mirror of
https://gitlab.com/apparmor/apparmor
synced 2025-08-22 01:57:43 +00:00
Split out parsing and expression trees from regexp.y
Start of splitting regexp.y into logical components instead of the mess it is today. Split out the expr-tree and parsing components from regexp.y int expr-tree.x and parse.y and since regexp.y no longer does parsing rename it to hfa.cc Some code cleanups snuck their way into this patch and since I am to lazy to redo it, I have left them in. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-By: Steve Beattie <sbeattie@ubuntu.com>
This commit is contained in:
John Johansen
parent
50760ef05b
commit
846cee5066
@ -12,14 +12,20 @@ BISON := bison
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all : ${TARGET}
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libapparmor_re.a: regexp.o
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libapparmor_re.a: parse.o expr-tree.o hfa.o
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ar ${ARFLAGS} $@ $^
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regexp.o : regexp.cc apparmor_re.h
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expr-tree.o: expr-tree.cc expr-tree.h
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$(LINK.cc) $< -c -o $@
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regexp.cc : regexp.y flex-tables.h ../immunix.h
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hfa.o: hfa.cc apparmor_re.h
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$(LINK.cc) $< -c -o $@
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parse.o : parse.cc apparmor_re.h expr-tree.h
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$(LINK.cc) $< -c -o $@
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parse.cc : parse.y flex-tables.h ../immunix.h
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${BISON} -o $@ $<
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clean:
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rm -f regexp.o regexp.cc regexp.so regexp.a regexp ${TARGET}
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rm -f *.o parse.cc ${TARGET}
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@ -10,6 +10,8 @@
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#ifndef APPARMOR_RE_H
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#define APPARMOR_RE_H
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#include <stdint.h>
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typedef enum dfaflags {
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DFA_CONTROL_EQUIV = 1 << 0,
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DFA_CONTROL_TREE_NORMAL = 1 << 1,
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576
parser/libapparmor_re/expr-tree.cc
Normal file
576
parser/libapparmor_re/expr-tree.cc
Normal file
@ -0,0 +1,576 @@
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/*
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* (C) 2006, 2007 Andreas Gruenbacher <agruen@suse.de>
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* Copyright (c) 2003-2008 Novell, Inc. (All rights reserved)
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* Copyright 2009-2010 Canonical Ltd.
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*
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* The libapparmor library is licensed under the terms of the GNU
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* Lesser General Public License, version 2.1. Please see the file
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* COPYING.LGPL.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*
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* Functions to create/manipulate an expression tree for regular expressions
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* that have been parsed.
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*
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* The expression tree can be used directly after the parse creates it, or
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* it can be factored so that the set of important nodes is smaller.
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* Having a reduced set of important nodes generally results in a dfa that
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* is closer to minimum (fewer redundant states are created). It also
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* results in fewer important nodes in a the state set during subset
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* construction resulting in less memory used to create a dfa.
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*
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* Generally it is worth doing expression tree simplification before dfa
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* construction, if the regular expression tree contains any alternations.
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* Even if the regular expression doesn't simplification should be fast
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* enough that it can be used with minimal overhead.
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*/
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#include <stdio.h>
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#include <string.h>
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#include "expr-tree.h"
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#include "apparmor_re.h"
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/* Use a single static EpsNode as it carries no node specific information */
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EpsNode epsnode;
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ostream& operator<<(ostream& os, uchar c)
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{
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const char *search = "\a\033\f\n\r\t|*+[](). ",
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*replace = "aefnrt|*+[](). ", *s;
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if ((s = strchr(search, c)) && *s != '\0')
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os << '\\' << replace[s - search];
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else if (c < 32 || c >= 127)
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os << '\\' << '0' << char('0' + (c >> 6))
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<< char('0' + ((c >> 3) & 7)) << char('0' + (c & 7));
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else
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os << (char)c;
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return os;
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}
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/**
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* Text-dump a state (for debugging).
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*/
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ostream& operator<<(ostream& os, const NodeSet& state)
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{
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os << '{';
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if (!state.empty()) {
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NodeSet::iterator i = state.begin();
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for(;;) {
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os << (*i)->label;
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if (++i == state.end())
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break;
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os << ',';
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}
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}
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os << '}';
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return os;
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}
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ostream& operator<<(ostream& os, Node& node)
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{
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node.dump(os);
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return os;
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}
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/**
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* hash_NodeSet - generate a hash for the Nodes in the set
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*/
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unsigned long hash_NodeSet(NodeSet *ns)
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{
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unsigned long hash = 5381;
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for (NodeSet::iterator i = ns->begin(); i != ns->end(); i++) {
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hash = ((hash << 5) + hash) + (unsigned long) *i;
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}
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return hash;
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}
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/**
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* label_nodes - label the node positions for pretty-printing debug output
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*
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* TODO: separate - node labels should be separate and optional, if not
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* present pretty printing should use Node address
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*/
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void label_nodes(Node *root)
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{
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int nodes = 1;
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for (depth_first_traversal i(root); i; i++)
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i->label = nodes++;
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}
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/**
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* Text-dump the syntax tree (for debugging).
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*/
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void Node::dump_syntax_tree(ostream& os)
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{
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for (depth_first_traversal i(this); i; i++) {
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os << i->label << '\t';
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if ((*i)->child[0] == 0)
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os << **i << '\t' << (*i)->followpos << endl;
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else {
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if ((*i)->child[1] == 0)
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os << (*i)->child[0]->label << **i;
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else
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os << (*i)->child[0]->label << **i
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<< (*i)->child[1]->label;
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os << '\t' << (*i)->firstpos
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<< (*i)->lastpos << endl;
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}
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}
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os << endl;
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}
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/*
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* Normalize the regex parse tree for factoring and cancelations. Normalization
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* reorganizes internal (alt and cat) nodes into a fixed "normalized" form that
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* simplifies factoring code, in that it produces a canonicalized form for
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* the direction being normalized so that the factoring code does not have
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* to consider as many cases.
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*
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* left normalization (dir == 0) uses these rules
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* (E | a) -> (a | E)
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* (a | b) | c -> a | (b | c)
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* (ab)c -> a(bc)
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*
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* right normalization (dir == 1) uses the same rules but reversed
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* (a | E) -> (E | a)
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* a | (b | c) -> (a | b) | c
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* a(bc) -> (ab)c
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*
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* Note: This is written iteratively for a given node (the top node stays
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* fixed and the children are rotated) instead of recursively.
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* For a given node under examination rotate over nodes from
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* dir to !dir. Until no dir direction node meets the criterial.
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* Then recurse to the children (which will have a different node type)
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* to make sure they are normalized.
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* Normalization of a child node is guarenteed to not affect the
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* normalization of the parent.
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*
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* For cat nodes the depth first traverse order is guarenteed to be
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* maintained. This is not necessary for altnodes.
