From: Chandler Carruth <chandlerc@gmail.com>
Date: Fri, 4 Nov 2016 06:11:54 +0000 (+0000)
Subject: Add an assert to further check the invariant that a null pointer
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=bff9f7176a483c4f85fe486ad38eddd700deffb2;p=clang

Add an assert to further check the invariant that a null pointer
corresponds to another argument being valid.

This makes it clear that the code is correct despite the PVS-Studio
report that a pointer might be dereferenced prior to being checked for
whether it is null. It likely is also enough for static analyzers to not
flag the code.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@285982 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index d208a322c8..e7d0d2f6b0 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -2539,6 +2539,10 @@ ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
                                       SourceLocation RBracLoc,
                                       MultiExprArg ArgsIn,
                                       bool isImplicit) {
+  assert((Receiver || SuperLoc.isValid()) && "If the Receiver is null, the "
+                                             "SuperLoc must be valid so we can "
+                                             "use it instead.");
+
   // The location of the receiver.
   SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();
   SourceRange RecRange =