This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Unicode 15.0 adds 4,489 characters, for a total of 149,186 characters.
These additions include 2 new scripts along with 20 new emoji characters,
and 4,193 CJK ideographs.
This changes modify most existing tables including
- XID_Start/XID_Continue in Clang
- The character name database (used by \N{} in Clang)
- The list of formattable/printable codepoints
- The case folding algorithm (which we had not updated since Unicode 9)
- The list of nonspacing/enclosing marks used by the column width
computation algorithm. The rest of the column width algorithm
is not updated.
Reviewed By: tahonermann
Differential Revision: https://reviews.llvm.org/D133807
Implements [[ https://wg21.link/p2071r1 | P2071 Named Universal Character Escapes ]] - as an extension in all language mode, the patch not warn in c++23 mode will be done later once this paper is plenary approved (in July).
We add
* A code generator that transforms `UnicodeData.txt` and `NameAliases.txt` to a space efficient data structure that can be queried in `O(NameLength)`
* A set of functions in `Unicode.h` to query that data, including
* A function to find an exact match of a given Unicode character name
* A function to perform a loose (ignoring case, space, underscore, medial hyphen) matching
* A function returning the best matching codepoint for a given string per edit distance
* Support of `\N{}` escape sequences in String and character Literals, with loose and typos diagnostics/fixits
* Support of `\N{}` as UCN with loose matching diagnostics/fixits.
Loose matching is considered an error to match closely the semantics of P2071.
The generated data contributes to 280kB of data to the binaries.
`UnicodeData.txt` and `NameAliases.txt` are not committed to the repository in this patch, and regenerating the data is a manual process.
Reviewed By: tahonermann
Differential Revision: https://reviews.llvm.org/D123064