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*
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* Eg. For left normalization
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*
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* |1 |1
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* / \ / \
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* |2 T -> a |2
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* / \ / \
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* |3 c b |3
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* / \ / \
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* a b c T
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*
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*/
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static void rotate_node(Node *t, int dir) {
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// (a | b) | c -> a | (b | c)
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// (ab)c -> a(bc)
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Node *left = t->child[dir];
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t->child[dir] = left->child[dir];
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left->child[dir] = left->child[!dir];
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left->child[!dir] = t->child[!dir];
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t->child[!dir] = left;
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}
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void normalize_tree(Node *t, int dir)
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{
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if (dynamic_cast<LeafNode *>(t))
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return;
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for (;;) {
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if ((&epsnode == t->child[dir]) &&
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(&epsnode != t->child[!dir]) &&
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dynamic_cast<TwoChildNode *>(t)) {
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// (E | a) -> (a | E)
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// Ea -> aE
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Node *c = t->child[dir];
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t->child[dir] = t->child[!dir];
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t->child[!dir] = c;
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// Don't break here as 'a' may be a tree that
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// can be pulled up.
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} else if ((dynamic_cast<AltNode *>(t) &&
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dynamic_cast<AltNode *>(t->child[dir])) ||
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(dynamic_cast<CatNode *>(t) &&
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dynamic_cast<CatNode *>(t->child[dir]))) {
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// (a | b) | c -> a | (b | c)
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// (ab)c -> a(bc)
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rotate_node(t, dir);
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} else if (dynamic_cast<AltNode *>(t) &&
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dynamic_cast<CharSetNode *>(t->child[dir]) &&
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dynamic_cast<CharNode *>(t->child[!dir])) {
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// [a] | b -> b | [a]
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Node *c = t->child[dir];
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t->child[dir] = t->child[!dir];
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t->child[!dir] = c;
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} else {
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break;
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}
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}
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if (t->child[dir])
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normalize_tree(t->child[dir], dir);
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if (t->child[!dir])
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normalize_tree(t->child[!dir], dir);
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}
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//charset conversion is disabled for now,
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//it hinders tree optimization in some cases, so it need to be either
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//done post optimization, or have extra factoring rules added
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#if 0
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static Node *merge_charset(Node *a, Node *b)
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{
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if (dynamic_cast<CharNode *>(a) &&
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dynamic_cast<CharNode *>(b)) {
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Chars chars;
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chars.insert(dynamic_cast<CharNode *>(a)->c);
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chars.insert(dynamic_cast<CharNode *>(b)->c);
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CharSetNode *n = new CharSetNode(chars);
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return n;
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} else if (dynamic_cast<CharNode *>(a) &&
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dynamic_cast<CharSetNode *>(b)) {
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Chars *chars = &dynamic_cast<CharSetNode *>(b)->chars;
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chars->insert(dynamic_cast<CharNode *>(a)->c);
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return b;
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} else if (dynamic_cast<CharSetNode *>(a) &&
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dynamic_cast<CharSetNode *>(b)) {
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Chars *from = &dynamic_cast<CharSetNode *>(a)->chars;
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Chars *to = &dynamic_cast<CharSetNode *>(b)->chars;
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for (Chars::iterator i = from->begin(); i != from->end(); i++)
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to->insert(*i);
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return b;
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}
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//return ???;
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}
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static Node *alt_to_charsets(Node *t, int dir)
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{
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/*
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Node *first = NULL;
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Node *p = t;
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Node *i = t;
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for (;dynamic_cast<AltNode *>(i);) {
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if (dynamic_cast<CharNode *>(i->child[dir]) ||
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dynamic_cast<CharNodeSet *>(i->child[dir])) {
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if (!first) {
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first = i;
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p = i;
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i = i->child[!dir];
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} else {
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first->child[dir] = merge_charset(first->child[dir],
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i->child[dir]);
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p->child[!dir] = i->child[!dir];
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Node *tmp = i;
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i = tmp->child[!dir];
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tmp->child[!dir] = NULL;
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tmp->release();
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}
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} else {
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p = i;
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i = i->child[!dir];
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}
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}
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// last altnode of chain check other dir as well
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if (first && (dynamic_cast<charNode *>(i) ||
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dynamic_cast<charNodeSet *>(i))) {
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}
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*/
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/*
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if (dynamic_cast<CharNode *>(t->child[dir]) ||
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dynamic_cast<CharSetNode *>(t->child[dir]))
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char_test = true;
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(char_test &&
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(dynamic_cast<CharNode *>(i->child[dir]) ||
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dynamic_cast<CharSetNode *>(i->child[dir])))) {
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*/
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return t;
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}
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#endif
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static Node *basic_alt_factor(Node *t, int dir)
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{
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if (!dynamic_cast<AltNode *>(t))
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return t;
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if (t->child[dir]->eq(t->child[!dir])) {
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// (a | a) -> a
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Node *tmp = t->child[dir];
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t->child[dir] = NULL;
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t->release();
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return tmp;
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}
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// (ab) | (ac) -> a(b|c)
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if (dynamic_cast<CatNode *>(t->child[dir]) &&
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dynamic_cast<CatNode *>(t->child[!dir]) &&
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t->child[dir]->child[dir]->eq(t->child[!dir]->child[dir])) {
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// (ab) | (ac) -> a(b|c)
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Node *left = t->child[dir];
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Node *right = t->child[!dir];
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t->child[dir] = left->child[!dir];
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t->child[!dir] = right->child[!dir];
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right->child[!dir] = NULL;
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right->release();
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left->child[!dir] = t;
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return left;
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}
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// a | (ab) -> a (E | b) -> a (b | E)
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if (dynamic_cast<CatNode *>(t->child[!dir]) &&
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t->child[dir]->eq(t->child[!dir]->child[dir])) {
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Node *c = t->child[!dir];
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t->child[dir]->release();
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t->child[dir] = c->child[!dir];
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t->child[!dir] = &epsnode;
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c->child[!dir] = t;
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return c;
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}
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// ab | (a) -> a (b | E)
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if (dynamic_cast<CatNode *>(t->child[dir]) &&
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t->child[dir]->child[dir]->eq(t->child[!dir])) {
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Node *c = t->child[dir];
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t->child[!dir]->release();
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t->child[dir] = c->child[!dir];
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t->child[!dir] = &epsnode;
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c->child[!dir] = t;
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return c;
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}
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return t;
|
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}
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static Node *basic_simplify(Node *t, int dir)
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{
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if (dynamic_cast<CatNode *>(t) &&
|
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&epsnode == t->child[!dir]) {
|
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// aE -> a
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Node *tmp = t->child[dir];
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t->child[dir] = NULL;
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t->release();
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return tmp;
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}
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return basic_alt_factor(t, dir);
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}
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/*
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* assumes a normalized tree. reductions shown for left normalization
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* aE -> a
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* (a | a) -> a
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** factoring patterns
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* a | (a | b) -> (a | b)
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* a | (ab) -> a (E | b) -> a (b | E)
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* (ab) | (ac) -> a(b|c)
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*
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* returns t - if no simplifications were made
|
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* a new root node - if simplifications were made
|
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*/
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Node *simplify_tree_base(Node *t, int dir, bool &mod)
|
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{
|
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if (dynamic_cast<ImportantNode *>(t))
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return t;
|
||||
|
||||
for (int i=0; i < 2; i++) {
|
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if (t->child[i]) {
|
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Node *c = simplify_tree_base(t->child[i], dir, mod);
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if (c != t->child[i]) {
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t->child[i] = c;
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mod = true;
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}
|
||||
}
|
||||
}
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// only iterate on loop if modification made
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for (;; mod = true) {
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Node *tmp = basic_simplify(t, dir);
|
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if (tmp != t) {
|
||||
t = tmp;
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||||
continue;
|
||||
}
|
||||
|
||||
|
||||
/* all tests after this must meet 2 alt node condition */
|
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if (!dynamic_cast<AltNode *>(t) ||
|
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!dynamic_cast<AltNode *>(t->child[!dir]))
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break;
|
||||
|
||||
// a | (a | b) -> (a | b)
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||||
// a | (b | (c | a)) -> (b | (c | a))
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Node *p = t;
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||||
Node *i = t->child[!dir];
|
||||
for (;dynamic_cast<AltNode *>(i); p = i, i = i->child[!dir]) {
|
||||
if (t->child[dir]->eq(i->child[dir])) {
|
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Node *tmp = t->child[!dir];
|
||||
t->child[!dir] = NULL;
|
||||
t->release();
|
||||
t = tmp;
|
||||
continue;
|
||||
}
|
||||
}
|
||||
// last altnode of chain check other dir as well
|
||||
if (t->child[dir]->eq(p->child[!dir])) {
|
||||
Node *tmp = t->child[!dir];
|
||||
t->child[!dir] = NULL;
|
||||
t->release();
|
||||
t = tmp;
|
||||
continue;
|
||||
}
|
||||
|
||||
//exact match didn't work, try factoring front
|
||||
//a | (ac | (ad | () -> (a (E | c)) | (...)
