_enabled,
and the bignum functions inspect bignum contents in memory.
* src/data.c (Feq):
* src/xfaces.c (Fface_attribute_relative_p):
No longer const, since they might abort when debugging.
* src/pdumper.h (pdumper_object_p, pdumper_cold_object_p)
(pdumper_find_object_type, pdumper_object_p_precise):
These are not const functions.  But there is no need to declare
them to be pure, either, as they’re inline so the compiler can
figure it out.

lib-src/make-docfile.c

@@ -577,7 +577,13 @@ struct global
 };
 
 /* Bit values for FLAGS field from the above.  Applied for DEFUNs only.  */
-enum { DEFUN_noreturn = 1, DEFUN_const = 2, DEFUN_noinline = 4 };
+enum
+  {
+    DEFUN_noreturn = 1,
+    DEFUN_const = 2,
+    DEFUN_noinline = 4,
+    DEFUN_pure = 8,
+  };
 
 /* All the variable names we saw while scanning C sources in `-g'
    mode.  */
@@ -752,6 +758,8 @@ write_globals (void)
 	    fputs (" ATTRIBUTE_COLD", stdout);
 	  if (globals[i].flags & DEFUN_const)
 	    fputs (" ATTRIBUTE_CONST", stdout);
+	  if (globals[i].flags & DEFUN_pure)
+	    fputs (" ATTRIBUTE_PURE", stdout);
 
 	  puts (";");
 	}
@@ -1062,7 +1070,7 @@ scan_c_stream (FILE *infile)
 		   attributes: attribute1 attribute2 ...)
 	       (Lisp_Object arg...)
 
-	     Now only `const', `noinline' and `noreturn' attributes
+	     Now only 'const', 'noinline', 'noreturn', and 'pure' attributes
 	     are used.  */
 
 	  /* Advance to the end of docstring.  */
@@ -1110,6 +1118,8 @@ scan_c_stream (FILE *infile)
 		g->flags |= DEFUN_noreturn;
 	      if (strstr (input_buffer, "const"))
 		g->flags |= DEFUN_const;
+	      if (strstr (input_buffer, "pure"))
+		g->flags |= DEFUN_pure;
 
 	      /* Although the noinline attribute is no longer used,
 		 leave its support in, in case it's needed later.  */

src/bignum.h

@@ -56,7 +56,7 @@ extern void emacs_mpz_mul_2exp (mpz_t, mpz_t const, EMACS_INT)
   ARG_NONNULL ((1, 2));
 extern void emacs_mpz_pow_ui (mpz_t, mpz_t const, unsigned long)
   ARG_NONNULL ((1, 2));
-extern double mpz_get_d_rounded (mpz_t const) ATTRIBUTE_CONST;
+extern double mpz_get_d_rounded (mpz_t const) ATTRIBUTE_PURE;
 extern Lisp_Object get_random_bignum (struct Lisp_Bignum const *);
 
 INLINE_HEADER_BEGIN

src/data.c

@@ -166,8 +166,7 @@ slow_eq (Lisp_Object x, Lisp_Object y)
 }
 
 DEFUN ("eq", Feq, Seq, 2, 2, 0,
-       doc: /* Return t if the two args are the same Lisp object.  */
+       doc: /* Return t if the two args are the same Lisp object.  */)
-       attributes: const)
   (Lisp_Object obj1, Lisp_Object obj2)
 {
   if (EQ (obj1, obj2))
@@ -373,7 +372,7 @@ Ignore `symbols-with-pos-enabled'.  */
 
 DEFUN ("symbolp", Fsymbolp, Ssymbolp, 1, 1, 0,
        doc: /* Return t if OBJECT is a symbol.  */
-       attributes: const)
+       attributes: pure)
   (Lisp_Object object)
 {
   if (SYMBOLP (object))
@@ -551,7 +550,7 @@ DEFUN ("interpreted-function-p", Finterpreted_function_p,
 
 DEFUN ("module-function-p", Fmodule_function_p, Smodule_function_p, 1, 1, NULL,
        doc: /* Return t if OBJECT is a function loaded from a dynamic module.  */
-       attributes: const)
+       attributes: pure)
   (Lisp_Object object)
 {
   return MODULE_FUNCTIONP (object) ? Qt : Qnil;
@@ -569,7 +568,7 @@ DEFUN ("char-or-string-p", Fchar_or_string_p, Schar_or_string_p, 1, 1, 0,
 
