Correctly macroexpand top-level forms during eager macroexpand

* lisp/emacs-lisp/byte-run.el (eval-when-compile, eval-and-compile):
Improve docstrings.

* lisp/emacs-lisp/macroexp.el (internal-macroexpand-for-load): Add
`full-p' parameter; when nil, call `macroexpand' instead of
`macroexpand-all'.

* src/lread.c (readevalloop_eager_expand_eval): New function
that can recurse into toplevel forms.
(readevalloop): Call it.
* src/lisp.h: Declare Qprogn.
* src/callint.c (Qprogn): No longer static.

* test/automated/bytecomp-tests.el (test-byte-comp-compile-and-load):
Add compile flag.
(test-byte-comp-macro-expansion)
(test-byte-comp-macro-expansion-eval-and-compile)
(test-byte-comp-macro-expansion-eval-when-compile)
(test-byte-comp-macro-expand-lexical-override): Use it.
(test-eager-load-macro-expansion)
(test-eager-load-macro-expansion-eval-and-compile)
(test-eager-load-macro-expansion-eval-when-compile)
(test-eager-load-macro-expand-lexical-override): New tests.

2 files changed, 14 insertions, 5 deletions

diff --git a/lisp/emacs-lisp/byte-run.el b/lisp/emacs-lisp/byte-run.el
index dc08b870569..be011e2146c 100644
--- a/lisp/emacs-lisp/byte-run.el
+++ b/lisp/emacs-lisp/byte-run.el
@@ -398,13 +398,20 @@ If you think you need this, you're probably making a mistake somewhere."
 
 (defmacro eval-when-compile (&rest body)
   "Like `progn', but evaluates the body at compile time if you're compiling.
-Thus, the result of the body appears to the compiler as a quoted constant.
-In interpreted code, this is entirely equivalent to `progn'."
+Thus, the result of the body appears to the compiler as a quoted
+constant.  In interpreted code, this is entirely equivalent to
+`progn', except that the value of the expression may be (but is
+not necessarily) computed at load time if eager macro expansion
+is enabled."
   (declare (debug (&rest def-form)) (indent 0))
   (list 'quote (eval (cons 'progn body) lexical-binding)))
 
 (defmacro eval-and-compile (&rest body)
-  "Like `progn', but evaluates the body at compile time and at load time."
+  "Like `progn', but evaluates the body at compile time and at
+load time.  In interpreted code, this is entirely equivalent to
+`progn', except that the value of the expression may be (but is
+not necessarily) computed at load time if eager macro expansion
+is enabled."
   (declare (debug t) (indent 0))
   ;; When the byte-compiler expands code, this macro is not used, so we're
   ;; either about to run `body' (plain interpretation) or we're doing eager
diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el
index c2bfc891b72..44727daf76a 100644
--- a/lisp/emacs-lisp/macroexp.el
+++ b/lisp/emacs-lisp/macroexp.el
@@ -405,7 +405,7 @@ symbol itself."
 (defvar macroexp--pending-eager-loads nil
   "Stack of files currently undergoing eager macro-expansion.")
 
-(defun internal-macroexpand-for-load (form)
+(defun internal-macroexpand-for-load (form full-p)
   ;; Called from the eager-macroexpansion in readevalloop.
   (cond
    ;; Don't repeat the same warning for every top-level element.
@@ -428,7 +428,9 @@ symbol itself."
     (condition-case err
         (let ((macroexp--pending-eager-loads
                (cons load-file-name macroexp--pending-eager-loads)))
-          (macroexpand-all form))
+          (if full-p
+              (macroexpand-all form)
+            (macroexpand form)))
       (error
        ;; Hopefully this shouldn't happen thanks to the cycle detection,
        ;; but in case it does happen, let's catch the error and give the