StringExtras.cpp revision 360784 
1//===-- StringExtras.cpp - Implement the StringExtras header --------------===//
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 the StringExtras.h header
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/ADT/StringExtras.h"
14#include "llvm/ADT/SmallVector.h"
15#include "llvm/Support/raw_ostream.h"
16using namespace llvm;
17
18/// StrInStrNoCase - Portable version of strcasestr.  Locates the first
19/// occurrence of string 's1' in string 's2', ignoring case.  Returns
20/// the offset of s2 in s1 or npos if s2 cannot be found.
21StringRef::size_type llvm::StrInStrNoCase(StringRef s1, StringRef s2) {
22  size_t N = s2.size(), M = s1.size();
23  if (N > M)
24    return StringRef::npos;
25  for (size_t i = 0, e = M - N + 1; i != e; ++i)
26    if (s1.substr(i, N).equals_lower(s2))
27      return i;
28  return StringRef::npos;
29}
30
31/// getToken - This function extracts one token from source, ignoring any
32/// leading characters that appear in the Delimiters string, and ending the
33/// token at any of the characters that appear in the Delimiters string.  If
34/// there are no tokens in the source string, an empty string is returned.
35/// The function returns a pair containing the extracted token and the
36/// remaining tail string.
37std::pair<StringRef, StringRef> llvm::getToken(StringRef Source,
38                                               StringRef Delimiters) {
39  // Figure out where the token starts.
40  StringRef::size_type Start = Source.find_first_not_of(Delimiters);
41
42  // Find the next occurrence of the delimiter.
43  StringRef::size_type End = Source.find_first_of(Delimiters, Start);
44
45  return std::make_pair(Source.slice(Start, End), Source.substr(End));
46}
47
48/// SplitString - Split up the specified string according to the specified
49/// delimiters, appending the result fragments to the output list.
50void llvm::SplitString(StringRef Source,
51                       SmallVectorImpl<StringRef> &OutFragments,
52                       StringRef Delimiters) {
53  std::pair<StringRef, StringRef> S = getToken(Source, Delimiters);
54  while (!S.first.empty()) {
55    OutFragments.push_back(S.first);
56    S = getToken(S.second, Delimiters);
57  }
58}
59
60void llvm::printEscapedString(StringRef Name, raw_ostream &Out) {
61  for (unsigned i = 0, e = Name.size(); i != e; ++i) {
62    unsigned char C = Name[i];
63    if (C == '\\')
64      Out << '\\' << C;
65    else if (isPrint(C) && C != '"')
66      Out << C;
67    else
68      Out << '\\' << hexdigit(C >> 4) << hexdigit(C & 0x0F);
69  }
70}
71
72void llvm::printHTMLEscaped(StringRef String, raw_ostream &Out) {
73  for (char C : String) {
74    if (C == '&')
75      Out << "&amp;";
76    else if (C == '<')
77      Out << "&lt;";
78    else if (C == '>')
79      Out << "&gt;";
80    else if (C == '\"')
81      Out << "&quot;";
82    else if (C == '\'')
83      Out << "&apos;";
84    else
85      Out << C;
86  }
87}
88
89void llvm::printLowerCase(StringRef String, raw_ostream &Out) {
90  for (const char C : String)
91    Out << toLower(C);
92}
93