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
5da7c04 introduced a regression in the NOLINT macro checking loop, replacing the
call to `getImmediateExpansionRange().getBegin()` with
`getImmediateMacroCallerLoc()`, which has similar but subtly different
behaviour.
The consequence is that NOLINTs cannot suppress diagnostics when they are
attached to a token that came from a macro **argument**, rather than elsewhere
in the macro expansion.
Revert to pre-patch behaviour and add test cases to cover this issue.
Differential Revision: https://reviews.llvm.org/D126138
Support for NOLINT(BEGIN/END) blocks (implemented in D108560) is
currently costly. This patch aims to improve the performance with the
following changes:
- The use of tokenized NOLINTs instead of a series of repetitive ad-hoc
string operations (`find()`, `split()`, `slice()`, regex matching etc).
- The caching of NOLINT(BEGIN/END) block locations. Determining these
locations each time a new diagnostic is raised is wasteful as it
requires reading and parsing the entire source file.
Move NOLINT-specific code from `ClangTidyDiagnosticConsumer` to new
purpose-built class `NoLintDirectiveHandler`.
Differential Revision: https://reviews.llvm.org/D116085