Add `macroexp--dynamic-variable-p`

This predicate can be used for discriminating between lexically and
dynamically bound variables during macro-expansion (only).
It is restricted to internal use for the time being.

* lisp/emacs-lisp/bytecomp.el (byte-compile-initial-macro-environment):
Use macroexpand--all-toplevel.
* lisp/emacs-lisp/macroexp.el (macroexp-dynamic-variable-p): New.
(macroexp--expand-all): Maintain macroexp--dynvars.
(macroexpand-all): Rebind macroexp--dynvars.
(macroexpand--all-toplevel): New.
(internal-macroexpand-for-load): Use macroexpand--all-toplevel.
* src/eval.c (eval_sub): Transfer defvar declarations from
Vinternal_interpreter_environment into macroexp--dynvars during
lazy macro-expansion.
* src/lread.c (readevalloop): Rebind macroexp--dynvars around
read-and-evaluate operations.
(syms_of_lread): Define macroexp--dynvars.
* test/lisp/emacs-lisp/macroexp-resources/vk.el: New file.
* test/lisp/emacs-lisp/macroexp-tests.el (macroexp-tests--run-emacs)
(macroexp-tests--eval-in-subprocess)
(macroexp-tests--byte-compile-in-subprocess)
(macroexp--tests-dynamic-variable-p): Add tests.

1 files changed, 56 insertions, 1 deletions

diff --git a/test/lisp/emacs-lisp/macroexp-tests.el b/test/lisp/emacs-lisp/macroexp-tests.el
index 89d3882d1da..292c11ac6cd 100644
--- a/test/lisp/emacs-lisp/macroexp-tests.el
+++ b/test/lisp/emacs-lisp/macroexp-tests.el
@@ -24,6 +24,9 @@
 
 ;;; Code:
 
+(require 'macroexp)
+(require 'ert-x)
+
 (ert-deftest macroexp--tests-fgrep ()
   (should (equal (macroexp--fgrep '((x) (y)) '([x] z ((u))))
                  '((x))))
@@ -67,6 +70,58 @@
     (should (equal "m1.el"
                    (file-name-nondirectory macroexp--m1-tests-comp-filename)))))
 
+(defun macroexp-tests--run-emacs (&rest args)
+  "Run Emacs in batch mode with ARGS, return output."
+  (let ((emacs (expand-file-name invocation-name invocation-directory)))
+    (with-temp-buffer
+      (let ((res (apply #'call-process emacs nil t nil
+                        "-Q" "--batch" args))
+            (output (buffer-string)))
+        (unless (equal res 0)
+          (message "%s" output)
+          (error "Inferior Emacs exited with status %S" res))
+        output))))
+
+(defun macroexp-tests--eval-in-subprocess (file expr)
+  (let ((output (macroexp-tests--run-emacs
+                 "-l" file (format "--eval=(print %S)" expr))))
+    (car (read-from-string output))))
+
+(defun macroexp-tests--byte-compile-in-subprocess (file)
+  "Byte-compile FILE using a subprocess to avoid contaminating the lisp state."
+  (let ((output (macroexp-tests--run-emacs "-f" "batch-byte-compile" file)))
+    (when output
+      (message "%s" output))))
+
+(ert-deftest macroexp--tests-dynamic-variable-p ()
+  "Test `macroexp--dynamic-variable-p'."
+  (let* ((vk-el (ert-resource-file "vk.el"))
+         (vk-elc (concat vk-el "c"))
+         (expr '(list (vk-f1 0)
+                      (vk-f2 0)
+                      vk-val3
+                      (funcall vk-f4 0)
+                      (funcall vk-f5 0)
+                      (vk-f6)
+                      (vk-f7))))
+    ;; We compile and run the test in separate processes for complete
+    ;; isolation between test cases.
+    (should (equal (macroexp-tests--eval-in-subprocess vk-el expr)
+                   '((dyn dyn dyn dyn lex lex)
+                     (dyn dyn lex lex)
+                     (dyn dyn dyn dyn lex lex)
+                     (dyn dyn dyn dyn dyn)
+                     (dyn dyn dyn lex lex)
+                     (dyn dyn dyn dyn)
+                     (dyn dyn dyn lex))))
+    (macroexp-tests--byte-compile-in-subprocess vk-el)
+    (should (equal (macroexp-tests--eval-in-subprocess vk-elc expr)
+                   '((dyn dyn dyn dyn lex lex)
+                     (dyn dyn lex lex)
+                     (dyn dyn dyn dyn lex lex)
+                     (dyn dyn dyn dyn dyn)
+                     (dyn dyn dyn lex lex)
+                     (dyn dyn dyn dyn)
+                     (dyn dyn dyn lex))))))
 
-(provide 'macroexp-tests)
 ;;; macroexp-tests.el ends here