Add ``-debug-cross-check-core-solver`` option to allow cross-checking

with another solver. For example the core solver can be STP and the
cross checking solver can be Z3.

Unfortunately a few fragile tests don't pass when actually using this
option.

4 files changed, 30 insertions, 1 deletions

diff --git a/include/klee/CommandLine.h b/include/klee/CommandLine.h
index 00cdeebb..dc69de6e 100644
--- a/include/klee/CommandLine.h
+++ b/include/klee/CommandLine.h
@@ -44,9 +44,17 @@ enum QueryLoggingSolverType
  */
 extern llvm::cl::list<QueryLoggingSolverType> queryLoggingOptions;
 
-enum CoreSolverType { STP_SOLVER, METASMT_SOLVER, DUMMY_SOLVER, Z3_SOLVER };
+enum CoreSolverType {
+  STP_SOLVER,
+  METASMT_SOLVER,
+  DUMMY_SOLVER,
+  Z3_SOLVER,
+  NO_SOLVER
+};
 extern llvm::cl::opt<CoreSolverType> CoreSolverToUse;
 
+extern llvm::cl::opt<CoreSolverType> DebugCrossCheckCoreSolverWith;
+
 #ifdef ENABLE_METASMT
 
 enum MetaSMTBackendType
diff --git a/lib/Basic/CmdLineOptions.cpp b/lib/Basic/CmdLineOptions.cpp
index 20c190a5..70ef999e 100644
--- a/lib/Basic/CmdLineOptions.cpp
+++ b/lib/Basic/CmdLineOptions.cpp
@@ -139,6 +139,19 @@ llvm::cl::opt<CoreSolverType> CoreSolverToUse(
                      clEnumValN(Z3_SOLVER, "z3", "Z3" Z3_IS_DEFAULT_STR),
                      clEnumValEnd),
     llvm::cl::init(DEFAULT_CORE_SOLVER));
+
+llvm::cl::opt<CoreSolverType> DebugCrossCheckCoreSolverWith(
+    "debug-cross-check-core-solver",
+    llvm::cl::desc(
+        "Specifiy a solver to use for cross checking with the core solver"),
+    llvm::cl::values(clEnumValN(STP_SOLVER, "stp", "stp"),
+                     clEnumValN(METASMT_SOLVER, "metasmt", "metaSMT"),
+                     clEnumValN(DUMMY_SOLVER, "dummy", "Dummy solver"),
+                     clEnumValN(Z3_SOLVER, "z3", "Z3"),
+                     clEnumValN(NO_SOLVER, "none",
+                                "Do not cross check (default)"),
+                     clEnumValEnd),
+    llvm::cl::init(NO_SOLVER));
 }
 #undef STP_IS_DEFAULT_STR
 #undef METASMT_IS_DEFAULT_STR
diff --git a/lib/Basic/ConstructSolverChain.cpp b/lib/Basic/ConstructSolverChain.cpp
index b48c5cb0..2df87d51 100644
--- a/lib/Basic/ConstructSolverChain.cpp
+++ b/lib/Basic/ConstructSolverChain.cpp
@@ -62,6 +62,10 @@ Solver *constructSolverChain(Solver *coreSolver, std::string querySMT2LogPath,
     llvm::errs() << "Logging all queries in .smt2 format to "
                  << querySMT2LogPath.c_str() << "\n";
   }
+  if (DebugCrossCheckCoreSolverWith != NO_SOLVER) {
+    Solver *oracleSolver = createCoreSolver(DebugCrossCheckCoreSolverWith);
+    solver = createValidatingSolver(/*s=*/solver, /*oracle=*/oracleSolver);
+  }
 
   return solver;
 }
diff --git a/lib/Solver/CoreSolver.cpp b/lib/Solver/CoreSolver.cpp
index 66328f30..783047f8 100644
--- a/lib/Solver/CoreSolver.cpp
+++ b/lib/Solver/CoreSolver.cpp
@@ -83,11 +83,15 @@ Solver *createCoreSolver(CoreSolverType cst) {
     return createDummySolver();
   case Z3_SOLVER:
 #ifdef ENABLE_Z3
+    llvm::errs() << "Using Z3 solver backend\n";
     return new Z3Solver();
 #else
     llvm::errs() << "Not compiled with Z3 support\n";
     return NULL;
 #endif
+  case NO_SOLVER:
+    llvm::errs() << "Invalid solver\n";
+    return NULL;
   default:
     llvm_unreachable("Unsupported CoreSolverType");
   }