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qpdf/libtests/qintc.cc
Jay Berkenbilt d71f05ca07 Fix sign and conversion warnings (major)
This makes all integer type conversions that have potential data loss
explicit with calls that do range checks and raise an exception. After
this commit, qpdf builds with no warnings when -Wsign-conversion
-Wconversion is used with gcc or clang or when -W3 -Wd4800 is used
with MSVC. This significantly reduces the likelihood of potential
crashes from bogus integer values.

There are some parts of the code that take int when they should take
size_t or an offset. Such places would make qpdf not support files
with more than 2^31 of something that usually wouldn't be so large. In
the event that such a file shows up and is valid, at least qpdf would
raise an error in the right spot so the issue could be legitimately
addressed rather than failing in some weird way because of a silent
overflow condition.
2019-06-21 13:17:21 -04:00

58 lines
2.0 KiB
C++

#include <qpdf/QIntC.hh>
#include <stdint.h>
#include <cassert>
#define try_convert(exp_pass, fn, i) \
try_convert_real(#fn "(" #i ")", exp_pass, fn, i)
template <typename From, typename To>
static void try_convert_real(
char const* description, bool exp_pass,
To (*fn)(From const&), From const& i)
{
bool passed = false;
try
{
To result = fn(i);
passed = true;
std::cout << description << ": " << i << " " << result;
}
catch (std::range_error& e)
{
std::cout << description << ": " << e.what();
passed = false;
}
std::cout << ((passed == exp_pass) ? " PASSED" : " FAILED") << std::endl;
}
int main()
{
uint32_t u1 = 3141592653U; // Too big for signed type
int32_t i1 = -1153374643; // Same bit pattern as u1
uint64_t ul1 = 1099511627776LL; // Too big for 32-bit
uint64_t ul2 = 12345; // Fits into 32-bit
int32_t i2 = 81; // Fits in char and uchar
char c1 = '\xf7'; // Signed vaule when char
// Verify i1 and u1 have same bit pattern
assert(static_cast<uint32_t>(i1) == u1);
// Verify that we can unsafely convert between char and unsigned char
assert(c1 == static_cast<char>(static_cast<unsigned char>(c1)));
try_convert(true, QIntC::to_int<int32_t>, i1);
try_convert(true, QIntC::to_uint<uint32_t>, u1);
try_convert(false, QIntC::to_int<uint32_t>, u1);
try_convert(false, QIntC::to_uint<int32_t>, i1);
try_convert(false, QIntC::to_int<uint64_t>, ul1);
try_convert(true, QIntC::to_int<uint64_t>, ul2);
try_convert(true, QIntC::to_uint<uint64_t>, ul2);
try_convert(true, QIntC::to_offset<uint32_t>, u1);
try_convert(true, QIntC::to_offset<int32_t>, i1);
try_convert(false, QIntC::to_ulonglong<int32_t>, i1);
try_convert(true, QIntC::to_char<int32_t>, i2);
try_convert(true, QIntC::to_uchar<int32_t>, i2);
try_convert(false, QIntC::to_uchar<char>, c1);
return 0;
}