1 // Copyright 2008 The RE2 Authors. All Rights Reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // Regular expression generator: generates all possible 6 // regular expressions within given parameters (see below for details). 7 8 #ifndef RE2_TESTING_REGEXP_GENERATOR_H__ 9 #define RE2_TESTING_REGEXP_GENERATOR_H__ 10 11 #include <string> 12 #include <vector> 13 #include "util/random.h" 14 #include "util/util.h" 15 #include "re2/stringpiece.h" 16 17 namespace re2 { 18 19 // Regular expression generator. 20 // 21 // Given a set of atom expressions like "a", "b", or "." 22 // and operators like "%s*", generates all possible regular expressions 23 // using at most maxbases base expressions and maxops operators. 24 // For each such expression re, calls HandleRegexp(re). 25 // 26 // Callers are expected to subclass RegexpGenerator and provide HandleRegexp. 27 // 28 class RegexpGenerator { 29 public: 30 RegexpGenerator(int maxatoms, int maxops, const vector<string>& atoms, 31 const vector<string>& ops); 32 virtual ~RegexpGenerator() {} 33 34 // Generates all the regular expressions, calling HandleRegexp(re) for each. 35 void Generate(); 36 37 // Generates n random regular expressions, calling HandleRegexp(re) for each. 38 void GenerateRandom(int32 seed, int n); 39 40 // Handles a regular expression. Must be provided by subclass. 41 virtual void HandleRegexp(const string& regexp) = 0; 42 43 // The egrep regexp operators: * + ? | and concatenation. 44 static const vector<string>& EgrepOps(); 45 46 private: 47 void RunPostfix(const vector<string>& post); 48 void GeneratePostfix(vector<string>* post, int nstk, int ops, int lits); 49 bool GenerateRandomPostfix(vector<string>* post, int nstk, int ops, int lits); 50 51 int maxatoms_; // Maximum number of atoms allowed in expr. 52 int maxops_; // Maximum number of ops allowed in expr. 53 vector<string> atoms_; // Possible atoms. 54 vector<string> ops_; // Possible ops. 55 ACMRandom* acm_; // Random generator. 56 DISALLOW_EVIL_CONSTRUCTORS(RegexpGenerator); 57 }; 58 59 // Helpers for preparing arguments to RegexpGenerator constructor. 60 61 // Returns one string for each character in s. 62 vector<string> Explode(const StringPiece& s); 63 64 // Splits string everywhere sep is found, returning 65 // vector of pieces. 66 vector<string> Split(const StringPiece& sep, const StringPiece& s); 67 68 } // namespace re2 69 70 #endif // RE2_TESTING_REGEXP_GENERATOR_H__ 71
