[analyzer] Add pointer escape type param to checkPointerEscape callback

The checkPointerEscape callback previously did not specify how a
pointer escaped. This change includes an enum which describes the
different ways a pointer may escape. This enum is passed to the
checkPointerEscape callback when a pointer escapes. If the escape
is due to a function call, the call is passed. This changes
previous behavior where the call is passed as NULL if the escape
was due to indirectly invalidating the region the pointer referenced.

A patch by Branden Archer!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174677 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index 33553a1..9afd8cf 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -158,7 +158,8 @@
 
   ProgramStateRef checkPointerEscape(ProgramStateRef State,
                                     const InvalidatedSymbols &Escaped,
-                                    const CallEvent *Call) const;
+                                    const CallEvent *Call,
+                                    PointerEscapeKind Kind) const;
 
   void printState(raw_ostream &Out, ProgramStateRef State,
                   const char *NL, const char *Sep) const;
@@ -1450,11 +1451,15 @@
 
 ProgramStateRef MallocChecker::checkPointerEscape(ProgramStateRef State,
                                              const InvalidatedSymbols &Escaped,
-                                             const CallEvent *Call) const {
+                                             const CallEvent *Call,
+                                             PointerEscapeKind Kind) const {
   // If we know that the call does not free memory, keep tracking the top
   // level arguments.       
-  if (Call && doesNotFreeMemory(Call, State))
+  if ((Kind == PSK_DirectEscapeOnCall ||
+       Kind == PSK_IndirectEscapeOnCall) &&
+      doesNotFreeMemory(Call, State)) {
     return State;
+  }
 
   for (InvalidatedSymbols::const_iterator I = Escaped.begin(),
                                           E = Escaped.end();