Added GRBlockCounter class, which tracks the number of times blocks

have been visited in a path.  Added GRBlockCounter as an item to be
enqueued to the worklist.

Modified "ProcessBranch" in GRConstants to prune branches with symbolic
conditions that have been already taken.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@47010 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 54 insertions, 0 deletions

diff --git a/Analysis/GRBlockCounter.cpp b/Analysis/GRBlockCounter.cpp
new file mode 100644
index 0000000000..def87c2c47
--- /dev/null
+++ b/Analysis/GRBlockCounter.cpp
@@ -0,0 +1,54 @@
+//==- GRBlockCounter.h - ADT for counting block visits -------------*- C++ -*-//
+//             
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines GRBlockCounter, an abstract data type used to count
+//  the number of times a given block has been visited along a path
+//  analyzed by GREngine.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/PathSensitive/GRBlockCounter.h"
+#include "llvm/ADT/ImmutableMap.h"
+
+using namespace clang;
+
+typedef llvm::ImmutableMap<unsigned,unsigned> CountMap;
+
+static inline CountMap GetMap(void* D) {
+  return CountMap(static_cast<CountMap::TreeTy*>(D));
+}
+
+static inline CountMap::Factory& GetFactory(void* F) {
+  return *static_cast<CountMap::Factory*>(F);
+}
+
+unsigned GRBlockCounter::getNumVisited(unsigned BlockID) const {
+  CountMap M = GetMap(Data);
+  CountMap::TreeTy* T = M.SlimFind(BlockID);
+  return T ? T->getValue().second : 0;
+}
+
+GRBlockCounter::Factory::Factory(llvm::BumpPtrAllocator& Alloc) {
+  F = new CountMap::Factory(Alloc);
+}
+
+GRBlockCounter::Factory::~Factory() {
+  delete static_cast<CountMap*>(F);
+}
+
+GRBlockCounter
+GRBlockCounter::Factory::IncrementCount(GRBlockCounter BC, unsigned BlockID) {
+  return GRBlockCounter(GetFactory(F).Add(GetMap(BC.Data), BlockID,
+                                        BC.getNumVisited(BlockID)+1).getRoot());
+}
+
+GRBlockCounter
+GRBlockCounter::Factory::GetEmptyCounter() {
+  return GRBlockCounter(GetFactory(F).GetEmptyMap().getRoot());
+}