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Diffstat (limited to 'lib/Support/StringExtras.cpp')
-rw-r--r-- | lib/Support/StringExtras.cpp | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/lib/Support/StringExtras.cpp b/lib/Support/StringExtras.cpp new file mode 100644 index 0000000..1618086 --- /dev/null +++ b/lib/Support/StringExtras.cpp @@ -0,0 +1,114 @@ +//===-- StringExtras.cpp - Implement the StringExtras header --------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the StringExtras.h header +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/StringExtras.h" +#include <cstring> +using namespace llvm; + +/// getToken - This function extracts one token from source, ignoring any +/// leading characters that appear in the Delimiters string, and ending the +/// token at any of the characters that appear in the Delimiters string. If +/// there are no tokens in the source string, an empty string is returned. +/// The Source source string is updated in place to remove the returned string +/// and any delimiter prefix from it. +std::string llvm::getToken(std::string &Source, const char *Delimiters) { + size_t NumDelimiters = std::strlen(Delimiters); + + // Figure out where the token starts. + std::string::size_type Start = + Source.find_first_not_of(Delimiters, 0, NumDelimiters); + if (Start == std::string::npos) Start = Source.size(); + + // Find the next occurance of the delimiter. + std::string::size_type End = + Source.find_first_of(Delimiters, Start, NumDelimiters); + if (End == std::string::npos) End = Source.size(); + + // Create the return token. + std::string Result = std::string(Source.begin()+Start, Source.begin()+End); + + // Erase the token that we read in. + Source.erase(Source.begin(), Source.begin()+End); + + return Result; +} + +/// SplitString - Split up the specified string according to the specified +/// delimiters, appending the result fragments to the output list. +void llvm::SplitString(const std::string &Source, + std::vector<std::string> &OutFragments, + const char *Delimiters) { + std::string S = Source; + + std::string S2 = getToken(S, Delimiters); + while (!S2.empty()) { + OutFragments.push_back(S2); + S2 = getToken(S, Delimiters); + } +} + + + +/// UnescapeString - Modify the argument string, turning two character sequences +/// @verbatim +/// like '\\' 'n' into '\n'. This handles: \e \a \b \f \n \r \t \v \' \ and +/// \num (where num is a 1-3 byte octal value). +/// @endverbatim +void llvm::UnescapeString(std::string &Str) { + for (unsigned i = 0; i != Str.size(); ++i) { + if (Str[i] == '\\' && i != Str.size()-1) { + switch (Str[i+1]) { + default: continue; // Don't execute the code after the switch. + case 'a': Str[i] = '\a'; break; + case 'b': Str[i] = '\b'; break; + case 'e': Str[i] = 27; break; + case 'f': Str[i] = '\f'; break; + case 'n': Str[i] = '\n'; break; + case 'r': Str[i] = '\r'; break; + case 't': Str[i] = '\t'; break; + case 'v': Str[i] = '\v'; break; + case '"': Str[i] = '\"'; break; + case '\'': Str[i] = '\''; break; + case '\\': Str[i] = '\\'; break; + } + // Nuke the second character. + Str.erase(Str.begin()+i+1); + } + } +} + +/// EscapeString - Modify the argument string, turning '\\' and anything that +/// doesn't satisfy std::isprint into an escape sequence. +void llvm::EscapeString(std::string &Str) { + for (unsigned i = 0; i != Str.size(); ++i) { + if (Str[i] == '\\') { + ++i; + Str.insert(Str.begin()+i, '\\'); + } else if (Str[i] == '\t') { + Str[i++] = '\\'; + Str.insert(Str.begin()+i, 't'); + } else if (Str[i] == '"') { + Str.insert(Str.begin()+i++, '\\'); + } else if (Str[i] == '\n') { + Str[i++] = '\\'; + Str.insert(Str.begin()+i, 'n'); + } else if (!std::isprint(Str[i])) { + // Always expand to a 3-digit octal escape. + unsigned Char = Str[i]; + Str[i++] = '\\'; + Str.insert(Str.begin()+i++, '0'+((Char/64) & 7)); + Str.insert(Str.begin()+i++, '0'+((Char/8) & 7)); + Str.insert(Str.begin()+i , '0'+( Char & 7)); + } + } +} |