[clang-tidy] Improve sizeof(pointer) handling in bugprone-sizeof-expression

clang-tools-extra/docs/ReleaseNotes.rst

@@ -227,6 +227,12 @@ Changes in existing checks
   <clang-tidy/checks/bugprone/optional-value-conversion>` check by eliminating
   false positives resulting from use of optionals in unevaluated context.
 
+- Improved :doc:`bugprone-sizeof-expression
+  <clang-tidy/checks/bugprone/sizeof-expression>` check by eliminating some
+  false positives and adding a new (off-by-default) option
+  ``WarnOnSizeOfPointer`` that reports all ``sizeof(pointer)`` expressions
+  (except for a few that are idiomatic).
+
 - Improved :doc:`bugprone-suspicious-include
   <clang-tidy/checks/bugprone/suspicious-include>` check by replacing the local
   options `HeaderFileExtensions` and `ImplementationFileExtensions` by the

clang-tools-extra/docs/clang-tidy/checks/bugprone/sizeof-expression.rst

@@ -190,11 +190,15 @@ Options
 
 .. option:: WarnOnSizeOfPointerToAggregate
 
-   When `true`, the check will warn on an expression like
-   ``sizeof(expr)`` where the expression is a pointer
-   to aggregate. Default is `true`.
+   When `true`, the check will warn when the argument of ``sizeof`` is either a
+   pointer-to-aggregate type, an expression returning a pointer-to-aggregate
+   value or an expression that returns a pointer from an array-to-pointer
+   conversion (that may be implicit or explicit, for example ``array + 2`` or
+   ``(int *)array``). Default is `true`.
 
 .. option:: WarnOnSizeOfPointer
 
-   When `true`, the check will warn on an expression like ``sizeof(expr)``
-   where the expression is a pointer. Default is `false`.
+   When `true`, the check will report all expressions where the argument of
+   ``sizeof`` is an expression that produces a pointer (except for a few
+   idiomatic expressions that are probably intentional and correct).
+   This detects occurrences of CWE 467. Default is `false`.