I'm trying to compile a bit of code that looks something like so: (examples starts on line 38, throw is 45)
VSShader::VSShader(_In_ ICore * const pCore, _In_ const String & path, _In_opt_ const char ** ppArgs) :
m_Core(pCore), m_Name(path), m_DefaultTechnique(nullptr)
{
CGcontext context = m_Core->GetCgContext();
if (!context || !cgIsContext(context))
{
throw Exception(L"Voodoo/Core", L"Unable to create parameter (core has no context).", pCore, "VSShader.cpp", __FUNCTION__ , 45);
}
int32_t len = m_Name.ToCharStr(0, nullptr);
std::vector<char> buffer(len);
path.ToCharStr(len, &buffer[0]);
m_CgEffect = cgCreateEffectFromFile(context, &buffer[0], ppArgs);
if (!cgIsEffect(m_CgEffect))
{
throw Exception(L"Voodoo/Core", L"Failed to create shader.", m_Core, "VSShader.cpp", __FUNCTION__ , 56);
}
else
{
cgSetEffectName(m_CgEffect, &buffer[0]);
}
this->Link();
}
The ctor being called looks like:
Exception
(
_In_ wchar_t * Module,
_In_ wchar_t * Message,
_In_opt_ ICore * pCore,
_In_ char * File,
_In_ char * Function,
_In_ int Line
);
When I run analysis on this, I get the error:
1>d:\code\voodooshader\framework\core\vsshader.cpp(45): warning C6385: Invalid data: accessing 'argument 3', the readable size is '1*0' bytes, but '4' bytes might be read: Lines: 40, 39, 41, 43
As best as I can tell, that's claiming the pointer has 0 readable bytes, and I'm trying to use 4 of those when passing it (incorrect and correct, respectively). This is a 32-bit build, so pointers should be 4 bytes.
If I change the m_Core in the throw to nullptr, I receive no errors anywhere, not just on the throw line (lines 39-41 & 43 also suddenly lack errors).
Even more unusual, if I comment out the throw entirely, I receive:
1>d:\code\voodooshader\framework\core\vsshader.cpp(56): warning C6385: Invalid data: accessing 'argument 3', the readable size is '1*0' bytes, but '4' bytes might be read: Lines: 40, 39, 41, 43, 48, 49, 50, 52, 54
This gives the same error on seemingly unrelated lines.
The MSDN example for the error appears unrelated in any meaningful way, discussing bad array access.
Is this a known error of some kind, a bug, or am I simply misreading it?
More importantly, how can I fix it (this is the only warning from the compiler or PREfast, on /w4 /wX, in an 11kloc codebase, because it loves to heap on the hateful irony :P).
Edit: After some discussion and testing, I've discovered two additional oddities:
If I remove the annotations entirely from the _In_ ICore* const pCore parameter, there is no error.
If I change the annotation on that parameter to _Pre_notnull_ ICore * const pCore, there is also no error. _Pre_notnull_ has most of the requirements of _In_, so this is a functional solution for the time being, but does not seem correct.
