[clang] [clang][analyzer] Add checker 'alpha.core.FixedAddressDereference' (PR #127191)

[Balazs Benics via cfe-commits]

=?utf-8?q?Balázs_Kéri?= <balazs.keri at ericsson.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/127191 at github.com>


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@@ -2919,6 +2921,42 @@ Check for assignment of a fixed address to a pointer.
    p = (int *) 0x10000; // warn
  }
 
+.. _alpha-core-FixedAddressDereference:
+
+alpha.core.FixedAddressDereference (C, C++, ObjC)
+"""""""""""""""""""""""""""""""""""""""""""""""""
+Check for dereferences of fixed values used as pointers.
+
+Similarly as at :ref:`_core-NullDereference`, the checker specifically does
+not report dereferences for x86 and x86-64 targets when the
+address space is 256 (x86 GS Segment), 257 (x86 FS Segment), or 258 (x86 SS
+segment). (See `X86/X86-64 Language Extensions
+<https://clang.llvm.org/docs/LanguageExtensions.html#memory-references-to-specified-segments>`__
+for reference.)
+
+If you want to disable this behavior, set the ``SuppressAddressSpaces`` option
+of checker ``core.NullDereference`` to false, like
+``-analyzer-config core.NullDereference:SuppressAddressSpaces=false``. The value
+of this option is used for both checkers.
----------------
steakhal wrote:

This part of the doc feels less relevant than an example. I'd rather move this after the examples, as this fine-tunes the behavior.

https://github.com/llvm/llvm-project/pull/127191