8.2.1 Redefined M4 Macros

All the M4 native macros are moved in the `m4_' pseudo-namespace, e.g., M4sugar renames define as m4_define etc. There is one exception: dnl kept its original name, and no m4_dnl is defined.

M4sugar redefines some M4 macros, and made them slightly incompatible with their native equivalent.

Macro: m4_defn (macro)

Contrary to the M4 builtin, this macro fails if macro is not defined. See m4_undefine.

Macro: m4_undefine (macro)

Contrary to the M4 builtin, this macro fails if macro is not defined. Use

m4_ifdef([macro], [m4_undefine([macro])])

to recover the behavior of the builtin.

Macro: m4_popdef (macro)

Contrary to the M4 builtin, this macro fails if macro is not defined. See m4_undefine.