Abolish max-specpdl-size (bug#57911)

The max-lisp-eval-depth limit is sufficient to prevent unbounded stack
growth including the specbind stack; simplify matters for the user by
not having them to worry about two different limits.  This change
turns max-specpdl-size into a harmless variable with no effects,
to keep existing code happy.

* lisp/subr.el (max-specpdl-size):
Define as an ordinary (but obsolete) dynamic variable.
* admin/grammars/Makefile.in:
* doc/lispintro/emacs-lisp-intro.texi (Loops & Recursion):
* doc/lispref/control.texi (Cleanups):
* doc/lispref/edebug.texi (Checking Whether to Stop):
* doc/lispref/eval.texi (Eval):
* doc/lispref/variables.texi (Local Variables):
* doc/misc/calc.texi (Recursion Depth):
Update documentation.
* etc/NEWS: Announce.
* src/eval.c
(FletX): Use safe iteration to guard against circular bindings list.
(syms_of_eval): Remove old max-specpdl-size definition.
(init_eval_once, restore_stack_limits, call_debugger)
(signal_or_quit, grow_specpdl_allocation):
* leim/Makefile.in:
* lisp/Makefile.in:
* lisp/calc/calc-stuff.el (calc-more-recursion-depth)
(calc-less-recursion-depth):
* lisp/calc/calc.el (calc-do):
* lisp/cedet/semantic/ede-grammar.el (ede-proj-makefile-insert-rules):
* lisp/cedet/semantic/grammar.el (semantic-grammar-batch-build-one-package):
* lisp/cus-start.el (standard):
* lisp/emacs-lisp/comp.el (comp--native-compile):
* lisp/emacs-lisp/edebug.el (edebug-max-depth):
(edebug-read-and-maybe-wrap-form, edebug-default-enter):
* lisp/emacs-lisp/regexp-opt.el (regexp-opt):
* lisp/eshell/esh-mode.el (eshell-mode):
* lisp/loadup.el (max-specpdl-size):
* lisp/mh-e/mh-e.el (mh-invisible-headers):
* lisp/net/shr.el (shr-insert-document, shr-descend):
* lisp/play/hanoi.el (hanoi-internal):
* lisp/progmodes/cperl-mode.el:
* src/fileio.c (Fdo_auto_save):
Remove references to and modifications of max-specpdl-size.

2 files changed, 3 insertions, 5 deletions

diff --git a/lisp/cedet/semantic/ede-grammar.el b/lisp/cedet/semantic/ede-grammar.el
index ff9f991ff4a..40ff8fc86d3 100644
--- a/lisp/cedet/semantic/ede-grammar.el
+++ b/lisp/cedet/semantic/ede-grammar.el
@@ -177,10 +177,9 @@ Lays claim to all -by.el, and -wy.el files."
 
 (cl-defmethod ede-proj-makefile-insert-rules :after ((this semantic-ede-proj-target-grammar))
     "Insert rules needed by THIS target.
-This raises `max-specpdl-size' and `max-lisp-eval-depth', which can be
-needed for the compilation of the resulting parsers."
-    (insert (format "%s: EMACSFLAGS+= --eval '(setq max-specpdl-size 1500 \
-max-lisp-eval-depth 700)'\n"
+This raises `max-lisp-eval-depth', which can be needed for the compilation
+of the resulting parsers."
+    (insert (format "%s: EMACSFLAGS+= --eval '(setq max-lisp-eval-depth 700)'\n"
 		    (oref this name))))
 
 (cl-defmethod ede-proj-makefile-insert-dist-dependencies ((this semantic-ede-proj-target-grammar))
diff --git a/lisp/cedet/semantic/grammar.el b/lisp/cedet/semantic/grammar.el
index 72037f47108..8ba0e346fff 100644
--- a/lisp/cedet/semantic/grammar.el
+++ b/lisp/cedet/semantic/grammar.el
@@ -1009,7 +1009,6 @@ Return non-nil if there were no errors, nil if errors."
              packagename (byte-compile-dest-file packagename))
             (let (;; Some complex grammar table expressions need a few
                   ;; more resources than the default.
-                  (max-specpdl-size    (max 3000 max-specpdl-size))
                   (max-lisp-eval-depth (max 1000 max-lisp-eval-depth))
                   )
               ;; byte compile the resultant file