Added a path-sensitive idempotent operation checker (-analyzer-idempotent-operation). Finds idempotent and/or tautological operations in a path sensitive context, flagging operations that have no effect or a predictable effect.

Example:
{
int a = 1;
int b = 5;
int c = b / a; // a is 1 on all paths
}

- New IdempotentOperationChecker class
- Moved recursive Stmt functions in r107675 to IdempotentOperationChecker
- Minor refactoring of SVal to allow checking for any integer
- Added command line option for check
- Added basic test cases

llvm-svn: 107706

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/Checker/AnalysisConsumer.cpp b/clang/lib/Checker/AnalysisConsumer.cpp
index 7c5f8ca56e1..35f5eecb38c 100644
--- a/clang/lib/Checker/AnalysisConsumer.cpp
+++ b/clang/lib/Checker/AnalysisConsumer.cpp
@@ -28,6 +28,7 @@
 #include "clang/Checker/PathSensitive/GRExprEngine.h"
 #include "clang/Checker/PathSensitive/GRTransferFuncs.h"
 #include "clang/Checker/PathDiagnosticClients.h"
+#include "GRExprEngineExperimentalChecks.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Frontend/AnalyzerOptions.h"
@@ -340,6 +341,9 @@ static void ActionGRExprEngine(AnalysisConsumer &C, AnalysisManager& mgr,
   if (C.Opts.EnableExperimentalChecks)
     RegisterExperimentalChecks(Eng);
 
+  if (C.Opts.EnableIdempotentOperationChecker)
+    RegisterIdempotentOperationChecker(Eng);
+
   // Set the graph auditor.
   llvm::OwningPtr<ExplodedNode::Auditor> Auditor;
   if (mgr.shouldVisualizeUbigraph()) {