This change expands testing of UTF-8, UTF-16, and UTF-32 character and string
literals as validation that WG14 N2728 (char16_t & char32_t string literals
shall be UTF-16 & UTF-32) has been implemented.
Reviewed By: cor3ntin, aaron.ballman
Differential Revision: https://reviews.llvm.org/D149098
This implements P2362, which has not yet been approved by the
C++ committee, but because wide-multi character literals are
implementation defined, clang might not have to wait for WG21.
This change is also being applied in C mode as the behavior is
implementation-defined in C as well and there's no benefit to
having different rules between the languages.
The other part of P2362, making non-representable character
literals ill-formed, is already implemented by clang
This commit improves Clang's diagnostics for string initialization.
Where it would previously say:
/tmp/a.c:3:9: error: array initializer must be an initializer list
wchar_t s[] = "Hi";
^
/tmp/a.c:4:6: error: array initializer must be an initializer list or string literal
char t[] = L"Hi";
^
It will now say
/tmp/a.c:3:9: error: initializing wide char array with non-wide string literal
wchar_t s[] = "Hi";
^
/tmp/a.c:4:6: error: initializing char array with wide string literal
char t[] = L"Hi";
^
As a bonus, it also fixes the fact that Clang would previously reject
this valid C11 code:
char16_t s[] = u"hi";
char32_t t[] = U"hi";
because it would only recognize the built-in types for char16_t and
char32_t, which do not exist in C.
llvm-svn: 181880
