Add two helpers for escaping and unescaping strings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29151 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-07-14 22:54:39 +00:00
parent 1e36126f5e
commit 53eca9466f

View File

@ -41,3 +41,53 @@ std::string llvm::getToken(std::string &Source, const char *Delimiters) {
return Result;
}
/// UnescapeString - Modify the argument string, turning two character sequences
/// 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).
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;
}
// 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] == '\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));
}
}
}