lib/Support/StringExtras.cpp

   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"
  16 using 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.
  21 StringRef::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.
  37 std::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.
  50 void 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
  60 void 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 (isPrint(C) && C != '\\' && C != '"')
  64       Out << C;
  65     else
  66       Out << '\\' << hexdigit(C >> 4) << hexdigit(C & 0x0F);
  67   }
  68 }
  69
  70 void llvm::printHTMLEscaped(StringRef String, raw_ostream &Out) {
  71   for (char C : String) {
  72     if (C == '&')
  73       Out << "&amp;";
  74     else if (C == '<')
  75       Out << "&lt;";
  76     else if (C == '>')
  77       Out << "&gt;";
  78     else if (C == '\"')
  79       Out << "&quot;";
  80     else if (C == '\'')
  81       Out << "&apos;";
  82     else
  83       Out << C;
  84   }
  85 }
  86
  87 void llvm::printLowerCase(StringRef String, raw_ostream &Out) {
  88   for (const char C : String)
  89     Out << toLower(C);
  90 }