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authorStephen Hines <srhines@google.com>2019-07-02 16:25:20 -0700
committerAli B <abittin@gmail.com>2019-07-05 19:33:16 +0300
commit9afee4e65dc5f9f5eb371683729ff67b8df81d03 (patch)
tree4cf241d6c9044f91ee8c06e6920174d06f8de0b6 /clang-r353983e/include/llvm/ADT/DeltaAlgorithm.h
parent2f19bd722c4c825320d1511c1ed83161b7f95d51 (diff)
Update prebuilt Clang to r353983e.HEADq10.0
clang 9.0.5 (based on r353983e) from build 5696680. Bug: http://b/135931688 Bug: http://b/136008926 Test: N/A Change-Id: I922d17410047d2e2df4625615352c588ee71b203
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+//===- DeltaAlgorithm.h - A Set Minimization Algorithm ---------*- C++ -*--===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_DELTAALGORITHM_H
+#define LLVM_ADT_DELTAALGORITHM_H
+
+#include <set>
+#include <vector>
+
+namespace llvm {
+
+/// DeltaAlgorithm - Implements the delta debugging algorithm (A. Zeller '99)
+/// for minimizing arbitrary sets using a predicate function.
+///
+/// The result of the algorithm is a subset of the input change set which is
+/// guaranteed to satisfy the predicate, assuming that the input set did. For
+/// well formed predicates, the result set is guaranteed to be such that
+/// removing any single element would falsify the predicate.
+///
+/// For best results the predicate function *should* (but need not) satisfy
+/// certain properties, in particular:
+/// (1) The predicate should return false on an empty set and true on the full
+/// set.
+/// (2) If the predicate returns true for a set of changes, it should return
+/// true for all supersets of that set.
+///
+/// It is not an error to provide a predicate that does not satisfy these
+/// requirements, and the algorithm will generally produce reasonable
+/// results. However, it may run substantially more tests than with a good
+/// predicate.
+class DeltaAlgorithm {
+public:
+ using change_ty = unsigned;
+ // FIXME: Use a decent data structure.
+ using changeset_ty = std::set<change_ty>;
+ using changesetlist_ty = std::vector<changeset_ty>;
+
+private:
+ /// Cache of failed test results. Successful test results are never cached
+ /// since we always reduce following a success.
+ std::set<changeset_ty> FailedTestsCache;
+
+ /// GetTestResult - Get the test result for the \p Changes from the
+ /// cache, executing the test if necessary.
+ ///
+ /// \param Changes - The change set to test.
+ /// \return - The test result.
+ bool GetTestResult(const changeset_ty &Changes);
+
+ /// Split - Partition a set of changes \p S into one or two subsets.
+ void Split(const changeset_ty &S, changesetlist_ty &Res);
+
+ /// Delta - Minimize a set of \p Changes which has been partioned into
+ /// smaller sets, by attempting to remove individual subsets.
+ changeset_ty Delta(const changeset_ty &Changes,
+ const changesetlist_ty &Sets);
+
+ /// Search - Search for a subset (or subsets) in \p Sets which can be
+ /// removed from \p Changes while still satisfying the predicate.
+ ///
+ /// \param Res - On success, a subset of Changes which satisfies the
+ /// predicate.
+ /// \return - True on success.
+ bool Search(const changeset_ty &Changes, const changesetlist_ty &Sets,
+ changeset_ty &Res);
+
+protected:
+ /// UpdatedSearchState - Callback used when the search state changes.
+ virtual void UpdatedSearchState(const changeset_ty &Changes,
+ const changesetlist_ty &Sets) {}
+
+ /// ExecuteOneTest - Execute a single test predicate on the change set \p S.
+ virtual bool ExecuteOneTest(const changeset_ty &S) = 0;
+
+ DeltaAlgorithm& operator=(const DeltaAlgorithm&) = default;
+
+public:
+ virtual ~DeltaAlgorithm();
+
+ /// Run - Minimize the set \p Changes by executing \see ExecuteOneTest() on
+ /// subsets of changes and returning the smallest set which still satisfies
+ /// the test predicate.
+ changeset_ty Run(const changeset_ty &Changes);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_ADT_DELTAALGORITHM_H