Index: cfe/trunk/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
===================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
@@ -1304,6 +1304,21 @@
                               DoNothing, DoNothing);
 }
 
+/// Returns true if the declaration 'D' is annotated with 'rcAnnotation'.
+static bool hasRCAnnotation(const Decl *D, StringRef rcAnnotation) {
+  for (const auto *Ann : D->specific_attrs<AnnotateAttr>()) {
+    if (Ann->getAnnotation() == rcAnnotation)
+      return true;
+  }
+  return false;
+}
+
+/// Returns true if the function declaration 'FD' contains
+/// 'rc_ownership_trusted_implementation' annotate attribute.
+static bool isTrustedReferenceCountImplementation(const FunctionDecl *FD) {
+  return hasRCAnnotation(FD, "rc_ownership_trusted_implementation");
+}
+
 //===----------------------------------------------------------------------===//
 // Summary creation for Selectors.
 //===----------------------------------------------------------------------===//
@@ -3380,6 +3395,9 @@
 
   // See if it's one of the specific functions we know how to eval.
   bool canEval = false;
+  // See if the function has 'rc_ownership_trusted_implementation'
+  // annotate attribute. If it does, we will not inline it.
+  bool hasTrustedImplementationAnnotation = false;
 
   QualType ResultTy = CE->getCallReturnType(C.getASTContext());
   if (ResultTy->isObjCIdType()) {
@@ -3395,6 +3413,11 @@
         cocoa::isRefType(ResultTy, "CV", FName)) {
       canEval = isRetain(FD, FName) || isAutorelease(FD, FName) ||
                 isMakeCollectable(FD, FName);
+    } else {
+      if (FD->getDefinition()) {
+        canEval = isTrustedReferenceCountImplementation(FD->getDefinition());
+        hasTrustedImplementationAnnotation = canEval;
+      }
     }
   }
 
@@ -3404,8 +3427,11 @@
   // Bind the return value.
   const LocationContext *LCtx = C.getLocationContext();
   SVal RetVal = state->getSVal(CE->getArg(0), LCtx);
-  if (RetVal.isUnknown()) {
-    // If the receiver is unknown, conjure a return value.
+  if (RetVal.isUnknown() ||
+      (hasTrustedImplementationAnnotation && !ResultTy.isNull())) {
+    // If the receiver is unknown or the function has
+    // 'rc_ownership_trusted_implementation' annotate attribute, conjure a
+    // return value.
     SValBuilder &SVB = C.getSValBuilder();
     RetVal = SVB.conjureSymbolVal(nullptr, CE, LCtx, ResultTy, C.blockCount());
   }
@@ -3421,8 +3447,9 @@
       Binding = getRefBinding(state, Sym);
 
     // Invalidate the argument region.
-    state = state->invalidateRegions(ArgRegion, CE, C.blockCount(), LCtx,
-                                     /*CausesPointerEscape*/ false);
+    state = state->invalidateRegions(
+        ArgRegion, CE, C.blockCount(), LCtx,
+        /*CausesPointerEscape*/ hasTrustedImplementationAnnotation);
 
     // Restore the refcount status of the argument.
     if (Binding)
Index: cfe/trunk/test/Analysis/retain-release-inline.m
===================================================================
--- cfe/trunk/test/Analysis/retain-release-inline.m
+++ cfe/trunk/test/Analysis/retain-release-inline.m
@@ -12,7 +12,7 @@
 //
 // It includes the basic definitions for the test cases below.
 //===----------------------------------------------------------------------===//
-
+#define NULL 0
 typedef unsigned int __darwin_natural_t;
 typedef unsigned long uintptr_t;
 typedef unsigned int uint32_t;
@@ -267,6 +267,10 @@
 
 extern CFStringRef CFStringCreateWithCStringNoCopy(CFAllocatorRef alloc, const char *cStr, CFStringEncoding encoding, CFAllocatorRef contentsDeallocator);
 
+typedef struct {
+  int ref;
+} isl_basic_map;
+
 //===----------------------------------------------------------------------===//
 // Test cases.
 //===----------------------------------------------------------------------===//
@@ -285,6 +289,7 @@
   foo(s);
   bar(s);
 }
+
 void test_neg() {
   NSString *s = [[NSString alloc] init]; // no-warning  
   foo(s);
@@ -294,6 +299,55 @@
   bar(s);
 }
 
+__attribute__((cf_returns_retained)) isl_basic_map *isl_basic_map_cow(__attribute__((cf_consumed)) isl_basic_map *bmap);
+void free(void *);
+
+// As 'isl_basic_map_free' is annotated with 'rc_ownership_trusted_implementation', RetainCountChecker trusts its
+// implementation and doesn't analyze its body. If the annotation 'rc_ownership_trusted_implementation' is removed,
+// a leak warning is raised by RetainCountChecker as the analyzer is unable to detect a decrement in the reference
+// count of 'bmap' along the path in 'isl_basic_map_free' assuming the predicate of the second 'if' branch to be
+// true or assuming both the predicates in the function to be false.
+__attribute__((annotate("rc_ownership_trusted_implementation"))) isl_basic_map *isl_basic_map_free(__attribute__((cf_consumed)) isl_basic_map *bmap) {
+  if (!bmap)
+    return NULL;
+
+  if (--bmap->ref > 0)
+    return NULL;
+
+  free(bmap);
+  return NULL;
+}
+
+// As 'isl_basic_map_copy' is annotated with 'rc_ownership_trusted_implementation', RetainCountChecker trusts its
+// implementation and doesn't analyze its body. If that annotation is removed, a 'use-after-release' warning might
+// be raised by RetainCountChecker as the pointer which is passed as an argument to this function and the pointer
+// which is returned from the function point to the same memory location.
+__attribute__((annotate("rc_ownership_trusted_implementation"))) __attribute__((cf_returns_retained)) isl_basic_map *isl_basic_map_copy(isl_basic_map *bmap) {
+  if (!bmap)
+    return NULL;
+
+  bmap->ref++;
+  return bmap;
+}
+
+void test_use_after_release_with_trusted_implementation_annotate_attribute(__attribute__((cf_consumed)) isl_basic_map *bmap) {
+  // After this call, 'bmap' has a +1 reference count.
+  bmap = isl_basic_map_cow(bmap);
+  // After the call to 'isl_basic_map_copy', 'bmap' has a +1 reference count.
+  isl_basic_map *temp = isl_basic_map_cow(isl_basic_map_copy(bmap));
+  // After this call, 'bmap' has a +0 reference count.
+  isl_basic_map *temp2 = isl_basic_map_cow(bmap); // no-warning
+  isl_basic_map_free(temp2);
+  isl_basic_map_free(temp);
+}
+
+void test_leak_with_trusted_implementation_annotate_attribute(__attribute__((cf_consumed)) isl_basic_map *bmap) {
+  // After this call, 'bmap' has a +1 reference count.
+  bmap = isl_basic_map_cow(bmap); // no-warning
+  // After this call, 'bmap' has a +0 reference count.
+  isl_basic_map_free(bmap);
+}
+
 //===----------------------------------------------------------------------===//
 // Test returning retained and not-retained values.
 //===----------------------------------------------------------------------===//