From ecc7fae9cbac9aa970aac072276e5bca1c583c02 Mon Sep 17 00:00:00 2001
From: Martin Nowack <m.nowack@imperial.ac.uk>
Date: Sun, 29 Jul 2018 16:51:32 +0100
Subject: 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.
---
 lib/Module/Checks.cpp | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'lib')

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;
-- 
cgit 1.4.1