This bug was introduced by the lexical variable constant propagation
mechanism. It was discovered by Michael Heerdegen.
* lisp/emacs-lisp/byte-opt.el (byte-optimize-let-form)
(byte-optimize-body): Let the effects of a local defvar declaration be
scoped by let and let*, not any arbitrary Lisp expression body (such
as progn).
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-tests--get-vars)
(bytecomp-local-defvar): New test.
Lexical variables bound to a constant value (symbol, number or string)
are substituted at their point of use and the variable then eliminated
if possible. Example:
(let ((x (+ 2 3))) (f x)) => (f 5)
This reduces code size, eliminates stack operations, and enables
further optimisations. The implementation is conservative, and is
strongly curtailed by the presence of variable mutation, conditions
and loops.
* lisp/emacs-lisp/byte-opt.el
(byte-optimize-enable-variable-constprop)
(byte-optimize-warn-eliminated-variable): New constants.
(byte-optimize--lexvars, byte-optimize--vars-outside-condition)
(byte-optimize--vars-outside-loop, byte-optimize--dynamic-vars):
New dynamic variables.
(byte-optimize--substitutable-p, byte-optimize-let-form):
New functions.
(byte-optimize-form-code-walker): Adapt clauses for variable
constprop, and add clauses for 'setq' and 'defvar'.
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-test-var)
(bytecomp-test-get-var, bytecomp-test-identity)
(byte-opt-testsuite-arith-data): Add test cases.
For discussion, see the following thread:
https://lists.gnu.org/r/emacs-devel/2021-01/msg01111.html
* test/lisp/autorevert-tests.el
(auto-revert-test07-auto-revert-several-buffers):
* test/lisp/emacs-lisp/seq-tests.el (test-seq-do-indexed)
(test-seq-random-elt-take-all): Fix errors from using add-to-list on
lexical variables.
* test/lisp/emacs-lisp/cl-lib-tests.el
(cl-lib-defstruct-record): Expect test to succeed when byte-compiled
following change of 2021-01-23 'Fix missing file&line info in
"Unknown defun property" warnings'.
(cl-lib-tests--dummy-function): Remove; no longer needed.
(old-struct): Silence byte-compiler warning about unused lexical
variable.
Before this patch doing:
rm lisp/calendar/calendar.elc
make lisp/calendar/cal-hebrew.elc
would spew out lots of spurious such warnings about a `date` argument,
pointing to code which has no `date` argument in sight. This was
because that code had calls to inlinable functions (taking a `date`
argument) defined in `calendar.el`, and while `date` is a normal
lexical var at the site of those functions' definitions, it was
declared as dynbound at the call site.
* lisp/emacs-lisp/byte-opt.el (byte-compile-inline-expand):
Don't impose our local context onto the inlined function.
* test/lisp/emacs-lisp/bytecomp-tests.el: Add matching test.
(pcase--split-pred, pcase--funcall): Adjust for `not`.
(pcase--get-macroexpander): New function.
(pcase--edebug-match-macro, pcase--make-docstring)
(pcase--macroexpand): Use it.
* lisp/emacs-lisp/radix-tree.el (radix-tree-leaf): Use it!
* doc/lispref/control.texi (The @code{pcase} macro): Document it.
* lisp/emacs-lisp/ert.el (ert--explain-equal-rec): Remove redundant test.
* test/lisp/progmodes/elisp-mode-tests.el (xref-elisp-test-run):
Make sure file names can be compared as strings, by running them
through 'file-truename'. Reported by Vin Shelton
<acs@alumni.princeton.edu>.
* test/lisp/emacs-lisp/bytecomp-tests.el ("warn-obsolete-hook.el")
("warn-obsolete-variable.el"): Use [^z-a] to match a newline as
well. Reported by Vin Shelton <acs@alumni.princeton.edu>.
Implement a limited form of tail-call optimization for the special
case of recursive functions defined with `cl-labels`. Only self-recursion
is optimized, no attempt is made to handle more complex cases such a mutual
recursion.
The main benefit is to reduce the use of the stack, tho in my limited
tests, this can also improve performance (about half of the way to
a hand-written `while` loop).
(cl--self-tco): New function.
(cl-labels): Use it.
* lisp/subr.el (letrec): Optimize single-binding corner case.
* test/lisp/emacs-lisp/cl-macs-tests.el (cl-macs--labels): Add tests
to check that TCO is working.
* lisp/emacs-lisp/eieio-core.el (eieio-defclass-autoload): Try to make
the wording of the warning about the obsoleted variable less confusing.
* lisp/emacs-lisp/bytecomp.el (byte-compile-check-variable): Don't
warn for lexical variables (Bug#39169). Fix spurious `or'.
* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp/warn-obsolete-variable-bound\.el): New test.
* test/lisp/emacs-lisp/bytecomp-resources/warn-obsolete-variable-bound.el:
New file.
* test/lisp/emacs-lisp/package-tests.el
(package-test-list-filter-by-name, package-test-list-clear-filter):
Use ansi-color instead of tetris, which no longer has a version:.
* lisp/emacs-lisp/find-func.el (find-function-search-for-symbol): If
our regexp algorithm could not find a location for the symbol
definition, resort to find-function--search-by-expanding-macros.
* test/lisp/emacs-lisp/find-func-tests.el: Add a automatic test for a
function and variable generated by a macro.
* etc/NEWS: Advertise the improved functionality (bug#45443).
* lisp/emacs-lisp/bytecomp.el (byte-compile-file): Don’t fail if
target filename doesn’t contain a directory name.
* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp-tests--target-file-no-directory): New unit test.
See Bug#44631. While testing for a readonly output directory has
slightly different semantics, in practice they should cover cases
where Emacs is sandboxed and can only write to the destination file,
not its directory.
* lisp/emacs-lisp/bytecomp.el (byte-compile-file): Handle the case
where the output directory is not writable.
* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp-tests--not-writable-directory)
(bytecomp-tests--dest-mountpoint): New unit tests.
