[analyzer] Split the MallocChecker into two versions - pessimistic and

optimistic.

TODO: actually implement the pessimistic version of the checker. Ex: it
needs to assume that any function that takes a pointer might free it.

The optimistic version relies on annotations to tell us which functions
can free the pointer.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150111 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 22 insertions, 4 deletions

diff --git a/lib/StaticAnalyzer/Checkers/Checkers.td b/lib/StaticAnalyzer/Checkers/Checkers.td
index 24a79485c8..f130b2560c 100644
--- a/lib/StaticAnalyzer/Checkers/Checkers.td
+++ b/lib/StaticAnalyzer/Checkers/Checkers.td
@@ -282,8 +282,12 @@ def ChrootChecker : Checker<"Chroot">,
   HelpText<"Check improper use of chroot">,
   DescFile<"ChrootChecker.cpp">;
 
-def MallocChecker : Checker<"Malloc">,
-  HelpText<"Check for potential memory leaks, double free, and use-after-free problems">,
+def MallocOptimistic : Checker<"MallocWithAnnotations">,
+  HelpText<"Check for memory leaks, double free, and use-after-free problems. Assumes that all user-defined functions which might free a pointer are annotated.">,
+  DescFile<"MallocChecker.cpp">;
+
+def MallocPessimistic : Checker<"Malloc">,
+  HelpText<"Check for memory leaks, double free, and use-after-free problems.">,
   DescFile<"MallocChecker.cpp">;
 
 def MallocSizeofChecker : Checker<"MallocSizeof">,
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index 3e66929fdb..b14b400202 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -83,6 +83,16 @@ class MallocChecker : public Checker<check::DeadSymbols,
 
 public:
   MallocChecker() : II_malloc(0), II_free(0), II_realloc(0), II_calloc(0) {}
+
+  /// In pessimistic mode, the checker assumes that it does not know which
+  /// functions might free the memory.
+  struct ChecksFilter {
+    DefaultBool CMallocPessimistic;
+    DefaultBool CMallocOptimistic;
+  };
+
+  ChecksFilter Filter;
+
   void initIdentifierInfo(CheckerContext &C) const;
 
   void checkPostStmt(const CallExpr *CE, CheckerContext &C) const;
@@ -750,6 +760,10 @@ void MallocChecker::checkBind(SVal location, SVal val,
   }
 }
 
-void ento::registerMallocChecker(CheckerManager &mgr) {
-  mgr.registerChecker<MallocChecker>();
+#define REGISTER_CHECKER(name) \
+void ento::register##name(CheckerManager &mgr) {\
+  mgr.registerChecker<MallocChecker>()->Filter.C##name = true;\
 }
+
+REGISTER_CHECKER(MallocPessimistic)
+REGISTER_CHECKER(MallocOptimistic)