This patch adds a new preprocessor extension ``#pragma clang final``
which enables warning on undefinition and re-definition of macros.
The intent of this warning is to extend beyond ``-Wmacro-redefined`` to
warn against any and all alterations to macros that are marked `final`.
This warning is part of the ``-Wpedantic-macros`` diagnostics group.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D108567
This patch adds `#pragma clang restrict_expansion ` to enable flagging
macros as unsafe for header use. This is to allow macros that may have
ABI implications to be avoided in headers that have ABI stability
promises.
Using macros in headers (particularly public headers) can cause a
variety of issues relating to ABI and modules. This new pragma logs
warnings when using annotated macros outside the main source file.
This warning is added under a new diagnostics group -Wpedantic-macros
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D107095
Chris Bieneman