LLVM 20.0.0git
Regex.h
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1//===-- Regex.h - Regular Expression matcher implementation -*- C++ -*-----===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements a POSIX regular expression matcher. Both Basic and
10// Extended POSIX regular expressions (ERE) are supported. EREs were extended
11// to support backreferences in matches.
12// This implementation also supports matching strings with embedded NUL chars.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_SUPPORT_REGEX_H
17#define LLVM_SUPPORT_REGEX_H
18
20#include <string>
21
22struct llvm_regex;
23
24namespace llvm {
25 class StringRef;
26 template<typename T> class SmallVectorImpl;
27
28 class Regex {
29 public:
30 enum RegexFlags : unsigned {
32 /// Compile for matching that ignores upper/lower case distinctions.
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.
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.
44
46 };
47
48 Regex();
49 /// Compiles the given regular expression \p Regex.
50 ///
51 /// \param Regex - referenced string is no longer needed after this
52 /// constructor does finish. Only its compiled form is kept stored.
54 Regex(StringRef Regex, unsigned Flags);
55 Regex(const Regex &) = delete;
57 std::swap(preg, regex.preg);
58 std::swap(error, regex.error);
59 return *this;
60 }
61 Regex(Regex &&regex);
62 ~Regex();
63
64 /// isValid - returns the error encountered during regex compilation, if
65 /// any.
66 bool isValid(std::string &Error) const;
67 bool isValid() const { return !error; }
68
69 /// getNumMatches - In a valid regex, return the number of parenthesized
70 /// matches it contains. The number filled in by match will include this
71 /// many entries plus one for the whole regex (as element 0).
72 unsigned getNumMatches() const;
73
74 /// matches - Match the regex against a given \p String.
75 ///
76 /// \param Matches - If given, on a successful match this will be filled in
77 /// with references to the matched group expressions (inside \p String),
78 /// the first group is always the entire pattern.
79 ///
80 /// \param Error - If non-null, any errors in the matching will be recorded
81 /// as a non-empty string. If there is no error, it will be an empty string.
82 ///
83 /// This returns true on a successful match.
84 bool match(StringRef String, SmallVectorImpl<StringRef> *Matches = nullptr,
85 std::string *Error = nullptr) const;
86
87 /// sub - Return the result of replacing the first match of the regex in
88 /// \p String with the \p Repl string. Backreferences like "\0" and "\g<1>"
89 /// in the replacement string are replaced with the appropriate match
90 /// substring.
91 ///
92 /// Note that the replacement string has backslash escaping performed on
93 /// it. Invalid backreferences are ignored (replaced by empty strings).
94 ///
95 /// \param Error If non-null, any errors in the substitution (invalid
96 /// backreferences, trailing backslashes) will be recorded as a non-empty
97 /// string. If there is no error, it will be an empty string.
98 std::string sub(StringRef Repl, StringRef String,
99 std::string *Error = nullptr) const;
100
101 /// If this function returns true, ^Str$ is an extended regular
102 /// expression that matches Str and only Str.
103 static bool isLiteralERE(StringRef Str);
104
105 /// Turn String into a regex by escaping its special characters.
106 static std::string escape(StringRef String);
107
108 private:
109 struct llvm_regex *preg;
110 int error;
111 };
112}
113
114#endif // LLVM_SUPPORT_REGEX_H
#define error(X)
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
Regex(const Regex &)=delete
RegexFlags
Definition: Regex.h:30
@ Newline
Compile for newline-sensitive matching.
Definition: Regex.h:39
@ IgnoreCase
Compile for matching that ignores upper/lower case distinctions.
Definition: Regex.h:33
@ NoFlags
Definition: Regex.h:31
@ BasicRegex
By default, the POSIX extended regular expression (ERE) syntax is assumed.
Definition: Regex.h:43
static std::string escape(StringRef String)
Turn String into a regex by escaping its special characters.
Definition: Regex.cpp:239
Regex & operator=(Regex regex)
Definition: Regex.h:56
bool isValid() const
Definition: Regex.h:67
std::string sub(StringRef Repl, StringRef String, std::string *Error=nullptr) const
sub - Return the result of replacing the first match of the regex in String with the Repl string.
Definition: Regex.cpp:137
static bool isLiteralERE(StringRef Str)
If this function returns true, ^Str$ is an extended regular expression that matches Str and only Str.
Definition: Regex.cpp:232
unsigned getNumMatches() const
getNumMatches - In a valid regex, return the number of parenthesized matches it contains.
Definition: Regex.cpp:79
bool match(StringRef String, SmallVectorImpl< StringRef > *Matches=nullptr, std::string *Error=nullptr) const
matches - Match the regex against a given String.
Definition: Regex.cpp:83
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition: BitVector.h:860