From efdb7fe53b14a3689a0b0fb50e5f0551aa606d15 Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Tue, 10 May 2011 22:10:35 +0000
Subject: [PATCH] Fix crash in -Wuninitialized when using switch statments
 whose condition is a logical operation.

llvm-svn: 131158
---
 clang/lib/Analysis/UninitializedValues.cpp | 14 +++++++++-----
 clang/test/Sema/uninit-variables.c         | 13 +++++++++++++
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/clang/lib/Analysis/UninitializedValues.cpp b/clang/lib/Analysis/UninitializedValues.cpp
index 88a2db751a43..fc0b904c83cd 100644
--- a/clang/lib/Analysis/UninitializedValues.cpp
+++ b/clang/lib/Analysis/UninitializedValues.cpp
@@ -214,11 +214,15 @@ static BinaryOperator *getLogicalOperatorInChain(const CFGBlock *block) {
   if (!b || !b->isLogicalOp())
     return 0;
   
-  if (block->pred_size() == 2 &&
-      ((block->succ_size() == 2 && block->getTerminatorCondition() == b) ||
-       block->size() == 1))
-    return b;
-  
+  if (block->pred_size() == 2) {
+    if (block->getTerminatorCondition() == b) {
+      if (block->succ_size() == 2)
+      return b;
+    }
+    else if (block->size() == 1)
+      return b;
+  }
+
   return 0;
 }
 
diff --git a/clang/test/Sema/uninit-variables.c b/clang/test/Sema/uninit-variables.c
index 60cae802ae73..b70a29519c41 100644
--- a/clang/test/Sema/uninit-variables.c
+++ b/clang/test/Sema/uninit-variables.c
@@ -339,3 +339,16 @@ int test51(void)
     return a; // no-warning
 }
 
+// FIXME: This is a false positive, but it tests logical operations in switch statements.
+int test52(int a, int b) {
+  int x;  // expected-note {{variable 'x' is declared here}} expected-note {{add initialization to silence this warning}}
+  switch (a || b) { // expected-warning {{switch condition has boolean value}}
+    case 0:
+      x = 1;
+      break;
+    case 1:
+      x = 2;
+      break;
+  }
+  return x; // expected-warning {{variable 'x' may be uninitialized when used here}}
+}