expression inside the parentheses is a valid UTF-8 string literal.
Previously clang emitted an expression like @("abc") as a message send
to stringWithUTF8String. This commit makes clang emit the boxed
expression as a compile-time constant instead.
This commit also has the effect of silencing the nullable-to-nonnull
conversion warning clang started emitting after r317727, which
originally motivated this commit (see https://oleb.net/2018/@keypath).
rdar://problem/42684601
Differential Revision: https://reviews.llvm.org/D58729
llvm-svn: 355662
Objective-C NSString has a class method stringWithUTF8String that creates a new
NSString from a C string. Objective-C box expression @(...) can be used to
create an NSString instead of invoking the stringWithUTF8String method directly
(The compiler lowers it down to the invocation though). This commit ensures that
the type of @(string-value) gets the same nullability attributes as the return
type of stringWithUTF8String to ensure that the diagnostics are consistent
between the two.
rdar://33847186
Differential Revision: https://reviews.llvm.org/D39762
llvm-svn: 317727
Akira Hatanaka