[static analyzer] add a simple "CallEffects" API to query the retain count semantics of a method.

This is intended to be a simplified API, whose internals are
deliberately less efficient for the purpose of a simplified interface,
for use with clients that want to query the analyzer's heuristics for
determining retain count semantics.

There are no immediate clients, but it is intended to be used
by the ObjC modernizer.

llvm-svn: 188433

1 files changed, 44 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
index f337a903e98..1a1fa4e2e9a 100644
--- a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
@@ -317,6 +317,16 @@ public:
 
     return DefaultArgEffect;
   }
+
+  /// Return the number of argument effects.  This is O(n) in the number
+  /// of arguments.
+  unsigned getNumArgs() const {
+    unsigned N = 0;
+    for (ArgEffects::iterator I = Args.begin(), E = Args.end(); I != E; ++I) {
+      ++N;
+    };
+    return N;
+  }
   
   void addArg(ArgEffects::Factory &af, unsigned idx, ArgEffect e) {
     Args = af.add(Args, idx, e);
@@ -3675,3 +3685,37 @@ void ento::registerRetainCountChecker(CheckerManager &Mgr) {
   Mgr.registerChecker<RetainCountChecker>(Mgr.getAnalyzerOptions());
 }
 
+//===----------------------------------------------------------------------===//
+// Implementation of the CallEffects API.
+//===----------------------------------------------------------------------===//
+
+namespace clang { namespace ento { namespace objc_retain {
+
+// This is a bit gross, but it allows us to populate CallEffects without
+// creating a bunch of accessors.  This kind is very localized, so the
+// damage of this macro is limited.
+#define createCallEffect(D, KIND)\
+  ASTContext &Ctx = D->getASTContext();\
+  LangOptions L = Ctx.getLangOpts();\
+  RetainSummaryManager M(Ctx, L.GCOnly, L.ObjCAutoRefCount);\
+  const RetainSummary *S = M.get ## KIND ## Summary(D);\
+  CallEffects CE(S->getRetEffect());\
+  CE.Receiver = S->getReceiverEffect();\
+  unsigned N = S->getNumArgs();\
+  for (unsigned i = 0; i < N; ++i) {\
+    CE.Args.push_back(S->getArg(i));\
+  }
+
+CallEffects CallEffects::getEffect(const ObjCMethodDecl *MD) {
+  createCallEffect(MD, Method);
+  return CE;
+}
+
+CallEffects CallEffects::getEffect(const FunctionDecl *FD) {
+  createCallEffect(FD, Function);
+  return CE;
+}
+
+#undef createCallEffect
+
+}}}