|
||||
//ab | (ac | (...)) -> (a (b | c)) | (...)
|
||||
//ab | (a | (...)) -> (a (b | E)) | (...)
|
||||
Node *pp;
|
||||
int count = 0;
|
||||
Node *subject = t->child[dir];
|
||||
Node *a = subject;
|
||||
if (dynamic_cast<CatNode *>(subject))
|
||||
a = subject->child[dir];
|
||||
|
||||
for (pp = p = t, i = t->child[!dir];
|
||||
dynamic_cast<AltNode *>(i); ) {
|
||||
if ((dynamic_cast<CatNode *>(i->child[dir]) &&
|
||||
a->eq(i->child[dir]->child[dir])) ||
|
||||
(a->eq(i->child[dir]))) {
|
||||
// extract matching alt node
|
||||
p->child[!dir] = i->child[!dir];
|
||||
i->child[!dir] = subject;
|
||||
subject = basic_simplify(i, dir);
|
||||
if (dynamic_cast<CatNode *>(subject))
|
||||
a = subject->child[dir];
|
||||
else
|
||||
a = subject;
|
||||
|
||||
i = p->child[!dir];
|
||||
count++;
|
||||
} else {
|
||||
pp = p; p = i; i = i->child[!dir];
|
||||
}
|
||||
}
|
||||
|
||||
// last altnode in chain check other dir as well
|
||||
if ((dynamic_cast<CatNode *>(i) &&
|
||||
a->eq(i->child[dir])) ||
|
||||
(a->eq(i))) {
|
||||
count++;
|
||||
if (t == p) {
|
||||
t->child[dir] = subject;
|
||||
t = basic_simplify(t, dir);
|
||||
} else {
|
||||
t->child[dir] = p->child[dir];
|
||||
p->child[dir] = subject;
|
||||
pp->child[!dir] = basic_simplify(p, dir);
|
||||
}
|
||||
} else {
|
||||
t->child[dir] = i;
|
||||
p->child[!dir] = subject;
|
||||
}
|
||||
|
||||
if (count == 0)
|
||||
break;
|
||||
}
|
||||
return t;
|
||||
}
|
||||
|
||||
int debug_tree(Node *t)
|
||||
{
|
||||
int nodes = 1;
|
||||
|
||||
if (!dynamic_cast<ImportantNode *>(t)) {
|
||||
if (t->child[0])
|
||||
nodes += debug_tree(t->child[0]);
|
||||
if (t->child[1])
|
||||
nodes += debug_tree(t->child[1]);
|
||||
}
|
||||
return nodes;
|
||||
}
|
||||
|
||||
static void count_tree_nodes(Node *t, struct node_counts *counts)
|
||||
{
|
||||
if (dynamic_cast<AltNode *>(t)) {
|
||||
counts->alt++;
|
||||
count_tree_nodes(t->child[0], counts);
|
||||
count_tree_nodes(t->child[1], counts);
|
||||
} else if (dynamic_cast<CatNode *>(t)) {
|
||||
counts->cat++;
|
||||
count_tree_nodes(t->child[0], counts);
|
||||
count_tree_nodes(t->child[1], counts);
|
||||
} else if (dynamic_cast<PlusNode *>(t)) {
|
||||
counts->plus++;
|
||||
count_tree_nodes(t->child[0], counts);
|
||||
} else if (dynamic_cast<StarNode *>(t)) {
|
||||
counts->star++;
|
||||
count_tree_nodes(t->child[0], counts);
|
||||
} else if (dynamic_cast<CharNode *>(t)) {
|
||||
counts->charnode++;
|
||||
} else if (dynamic_cast<AnyCharNode *>(t)) {
|
||||
counts->any++;
|
||||
} else if (dynamic_cast<CharSetNode *>(t)) {
|
||||
counts->charset++;
|
||||
} else if (dynamic_cast<NotCharSetNode *>(t)) {
|
||||
counts->notcharset++;
|
||||
}
|
||||
}
|
||||
|
||||
#include "stdio.h"
|
||||
#include "stdint.h"
|
||||
#include "apparmor_re.h"
|
||||
|
||||
Node *simplify_tree(Node *t, dfaflags_t flags)
|
||||
{
|
||||
bool update;
|
||||
|
||||
if (flags & DFA_DUMP_TREE_STATS) {
|
||||
struct node_counts counts = { 0, 0, 0, 0, 0, 0, 0, 0 };
|
||||
count_tree_nodes(t, &counts);
|
||||
fprintf(stderr, "expr tree: c %d, [] %d, [^] %d, | %d, + %d, * %d, . %d, cat %d\n", counts.charnode, counts.charset, counts.notcharset, counts.alt, counts.plus, counts.star, counts.any, counts.cat);
|
||||
}
|
||||
do {
|
||||
update = false;
|
||||
//default to right normalize first as this reduces the number
|
||||
//of trailing nodes which might follow an internal *
|
||||
//or **, which is where state explosion can happen
|
||||
//eg. in one test this makes the difference between
|
||||
// the dfa having about 7 thousands states,
|
||||
// and it having about 1.25 million states
|
||||
int dir = 1;
|
||||
if (flags & DFA_CONTROL_TREE_LEFT)
|
||||
dir = 0;
|
||||
for (int count = 0; count < 2; count++) {
|
||||
bool modified;
|
||||
do {
|
||||
modified = false;
|
||||
if (flags & DFA_CONTROL_TREE_NORMAL)
|
||||
normalize_tree(t, dir);
|
||||
t = simplify_tree_base(t, dir, modified);
|
||||
if (modified)
|
||||
update = true;
|
||||
} while (modified);
|
||||
if (flags & DFA_CONTROL_TREE_LEFT)
|
||||
dir++;
|
||||
else
|
||||
dir--;
|
||||
}
|
||||
} while(update);
|
||||
if (flags & DFA_DUMP_TREE_STATS) {
|
||||
struct node_counts counts = { 0, 0, 0, 0, 0, 0, 0, 0 };
|
||||
count_tree_nodes(t, &counts);
|
||||
fprintf(stderr, "simplified expr tree: c %d, [] %d, [^] %d, | %d, + %d, * %d, . %d, cat %d\n", counts.charnode, counts.charset, counts.notcharset, counts.alt, counts.plus, counts.star, counts.any, counts.cat);
|
||||
}
|
||||
return t;
|
||||
}
|
||||
|
||||
627
parser/libapparmor_re/expr-tree.h
Normal file
627
parser/libapparmor_re/expr-tree.h
Normal file
@ -0,0 +1,627 @@
|
||||
/*
|
||||
* (C) 2006, 2007 Andreas Gruenbacher <agruen@suse.de>
|
||||
* Copyright (c) 2003-2008 Novell, Inc. (All rights reserved)
|
||||
* Copyright 2009-2010 Canonical Ltd.
