Clang has traditionally allowed C programs to implicitly convert
integers to pointers and pointers to integers, despite it not being
valid to do so except under special circumstances (like converting the
integer 0, which is the null pointer constant, to a pointer). In C89,
this would result in undefined behavior per 3.3.4, and in C99 this rule
was strengthened to be a constraint violation instead. Constraint
violations are most often handled as an error.
This patch changes the warning to default to an error in all C modes
(it is already an error in C++). This gives us better security posture
by calling out potential programmer mistakes in code but still allows
users who need this behavior to use -Wno-error=int-conversion to retain
the warning behavior, or -Wno-int-conversion to silence the diagnostic
entirely.
Differential Revision: https://reviews.llvm.org/D129881
Eliminate clutter by reorganizing the Lit test files for clang-tidy:
- Move checkers/<module>-* to checkers/<module>/*.
- Move module specific inputs from Inputs to <module>/Inputs. Remove
any module prefix from the file or subdirectory name as they are no
longer needed.
- Introduce a Lit substitution %clang_tidy_headers for the system
headers in checkers/Inputs/Headers and use this throughout. This
avoids referencing system headers through a relative path to the
parent directory and makes it clear that these fake system headers are
shared among all modules.
- Update add_new_check.py to follow the above conventions when creating
the boiler plate test files for a new check.
- Update Contributing.rst to describe per-module Inputs directory and
fix link to test source code.
Differential Revision: https://reviews.llvm.org/D128072
Aaron Ballman