From: Ted Kremenek <kremenek@apple.com>
Date: Thu, 27 Feb 2014 00:24:03 +0000 (+0000)
Subject: [CFG] Encode unreachable block information for successors when visiting 'if' statements.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5610fa2f6a3f7f17667fa78a595489ed87809f46;p=clang

[CFG] Encode unreachable block information for successors when visiting 'if' statements.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@202326 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 72272c0d34..0251927cc5 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -1880,9 +1880,10 @@ CFGBlock *CFGBuilder::VisitIfStmt(IfStmt *I) {
   // See if this is a known constant.
   const TryResult &KnownVal = tryEvaluateBool(I->getCond());
 
-  // Now add the successors.
-  addSuccessor(Block, KnownVal.isFalse() ? NULL : ThenBlock);
-  addSuccessor(Block, KnownVal.isTrue()? NULL : ElseBlock);
+  // Add the successors.  If we know that specific branches are
+  // unreachable, inform addSuccessor() of that knowledge.
+  addSuccessor(Block, ThenBlock, /* isReachable = */ !KnownVal.isFalse());
+  addSuccessor(Block, ElseBlock, /* isReachable = */ !KnownVal.isTrue());
 
   // Add the condition as the last statement in the new block.  This may create
   // new blocks as the condition may contain control-flow.  Any newly created