ShiftChecker: Instrument shift instructions only once

As the shift checker could be executed multiple times, we need to avoid
that shift instructions are instrumented multiple times as well.

Mark the instrumented instruction using metadata and avoid it in
successive runs.

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/Module/Checks.cpp b/lib/Module/Checks.cpp
index 53ba4266..9286c491 100644
--- a/lib/Module/Checks.cpp
+++ b/lib/Module/Checks.cpp
@@ -116,6 +116,9 @@ bool OvershiftCheckPass::runOnModule(Module &M) {
             continue;
         }
 
+        if (KleeIRMetaData::hasAnnotation(I, "klee.check.shift", "True"))
+          continue;
+
         shiftInstructions.push_back(binOp);
       }
     }
@@ -126,6 +129,7 @@ bool OvershiftCheckPass::runOnModule(Module &M) {
 
   // Retrieve the checker function
   auto &ctx = M.getContext();
+  KleeIRMetaData md(ctx);
   auto overshiftCheckFunction = cast<Function>(M.getOrInsertFunction(
       "klee_overshift_check", Type::getVoidTy(ctx), Type::getInt64Ty(ctx),
       Type::getInt64Ty(ctx), NULL));
@@ -147,6 +151,7 @@ bool OvershiftCheckPass::runOnModule(Module &M) {
     args.push_back(shiftValue);
 
     Builder.CreateCall(overshiftCheckFunction, args);
+    md.addAnnotation(*shiftInst, "klee.check.shift", "True");
   }
 
   return true;