cppcheck/lib/mathlib.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2014 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 <string>
#include <sstream>
#include <cstdlib>
#include <cmath>
#include <cctype>
#include <limits>
MathLib::bigint MathLib::toLongNumber(const std::string &str)
{
// hexadecimal numbers:
if (isHex(str)) {
if (str[0] == '-') {
bigint ret = 0;
std::istringstream istr(str);
istr >> std::hex >> ret;
return ret;
} else {
unsigned long long ret = 0;
std::istringstream istr(str);
istr >> std::hex >> ret;
return (bigint)ret;
}
}
// octal numbers:
if (isOct(str)) {
bigint ret = 0;
std::istringstream istr(str);
istr >> std::oct >> ret;
return ret;
}
// 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))
return static_cast<bigint>(std::atof(str.c_str()));
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;
// 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)
{
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// every number that contains a . is a float
if (s.find("." , 0) != std::string::npos)
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return true;
// scientific notation (without dot!)
std::string::const_iterator it=s.begin();
if (*it=='+' || *it=='-') { // mantissa sign char
++it;
if (it == s.end())
return false;
}
if (!std::isdigit(*it))
return false;
++it;
while (std::isdigit(*it)) { // number
++it;
if (it == s.end())
return false;
}
if (*it!='e' && *it!='E')
return false;
else
++it;
if (it == s.end())
return false; // incomplete exponent number
if (*it=='+' || *it=='-') { // exponent sign char
++it;
if (it == s.end())
return false; // incomplete exponent number
}
while (std::isdigit(*it)) { // number
++it;
if (it == s.end())
return true;
}
if (it==s.end())
return true;
if ((*it=='f' || *it=='F') && (it+1)==s.end()) // trailing 'f'/'F' to indicate a float literal (as opposed to a double literal)
return true;
return false;
}
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);
}
bool MathLib::isOct(const std::string& str)
{
const bool sign = str[0]=='-' || str[0]=='+';
return (str[sign?1:0] == '0' && (str.size() == 1 || isOctalDigit(str[sign?2:1])) && !isFloat(str));
}
bool MathLib::isHex(const std::string& str)
{
const bool sign = str[0]=='-' || str[0]=='+';
return (str.compare(sign?1:0, 2, "0x") == 0 || str.compare(sign?1:0, 2, "0X") == 0);
}
bool MathLib::isBin(const std::string& str)
{
const bool sign = str[0]=='-' || str[0]=='+';
return ((str.compare(sign?1:0, 2, "0b") == 0 || str.compare(sign?1:0, 2, "0B") == 0) && str.find_first_not_of("10bB", 1) == std::string::npos);
}
bool MathLib::isInt(const std::string & s)
{
// perform prechecks:
// ------------------
// first check, if a point is found, it is an floating point value
const std::string charsToIndicateAFloat=".eE";
if (s.find_last_of(charsToIndicateAFloat) != std::string::npos)
return false;
// prechecking has nothing found,...
// gather information
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enum Representation {
eOctal, // starts with 0
eHex, // starts with 0x
eDefault // Numbers with a (possible) trailing u or U or l or L for unsigned or long datatypes
};
// create an instance
Representation Mode = eDefault;
// remember position
unsigned long n = 0;
// eat up whitespace
while (std::isspace(s[n])) ++n;
// determine type
if (isHex(s)) {
Mode = eHex;
} else if (isOct(s)) {
Mode = eOctal;
}
// check sign
if (s[n] == '-' || s[n] == '+') ++n;
if (Mode == eHex) {
++n; // 0
++n; // x
while (std::isxdigit(s[n]))
++n;
while (std::tolower(s[n]) == 'u' || std::tolower(s[n]) == 'l') ++n; // unsigned or long (long)
}
// check octal notation
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else if (Mode == eOctal) {
++n; // 0
while (isOctalDigit(s[n]))
++n;
while (std::tolower(s[n]) == 'u' || std::tolower(s[n]) == 'l') ++n; // unsigned or long (long)
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} else if (Mode == eDefault) {
// starts with digit
bool bStartsWithDigit=false;
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while (std::isdigit(s[n])) {
bStartsWithDigit=true;
++n;
};
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while (std::tolower(s[n]) == 'u' || std::tolower(s[n]) == 'l') ++n; // unsigned or long (long)
if (!bStartsWithDigit)
return false;
}
// eat up whitespace
while (std::isspace(s[n]))
++n;
// if everything goes good, we are at the end of the string and no digits/character
// is here --> return true, but if something was found e.g. 12E+12AA return false
return (n >= s.length());
}
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::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 (second == "0.0") {
if (first=="0.0" || first=="+0.0")
return "nan.0";
if (first=="-0.0")
return "-nan.0";
return (first[0] == '-') ? "-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)) {
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);
}
bool MathLib::isNullValue(const std::string &str)
{
return (str == "-0" || str == "0" || str == "+0"
|| str == "-0.0" || str == "0.0" || str == "+0.0"
|| str == "-0." || str == "+0."
|| str == "-0E-00" || str == "-0E+00" || str == "+0E+00" || str == "+0E-00"
|| str == "-0e-00" || str == "-0e+00" || str == "+0e+00" || str == "+0e-00"
|| str == "-0E-0");
}
bool MathLib::isOctalDigit(char c)
{
return (c == '0' || c == '1' || c == '2' || c == '3' || c == '4' || c == '5' || c == '6' || c == '7');
}