Fix compilation error with simultaneous dynamic+lexical scoping.

Add warning when a defvar appears after the first let-binding.
* lisp/emacs-lisp/bytecomp.el (byte-compile-lexical-variables): New var.
(byte-compile-close-variables): Initialize it.
(byte-compile--declare-var): New function.
(byte-compile-file-form-defvar)
(byte-compile-file-form-define-abbrev-table)
(byte-compile-file-form-custom-declare-variable): Use it.
(byte-compile-make-lambda-lexenv): Change the argument.  Simplify.
(byte-compile-lambda): Share call to byte-compile-arglist-vars.
(byte-compile-bind): Handle dynamic bindings that shadow
lexical bindings.
(byte-compile-unbind): Make arg non-optional.
(byte-compile-let): Simplify.
* lisp/emacs-lisp/cconv.el (byte-compile-lexical-variables): Declare var.
(cconv--analyse-function, cconv-analyse-form): Populate it.
Protect byte-compile-bound-variables to limit the scope of defvars.
(cconv-analyse-form): Add missing rule for (defvar <foo>).
Remove unneeded rule for `declare'.

* lisp/emacs-lisp/cl-macs.el (cl--compiler-macro-adjoin): Use macroexp-let2
so as to avoid depending on cl-adjoin at run-time.
* lisp/emacs-lisp/cl-lib.el (cl-pushnew): Use backquotes.

* lisp/emacs-lisp/macroexp.el (macroexp--compiling-p): New function.
(macroexp--warn-and-return): Use it.

1 files changed, 10 insertions, 5 deletions

diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el
index 6bb796434fd..e8b513fcd3e 100644
--- a/lisp/emacs-lisp/macroexp.el
+++ b/lisp/emacs-lisp/macroexp.el
@@ -111,15 +111,20 @@ and also to avoid outputting the warning during normal execution."
        (funcall (eval (cadr form)))
        (byte-compile-constant nil)))
 
+(defun macroexp--compiling-p ()
+  "Return non-nil if we're macroexpanding for the compiler."
+  ;; FIXME: ¡¡Major Ugly Hack!! To determine whether the output of this
+  ;; macro-expansion will be processed by the byte-compiler, we check
+  ;; circumstantial evidence.
+  (member '(declare-function . byte-compile-macroexpand-declare-function)
+          macroexpand-all-environment))
+
+
 (defun macroexp--warn-and-return (msg form)
   (let ((when-compiled (lambda () (byte-compile-log-warning msg t))))
     (cond
      ((null msg) form)
-     ;; FIXME: ¡¡Major Ugly Hack!! To determine whether the output of this
-     ;; macro-expansion will be processed by the byte-compiler, we check
-     ;; circumstantial evidence.
-     ((member '(declare-function . byte-compile-macroexpand-declare-function)
-                macroexpand-all-environment)
+     ((macroexp--compiling-p)
       `(progn
          (macroexp--funcall-if-compiled ',when-compiled)
          ,form))