Executes forms from left to right. Within the dynamic environment of with-compilation-unit, actions deferred by the compiler until the end of compilation will be deferred until the end of the outermost call to with-compilation-unit.
If nested dynamically only the outer call to with-compilation-unit has any effect unless the value associated with
:override is true, in which case warnings are deferred only to the end of the innermost call for which override is true.
Any implementation-dependent extensions can only be provided as the result of an explicit programmer request by use of an implementation-dependent keyword. Implementations are forbidden from attaching additional meaning to a use of this macro which involves either no keywords or just the keyword
If an implementation would normally defer certain kinds of warnings, such as warnings about undefined functions, to the end of a compilation unit (such as a file), the following example shows how to cause those warnings to be deferred to the end of the compilation of several files.
(compile-files "A" "B" "C")
Note however that if the implementation does not normally defer any warnings, use of with-compilation-unit might not have any effect.