Built-in macros that execute arbitrary code

[Eshel Yaron]

Hi all,

Yesterday I found out about another built-in macro that can execute
arbitrary code during macro-expansion: cl-macrolet.  Here's a simple
example of (ab)using this macro to create a file during macro-expansion:

(cl-macrolet ((foo () (call-process "touch" nil nil nil "/tmp/owned")))
  (foo))

This expands to just 0 after "touch"ing the file /tmp/owned.  Note that
this happens during macro-expansion, not in runtime.

So the built-in macros I currently know of that run arbitrary code are:

static-if, cl-eval-when, eval-when-compile, eval-and-compile,
let-when-compile, rx, cl-macrolet.

Any others that I missed?


Regards,

Eshel