|
||||
*
|
||||
* The libapparmor library is licensed under the terms of the GNU
|
||||
* Lesser General Public License, version 2.1. Please see the file
|
||||
* COPYING.LGPL.
|
||||
*
|
||||
* This library is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU Lesser General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU Lesser General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
*
|
||||
* Functions to create/manipulate an expression tree for regular expressions
|
||||
* that have been parsed.
|
||||
*
|
||||
* The expression tree can be used directly after the parse creates it, or
|
||||
* it can be factored so that the set of important nodes is smaller.
|
||||
* Having a reduced set of important nodes generally results in a dfa that
|
||||
* is closer to minimum (fewer redundant states are created). It also
|
||||
* results in fewer important nodes in a the state set during subset
|
||||
* construction resulting in less memory used to create a dfa.
|
||||
*
|
||||
* Generally it is worth doing expression tree simplification before dfa
|
||||
* construction, if the regular expression tree contains any alternations.
|
||||
* Even if the regular expression doesn't simplification should be fast
|
||||
* enough that it can be used with minimal overhead.
|
||||
*/
|
||||
#ifndef __LIBAA_RE_EXPR_H
|
||||
#define __LIBAA_RE_EXPR_H
|
||||
|
||||
#include <map>
|
||||
#include <set>
|
||||
#include <stack>
|
||||
#include <ostream>
|
||||
|
||||
#include "apparmor_re.h"
|
||||
|
||||
using namespace std;
|
||||
|
||||
typedef unsigned char uchar;
|
||||
typedef set<uchar> Chars;
|
||||
|
||||
ostream& operator<<(ostream& os, uchar c);
|
||||
|
||||
/* Compute the union of two sets. */
|
||||
template<class T>
|
||||
set<T> operator+(const set<T>& a, const set<T>& b)
|
||||
{
|
||||
set<T> c(a);
|
||||
c.insert(b.begin(), b.end());
|
||||
return c;
|
||||
}
|
||||
|
||||
/**
|
||||
* When creating DFAs from regex trees, a DFA state is constructed from
|
||||
* a set of important nodes in the syntax tree. This includes AcceptNodes,
|
||||
* which indicate that when a match ends in a particular state, the
|
||||
* regular expressions that the AcceptNode belongs to match.
|
||||
*/
|
||||
class Node;
|
||||
class ImportantNode;
|
||||
typedef set <ImportantNode *> NodeSet;
|
||||
|
||||
/**
|
||||
* Text-dump a state (for debugging).
|
||||
*/
|
||||
ostream& operator<<(ostream& os, const NodeSet& state);
|
||||
|
||||
/**
|
||||
* Out-edges from a state to another: we store the follow-set of Nodes
|
||||
* for each input character that is not a default match in
|
||||
* cases (i.e., following a CharNode or CharSetNode), and default
|
||||
* matches in otherwise as well as in all matching explicit cases
|
||||
* (i.e., following an AnyCharNode or NotCharSetNode). This avoids
|
||||
* enumerating all the explicit tranitions for default matches.
|
||||
*/
|
||||
typedef struct NodeCases {
|
||||
typedef map<uchar, NodeSet *>::iterator iterator;
|
||||
iterator begin() { return cases.begin(); }
|
||||
iterator end() { return cases.end(); }
|
||||
|
||||
NodeCases() : otherwise(0) { }
|
||||
map<uchar, NodeSet *> cases;
|
||||
NodeSet *otherwise;
|
||||
} NodeCases;
|
||||
|
||||
|
||||
ostream& operator<<(ostream& os, Node& node);
|
||||
|
||||
/* An abstract node in the syntax tree. */
|
||||
class Node {
|
||||
public:
|
||||
Node() :
|
||||
nullable(false) { child[0] = child[1] = 0; }
|
||||
Node(Node *left) :
|
||||
nullable(false) { child[0] = left; child[1] = 0; }
|
||||
Node(Node *left, Node *right) :
|
||||
nullable(false) { child[0] = left; child[1] = right; }
|
||||
virtual ~Node()
|
||||
{
|
||||
if (child[0])
|
||||
child[0]->release();
|
||||
if (child[1])
|
||||
child[1]->release();
|
||||
}
|
||||
|
||||
/**
|
||||
* See the "Dragon Book" for an explanation of nullable, firstpos,
|
||||
* lastpos, and followpos.
|
||||
*/
|
||||
virtual void compute_nullable() { }
|
||||
virtual void compute_firstpos() = 0;
|
||||
virtual void compute_lastpos() = 0;
|
||||
virtual void compute_followpos() { }
|
||||
virtual int eq(Node *other) = 0;
|
||||
virtual ostream& dump(ostream& os) = 0;
|
||||
void dump_syntax_tree(ostream& os);
|
||||
|
||||
bool nullable;
|
||||
NodeSet firstpos, lastpos, followpos;
|
||||
/* child 0 is left, child 1 is right */
|
||||
Node *child[2];
|
||||
|
||||
unsigned int label; /* unique number for debug etc */
|
||||
/**
|
||||
* We indirectly release Nodes through a virtual function because
|
||||
* accept and Eps Nodes are shared, and must be treated specially.
