[analyzer] Allow IvarInvalidation checker to suppress warnings via

assertions.

To ensure that custom assertions/conditional would also be supported,
just check if the ivar that needs to be invalidated or set to nil is
compared against 0.

Unfortunately, this will not work for code containing 'assert(IvarName)'

llvm-svn: 172147

2 files changed, 35 insertions, 7 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/IvarInvalidationChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/IvarInvalidationChecker.cpp
index fd763d46f98..80cb58d76b8 100644
--- a/clang/lib/StaticAnalyzer/Checkers/IvarInvalidationChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/IvarInvalidationChecker.cpp
@@ -576,15 +576,23 @@ void IvarInvalidationChecker::MethodCrawler::VisitBinaryOperator(
     const BinaryOperator *BO) {
   VisitStmt(BO);
 
-  if (BO->getOpcode() != BO_Assign)
+  // Do we assign/compare against zero? If yes, check the variable we are
+  // assigning to.
+  BinaryOperatorKind Opcode = BO->getOpcode();
+  if (Opcode != BO_Assign &&
+      Opcode != BO_EQ &&
+      Opcode != BO_NE)
     return;
 
-  // Do we assign zero?
-  if (!isZero(BO->getRHS()))
-    return;
+  if (isZero(BO->getRHS())) {
+      check(BO->getLHS());
+      return;
+  }
 
-  // Check the variable we are assigning to.
-  check(BO->getLHS());
+  if (Opcode != BO_Assign && isZero(BO->getLHS())) {
+    check(BO->getRHS());
+    return;
+  }
 }
 
 void IvarInvalidationChecker::MethodCrawler::VisitObjCMessageExpr(
diff --git a/clang/test/Analysis/objc_invalidation.m b/clang/test/Analysis/objc_invalidation.m
index 8e9cd488a8c..f21bfdf474f 100644
--- a/clang/test/Analysis/objc_invalidation.m
+++ b/clang/test/Analysis/objc_invalidation.m
@@ -1,4 +1,10 @@
 // RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.osx.cocoa.InstanceVariableInvalidation -fobjc-default-synthesize-properties -verify %s
+extern void __assert_fail (__const char *__assertion, __const char *__file,
+    unsigned int __line, __const char *__function)
+     __attribute__ ((__noreturn__));
+
+#define assert(expr) \
+  ((expr)  ? (void)(0)  : __assert_fail (#expr, __FILE__, __LINE__, __func__))
 
 @protocol NSObject
 @end
@@ -168,10 +174,24 @@ extern void NSLog(NSString *format, ...) __attribute__((format(__NSString__, 1,
 @interface Child: Parent <Invalidation2, IDEBuildable> 
 @end
 
-@implementation Parent
+@implementation Parent{
+  @private
+  Invalidation2Class *Ivar10;
+  Invalidation2Class *Ivar11;
+  Invalidation2Class *Ivar12;
+}
+
 @synthesize ObjB = _ObjB;
 - (void)invalidate{
   _ObjB = ((void*)0);
+  
+  assert(Ivar10 == 0);
+
+  if (__builtin_expect(!(Ivar11 == ((void*)0)), 0))
+    assert(0);
+
+  assert(0 == Ivar12);
+
 }
 @end