kicad-developers team mailing list archive

[Cirilo Bernardo <cirilo.bernardo@xxxxxxxxx>]

There is one other way which I found after much digging
and it involves a GCC extension. Since we use GCC on
Windows this might be acceptable:

a. create a derived class of std::ifstream/ofstream. On
Windows the derived class will be used while on other
OS it will simply be typedef to std::ifstream/ofstream

b. overload open() to use the gcc extension like this:
__gnu_cxx::stdio_filebuf buf( _wopen ( utf8_filename, _O_RDONLY ) );
std::istream mystream ( &buf );

The destructor must contain code to delete buf since
the istream will not delete it on destruction.

If that would be acceptable I'll make some test
programs and work on a patch set. This solution
would also work on OCE and I can talk to the OCE
patch team to see what they think of it.

- Cirilo


On Mon, Feb 27, 2017 at 4:54 AM, Wayne Stambaugh <stambaughw@xxxxxxxxx> wrote:
> On 2/26/2017 1:50 AM, Cirilo Bernardo wrote:
>> Hi folks,
>>
>>  This whole thing with UTF-8 filenames in Windows is a disaster.
>> What I've found so far:
>>
>> 1. Regarding OCE: Since OCE 0.17 (OpenCascade 6.8) UTF8
>> filenames have been supported when built with MSVC but
>> obviously not with MinGW.
>>
>> 2. MinGW does not provide any means of transparently using
>> UTF-8 filenames. All filenames within the STL *must* be
>> char* and MinGW *will* simply pass these on to OpenFileA()
>> on Windows resulting in UTF-8 being interpreted as ASCII-8
>> (and who uses ASCII-8 filenames anyway).
>>
>> So everything hinges on (2). If OCE uses std::stream then
>> fixing all issues under Windows is a lost cause. If OCE
>> simply plays with FILE* then it can be patched to work
>> in MinGW by invoking _wfopen() rather than fopen().
>>
>> As for kicad itself, std::stream is used in:
>> (a) VRML export
>> (b) IDF static library
>> (c) Scenegraph dynamic library for 3D plugins
>>
>> 2 paths forward come to mind and both will involve some work:
>>
>> (1) Move to the MSVC build system on Windows: this makes
>> it possible for us to use Microsoft extensions to STL to deal
>> with non-ASCII filename issues. There is no need to dig into
>> the OCE code since we know it will work correctly when built
>> with MSVC.
>
> This is not an acceptable solution.  It's not portable and would limit
> windows builds to using msvc.
>
>>
>> (2) Rework kicad code to play with FILE* (or wxFileStream)
>> rather than std::ifstream/ofstream. Although this will fix the
>> issues which are confined to kicad's source, it does nothing
>> to address the OCE issue. Whether or not OCE in MinGW
>> is a lost cause remains to be seen.
>
> FILE* is how we pretty much do it everywhere else in KiCad with good
> results so I don't see any reason not to do it this way with the model
> parser code.  At least it's portable across all build platforms.
> Doesn't oce have a reader function that takes a FILE *?
>
>>
>> One other possibility (but one which I hadn't looked into)
>> is to see if the STL implementation within MinGW uses the
>> MinGW-CRT. If it does then it may be possible to fix
>> everything by ensuring that the MinGW-CRT converts all
>> filenames to UTF16 and opens a file using FileOpenW().
>> In all cases this is not a pleasant task.
>>
>> Any comments/suggestions?
>>
>> - Cirilo
>>
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>
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