-
- case PATSUBST: {
- StringInit *LHSs = dynamic_cast<StringInit*>(LHS);
- StringInit *MHSs = dynamic_cast<StringInit*>(MHS);
- StringInit *RHSs = dynamic_cast<StringInit*>(RHS);
-
- if (LHSs && MHSs && RHSs) {
- regex_t compiled;
- int err = regcomp (&compiled, LHSs->getValue().c_str(), REG_EXTENDED);
- if (err != 0) {
- size_t length = regerror (err, &compiled, NULL, 0);
- char *buffer = new char[length];
- (void) regerror (err, &compiled, buffer, length);
- std::string errmsg = buffer;
- delete[] buffer;
- regfree(&compiled);
- throw errmsg;
- }
- regmatch_t matches[10];
- int result = regexec(&compiled, RHSs->getValue().c_str(), 10, matches, 0);
- if (result == REG_ESPACE) {
- size_t length = regerror (err, &compiled, NULL, 0);
- char *buffer = new char[length];
- (void) regerror (err, &compiled, buffer, length);
- std::string errmsg = buffer;
- delete[] buffer;
- regfree(&compiled);
- throw errmsg;
- }
- regfree(&compiled);
- if (result == 0) {
- // Parse the substitution string looking for $1, $2, etc. and
- // substitute strings. If there are no $1, etc. just replace
- // the whole string.
- std::string replacement = MHSs->getValue();
- size_t pos = replacement.find("$");
- while (pos != std::string::npos && pos+1 < replacement.size()) {
- if (std::isdigit(replacement[pos+1])) {
- std::string sidx(&replacement[pos+1], 1);
- std::istringstream str(sidx);
- int idx;
- if (str >> idx) {
- replacement.replace(pos, 2, RHSs->getValue(), matches[idx].rm_so,
- matches[idx].rm_eo - matches[idx].rm_so);
- }
- else {
- throw "unexpected failure in patsubst index calculation";
- }
- }
- else if (replacement[pos+1] == '$') {
- replacement.replace(pos, 2, "$");
- }
- pos = replacement.find("$", pos+1);
- }
- return new StringInit(replacement);
- }
- else {
- // No match, just pass the string through
- return RHSs;
- }
- }
- break;
- }