40 lines
1.4 KiB
C++
40 lines
1.4 KiB
C++
#include <stdexcept>
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#include <iostream>
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#include <array>
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#include <boost/safe_numerics/safe_integer_range.hpp>
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void detected_msg(bool detected){
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std::cout << (detected ? "error detected!" : "error NOT detected! ") << std::endl;
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}
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int main(int, const char *[]){
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// problem: array index values can exceed array bounds
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std::cout << "example 5: ";
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std::cout << "array index values can exceed array bounds" << std::endl;
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std::cout << "Not using safe numerics" << std::endl;
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std::array<int, 37> i_array;
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// unsigned int i_index = 43;
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// the following corrupts memory.
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// This may or may not be detected at run time.
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// i_array[i_index] = 84; // comment this out so it can be tested!
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std::cout << "error NOT detected!" << std::endl;
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// solution: replace unsigned array index with safe_unsigned_range
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std::cout << "Using safe numerics" << std::endl;
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try{
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using namespace boost::safe_numerics;
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using i_index_t = safe_unsigned_range<0, i_array.size() - 1>;
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i_index_t i_index;
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i_index = 36; // this works fine
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i_array[i_index] = 84;
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i_index = 43; // throw exception here!
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std::cout << "error NOT detected!" << std::endl; // so we never arrive here
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}
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catch(const std::exception & e){
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std::cout << "error detected:" << e.what() << std::endl;
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}
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return 0;
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}
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