Add more function declarations

* lisp/subr.el (buffer-narrowed-p, sha1, match-substitute-replacement)
(version-to-list, version<, version<=, version=)
(function-get, subregexp-context-p, split-string)
(combine-and-quote-strings, split-string-and-unquote)
(replace-regexp-in-string, syntax-after)
(string-trim-left, string-trim):
* lisp/emacs-lisp/subr-x.el (hash-table-empty-p, hash-table-keys)
(hash-table-values, string-glyph-split)
(string-clean-whitespace, string-fill, string-limit)
(string-pixel-width):
* lisp/env.el (substitute-env-vars, substitute-env-in-file-name)
(setenv-internal):
* lisp/emacs-lisp/rx.el (rx-to-string):
* lisp/emacs-lisp/regexp-opt.el (regexp-opt-depth)
(regexp-opt-charset):
Add appropriate declarations: pure, side-effect-free, and/or
important-return-value.

1 files changed, 3 insertions, 0 deletions

diff --git a/lisp/env.el b/lisp/env.el
index faafcb6250f..281934af054 100644
--- a/lisp/env.el
+++ b/lisp/env.el
@@ -76,6 +76,7 @@ If it is non-nil and not a function, references to undefined variables are
 left unchanged.
 
 Use `$$' to insert a single dollar sign."
+  (declare (important-return-value t))
   (let ((start 0))
     (while (string-match env--substitute-vars-regexp string start)
       (cond ((match-beginning 1)
@@ -94,6 +95,7 @@ Use `$$' to insert a single dollar sign."
     string))
 
 (defun substitute-env-in-file-name (filename)
+  (declare (important-return-value t))
   (substitute-env-vars filename
                        ;; How 'bout we lookup other tables than the env?
                        ;; E.g. we could accept bookmark names as well!
@@ -104,6 +106,7 @@ Use `$$' to insert a single dollar sign."
 (defun setenv-internal (env variable value keep-empty)
   "Set VARIABLE to VALUE in ENV, adding empty entries if KEEP-EMPTY.
 Changes ENV by side-effect, and returns its new value."
+  (declare (important-return-value t))
   (let ((pattern (concat "\\`" (regexp-quote variable) "\\(=\\|\\'\\)"))
 	(case-fold-search nil)
 	(scan env)