cppcheck/lib/mathlib.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
2015-01-03 12:14:58 +01:00
* Copyright (C) 2007-2015 Daniel Marjamäki and Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "mathlib.h"
#include "errorlogger.h"
#include <cmath>
#include <cctype>
#include <limits>
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MathLib::biguint MathLib::toULongNumber(const std::string & str)
{
// hexadecimal numbers:
if (isHex(str)) {
if (str[0] == '-') {
biguint ret = 0;
std::istringstream istr(str);
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istr >> std::hex >> ret;
return ret;
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} else {
unsigned long long ret = 0;
std::istringstream istr(str);
istr >> std::hex >> ret;
return (biguint)ret;
}
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}
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// octal numbers:
if (isOct(str)) {
biguint ret = 0;
std::istringstream istr(str);
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istr >> std::oct >> ret;
return ret;
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}
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// binary numbers:
if (isBin(str)) {
biguint ret = 0;
for (std::string::size_type i = str[0] == '0'?2:3; i < str.length(); i++) {
ret <<= 1;
if (str[i] == '1')
ret |= 1;
}
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/* if (str[0] == '-')
ret = -ret; */
return ret;
}
if (isFloat(str)) {
// Things are going to be less precise now: the value can't b represented in the biguint type.
// Use min/max values as an approximation. See #5843
const double doubleval = std::atof(str.c_str());
if (doubleval > (double)std::numeric_limits<biguint>::max())
return std::numeric_limits<biguint>::max();
else
return static_cast<biguint>(doubleval);
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}
biguint ret = 0;
std::istringstream istr(str);
istr >> ret;
return ret;
}
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MathLib::bigint MathLib::toLongNumber(const std::string & str)
{
// hexadecimal numbers:
if (isHex(str)) {
if (str[0] == '-') {
bigint ret = 0;
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std::istringstream istr(str);
istr >> std::hex >> ret;
return ret;
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} else {
unsigned long long ret = 0;
std::istringstream istr(str);
istr >> std::hex >> ret;
return (bigint)ret;
}
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}
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// octal numbers:
if (isOct(str)) {
bigint ret = 0;
std::istringstream istr(str);
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istr >> std::oct >> ret;
return ret;
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}
// binary numbers:
if (isBin(str)) {
bigint ret = 0;
for (std::string::size_type i = str[0] == '0'?2:3; i < str.length(); i++) {
ret <<= 1;
if (str[i] == '1')
ret |= 1;
}
if (str[0] == '-')
ret = -ret;
return ret;
}
if (isFloat(str)) {
// Things are going to be less precise now: the value can't be represented in the bigint type.
// Use min/max values as an approximation. See #5843
const double doubleval = std::atof(str.c_str());
if (doubleval > (double)std::numeric_limits<bigint>::max())
return std::numeric_limits<bigint>::max();
else if (doubleval < (double)std::numeric_limits<bigint>::min())
return std::numeric_limits<bigint>::min();
else
return static_cast<bigint>(doubleval);
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}
bigint ret = 0;
std::istringstream istr(str);
istr >> ret;
return ret;
}
double MathLib::toDoubleNumber(const std::string &str)
{
if (isHex(str))
return static_cast<double>(toLongNumber(str));
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// nullcheck
else if (isNullValue(str))
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return 0.0;
else if (isFloat(str)) // Workaround libc++ bug at http://llvm.org/bugs/show_bug.cgi?id=17782
return std::strtod(str.c_str(), 0);
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// otherwise, convert to double
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std::istringstream istr(str);
double ret;
istr >> ret;
return ret;
}
template<> std::string MathLib::toString(double value)
{
std::ostringstream result;
result.precision(12);
result << value;
if (result.str() == "-0")
return "0.0";
if (result.str().find(".") == std::string::npos)
return result.str() + ".0";
return result.str();
}
bool MathLib::isFloat(const std::string &s)
{
if (s.empty())
return false;
enum State {
START, BASE_PLUSMINUS, BASE_DIGITS1, LEADING_DECIMAL, TRAILING_DECIMAL, BASE_DIGITS2, E, MANTISSA_PLUSMINUS, MANTISSA_DIGITS, F, L
} state = START;
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for (std::string::const_iterator it = s.begin(); it != s.end(); ++it) {
switch (state) {
case START:
if (*it=='+' || *it=='-')
state=BASE_PLUSMINUS;
else if (*it=='.')
state=LEADING_DECIMAL;
else if (std::isdigit(*it))
state=BASE_DIGITS1;
else
return false;
break;
case BASE_PLUSMINUS:
if (*it=='.')
