diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h
@@ -28,7 +28,9 @@
 namespace clang {
 namespace ento {
 
-enum CallDescriptionFlags : int {
+enum CallDescriptionFlags : unsigned {
+  CDF_None = 0,
+
   /// Describes a C standard function that is sometimes implemented as a macro
   /// that expands to a compiler builtin with some __builtin prefix.
   /// The builtin may as well have a few extra arguments on top of the requested
@@ -61,7 +63,8 @@
   /// @param RequiredArgs The number of arguments that is expected to match a
   /// call. Omit this parameter to match every occurrence of call with a given
   /// name regardless the number of arguments.
-  CallDescription(int Flags, ArrayRef<const char *> QualifiedName,
+  CallDescription(CallDescriptionFlags Flags,
+                  ArrayRef<const char *> QualifiedName,
                   MaybeUInt RequiredArgs = None,
                   MaybeUInt RequiredParams = None);
 
diff --git a/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp
@@ -72,42 +72,27 @@
                                                    SVal) const;
 
   CallDescriptionMap<NoItParamFn> NoIterParamFunctions = {
-    {{0, "clear", 0},
-     &ContainerModeling::handleClear},
-    {{0, "assign", 2},
-     &ContainerModeling::handleAssign},
-    {{0, "push_back", 1},
-     &ContainerModeling::handlePushBack},
-    {{0, "emplace_back", 1},
-     &ContainerModeling::handlePushBack},
-    {{0, "pop_back", 0},
-     &ContainerModeling::handlePopBack},
-    {{0, "push_front", 1},
-     &ContainerModeling::handlePushFront},
-    {{0, "emplace_front", 1},
-     &ContainerModeling::handlePushFront},
-    {{0, "pop_front", 0},
-     &ContainerModeling::handlePopFront},
+      {{"clear", 0}, &ContainerModeling::handleClear},
+      {{"assign", 2}, &ContainerModeling::handleAssign},
+      {{"push_back", 1}, &ContainerModeling::handlePushBack},
+      {{"emplace_back", 1}, &ContainerModeling::handlePushBack},
+      {{"pop_back", 0}, &ContainerModeling::handlePopBack},
+      {{"push_front", 1}, &ContainerModeling::handlePushFront},
+      {{"emplace_front", 1}, &ContainerModeling::handlePushFront},
+      {{"pop_front", 0}, &ContainerModeling::handlePopFront},
   };
-                                                          
+
   CallDescriptionMap<OneItParamFn> OneIterParamFunctions = {
-    {{0, "insert", 2},
-     &ContainerModeling::handleInsert},
-    {{0, "emplace", 2},
-     &ContainerModeling::handleInsert},
-    {{0, "erase", 1},
-     &ContainerModeling::handleErase},
-    {{0, "erase_after", 1},
-     &ContainerModeling::handleEraseAfter},
+      {{"insert", 2}, &ContainerModeling::handleInsert},
+      {{"emplace", 2}, &ContainerModeling::handleInsert},
+      {{"erase", 1}, &ContainerModeling::handleErase},
+      {{"erase_after", 1}, &ContainerModeling::handleEraseAfter},
   };
-                                                          
+
   CallDescriptionMap<TwoItParamFn> TwoIterParamFunctions = {
-    {{0, "erase", 2},
-     &ContainerModeling::handleErase},
-    {{0, "erase_after", 2},
-     &ContainerModeling::handleEraseAfter},
+      {{"erase", 2}, &ContainerModeling::handleErase},
+      {{"erase_after", 2}, &ContainerModeling::handleEraseAfter},
   };
-                                                          
 };
 
 bool isBeginCall(const FunctionDecl *Func);
diff --git a/clang/lib/StaticAnalyzer/Checkers/DebugContainerModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/DebugContainerModeling.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/DebugContainerModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/DebugContainerModeling.cpp
@@ -41,10 +41,10 @@
                                                  CheckerContext &) const;
 
   CallDescriptionMap<FnCheck> Callbacks = {
-    {{0, "clang_analyzer_container_begin", 1},
-     &DebugContainerModeling::analyzerContainerBegin},
-    {{0, "clang_analyzer_container_end", 1},
-     &DebugContainerModeling::analyzerContainerEnd},
+      {{"clang_analyzer_container_begin", 1},
+       &DebugContainerModeling::analyzerContainerBegin},
+      {{"clang_analyzer_container_end", 1},
+       &DebugContainerModeling::analyzerContainerEnd},
   };
 
 public:
diff --git a/clang/lib/StaticAnalyzer/Checkers/DebugIteratorModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/DebugIteratorModeling.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/DebugIteratorModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/DebugIteratorModeling.cpp
@@ -42,12 +42,12 @@
                                                  CheckerContext &) const;
 
   CallDescriptionMap<FnCheck> Callbacks = {
-    {{0, "clang_analyzer_iterator_position", 1},
-     &DebugIteratorModeling::analyzerIteratorPosition},
-    {{0, "clang_analyzer_iterator_container", 1},
-     &DebugIteratorModeling::analyzerIteratorContainer},
-    {{0, "clang_analyzer_iterator_validity", 1},
-     &DebugIteratorModeling::analyzerIteratorValidity},
+      {{"clang_analyzer_iterator_position", 1},
+       &DebugIteratorModeling::analyzerIteratorPosition},
+      {{"clang_analyzer_iterator_container", 1},
+       &DebugIteratorModeling::analyzerIteratorContainer},
+      {{"clang_analyzer_iterator_validity", 1},
+       &DebugIteratorModeling::analyzerIteratorValidity},
   };
 
 public:
diff --git a/clang/lib/StaticAnalyzer/Core/CallDescription.cpp b/clang/lib/StaticAnalyzer/Core/CallDescription.cpp
--- a/clang/lib/StaticAnalyzer/Core/CallDescription.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallDescription.cpp
@@ -34,7 +34,7 @@
   return None;
 }
 
-ento::CallDescription::CallDescription(int Flags,
+ento::CallDescription::CallDescription(CallDescriptionFlags Flags,
                                        ArrayRef<const char *> QualifiedName,
                                        MaybeUInt RequiredArgs /*= None*/,
                                        MaybeUInt RequiredParams /*= None*/)
@@ -50,7 +50,7 @@
 ento::CallDescription::CallDescription(ArrayRef<const char *> QualifiedName,
                                        MaybeUInt RequiredArgs /*= None*/,
                                        MaybeUInt RequiredParams /*= None*/)
-    : CallDescription(0, QualifiedName, RequiredArgs, RequiredParams) {}
+    : CallDescription(CDF_None, QualifiedName, RequiredArgs, RequiredParams) {}
 
 bool ento::CallDescription::matches(const CallEvent &Call) const {
   // FIXME: Add ObjC Message support.