 DEFUN ("integerp", Fintegerp, Sintegerp, 1, 1, 0,
        doc: /* Return t if OBJECT is an integer.  */
-       attributes: const)
+       attributes: pure)
   (Lisp_Object object)
 {
   if (INTEGERP (object))
@@ -598,7 +597,7 @@ DEFUN ("natnump", Fnatnump, Snatnump, 1, 1, 0,
 
 DEFUN ("numberp", Fnumberp, Snumberp, 1, 1, 0,
        doc: /* Return t if OBJECT is a number (floating point or integer).  */
-       attributes: const)
+       attributes: pure)
   (Lisp_Object object)
 {
   if (NUMBERP (object))

src/lisp.h

@@ -619,7 +619,7 @@ INLINE void set_sub_char_table_contents (Lisp_Object, ptrdiff_t,
 /* Defined in bignum.c.  */
 extern int check_int_nonnegative (Lisp_Object);
 extern intmax_t check_integer_range (Lisp_Object, intmax_t, intmax_t);
-extern double bignum_to_double (Lisp_Object) ATTRIBUTE_CONST;
+extern double bignum_to_double (Lisp_Object) ATTRIBUTE_PURE;
 extern Lisp_Object make_bigint (intmax_t);
 extern Lisp_Object make_biguint (uintmax_t);
 extern uintmax_t check_uinteger_max (Lisp_Object, uintmax_t);
@@ -4105,9 +4105,9 @@ set_sub_char_table_contents (Lisp_Object table, ptrdiff_t idx, Lisp_Object val)
 
 /* Defined in bignum.c.  This part of bignum.c's API does not require
    the caller to access bignum internals; see bignum.h for that.  */
-extern intmax_t bignum_to_intmax (Lisp_Object) ATTRIBUTE_CONST;
+extern intmax_t bignum_to_intmax (Lisp_Object) ATTRIBUTE_PURE;
-extern uintmax_t bignum_to_uintmax (Lisp_Object) ATTRIBUTE_CONST;
+extern uintmax_t bignum_to_uintmax (Lisp_Object) ATTRIBUTE_PURE;
-extern ptrdiff_t bignum_bufsize (Lisp_Object, int) ATTRIBUTE_CONST;
+extern ptrdiff_t bignum_bufsize (Lisp_Object, int) ATTRIBUTE_PURE;
 extern ptrdiff_t bignum_to_c_string (char *, ptrdiff_t, Lisp_Object, int);
 extern Lisp_Object bignum_to_string (Lisp_Object, int);
 extern Lisp_Object make_bignum_str (char const *, int);

src/pdumper.h

@@ -158,7 +158,7 @@ extern struct pdumper_loaded_dump dump_public;
 /* Return whether the OBJ points somewhere into the loaded dump image.
    Works even when we have no dump loaded --- in this case, it just
    returns false.  */
-INLINE _GL_ATTRIBUTE_CONST bool
+INLINE bool
 pdumper_object_p (const void *obj)
 {
 #ifdef HAVE_PDUMPER
@@ -176,7 +176,7 @@ extern bool pdumper_cold_object_p_impl (const void *obj);
    Only bool-vectors and floats should end up there.
    pdumper_object_p() and pdumper_object_p_precise() must have
    returned true for OBJ before calling this function.  */
-INLINE _GL_ATTRIBUTE_CONST bool
+INLINE bool
 pdumper_cold_object_p (const void *obj)
 {
 #ifdef HAVE_PDUMPER
@@ -193,7 +193,7 @@ extern int pdumper_find_object_type_impl (const void *obj);
 /* Return the type of the dumped object that starts at OBJ.  It is a
    programming error to call this routine for an OBJ for which
    pdumper_object_p would return false.  */
-INLINE _GL_ATTRIBUTE_CONST int
+INLINE int
 pdumper_find_object_type (const void *obj)
 {
 #ifdef HAVE_PDUMPER
@@ -216,7 +216,7 @@ pdumper_valid_object_type_p (int type)
    the loaded dump image.  It is a programming error to call this
    routine for an OBJ for which pdumper_object_p would return
    false.  */
-INLINE _GL_ATTRIBUTE_CONST bool
+INLINE bool
 pdumper_object_p_precise (const void *obj)
 {
 #ifdef HAVE_PDUMPER

src/xfaces.c

@@ -4194,8 +4194,7 @@ with the value VALUE is relative.
 A relative value is one that doesn't entirely override whatever is
 inherited from another face.  For most possible attributes,
 the only relative value that users see is `unspecified'.
-However, for :height, floating point values are also relative.  */
+However, for :height, floating point values are also relative.  */)
-       attributes: const)
   (Lisp_Object attribute, Lisp_Object value)
 {
   if (EQ (value, Qunspecified) || (EQ (value, QCignore_defface)))