Implemented bounded merging functionality

1 files changed, 76 insertions, 0 deletions

diff --git a/lib/Core/MergeHandler.cpp b/lib/Core/MergeHandler.cpp
new file mode 100644
index 00000000..ad8ffd62
--- /dev/null
+++ b/lib/Core/MergeHandler.cpp
@@ -0,0 +1,76 @@
+//===-- MergeHandler.cpp --------------------------------------------------===//
+//
+//                     The KLEE Symbolic Virtual Machine
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "klee/MergeHandler.h"
+
+#include "CoreStats.h"
+#include "Executor.h"
+#include "klee/ExecutionState.h"
+
+namespace klee {
+llvm::cl::opt<bool>
+    UseMerge("use-merge",
+        llvm::cl::init(false),
+        llvm::cl::desc("Enable support for klee_open_merge() and klee_close_merge() (experimental)"));
+
+llvm::cl::opt<bool>
+    DebugLogMerge("debug-log-merge",
+        llvm::cl::init(false),
+        llvm::cl::desc("Enhanced verbosity for region based merge operations"));
+
+void MergeHandler::addClosedState(ExecutionState *es,
+                                         llvm::Instruction *mp) {
+  auto closePoint = reachedMergeClose.find(mp);
+
+  // If no other state has yet encountered this klee_close_merge instruction,
+  // add a new element to the map
+  if (closePoint == reachedMergeClose.end()) {
+    reachedMergeClose[mp].push_back(es);
+    executor->pauseState(*es);
+  } else {
+    // Otherwise try to merge with any state in the map element for this
+    // instruction
+    auto &cpv = closePoint->second;
+    bool mergedSuccessful = false;
+
+    for (auto& mState: cpv) {
+      if (mState->merge(*es)) {
+        executor->terminateState(*es);
+        mergedSuccessful = true;
+        break;
+      }
+    }
+    if (!mergedSuccessful) {
+      cpv.push_back(es);
+      executor->pauseState(*es);
+    }
+  }
+}
+
+void MergeHandler::releaseStates() {
+  for (auto& curMergeGroup: reachedMergeClose) {
+    for (auto curState: curMergeGroup.second) {
+      executor->continueState(*curState);
+    }
+  }
+  reachedMergeClose.clear();
+}
+
+bool MergeHandler::hasMergedStates() {
+  return (!reachedMergeClose.empty());
+}
+
+MergeHandler::MergeHandler(Executor *_executor)
+    : executor(_executor), refCount(0) {
+}
+
+MergeHandler::~MergeHandler() {
+  releaseStates();
+}
+}