From: Johannes Doerfert <johannes@jdoerfert.de>
Date: Wed, 14 Oct 2020 18:54:20 +0000 (-0500)
Subject: [LangRef] Clarify `dereferenceable` -> `nonnull` implication
X-Git-Tag: llvmorg-13-init~7942
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=14077836ec0575320042585a80e4227bb0ee5be0;p=platform%2Fupstream%2Fllvm.git

[LangRef] Clarify `dereferenceable` -> `nonnull` implication

If `null_pointer_is_valid` is present, `dereferenceable` does not imply
`nonnull`, make it clear.

Came up in D17993.

Reviewed By: aqjune

Differential Revision: https://reviews.llvm.org/D89417
---

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index a70952d..7e3320b 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -1234,7 +1234,8 @@ Currently, only the following parameter attributes are defined:
     size of the pointee type. The ``nonnull`` attribute does not imply
     dereferenceability (consider a pointer to one element past the end of an
     array), however ``dereferenceable(<n>)`` does imply ``nonnull`` in
-    ``addrspace(0)`` (which is the default address space).
+    ``addrspace(0)`` (which is the default address space), except if the
+    ``null_pointer_is_valid`` function attribute is present.
 
 ``dereferenceable_or_null(<n>)``
     This indicates that the parameter or return value isn't both