[all-commits] [llvm/llvm-project] 41ce74: [Clang][Sema] Add -Wincompatible-function-pointer-...

[Sami Tolvanen via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 41ce74e6e983f523d44d3a80be5ae778c35df85a
      https://github.com/llvm/llvm-project/commit/41ce74e6e983f523d44d3a80be5ae778c35df85a
  Author: Sami Tolvanen <samitolvanen at google.com>
  Date:   2022-11-07 (Mon, 07 Nov 2022)

  Changed paths:
    M clang/docs/ReleaseNotes.rst
    M clang/include/clang/Basic/DiagnosticSemaKinds.td
    M clang/include/clang/Sema/Sema.h
    M clang/lib/Sema/SemaExpr.cpp
    A clang/test/Sema/incompatible-function-pointer-types-strict.c

  Log Message:
  -----------
  [Clang][Sema] Add -Wincompatible-function-pointer-types-strict

Clang supports indirect call Control-Flow Integrity (CFI) sanitizers
(e.g. -fsanitize=cfi-icall), which enforce an exact type match
between a function pointer and the target function. Unfortunately,
Clang doesn't provide diagnostics that help developers avoid
function pointer assignments that can lead to runtime CFI
failures. -Wincompatible-function-pointer-types doesn't warn about
enum to integer mismatches if the types are otherwise compatible, for
example, which isn't sufficient with CFI.

Add -Wincompatible-function-pointer-types-strict, which checks for a
stricter function type compatibility in assignments and helps warn about
assignments that can potentially lead to CFI failures.

Reviewed By: aaron.ballman, nickdesaulniers

Differential Revision: https://reviews.llvm.org/D136790