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IDebugControl::OutputVaList and %I broken?
I'm unable to use the documented %I specifier to output ULONG64 parameters as 64 or 32 bit numbers.
Simple test code looks like this:
void Test(IDebugControl*pDC, PCSTR Fmt, ...)
{
va_list val;
va_start(val, Fmt);
pDC->OutputVaList(DEBUG_OUTPUT_NORMAL, Fmt, val);
va_end(val);
}
IDebugControl*pDbgCtl = ...;
Test(pDbgCtl, "Value=%I\n", 0x1122334455667788ull);
In a 64-bit extension it prints "Field formatting string too long" and "Unknown format character" in 32-bit.
I'm specifically looking for the supposed ability to print fewer leading zeros when the 64-bit value is <= 0xffffffff. I don't want to convert to a string on my own first, I just want to replace %p in a few places...
Simple test code looks like this:
void Test(IDebugControl*pDC, PCSTR Fmt, ...)
{
va_list val;
va_start(val, Fmt);
pDC->OutputVaList(DEBUG_OUTPUT_NORMAL, Fmt, val);
va_end(val);
}
IDebugControl*pDbgCtl = ...;
Test(pDbgCtl, "Value=%I\n", 0x1122334455667788ull);
In a 64-bit extension it prints "Field formatting string too long" and "Unknown format character" in 32-bit.
I'm specifically looking for the supposed ability to print fewer leading zeros when the 64-bit value is <= 0xffffffff. I don't want to convert to a string on my own first, I just want to replace %p in a few places...
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Comments
Out("Rva For Inaddress %I64x is %I64X\n" ,inaddr ,(inaddr - Modbase));
On 11/25/16, [email protected] <[email protected]> wrote:
> I'm unable to use the documented %I specifier to output ULONG64 parameters
> as 64 or 32 bit numbers.
>
> Simple test code looks like this:
>
> void Test(IDebugControl*pDC, PCSTR Fmt, ...)
> {
> va_list val;
> va_start(val, Fmt);
> pDC->OutputVaList(DEBUG_OUTPUT_NORMAL, Fmt, val);
> va_end(val);
> }
>
> IDebugControl*pDbgCtl = ...;
> Test(pDbgCtl, "Value=%I\n", 0x1122334455667788ull);
>
> In a 64-bit extension it prints "Field formatting string too long" and
> "Unknown format character" in 32-bit.
>
> I'm specifically looking for the supposed ability to print fewer leading
> zeros when the 64-bit value is <= 0xffffffff. I don't want to convert to a
> string on my own first, I just want to replace %p in a few places...
>
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>
> I'm unable to use the documented %I specifier to output ULONG64 parameters as 64 or 32 bit
> numbers.
The capital-I thing in a Microsoft printf string is not a specifier. It is a modifier. You need to follow it with the actual specifier, as in "%Id" or "%Ix".
However, %Id is the wrong thing to use for ULONG64. A ULONG64 is always 64 bits. "%Id" tells printf "you should expect a 32-bit thing in a 32-bit build". That's not what you are providing.
You should use "%I64d" or "%I64x" in this case.
?
Tim Roberts, [email protected]
Providenza & Boekelheide, Inc.
Tim Roberts, [email protected]
Providenza & Boekelheide, Inc.
I know %I is normally a Microsoft specific modifier but OutputVaList is not in any way a normal printf function (%p is always ULONG64 and it supports strange things like %msa, %y etc.).
If you look at the documentation for OutputVaList which is currently located @ https://msdn.microsoft.com/en-us/library/windows/hardware/ff553280(v=vs.85).aspx you will see a table of _specifiers_ including "%I" and it specifically says the argument is always ULONG64 and "If this is greater than 0xFFFFFFFF, it is printed as a 64-bit value; otherwise, it is printed as a 32-bit value." which is exactly what I want, I just can't get it to work.
So my question is, is the documentation wrong or is the implementation broken?
Has it always been broken or does it work in some versions?