Initial commit of Hyperscan

src/parser/ComponentAssertion.cpp

@@ -0,0 +1,121 @@
+/*
+ * 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 Lookahead/lookbehind zero-width assertions.
+ */
+#include "ComponentAssertion.h"
+#include "buildstate.h"
+#include "position.h"
+#include "position_info.h"
+#include "ue2common.h"
+
+#include <cassert>
+#include <algorithm>
+
+using namespace std;
+
+namespace ue2 {
+
+ComponentAssertion::ComponentAssertion(enum Direction dir, enum Sense sense)
+    : m_dir(dir), m_sense(sense) {}
+
+ComponentAssertion::~ComponentAssertion() { }
+
+ComponentAssertion *ComponentAssertion::clone() const {
+    return new ComponentAssertion(*this);
+}
+
+Component * ComponentAssertion::accept(ComponentVisitor &v) {
+    Component *c = v.visit(this);
+    if (c != this) {
+        v.post(this);
+        return c;
+    }
+
+    for (auto i = children.begin(), e = children.end(); i != e; ++i) {
+        Component *child = i->get();
+        c = (*i)->accept(v);
+        if (c != child) {
+            // Child has been replaced (new Component pointer) or we've been
+            // instructed to delete it (null).
+            i->reset(c);
+        }
+    }
+
+    // Remove deleted children.
+    children.erase(remove(children.begin(), children.end(), nullptr),
+                   children.end());
+
+    v.post(this);
+    return this;
+}
+
+void ComponentAssertion::accept(ConstComponentVisitor &v) const {
+    v.pre(*this);
+    for (auto i = children.begin(), e = children.end(); i != e; ++i) {
+        (*i)->accept(v);
+        if (i + 1 != e) {
+            v.during(*this);
+        }
+    }
+
+    v.post(*this);
+}
+
+vector<PositionInfo> ComponentAssertion::first() const {
+    assert(0);
+    return vector<PositionInfo>();
+}
+
+vector<PositionInfo> ComponentAssertion::last() const {
+    assert(0);
+    return vector<PositionInfo>();
+}
+
+bool ComponentAssertion::empty() const {
+    return true;
+}
+
+void ComponentAssertion::notePositions(GlushkovBuildState &) {
+    assert(0);
+}
+
+void ComponentAssertion::buildFollowSet(GlushkovBuildState &,
+                                        const vector<PositionInfo> &) {
+    assert(0);
+}
+
+bool ComponentAssertion::repeatable() const {
+    // If this assertion has no children (it's an empty sequence, like that
+    // produced by '(?!)') then PCRE would throw a "nothing to repeat" error.
+    // So we do as well.
+    return !children.empty();
+}
+
+} // namespace ue2