https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91285
--- Comment #4 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- Note that all the standard C pragmas are even more restricted than GCC's statement-like pragmas - the standard pragmas (which aren't implemented in GCC) are defined by the C standard to be allowed only "either outside external declarations or preceding all explicit declarations and statements inside a compound statement". The wider the range of contexts in which a pragma is permitted, the harder it is to define its semantics. For diagnostic pragmas, note that some diagnostics are associated with a *range* of locations within an expression, leading to obvious questions about the semantics if diagnostic pragma state varies within that range. (Though that could also arise when statement-like pragmas are used within the existing statement expression extension.)