|
||||
* We could use full reference counting here but the indirect release
|
||||
* is sufficient and has less overhead
|
||||
*/
|
||||
virtual void release(void) { delete this; }
|
||||
};
|
||||
|
||||
|
||||
class InnerNode : public Node {
|
||||
public:
|
||||
InnerNode() : Node() { };
|
||||
InnerNode(Node *left) : Node(left) {};
|
||||
InnerNode(Node *left, Node *right) : Node(left, right) { };
|
||||
};
|
||||
|
||||
class OneChildNode : public InnerNode {
|
||||
public:
|
||||
OneChildNode(Node *left) : InnerNode(left) { };
|
||||
};
|
||||
|
||||
class TwoChildNode : public InnerNode {
|
||||
public:
|
||||
TwoChildNode(Node *left, Node *right) : InnerNode(left, right) { };
|
||||
};
|
||||
|
||||
class LeafNode : public Node {
|
||||
public:
|
||||
LeafNode() : Node() { };
|
||||
};
|
||||
|
||||
/* Match nothing (//). */
|
||||
class EpsNode : public LeafNode {
|
||||
public:
|
||||
EpsNode() : LeafNode()
|
||||
{
|
||||
nullable = true;
|
||||
label = 0;
|
||||
}
|
||||
void release(void)
|
||||
{
|
||||
/* don't delete Eps nodes because there is a single static
|
||||
* instance shared by all trees. Look for epsnode in the code
|
||||
*/
|
||||
}
|
||||
|
||||
void compute_firstpos() { }
|
||||
void compute_lastpos() { }
|
||||
int eq(Node *other)
|
||||
{
|
||||
if (dynamic_cast<EpsNode *>(other))
|
||||
return 1;
|
||||
return 0;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
return os << "[]";
|
||||
}
|
||||
};
|
||||
|
||||
/**
|
||||
* Leaf nodes in the syntax tree are important to us: they describe the
|
||||
* characters that the regular expression matches. We also consider
|
||||
* AcceptNodes import: they indicate when a regular expression matches.
|
||||
*/
|
||||
class ImportantNode : public LeafNode {
|
||||
public:
|
||||
ImportantNode() : LeafNode() { }
|
||||
void compute_firstpos()
|
||||
{
|
||||
firstpos.insert(this);
|
||||
}
|
||||
void compute_lastpos() {
|
||||
lastpos.insert(this);
|
||||
}
|
||||
virtual void follow(NodeCases& cases) = 0;
|
||||
};
|
||||
|
||||
/* common base class for all the different classes that contain
|
||||
* character information.
|
||||
*/
|
||||
class CNode : public ImportantNode {
|
||||
public:
|
||||
CNode() : ImportantNode() { }
|
||||
};
|
||||
|
||||
/* Match one specific character (/c/). */
|
||||
class CharNode : public CNode {
|
||||
public:
|
||||
CharNode(uchar c) : c(c) { }
|
||||
void follow(NodeCases& cases)
|
||||
{
|
||||
NodeSet **x = &cases.cases[c];
|
||||
if (!*x) {
|
||||
if (cases.otherwise)
|
||||
*x = new NodeSet(*cases.otherwise);
|
||||
else
|
||||
*x = new NodeSet;
|
||||
}
|
||||
(*x)->insert(followpos.begin(), followpos.end());
|
||||
}
|
||||
int eq(Node *other)
|
||||
{
|
||||
CharNode *o = dynamic_cast<CharNode *>(other);
|
||||
if (o) {
|
||||
return c == o->c;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
return os << c;
|
||||
}
|
||||
|
||||
uchar c;
|
||||
};
|
||||
|
||||
/* Match a set of characters (/[abc]/). */
|
||||
class CharSetNode : public CNode {
|
||||
public:
|
||||
CharSetNode(Chars& chars) : chars(chars) { }
|
||||
void follow(NodeCases& cases)
|
||||
{
|
||||
for (Chars::iterator i = chars.begin(); i != chars.end(); i++) {
|
||||
NodeSet **x = &cases.cases[*i];
|
||||
if (!*x) {
|
||||
if (cases.otherwise)
|
||||
*x = new NodeSet(*cases.otherwise);
|
||||
else
|
||||
*x = new NodeSet;
|
||||
}
|
||||
(*x)->insert(followpos.begin(), followpos.end());
|
||||
}
|
||||
}
|
||||
int eq(Node *other)
|
||||
{
|
||||
CharSetNode *o = dynamic_cast<CharSetNode *>(other);
|
||||
if (!o || chars.size() != o->chars.size())
|
||||
return 0;
|
||||
|
||||
for (Chars::iterator i = chars.begin(), j = o->chars.begin();
|
||||
i != chars.end() && j != o->chars.end();
|
||||
i++, j++) {
|
||||
if (*i != *j)
|
||||
return 0;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
os << '[';
|
||||
for (Chars::iterator i = chars.begin(); i != chars.end(); i++)
|
||||
os << *i;
|
||||
return os << ']';
|
||||
}
|
||||
|
||||
Chars chars;
|
||||
};
|
||||
|
||||
/* Match all except one character (/[^abc]/). */
|
||||
class NotCharSetNode : public CNode {
|
||||
public:
|
||||
NotCharSetNode(Chars& chars) : chars(chars) { }
|
||||
void follow(NodeCases& cases)
|
||||
{
|
||||
if (!cases.otherwise)
|
||||
cases.otherwise = new NodeSet;
|
||||
for (Chars::iterator j = chars.begin(); j != chars.end(); j++) {
|
||||
NodeSet **x = &cases.cases[*j];
|
||||
if (!*x)
|
||||
*x = new NodeSet(*cases.otherwise);
|
||||
}
|
||||
/* Note: Add to the nonmatching characters after copying away
|
||||
* the old otherwise state for the matching characters.
