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      1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef TOOLS_GN_PATTERN_H_
      6 #define TOOLS_GN_PATTERN_H_
      7 
      8 #include <string>
      9 #include <vector>
     10 
     11 #include "tools/gn/value.h"
     12 
     13 class Pattern {
     14  public:
     15   struct Subrange {
     16     enum Type {
     17       LITERAL,  // Matches exactly the contents of the string.
     18       ANYTHING,  // * (zero or more chars).
     19       PATH_BOUNDARY  // '/' or beginning of string.
     20     };
     21 
     22     Subrange(Type t, const std::string& l = std::string())
     23         : type(t),
     24           literal(l) {
     25     }
     26 
     27     // Returns the minimum number of chars that this subrange requires.
     28     size_t MinSize() const {
     29       switch (type) {
     30         case LITERAL:
     31           return literal.size();
     32         case ANYTHING:
     33           return 0;
     34         case PATH_BOUNDARY:
     35           return 0;  // Can match beginning or end of string, which is 0 len.
     36         default:
     37           return 0;
     38       }
     39     }
     40 
     41     Type type;
     42 
     43     // When type == LITERAL this is the text to match.
     44     std::string literal;
     45   };
     46 
     47   Pattern(const std::string& s);
     48   ~Pattern();
     49 
     50   // Returns true if the current pattern matches the given string.
     51   bool MatchesString(const std::string& s) const;
     52 
     53  private:
     54   // allow_implicit_path_boundary determines if a path boundary should accept
     55   // matches at the beginning or end of the string.
     56   bool RecursiveMatch(const std::string& s,
     57                       size_t begin_char,
     58                       size_t subrange_index,
     59                       bool allow_implicit_path_boundary) const;
     60 
     61   std::vector<Subrange> subranges_;
     62 
     63   // Set to true when the subranges are "*foo" ("ANYTHING" followed by a
     64   // literal). This covers most patterns so we optimize for this.
     65   bool is_suffix_;
     66 };
     67 
     68 class PatternList {
     69  public:
     70   PatternList();
     71   ~PatternList();
     72 
     73   bool is_empty() const { return patterns_.empty(); }
     74 
     75   void Append(const Pattern& pattern);
     76 
     77   // Initializes the pattern list from a give list of pattern strings. Sets
     78   // |*err| on failure.
     79   void SetFromValue(const Value& v, Err* err);
     80 
     81   bool MatchesString(const std::string& s) const;
     82   bool MatchesValue(const Value& v) const;
     83 
     84  private:
     85   std::vector<Pattern> patterns_;
     86 };
     87 
     88 #endif  // TOOLS_GN_PATTERN_H_
     89