Explicitly state the behavior of inbounds with a null pointer.

Eli Friedman · Eli Friedman · commit 13f2e353110c · 2017-02-23T00:48:18.000Z
See https://llvm.org/bugs/show_bug.cgi?id=31439; this reflects LLVM's behavior in practice, and should be compatible with C/C++ rules. Differential Revision: https://reviews.llvm.org/D28026 llvm-svn: 295916
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
@@ -7734,8 +7734,10 @@ offsets implied by the indices to the base address with infinitely
 precise signed arithmetic are not an *in bounds* address of that
 allocated object. The *in bounds* addresses for an allocated object are
 all the addresses that point into the object, plus the address one byte
-past the end. In cases where the base is a vector of pointers the
-``inbounds`` keyword applies to each of the computations element-wise.
+past the end. The only *in bounds* address for a null pointer in the
+default address-space is the null pointer itself. In cases where the
+base is a vector of pointers the ``inbounds`` keyword applies to each
+of the computations element-wise.
 
 If the ``inbounds`` keyword is not present, the offsets are added to the
 base address with silently-wrapping two's complement arithmetic. If the