|
||||
*/
|
||||
cases.otherwise->insert(followpos.begin(), followpos.end());
|
||||
for (NodeCases::iterator i = cases.begin(); i != cases.end();
|
||||
i++) {
|
||||
if (chars.find(i->first) == chars.end())
|
||||
i->second->insert(followpos.begin(),
|
||||
followpos.end());
|
||||
}
|
||||
}
|
||||
int eq(Node *other)
|
||||
{
|
||||
NotCharSetNode *o = dynamic_cast<NotCharSetNode *>(other);
|
||||
if (!o || chars.size() != o->chars.size())
|
||||
return 0;
|
||||
|
||||
for (Chars::iterator i = chars.begin(), j = o->chars.begin();
|
||||
i != chars.end() && j != o->chars.end();
|
||||
i++, j++) {
|
||||
if (*i != *j)
|
||||
return 0;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
os << "[^";
|
||||
for (Chars::iterator i = chars.begin(); i != chars.end(); i++)
|
||||
os << *i;
|
||||
return os << ']';
|
||||
}
|
||||
|
||||
Chars chars;
|
||||
};
|
||||
|
||||
/* Match any character (/./). */
|
||||
class AnyCharNode : public CNode {
|
||||
public:
|
||||
AnyCharNode() { }
|
||||
void follow(NodeCases& cases)
|
||||
{
|
||||
if (!cases.otherwise)
|
||||
cases.otherwise = new NodeSet;
|
||||
cases.otherwise->insert(followpos.begin(), followpos.end());
|
||||
for (NodeCases::iterator i = cases.begin(); i != cases.end();
|
||||
i++)
|
||||
i->second->insert(followpos.begin(), followpos.end());
|
||||
}
|
||||
int eq(Node *other)
|
||||
{
|
||||
if (dynamic_cast<AnyCharNode *>(other))
|
||||
return 1;
|
||||
return 0;
|
||||
}
|
||||
ostream& dump(ostream& os) {
|
||||
return os << ".";
|
||||
}
|
||||
};
|
||||
|
||||
/**
|
||||
* Indicate that a regular expression matches. An AcceptNode itself
|
||||
* doesn't match anything, so it will never generate any transitions.
|
||||
*/
|
||||
class AcceptNode : public ImportantNode {
|
||||
public:
|
||||
AcceptNode() {}
|
||||
void release(void)
|
||||
{
|
||||
/* don't delete AcceptNode via release as they are shared, and
|
||||
* will be deleted when the table the are stored in is deleted
|
||||
*/
|
||||
}
|
||||
|
||||
void follow(NodeCases& cases __attribute__((unused)))
|
||||
{
|
||||
/* Nothing to follow. */
|
||||
}
|
||||
|
||||
/* requires accept nodes to be common by pointer */
|
||||
int eq(Node *other)
|
||||
{
|
||||
if (dynamic_cast<AcceptNode *>(other))
|
||||
return (this == other);
|
||||
return 0;
|
||||
}
|
||||
};
|
||||
|
||||
/* Match a node zero or more times. (This is a unary operator.) */
|
||||
class StarNode : public OneChildNode {
|
||||
public:
|
||||
StarNode(Node *left) : OneChildNode(left)
|
||||
{
|
||||
nullable = true;
|
||||
}
|
||||
void compute_firstpos()
|
||||
{
|
||||
firstpos = child[0]->firstpos;
|
||||
}
|
||||
void compute_lastpos()
|
||||
{
|
||||
lastpos = child[0]->lastpos;
|
||||
}
|
||||
void compute_followpos()
|
||||
{
|
||||
NodeSet from = child[0]->lastpos, to = child[0]->firstpos;
|
||||
for(NodeSet::iterator i = from.begin(); i != from.end(); i++) {
|
||||
(*i)->followpos.insert(to.begin(), to.end());
|
||||
}
|
||||
}
|
||||
int eq(Node *other) {
|
||||
if (dynamic_cast<StarNode *>(other))
|
||||
return child[0]->eq(other->child[0]);
|
||||
return 0;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
os << '(';
|
||||
child[0]->dump(os);
|
||||
return os << ")*";
|
||||
}
|
||||
};
|
||||
|
||||
/* Match a node one or more times. (This is a unary operator.) */
|
||||
class PlusNode : public OneChildNode {
|
||||
public:
|
||||
PlusNode(Node *left) : OneChildNode(left) { }
|
||||
void compute_nullable()
|
||||
{
|
||||
nullable = child[0]->nullable;
|
||||
}
|
||||
void compute_firstpos()
|
||||
{
|
||||
firstpos = child[0]->firstpos;
|
||||
}
|
||||
void compute_lastpos()
|
||||
{
|
||||
lastpos = child[0]->lastpos;
|
||||
}
|
||||
void compute_followpos()
|
||||
{
|
||||
NodeSet from = child[0]->lastpos, to = child[0]->firstpos;
|
||||
for(NodeSet::iterator i = from.begin(); i != from.end(); i++) {
|
||||
(*i)->followpos.insert(to.begin(), to.end());
|
||||
}
|
||||
}
|
||||
int eq(Node *other)
|
||||
{
|
||||
if (dynamic_cast<PlusNode *>(other))
|
||||
return child[0]->eq(other->child[0]);
|
||||
return 0;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
os << '(';
|
||||
child[0]->dump(os);
|
||||
return os << ")+";
|
||||
}
|
||||
};
|
||||
|
||||
/* Match a pair of consecutive nodes. */
|
||||
class CatNode : public TwoChildNode {
|
||||
public:
|
||||
CatNode(Node *left, Node *right) : TwoChildNode(left, right) { }
|
||||
void compute_nullable()
|
||||
{
|
||||
nullable = child[0]->nullable && child[1]->nullable;
|
||||
}
|
||||
void compute_firstpos()
|
||||
{
|
||||
if (child[0]->nullable)
|
||||
firstpos = child[0]->firstpos + child[1]->firstpos;
|
||||
else
|
||||
firstpos = child[0]->firstpos;
|
||||
}
|
||||
void compute_lastpos()
|
||||
{
|
||||
if (child[1]->nullable)
|
||||
lastpos = child[0]->lastpos + child[1]->lastpos;
|
||||
else
|
||||
lastpos = child[1]->lastpos;
|
||||
}
|
||||
void compute_followpos()
|
||||
{
|
||||
NodeSet from = child[0]->lastpos, to = child[1]->firstpos;
|
||||
for(NodeSet::iterator i = from.begin(); i != from.end(); i++) {
|
||||
(*i)->followpos.insert(to.begin(), to.end());
|
||||
}
|
||||
}
|
||||
int eq(Node *other) {
|
||||
if (dynamic_cast<CatNode *>(other)) {
|
||||
if (!child[0]->eq(other->child[0]))
|
||||
return 0;
|
||||
return child[1]->eq(other->child[1]);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
child[0]->dump(os);
|
||||
child[1]->dump(os);
|
||||
return os;
|
||||
}
|
||||
};
|
||||
|
||||
/* Match one of two alternative nodes. */
|
||||
class AltNode : public TwoChildNode {
|
||||
public:
|
||||
AltNode(Node *left, Node *right) : TwoChildNode(left, right) { }
|
||||
void compute_nullable()
|
||||
{
|
||||
nullable = child[0]->nullable || child[1]->nullable;
|
||||
}
|
||||
void compute_lastpos()
|
||||
{
|
||||