state=LEADING_DECIMAL;
else if (std::isdigit(*it))
state=BASE_DIGITS1;
else if (*it=='e' || *it=='E')
state=E;
else
return false;
break;
case LEADING_DECIMAL:
if (std::isdigit(*it))
state=BASE_DIGITS2;
else if (*it=='e' || *it=='E')
state=E;
else
return false;
break;
case BASE_DIGITS1:
if (*it=='e' || *it=='E')
state=E;
else if (*it=='.')
state=TRAILING_DECIMAL;
else if (!std::isdigit(*it))
return false;
break;
case TRAILING_DECIMAL:
if (*it=='e' || *it=='E')
state=E;
else if (*it=='f' || *it=='F')
state=F;
else if (*it=='l' || *it=='L')
state=L;
else if (std::isdigit(*it))
state=BASE_DIGITS2;
else
return false;
break;
case BASE_DIGITS2:
if (*it=='e' || *it=='E')
state=E;
else if (*it=='f' || *it=='F')
state=F;
else if (*it=='l' || *it=='L')
state=L;
else if (!std::isdigit(*it))
return false;
break;
case E:
if (*it=='+' || *it=='-')
state=MANTISSA_PLUSMINUS;
else if (std::isdigit(*it))
state=MANTISSA_DIGITS;
else
return false;
break;
case MANTISSA_PLUSMINUS:
if (!std::isdigit(*it))
return false;
else
state=MANTISSA_DIGITS;
break;
case MANTISSA_DIGITS:
if (*it=='f' || *it=='F')
state=F;
else if (*it=='l' || *it=='L')
state=L;
else if (!std::isdigit(*it))
return false;
break;
case F:
return false;
case L:
return false;
}
}
return (state==BASE_DIGITS2 || state==MANTISSA_DIGITS || state==TRAILING_DECIMAL || state==F || state==L);
}
bool MathLib::isNegative(const std::string &s)
{
// remember position
std::string::size_type n = 0;
// eat up whitespace
while (std::isspace(s[n])) ++n;
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// every negative number has a negative sign
return (s[n] == '-');
}
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bool MathLib::isPositive(const std::string &s)
{
return !MathLib::isNegative(s);
}
/*! \brief Does the string represent an octal number?
* In case leading or trailing white space is provided, the function
* returns false.
* Additional information can be found here:
* http://gcc.gnu.org/onlinedocs/gcc/Binary-constants.html
*
* \param[in] s The string to check. In case the string is empty, the function returns false.
* \return Return true in case a octal number is provided and false otherwise.
**/
bool MathLib::isOct(const std::string& s)
{
enum Status {
START, PLUSMINUS, OCTAL_PREFIX, DIGITS
} state = START;
for (std::string::const_iterator it = s.begin(); it != s.end(); ++it) {
switch (state) {
case START:
if (*it == '+' || *it == '-')
state = PLUSMINUS;
else if (*it == '0')
state = OCTAL_PREFIX;
else
return false;
break;
case PLUSMINUS:
if (*it == '0')
state = OCTAL_PREFIX;
else
return false;
break;
case OCTAL_PREFIX:
if (isOctalDigit(*it))
state = DIGITS;
else
return false;
break;
case DIGITS:
if (isOctalDigit(*it))
state = DIGITS;
else
return isValidSuffix(it,s.end());
break;
}
}
return state == DIGITS;
}
bool MathLib::isHex(const std::string& s)
{
enum Status {
START, PLUSMINUS, HEX_PREFIX, DIGIT, DIGITS
} state = START;
for (std::string::const_iterator it = s.begin(); it != s.end(); ++it) {
switch (state) {
case START:
if (*it == '+' || *it == '-')
state = PLUSMINUS;
else if (*it == '0')
state = HEX_PREFIX;
else
return false;
break;
case PLUSMINUS:
if (*it == '0')
state = HEX_PREFIX;
else
return false;
break;
case HEX_PREFIX:
if (*it == 'x' || *it == 'X')
state = DIGIT;
else
return false;
break;
case DIGIT:
if (isxdigit(*it))
state = DIGITS;
else
return false;
break;
case DIGITS:
if (isxdigit(*it))
state = DIGITS;
else
return isValidSuffix(it,s.end());
break;
}
}
return state == DIGITS;
}
bool MathLib::isValidSuffix(std::string::const_iterator it, std::string::const_iterator end)
{
enum {START, SUFFIX_U, SUFFIX_UL, SUFFIX_ULL, SUFFIX_L, SUFFIX_LU, SUFFIX_LL, SUFFIX_LLU, SUFFIX_I, SUFFIX_I6, SUFFIX_I64} state = START;
for (; it != end; ++it) {
switch (state) {
case START:
if (*it == 'u' || *it == 'U')
state = SUFFIX_U;
else if (*it == 'l' || *it == 'L')
state = SUFFIX_L;
else if (*it == 'i')
state = SUFFIX_I;
else
return false;
break;
case SUFFIX_U:
if (*it == 'l' || *it == 'L')
state = SUFFIX_UL; // UL
else
return false;
break;
case SUFFIX_UL:
if (*it == 'l' || *it == 'L')
state = SUFFIX_ULL; // ULL
else
return false;
break;
case SUFFIX_L:
if (*it == 'u' || *it == 'U')
state = SUFFIX_LU; // LU
else if (*it == 'l' || *it == 'L')
state = SUFFIX_LL; // LL
else
return false;
break;
case SUFFIX_LU:
return false;
case SUFFIX_LL:
if (*it == 'u' || *it == 'U')
state = SUFFIX_LLU; // LLU
else
return false;
break;
case SUFFIX_I:
if (*it == '6')
state = SUFFIX_I6;
else
return false;
break;
case SUFFIX_I6:
if (*it == '4')
state = SUFFIX_I64;
else
return false;
break;
default:
return false;
}
}
return ((state == SUFFIX_U) ||
(state == SUFFIX_L) ||
(state == SUFFIX_UL) ||
(state == SUFFIX_LU) ||
(state == SUFFIX_LL) ||
(state == SUFFIX_ULL) ||
(state == SUFFIX_LLU) ||
(state == SUFFIX_I64));
}
/*! \brief Does the string represent a binary number?
