1 | //===-- Regex.h - Regular Expression matcher implementation -*- C++ -*-----===// |
2 | // |
3 | // The LLVM Compiler Infrastructure |
4 | // |
5 | // This file is distributed under the University of Illinois Open Source |
6 | // License. See LICENSE.TXT for details. |
7 | // |
8 | //===----------------------------------------------------------------------===// |
9 | // |
10 | // This file implements a POSIX regular expression matcher. Both Basic and |
11 | // Extended POSIX regular expressions (ERE) are supported. EREs were extended |
12 | // to support backreferences in matches. |
13 | // This implementation also supports matching strings with embedded NUL chars. |
14 | // |
15 | //===----------------------------------------------------------------------===// |
16 | |
17 | #ifndef LLVM_SUPPORT_REGEX_H |
18 | #define LLVM_SUPPORT_REGEX_H |
19 | |
20 | #include <string> |
21 | |
22 | struct llvm_regex; |
23 | |
24 | namespace llvm { |
25 | class StringRef; |
26 | template<typename T> class SmallVectorImpl; |
27 | |
28 | class Regex { |
29 | public: |
30 | enum { |
31 | NoFlags=0, |
32 | /// Compile for matching that ignores upper/lower case distinctions. |
33 | IgnoreCase=1, |
34 | /// Compile for newline-sensitive matching. With this flag '[^' bracket |
35 | /// expressions and '.' never match newline. A ^ anchor matches the |
36 | /// null string after any newline in the string in addition to its normal |
37 | /// function, and the $ anchor matches the null string before any |
38 | /// newline in the string in addition to its normal function. |
39 | Newline=2, |
40 | /// By default, the POSIX extended regular expression (ERE) syntax is |
41 | /// assumed. Pass this flag to turn on basic regular expressions (BRE) |
42 | /// instead. |
43 | BasicRegex=4 |
44 | }; |
45 | |
46 | Regex(); |
47 | /// Compiles the given regular expression \p Regex. |
48 | Regex(StringRef Regex, unsigned Flags = NoFlags); |
49 | Regex(const Regex &) = delete; |
50 | Regex &operator=(Regex regex) { |
51 | std::swap(preg, regex.preg); |
52 | std::swap(error, regex.error); |
53 | return *this; |
54 | } |
55 | Regex(Regex &®ex); |
56 | ~Regex(); |
57 | |
58 | /// isValid - returns the error encountered during regex compilation, or |
59 | /// matching, if any. |
60 | bool isValid(std::string &Error) const; |
61 | |
62 | /// getNumMatches - In a valid regex, return the number of parenthesized |
63 | /// matches it contains. The number filled in by match will include this |
64 | /// many entries plus one for the whole regex (as element 0). |
65 | unsigned getNumMatches() const; |
66 | |
67 | /// matches - Match the regex against a given \p String. |
68 | /// |
69 | /// \param Matches - If given, on a successful match this will be filled in |
70 | /// with references to the matched group expressions (inside \p String), |
71 | /// the first group is always the entire pattern. |
72 | /// |
73 | /// This returns true on a successful match. |
74 | bool match(StringRef String, SmallVectorImpl<StringRef> *Matches = nullptr); |
75 | |
76 | /// sub - Return the result of replacing the first match of the regex in |
77 | /// \p String with the \p Repl string. Backreferences like "\0" in the |
78 | /// replacement string are replaced with the appropriate match substring. |
79 | /// |
80 | /// Note that the replacement string has backslash escaping performed on |
81 | /// it. Invalid backreferences are ignored (replaced by empty strings). |
82 | /// |
83 | /// \param Error If non-null, any errors in the substitution (invalid |
84 | /// backreferences, trailing backslashes) will be recorded as a non-empty |
85 | /// string. |
86 | std::string sub(StringRef Repl, StringRef String, |
87 | std::string *Error = nullptr); |
88 | |
89 | /// If this function returns true, ^Str$ is an extended regular |
90 | /// expression that matches Str and only Str. |
91 | static bool isLiteralERE(StringRef Str); |
92 | |
93 | /// Turn String into a regex by escaping its special characters. |
94 | static std::string escape(StringRef String); |
95 | |
96 | private: |
97 | struct llvm_regex *preg; |
98 | int error; |
99 | }; |
100 | } |
101 | |
102 | #endif // LLVM_SUPPORT_REGEX_H |
103 | |