lastpos = child[0]->lastpos + child[1]->lastpos;
|
||||
}
|
||||
void compute_firstpos()
|
||||
{
|
||||
firstpos = child[0]->firstpos + child[1]->firstpos;
|
||||
}
|
||||
int eq(Node *other) {
|
||||
if (dynamic_cast<AltNode *>(other)) {
|
||||
if (!child[0]->eq(other->child[0]))
|
||||
return 0;
|
||||
return child[1]->eq(other->child[1]);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
ostream& dump(ostream& os)
|
||||
{
|
||||
os << '(';
|
||||
child[0]->dump(os);
|
||||
os << '|';
|
||||
child[1]->dump(os);
|
||||
os << ')';
|
||||
return os;
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
/* Traverse the syntax tree depth-first in an iterator-like manner. */
|
||||
class depth_first_traversal {
|
||||
stack<Node *> pos;
|
||||
void push_left(Node *node)
|
||||
{
|
||||
pos.push(node);
|
||||
|
||||
while (dynamic_cast<InnerNode *>(node)) {
|
||||
pos.push(node->child[0]);
|
||||
node = node->child[0];
|
||||
}
|
||||
}
|
||||
|
||||
public:
|
||||
depth_first_traversal(Node *node)
|
||||
{
|
||||
push_left(node);
|
||||
}
|
||||
Node *operator*()
|
||||
{
|
||||
return pos.top();
|
||||
}
|
||||
Node* operator->()
|
||||
{
|
||||
return pos.top();
|
||||
}
|
||||
operator bool()
|
||||
{
|
||||
return !pos.empty();
|
||||
}
|
||||
void operator++(int)
|
||||
{
|
||||
Node *last = pos.top();
|
||||
pos.pop();
|
||||
|
||||
if (!pos.empty()) {
|
||||
/* no need to dynamic cast, as we just popped a node so
|
||||
* the top node must be an inner node */
|
||||
InnerNode *node = (InnerNode *)(pos.top());
|
||||
if (node->child[1] && node->child[1] != last) {
|
||||
push_left(node->child[1]);
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
struct node_counts {
|
||||
int charnode;
|
||||
int charset;
|
||||
int notcharset;
|
||||
int alt;
|
||||
int plus;
|
||||
int star;
|
||||
int any;
|
||||
int cat;
|
||||
};
|
||||
|
||||
extern EpsNode epsnode;
|
||||
|
||||
int debug_tree(Node *t);
|
||||
Node *simplify_tree(Node *t, dfaflags_t flags);
|
||||
void label_nodes(Node *root);
|
||||
unsigned long hash_NodeSet(NodeSet *ns);
|
||||
|
||||
|
||||
/* Comparison operator for sets of <NodeSet *>.
|
||||
* Compare set hashes, and if the sets have the same hash
|
||||
* do compare pointer comparison on set of <Node *>, the pointer comparison
|
||||
* allows us to determine which Sets of <Node *> we have seen already from
|
||||
* new ones when constructing the DFA.
|
||||
*/
|
||||
struct deref_less_than {
|
||||
bool operator()(pair <unsigned long, NodeSet *> const & lhs,
|
||||
pair <unsigned long, NodeSet *> const & rhs) const
|
||||
{
|
||||
if (lhs.first == rhs.first)
|
||||
return *(lhs.second) < *(rhs.second);
|
||||
else
|
||||
return lhs.first < rhs.first;
|
||||
}
|
||||
};
|
||||
|
||||
#endif /* __LIBAA_RE_EXPR */
|
||||
File diff suppressed because it is too large
Load Diff
27
parser/libapparmor_re/parse.h
Normal file
27
parser/libapparmor_re/parse.h
Normal file
@ -0,0 +1,27 @@
|
||||
/*
|
||||
* (C) 2006, 2007 Andreas Gruenbacher <agruen@suse.de>
|
||||
* Copyright (c) 2003-2008 Novell, Inc. (All rights reserved)
|
||||
* Copyright 2009-2010 Canonical Ltd.
|
||||
*
|
||||
* The libapparmor library is licensed under the terms of the GNU
|
||||
* Lesser General Public License, version 2.1. Please see the file
|
||||
* COPYING.LGPL.
|
||||
*
|
||||
* This library is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU Lesser General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU Lesser General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
*
|
||||
* Parsing of regular expression into expression trees as implemented in
|
||||
* expr-tree
|
||||
*/
|
||||
#ifndef __LIBAA_RE_PARSE_H
|
||||
#define __LIBAA_RE_PARSE_H
|
||||
|
||||
int regex_parse(Node **tree, const char *rule);
|
||||
|
||||
#endif /* __LIBAA_RE_PARSE_H */
|
||||
266
parser/libapparmor_re/parse.y
Normal file
266
parser/libapparmor_re/parse.y
Normal file
@ -0,0 +1,266 @@
|
||||
/*
|
||||
* (C) 2006, 2007 Andreas Gruenbacher <agruen@suse.de>
|
||||
* Copyright (c) 2003-2008 Novell, Inc. (All rights reserved)
|
||||
* Copyright 2009-2010 Canonical Ltd.
|
||||
*
|
||||
* The libapparmor library is licensed under the terms of the GNU
|
||||
* Lesser General Public License, version 2.1. Please see the file
|
||||
* COPYING.LGPL.
|
||||
*
|
||||
* This library is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU Lesser General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU Lesser General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
*
|
||||
* Parsing of regular expression into expression trees as implemented in
|
||||
* expr-tree
|
||||
*/
|
||||
|
||||
%{
|
||||
/* #define DEBUG_TREE */
|
||||
#include "expr-tree.h"
|
||||
|
||||
%}
|
||||
|
||||
%union {
|
||||
char c;
|
||||
Node *node;
|
||||
Chars *cset;
|
||||
}
|
||||
|
||||
%{
|
||||
void regex_error(Node **, const char *, const char *);
|
||||
# define YYLEX_PARAM &text
|
||||
int regex_lex(YYSTYPE *, const char **);
|
||||
|
||||
static inline Chars*
|
||||
insert_char(Chars* cset, uchar a)
|
||||
{
|
||||
cset->insert(a);
|
||||
return cset;
|
||||
}
|
||||
|
||||
static inline Chars*
|
||||
insert_char_range(Chars* cset, uchar a, uchar b)
|
||||
{
|
||||
if (a > b)
|
||||
swap(a, b);
|
||||
for (uchar i = a; i <= b; i++)
|
||||
cset->insert(i);
|
||||
return cset;
|
||||
}
|
||||
%}
|
||||
|
||||
%pure-parser
|
||||
/* %error-verbose */
|
||||
%parse-param {Node **root}
|
||||
%parse-param {const char *text}
|
||||
%name-prefix = "regex_"
|
||||
|
||||
%token <c> CHAR
|
||||
%type <c> regex_char cset_char1 cset_char cset_charN
|
||||
%type <cset> charset cset_chars
|
||||
%type <node> regex expr terms0 terms qterm term
|
||||
|
||||
/**
|
||||
* Note: destroy all nodes upon failure, but *not* the start symbol once
|
||||
* parsing succeeds!