* In case leading or trailing white space is provided, the function
* returns false.
* Additional information can be found here:
* http://gcc.gnu.org/onlinedocs/gcc/Binary-constants.html
*
* \param[in] s The string to check. In case the string is empty, the function returns false.
* \return Return true in case a binary number is provided and false otherwise.
**/
bool MathLib::isBin(const std::string& s)
{
enum Status {
START, PLUSMINUS, GNU_BIN_PREFIX, DIGIT, DIGITS
} state = START;
for (std::string::const_iterator it = s.begin(); it != s.end(); ++it) {
switch (state) {
case START:
if (*it == '+' || *it == '-')
state = PLUSMINUS;
else if (*it == '0')
state = GNU_BIN_PREFIX;
else
return false;
break;
case PLUSMINUS:
if (*it == '0')
state = GNU_BIN_PREFIX;
else
return false;
break;
case GNU_BIN_PREFIX:
if (*it == 'b' || *it == 'B')
state = DIGIT;
else
return false;
break;
case DIGIT:
if (*it == '0' || *it == '1')
state = DIGITS;
else
return false;
break;
case DIGITS:
if (*it == '0' || *it == '1')
state = DIGITS;
else
return isValidSuffix(it,s.end());
break;
}
}
return state == DIGITS;
}
bool MathLib::isDec(const std::string & s)
{
enum Status {
START, PLUSMINUS, DIGIT
} state = START;
for (std::string::const_iterator it = s.begin(); it != s.end(); ++it) {
switch (state) {
case START:
if (*it == '+' || *it == '-')
state = PLUSMINUS;
else if (isdigit(*it))
state = DIGIT;
else
return false;
break;
case PLUSMINUS:
if (isdigit(*it))
state = DIGIT;
else
return false;
break;
case DIGIT:
if (isdigit(*it))
state = DIGIT;
else
return isValidSuffix(it,s.end());
break;
}
}
return state == DIGIT;
}
bool MathLib::isInt(const std::string & s)
{
return isDec(s) || isHex(s) || isOct(s) || isBin(s);
}
std::string MathLib::add(const std::string & first, const std::string & second)
{
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if (MathLib::isInt(first) && MathLib::isInt(second)) {
return toString(toLongNumber(first) + toLongNumber(second));
}
double d1 = toDoubleNumber(first);
double d2 = toDoubleNumber(second);
int count = 0;
while (d1 > 100000.0 * d2 && toString(d1+d2)==first && ++count<5)
d2 *= 10.0;
while (d2 > 100000.0 * d1 && toString(d1+d2)==second && ++count<5)
d1 *= 10.0;
return toString(d1 + d2);
}
std::string MathLib::subtract(const std::string &first, const std::string &second)
{
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if (MathLib::isInt(first) && MathLib::isInt(second)) {
return toString(toLongNumber(first) - toLongNumber(second));
}
if (first == second)
return "0.0" ;
double d1 = toDoubleNumber(first);
double d2 = toDoubleNumber(second);
int count = 0;
while (d1 > 100000.0 * d2 && toString(d1-d2)==first && ++count<5)
d2 *= 10.0;
while (d2 > 100000.0 * d1 && toString(d1-d2)==second && ++count<5)
d1 *= 10.0;
return toString(d1 - d2);
}
std::string MathLib::incdec(const std::string & var, const std::string & op)
{
if (op == "++")
return MathLib::add(var, "1");
else if (op == "--")
return MathLib::subtract(var, "1");
throw InternalError(0, std::string("Unexpected operation '") + op + "' in MathLib::incdec(). Please report this to Cppcheck developers.");
}
std::string MathLib::divide(const std::string &first, const std::string &second)
{
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if (MathLib::isInt(first) && MathLib::isInt(second)) {
const bigint a = toLongNumber(first);
const bigint b = toLongNumber(second);
if (a == std::numeric_limits<bigint>::min())
throw InternalError(0, "Internal Error: Division overflow");
if (b == 0)
throw InternalError(0, "Internal Error: Division by zero");
return toString(toLongNumber(first) / b);
} else if (isNullValue(second)) {
if (isNullValue(first))
return "nan.0";
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const int sign_first = (isPositive(first)) ? 1 : -1;
const int sign_second = (isPositive(second)) ? 1 : -1;
return (sign_first*sign_second == 1) ? "inf.0" : "-inf.0";
}
return toString(toDoubleNumber(first) / toDoubleNumber(second));
}
std::string MathLib::multiply(const std::string &first, const std::string &second)
{
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if (MathLib::isInt(first) && MathLib::isInt(second)) {
