C++ cstring::c_str方法代码示例

string translateRk86(cstring in) {
  string out;
  out.resize(in.size());
  const char* inp = in.c_str();
  char* o = (char*)out.c_str();
  while(*inp) {
    char c = translateRk86c(*inp++);
    if(c==0) raise("Имя файла "+in+" содержит неподдерживаемый РК86 символ.");
    *o++ = c;
  }
  return out;
}

bool fromstring(cstring s, double& out)
{
	out = 0;
	auto tmp_s = s.c_str();
	const char * tmp_cp = tmp_s;
	if (*tmp_cp != '-' && !isdigit(*tmp_cp)) return false;
	char * tmp_cpo;
	double ret = strtod(drop0x(tmp_cp), &tmp_cpo);
	if (tmp_cpo != tmp_cp + s.length()) return false;
	if (!isdigit(tmp_cpo[-1])) return false;
	if (ret==HUGE_VAL || ret==-HUGE_VAL) return false;
	out = ret;
	return true;
}

cstring ReferenceMap::newName(cstring base) {
    // Maybe in the future we'll maintain information with per-scope identifiers,
    // but today we are content to generate globally-unique identifiers.

    // If base has a suffix of the form _(\d+), then we discard the suffix.
    // under the assumption that it is probably a generated suffix.
    // This will not impact correctness.
    unsigned len = base.size();
    const char digits[] = "0123456789";
    const char* s = base.c_str();
    while (len > 0 && strchr(digits, s[len-1])) len--;
    if (len > 0 && base[len - 1] == '_')
        base = base.substr(0, len - 1);

    cstring name = cstring::make_unique(usedNames, base, '_');
    usedNames.insert(name);
    return name;
}

int wunlink(const wcstring &file_name)
{
    const cstring tmp = wcs2string(file_name);
    return unlink(tmp.c_str());
}

int waccess(const wcstring &file_name, int mode)
{
    const cstring tmp = wcs2string(file_name);
    return access(tmp.c_str(), mode);
}

int lwstat(const wcstring &file_name, struct stat *buf)
{
    const cstring tmp = wcs2string(file_name);
    return lstat(tmp.c_str(), buf);
}

DIR *wopendir(const wcstring &name)
{
    const cstring tmp = wcs2string(name);
    return opendir(tmp.c_str());
}

void ControlBodyTranslator::compileEmitField(const IR::Expression* expr, cstring field,
                                             unsigned alignment, EBPFType* type) {
    unsigned widthToEmit = dynamic_cast<IHasWidth*>(type)->widthInBits();
    cstring swap = "";
    if (widthToEmit == 16)
        swap = "htons";
    else if (widthToEmit == 32)
        swap = "htonl";
    if (!swap.isNullOrEmpty()) {
        builder->emitIndent();
        visit(expr);
        builder->appendFormat(".%s = %s(", field.c_str(), swap);
        visit(expr);
        builder->appendFormat(".%s)", field.c_str());
        builder->endOfStatement(true);
    }

    auto program = control->program;
    unsigned bitsInFirstByte = widthToEmit % 8;
    if (bitsInFirstByte == 0) bitsInFirstByte = 8;
    unsigned bitsInCurrentByte = bitsInFirstByte;
    unsigned left = widthToEmit;

    for (unsigned i=0; i < (widthToEmit + 7) / 8; i++) {
        builder->emitIndent();
        builder->appendFormat("%s = ((char*)(&", program->byteVar.c_str());
        visit(expr);
        builder->appendFormat(".%s))[%d]", field.c_str(), i);
        builder->endOfStatement(true);

        unsigned freeBits = alignment == 0 ? (8 - alignment) : 8;
        unsigned bitsToWrite = bitsInCurrentByte > freeBits ? freeBits : bitsInCurrentByte;

        BUG_CHECK((bitsToWrite > 0) && (bitsToWrite <= 8), "invalid bitsToWrite %d", bitsToWrite);
        builder->emitIndent();
        if (alignment == 0)
            builder->appendFormat("write_byte(%s, BYTES(%s) + %d, (%s) << %d)",
                                  program->packetStartVar.c_str(), program->offsetVar.c_str(), i,
                                  program->byteVar.c_str(), 8 - bitsToWrite);
        else
            builder->appendFormat("write_partial(%s + BYTES(%s) + %d, %d, (%s) << %d)",
                                  program->packetStartVar.c_str(), program->offsetVar.c_str(), i,
                                  alignment,
                                  program->byteVar.c_str(), 8 - bitsToWrite);
        builder->endOfStatement(true);
        left -= bitsToWrite;
        bitsInCurrentByte -= bitsToWrite;

        if (bitsInCurrentByte > 0) {
            builder->emitIndent();
            builder->appendFormat(
                "write_byte(%s, BYTES(%s) + %d + 1, (%s << %d))",
                program->packetStartVar.c_str(),
                program->offsetVar.c_str(), i, program->byteVar.c_str(), 8 - alignment % 8);
            builder->endOfStatement(true);
            left -= bitsInCurrentByte;
        }

        alignment = (alignment + bitsToWrite) % 8;
        bitsInCurrentByte = left >= 8 ? 8 : left;
    }

    builder->emitIndent();
    builder->appendFormat("%s += %d", program->offsetVar.c_str(), widthToEmit);
    builder->endOfStatement(true);
}