By default,-Wunused can be satisfied by a usage introduced by a macro expansion.

This is the revised behavior under-Wmacros:default. Previously, the default setting was-Wmacros:before, to lint only before any macros are expanded. The new behavior may reduce the need to suppress warnings.

Previously,-Wmacros:after could be used to lint only the expansion, but if the expansion introduces more unused definitions, then those will generate warnings under that mode.

Note that linting the macro expansion will also warn for-Xlint:missing-interpolator, since 2.13.14. Macros for test assertions that capture interpolations as regular string literals will warn. For example, if a macro transforms

val world = "world"assert(s"Hello, $world!".contains("Hell"))

into

assert(s"Hello, $world!".contains("Hell"), "Failed test: " + """s"Hello, $world!".contains("Hell")""")

Fixesscala/bug#12953