|
||||
*/
|
||||
%destructor { $$->release(); } expr terms0 terms qterm term
|
||||
|
||||
%%
|
||||
|
||||
/* FIXME: Does not parse "[--]", "[---]", "[^^-x]". I don't actually know
|
||||
which precise grammer Perl regexs use, and rediscovering that
|
||||
is proving to be painful. */
|
||||
|
||||
regex : /* empty */ { *root = $$ = &epsnode; }
|
||||
| expr { *root = $$ = $1; }
|
||||
;
|
||||
|
||||
expr : terms
|
||||
| expr '|' terms0 { $$ = new AltNode($1, $3); }
|
||||
| '|' terms0 { $$ = new AltNode(&epsnode, $2); }
|
||||
;
|
||||
|
||||
terms0 : /* empty */ { $$ = &epsnode; }
|
||||
| terms
|
||||
;
|
||||
|
||||
terms : qterm
|
||||
| terms qterm { $$ = new CatNode($1, $2); }
|
||||
;
|
||||
|
||||
qterm : term
|
||||
| term '*' { $$ = new StarNode($1); }
|
||||
| term '+' { $$ = new PlusNode($1); }
|
||||
;
|
||||
|
||||
term : '.' { $$ = new AnyCharNode; }
|
||||
| regex_char { $$ = new CharNode($1); }
|
||||
| '[' charset ']' { $$ = new CharSetNode(*$2);
|
||||
delete $2; }
|
||||
| '[' '^' charset ']'
|
||||
{ $$ = new NotCharSetNode(*$3);
|
||||
delete $3; }
|
||||
| '[' '^' '^' cset_chars ']'
|
||||
{ $4->insert('^');
|
||||
$$ = new NotCharSetNode(*$4);
|
||||
delete $4; }
|
||||
| '(' regex ')' { $$ = $2; }
|
||||
;
|
||||
|
||||
regex_char : CHAR
|
||||
| '^' { $$ = '^'; }
|
||||
| '-' { $$ = '-'; }
|
||||
| ']' { $$ = ']'; }
|
||||
;
|
||||
|
||||
charset : cset_char1 cset_chars
|
||||
{ $$ = insert_char($2, $1); }
|
||||
| cset_char1 '-' cset_charN cset_chars
|
||||
{ $$ = insert_char_range($4, $1, $3); }
|
||||
;
|
||||
|
||||
cset_chars : /* nothing */ { $$ = new Chars; }
|
||||
| cset_chars cset_charN
|
||||
{ $$ = insert_char($1, $2); }
|
||||
| cset_chars cset_charN '-' cset_charN
|
||||
{ $$ = insert_char_range($1, $2, $4); }
|
||||
;
|
||||
|
||||
cset_char1 : cset_char
|
||||
| ']' { $$ = ']'; }
|
||||
| '-' { $$ = '-'; }
|
||||
;
|
||||
|
||||
cset_charN : cset_char
|
||||
| '^' { $$ = '^'; }
|
||||
;
|
||||
|
||||
cset_char : CHAR
|
||||
| '[' { $$ = '['; }
|
||||
| '*' { $$ = '*'; }
|
||||
| '+' { $$ = '+'; }
|
||||
| '.' { $$ = '.'; }
|
||||
| '|' { $$ = '|'; }
|
||||
| '(' { $$ = '('; }
|
||||
| ')' { $$ = ')'; }
|
||||
;
|
||||
|
||||
%%
|
||||
|
||||
|
||||
int
|
||||
octdigit(char c)
|
||||
{
|
||||
if (c >= '0' && c <= '7')
|
||||
return c - '0';
|
||||
return -1;
|
||||
}
|
||||
|
||||
int
|
||||
hexdigit(char c)
|
||||
{
|
||||
if (c >= '0' && c <= '9')
|
||||
return c - '0';
|
||||
else if (c >= 'A' && c <= 'F')
|
||||
return 10 + c - 'A';
|
||||
else if (c >= 'a' && c <= 'f')
|
||||
return 10 + c - 'A';
|
||||
else
|
||||
return -1;
|
||||
}
|
||||
|
||||
int
|
||||
regex_lex(YYSTYPE *val, const char **pos)
|
||||
{
|
||||
int c;
|
||||
|
||||
val->c = **pos;
|
||||
switch(*(*pos)++) {
|
||||
case '\0':
|
||||
(*pos)--;
|
||||
return 0;
|
||||
|
||||
case '*': case '+': case '.': case '|': case '^': case '-':
|
||||
case '[': case ']': case '(' : case ')':
|
||||
return *(*pos - 1);
|
||||
|
||||
case '\\':
|
||||
val->c = **pos;
|
||||
switch(*(*pos)++) {
|
||||
case '\0':
|
||||
(*pos)--;
|
||||
/* fall through */
|
||||
case '\\':
|
||||
val->c = '\\';
|
||||
break;
|
||||
|
||||
case '0':
|
||||
val->c = 0;
|
||||
if ((c = octdigit(**pos)) >= 0) {
|
||||
val->c = c;
|
||||
(*pos)++;
|
||||
}
|
||||
if ((c = octdigit(**pos)) >= 0) {
|
||||
val->c = (val->c << 3) + c;
|
||||
(*pos)++;
|
||||
}
|
||||
if ((c = octdigit(**pos)) >= 0) {
|
||||
val->c = (val->c << 3) + c;
|
||||
(*pos)++;
|
||||
}
|
||||
break;
|
||||
|
||||
case 'x':
|
||||
val->c = 0;
|
||||
if ((c = hexdigit(**pos)) >= 0) {
|
||||
val->c = c;
|
||||
(*pos)++;
|
||||
}
|
||||
if ((c = hexdigit(**pos)) >= 0) {
|
||||
val->c = (val->c << 4) + c;
|
||||
(*pos)++;
|
||||
}
|
||||
break;
|
||||
|
||||
case 'a':
|
||||
val->c = '\a';
|
||||
break;
|
||||
|
||||
case 'e':
|
||||
val->c = 033 /* ESC */;
|
||||
break;
|
||||
|
||||
case 'f':
|
||||
val->c = '\f';
|
||||
break;
|
||||
|
||||
case 'n':
|
||||
val->c = '\n';
|
||||
break;
|
||||
|
||||
case 'r':
|
||||
val->c = '\r';
|
||||
break;
|
||||
|
||||
case 't':
|
||||
val->c = '\t';
|
||||
break;
|
||||
}
|
||||
}
|
||||
return CHAR;
|
||||
}
|
||||
|
||||
void
|
||||
regex_error(Node ** __attribute__((unused)),
|
||||
const char *text __attribute__((unused)),
|
||||
const char *error __attribute__((unused)))
|
||||
{
|
||||
/* We don't want the library to print error messages. */
|
||||
}
|
||||
@ -1,10 +0,0 @@
|
||||
#ifndef __REGEXP_H
|
||||
#define __REGEXP_H
|
||||
|
||||
/**
|
||||
* Flex file format, but without state compression and with negative
|
||||
* match results in the YYTD_ID_DEF table instead.
|
||||
*/
|
||||
#define YYTH_REGEXP_MAGIC 0x1B5E783D
|
||||
|
||||
#endif /* __REGEXP_H */
|
||||
Loading…
x
Reference in New Issue
Block a user