This is a more convenient behaviour (truncating on overflow and
always null terminating the buffer) compared to the MSVC
safe strcat_s which aborts the process if the string doesn't fit
into the target buffer.
Also mark the source buffer as const in the function prototype.
Make the MSVC "safe" version truncate instead of aborting the
process if the buffer is too small.
Update all the other functions to use the right parameter
(iSizeInBytes, not iCount) as 'n' parameter to strncpy.
(By passing iCount as parameter to the normal strncpy functions,
it meant that the resulting buffer actually never was null
terminated.)
Additionally make sure that the other implementations of WelsStrncpy
always null terminate the resulting buffer, just as the MSVC safe
version does when passed the _TRUNCATE parameter.
This simplifies the code and makes the buffer size checks
more consistent. Additionally, the previous version wrote
the extra space character without checking if it actually fit
into the buffer.
These were essentially useless - if strlen() ever was used as
fallback, it either indicated that those ports of the library
were insecure, or that strnlen never was required at all.
In this case it turned out to be the latter (at least after
the preceding cleanups) - all uses of it were with known null
terminated strings.
strlen is not dangerous if the string is known to be null
terminated (and MSVC does not warn about its use either).
For the cases in the decoder welsCodecTrace.cpp, the string
passed to all WriteString instances is produced by WelsVsnprintf
which always null terminates the buffer nowadays.
Additionally, as the string was passed to OutputDebugStringA
without any length specifier before, it was already assumed to
be null terminated.
The file name parameter passed to DumpDependencyRec and
DumpRecFrame in encoder.cpp is always null terminated,
which was already assumed as it is passed to WelsFopen as is.
As for the encoder utils.cpp, the strings returned by GetLogPath
are string constants that are null terminated.
The object files for this tool aren't built with the /GL flag
(Whole Program Optimization), leading to the following warning
when linking:
/LTCG specified but no code generation required; remove /LTCG from
the link command line to improve linker performance
Enabling link time code generation for the console front end binary
isn't of much use, since this tool in itself isn't performance
critical.
As long as WelsFileHandle* is equal to FILE* this doesn't matter,
but for consistency use the WelsF* functions for all handles
opened by WelsFopen, and use WelsFileHandle* as type for it
instead of FILE*.
Both encoder and decoder versions were functionally equivalent,
but I picked the decoder version (but added the static inline
keywords to it) since the encoder one was quite messy with a lot
of commented out code.
If the buffer is too small, there's no guarantee that it is
null terminated. The docs (on both unix and MSVC) say explicitly
that the function returns 0 and the buffer contents are
indeterminate in this case.
Otherwise builds on platforms other than MSVC might be
insecure.
Use vsnprintf_s with the _TRUNCATE flag instead of vsprintf_s
when using MSVC - this truncates the buffer instead of aborting
the whole process in case it's too small.
int8_t in general should to be defined as signed char, since there
are actual envrionments where a plain 'char' is unsigned.
This also reduces the differences between the typedef headers of
the different sub-libraries.
This makes them match the same macros in the main decoder/encoder
libraries. long_t (which is typedeffed to long) actually is 64
bit on 64 bit unix platforms, which might not be what was
intended.
Just use the standard inline keyword with sufficient backwards
compatibility defines, similar to how it is done in the main decoder
and encoder libraries.
Instead of using "defined(MSC_VER) || defined(__MINGW32__)" to
indicate the windows platform, just check for the _WIN32 define
instead.
Also remove an unused codepath - the removed codepath would
only be used under the condition
"(defined(MSC_VER) || defined(__MINGW32__)) && !defined(_WIN32)",
and I'm not aware of any environment with MSVC or MinGW that
doesn't define _WIN32, thus this codepath never was used.
This fixes two separate issues.
First, with the MSVC _snprintf implementations, the return value
is negative if the buffer wasn't large enough - this would in
the worst case lead to making iBufferUsed negative, writing before
the start of the buffer.
Secondly, when both iBufferUsed and iBufferLeft are accumulated,
one can't do "iBufferLeft -= iBufferUsed;". As an example,
say the buffer is 100 bytes in total and iBufferLeft is 40 and
iBufferUsed is 60. If SNPRINTF then writes 5 more bytes to the
buffer, iBufferUsed would be 65, but if we now do
"iBufferLeft -= iBufferUsed;" then iBufferLeft would end up as
-25 even though there's 35 bytes left in the buffer to use.
Therefore, we use a separate variable to store the return value
from the latest SNPRINTF call. This is checked to make sure it
wasn't negative, and only this amount is added to iBufferUsed
and subtracted from iBufferLeft.
This is the same pattern used in codec/encoder/core/src/utils.cpp.
strftime never returns negative numbers, so those calls don't
need as much checking.
Checking iBufferLeft > iBufferUsed does not make sense, since
this would stop writing into the buffer alredy after the buffer
is half full, when there is less space left than has been used.
The right check is iBufferLeft > 0.
The following pattern is unsafe on all platforms:
n = SNPRINTF(buf, ...);
buf[n] = '\0';
On windows, the _snprintf variants return a negative number
if the buffer was too small, thus buf[n] would be outside
of (before the start of) the buffer.
On other platforms, the C99 snprintf function returns the
total number of characters which would have been written if
the buffer had been large enough, which can be larger than
the buffer size itself, and thus buf[n] would be beyond the
end of the buffer.
The C99 snprintf function always null terminate the buffer.
These invocations of SNPRINTF are within !WIN32, so we can
be sure that the SNPRINTF call itself already null terminated
the buffer.
The decoder used WelsMedian while the encoder used WELS_MEDIAN.
The former has two different implementations, WELS_MEDIAN was
identical to the disabled version of WelsMedian.
Settle on using the same implementation for both decoder and
encoder - whichever version of the implementations is faster
should be used for both.
All functions that are assigned to function pointers with this
typedef (WelsHadamardQuant2x2Skip_c and WelsHadamardQuant2x2Skip_mmx)
use int32_t instead of BOOL_T for the return value.
No code exists within the project for building such a trace library.
This also fixes building on OS X with -Wno-deprecated-declarations
removed, since this code contained calls to deprecated functions
within #ifdef MACOS, which now are enabled when building on OS X.
The corresponding files for the decoder and encoder were
removed in ccca04453a. The 2008 version can be imported into
MSVC 2010 and 2012 just fine, reducing the amount of project files
to keep in sync.
This makes sure that e.g. "make clean" actually removes
the built exe files, and avoids relinking the exe files each
time make is run when cross compiling from linux to windows.
(Make on windows seems to have an exception that knows to skip
rebuilding the 'h264enc' target if 'h264enc' doesn't exist but
'h264enc.exe' does, but this exception doesn't work on normal
unix make.)