return toString(toLongNumber(first) * toLongNumber(second));
}
return toString(toDoubleNumber(first) * toDoubleNumber(second));
}
std::string MathLib::mod(const std::string &first, const std::string &second)
{
if (MathLib::isInt(first) && MathLib::isInt(second)) {
const bigint b = toLongNumber(second);
if (b == 0)
throw InternalError(0, "Internal Error: Division by zero");
return toString(toLongNumber(first) % b);
}
return toString(std::fmod(toDoubleNumber(first),toDoubleNumber(second)));
}
std::string MathLib::calculate(const std::string &first, const std::string &second, char action)
{
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switch (action) {
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case '+':
return MathLib::add(first, second);
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case '-':
return MathLib::subtract(first, second);
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case '*':
return MathLib::multiply(first, second);
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case '/':
return MathLib::divide(first, second);
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case '%':
return MathLib::mod(first, second);
case '&':
return MathLib::toString(MathLib::toLongNumber(first) & MathLib::toLongNumber(second));
case '|':
return MathLib::toString(MathLib::toLongNumber(first) | MathLib::toLongNumber(second));
case '^':
return MathLib::toString(MathLib::toLongNumber(first) ^ MathLib::toLongNumber(second));
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default:
throw InternalError(0, std::string("Unexpected action '") + action + "' in MathLib::calculate(). Please report this to Cppcheck developers.");
}
}
std::string MathLib::sin(const std::string &tok)
{
return toString(std::sin(toDoubleNumber(tok)));
}
std::string MathLib::cos(const std::string &tok)
{
return toString(std::cos(toDoubleNumber(tok)));
}
std::string MathLib::tan(const std::string &tok)
{
return toString(std::tan(toDoubleNumber(tok)));
}
std::string MathLib::abs(const std::string &tok)
{
return toString(std::abs(toDoubleNumber(tok)));
}
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bool MathLib::isEqual(const std::string &first, const std::string &second)
{
// this conversion is needed for formatting
// e.g. if first=0.1 and second=1.0E-1, the direct comparison of the strings would fail
return toString(toDoubleNumber(first)) == toString(toDoubleNumber(second));
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}
bool MathLib::isNotEqual(const std::string &first, const std::string &second)
{
return !isEqual(first, second);
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}
bool MathLib::isGreater(const std::string &first, const std::string &second)
{
return toDoubleNumber(first) > toDoubleNumber(second);
}
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bool MathLib::isGreaterEqual(const std::string &first, const std::string &second)
{
return toDoubleNumber(first) >= toDoubleNumber(second);
}
bool MathLib::isLess(const std::string &first, const std::string &second)
{
return toDoubleNumber(first) < toDoubleNumber(second);
}
bool MathLib::isLessEqual(const std::string &first, const std::string &second)
{
return toDoubleNumber(first) <= toDoubleNumber(second);
}
/*! \brief Does the string represent the numerical value of 0?
* In case leading or trailing white space is provided, the function
* returns false.
* Requirement for this function:
* - This code is allowed to be slow because of simplicity of the code.
*
* \param[in] str The string to check. In case the string is empty, the function returns false.
* \return Return true in case the string represents a numerical null value.
**/
bool MathLib::isNullValue(const std::string &str)
{
if (str.empty() || (!std::isdigit(static_cast<unsigned char>(str[0])) && (str.size() < 1 || (str[0] != '.' && str[0] != '-' && str[0] != '+'))))
return false; // Has to be a number
for (size_t i = 0; i < str.size(); i++) {
if (std::isdigit(static_cast<unsigned char>(str[i])) && str[i] != '0') // May not contain digits other than 0
return false;
if (str[i] == 'E' || str[i] == 'e')
return true;
}
return true;
}
bool MathLib::isOctalDigit(char c)
{
return (c >= '0' && c <= '7');
}