Initial commit of Hyperscan

src/parser/Component.h

@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2015, Intel Corporation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  * Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** \file
+ * \brief Base class for all components.
+ */
+
+#ifndef _RE_COMPONENT_H_
+#define _RE_COMPONENT_H_
+
+#include "ComponentVisitor.h"
+#include "ConstComponentVisitor.h"
+
+#include "position.h"
+#include "ue2common.h"
+
+#include <set>
+#include <string>
+#include <vector>
+
+namespace ue2 {
+
+class GlushkovBuildState;
+class PositionInfo;
+
+enum EmptyPathType {
+    NOT_EMPTY,       /**< component must consume characters */
+    EPS_ONLY_PATHS,  /**< eps path with no overhanging asserts */
+    BOUNDARY_PATHS   /**< eps paths some with overhanging asserts */
+};
+
+/** \brief Base class for regular expression parse tree components. */
+class Component {
+    friend class DumpVisitor;
+public:
+    /** \brief Constructor. */
+    Component();
+
+    /** \brief Destructor. */
+    virtual ~Component();
+
+    /** \brief Returns a newly-allocated deep copy of this component. */
+    virtual Component *clone() const = 0;
+
+    /** \brief Apply the given visitor functor. */
+    virtual Component *accept(ComponentVisitor &v) = 0;
+
+    /** \brief Apply the given const visitor functor. */
+    virtual void accept(ConstComponentVisitor &v) const = 0;
+
+    /** \brief Glushkov construction First() function.
+     * \return set of initial positions in this component. */
+    virtual std::vector<PositionInfo> first() const = 0;
+
+    /** \brief Glushkov construction Last() function.
+     * \return set of final positions in this component. */
+    virtual std::vector<PositionInfo> last() const = 0;
+
+    /** \brief Glushkov construction Empty() function.
+     * \return true iff the component accepts epsilon.
+     *
+     * Note: ^, $, etc are considered empty. */
+    virtual bool empty() const = 0;
+
+    /** \brief True iff epsilon can pass through the component.
+     *
+     * Note: ^, $, etc are not vacuous everywhere. */
+    virtual bool vacuous_everywhere(void) const;
+
+    /** \brief True iff the component is repeatable on its own, without being
+     * encapsulated in a sequence first.
+     *
+     * This is true for most components, but not for repeats, anchors and word
+     * boundaries. */
+    virtual bool repeatable() const;
+
+    /** \brief Optimisation pass on the component tree.
+     *
+     * Called before \ref notePositions. May modify to the component tree.
+     * Assumes no start of match information is required.
+     */
+    virtual void optimise(bool connected_to_sds);
+
+    /** \brief Informs the Glushkov build process of the positions used by this
+     * component. */
+    virtual void notePositions(GlushkovBuildState &bs) = 0;
+
+    /** \brief Glushkov construction Follow() function.
+     *
+     * Constructs (in \a bs) the set of positions in this component reachable
+     * from the positions in \a lastPos.
+     *
+     * \throw ParseError on failure
+     */
+    virtual void buildFollowSet(GlushkovBuildState &bs,
+                                const std::vector<PositionInfo> &lastPos) = 0;
+
+    /** \brief Return value is used for chaining, throws if finds embedded
+     * anchor. */
+    virtual bool checkEmbeddedStartAnchor(bool at_start) const;
+
+    /* \brief Return value is used for chaining, throws if finds embedded
+     * anchor. */
+    virtual bool checkEmbeddedEndAnchor(bool at_end) const;
+
+protected:
+    /** \brief Called during \ref notePositions. */
+    void recordPosBounds(u32 b, u32 e);
+
+    u32 pos_begin;
+    u32 pos_end;
+
+    // Protected copy ctor. Use clone instead.
+    Component(const Component &other)
+        : pos_begin(other.pos_begin), pos_end(other.pos_end) {}
+};
+
+} // namespace ue2
+
+#endif