[cmake-developers] QtAutogen 3.6.0 directory nesting overflow patch

[Brad King]

On 08/09/2016 11:45 AM, Sebastian Holtermann wrote:
> In the non-unique-qrc-name case the checksum is hard to reproduce for a 
> user. In this case I'd say CMake does not make any guaratees for
>   - the actual symbol name
>   - the symbol name to not change in the future
> It only guarantees the symbol to be unique within the project.
> 
> If the user really needs a guranteed symbol name, e.g. for a library, 
> he/she has to ensure that the BASENAME.qrc file name is unique within 
> the project. In CMake 3.5 this was a requirement anyway.

Okay.  Please update the documentation accordingly.

>> Why does cmFilePathUuid::GetChecksumString go through so many steps
>> of transformation?  Why not just take the original hex-valued hash
>> and use it directly (possibly truncated)?
> 
> Base64 uses 64 different characters. Hex values only 16.
> 
> I'm not tied to Base64 but I think it provies the best uniqueness
> with respect to the file-length and allowed-characters limitations.

Okay.  Please look at extending cmCryptoHash to offer access to
the _Final functions to get the binary digests directly as
`std::vector<unsigned char>` or something like that.  That will
avoid the binary->hex->binary conversion sequence before going
to Base64.  Also, please explain the motivation in comments.

Thanks,
-Brad