Make `defvaralias` signal an error upon attempts to create variable
alias cycles. This detects errors earlier and makes the alias
traversal during execution simpler and faster since no cycle detection
is needed elsewhere.
Now variable and function aliases are handled identically in these
respects.
* src/lisp.h (indirect_variable): Remove declaration.
* src/data.c (indirect_variable): Remove.
(Findirect_variable): Update doc string. Simplify alias resolution.
(Fboundp, find_symbol_value, set_internal, default_value)
(set_default_internal, Fmake_variable_buffer_local)
(Fmake_local_variable, Fkill_local_variable, Flocal_variable_p)
(Flocal_variable_if_set_p, Fvariable_binding_locus):
* src/buffer.c (buffer_local_value):
* src/eval.c (specbind): Simplify variable alias resolution.
(Fdefvaralias): Update doc string. Check for cycles.
* doc/lispref/variables.texi (Variable Aliases):
Mention that `defvaralias` can signal `cyclic-variable-indirection`
but `indirect-variable` cannot.
* etc/NEWS: Announce the change.
* test/src/eval-tests.el (eval-tests-defvaralias): New test.
This directory contains the architecture-independent files used by or
with Emacs. This includes some text files of documentation for GNU
Emacs or of interest to Emacs users, and the file of dumped docstrings
for Emacs functions and variables.
COPYRIGHT AND LICENSE INFORMATION FOR IMAGE FILES
File: emacs.icon
Author: Sun Microsystems, Inc
Copyright (C) 1999, 2001-2023 Free Software Foundation, Inc.
License: GNU General Public License version 3 or later (see COPYING)