2
1
mirror of https://github.com/qpdf/qpdf.git synced 2024-06-26 23:23:34 +00:00
qpdf/libqpdf/qpdf/BitWriter.hh
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

35 lines
744 B
C++

// Write bits into a bit stream. See BitStream for reading.
#ifndef BITWRITER_HH
#define BITWRITER_HH
#include <qpdf/DLL.h>
#include <stddef.h>
class Pipeline;
class BitWriter
{
public:
// Write bits to the pipeline. It is the caller's responsibility
// to eventually call finish on the pipeline.
QPDF_DLL
BitWriter(Pipeline* pl);
QPDF_DLL
void writeBits(unsigned long long val, size_t bits);
QPDF_DLL
void writeBitsSigned(long long val, size_t bits);
QPDF_DLL
void writeBitsInt(int val, size_t bits);
// Force any partial byte to be written to the pipeline.
QPDF_DLL
void flush();
private:
Pipeline* pl;
unsigned char ch;
size_t bit_offset;
};
#endif // BITWRITER_HH