[all-commits] [llvm/llvm-project] 217f0f: [Clang][Sema] Implement GCC -Wcast-function-type

[Yuanfang Chen via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 217f0f735afec57a51fa6f9ab863d4713a2f85e2
      https://github.com/llvm/llvm-project/commit/217f0f735afec57a51fa6f9ab863d4713a2f85e2
  Author: Yuanfang Chen <yuanfang.chen at sony.com>
  Date:   2021-03-24 (Wed, 24 Mar 2021)

  Changed paths:
    M clang/docs/DiagnosticsReference.rst
    M clang/include/clang/Basic/DiagnosticGroups.td
    M clang/include/clang/Basic/DiagnosticSemaKinds.td
    M clang/lib/Sema/SemaCast.cpp
    A clang/test/Sema/warn-cast-function-type.c
    A clang/test/Sema/warn-cast-function-type.cpp

  Log Message:
  -----------
  [Clang][Sema] Implement GCC -Wcast-function-type

```
Warn when a function pointer is cast to an incompatible function
pointer. In a cast involving function types with a variable argument
list only the types of initial arguments that are provided are
considered. Any parameter of pointer-type matches any other
pointer-type. Any benign differences in integral types are ignored, like
int vs. long on ILP32 targets. Likewise type qualifiers are ignored. The
function type void (*) (void) is special and matches everything, which
can be used to suppress this warning. In a cast involving pointer to
member types this warning warns whenever the type cast is changing the
pointer to member type. This warning is enabled by -Wextra.
```

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D97831