kicad-developers team mailing list archive

[Cirilo Bernardo <cirilo.bernardo@xxxxxxxxx>]

On Wed, Mar 1, 2017 at 10:33 AM, Wayne Stambaugh <stambaughw@xxxxxxxxx> wrote:
> On 2/28/2017 4:08 PM, Cirilo Bernardo wrote:
>> On Wed, Mar 1, 2017 at 12:18 AM, Wayne Stambaugh <stambaughw@xxxxxxxxx> wrote:
>>> On 2/27/2017 8:57 PM, Cirilo Bernardo wrote:
>>>> On Tue, Feb 28, 2017 at 1:07 AM, Wayne Stambaugh <stambaughw@xxxxxxxxx> wrote:
>>>>> On 2/26/2017 4:04 PM, Cirilo Bernardo wrote:
>>>>>> 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
>>>>>
>>>>> This seems reasonable to me.
>>>>>
>>>>
>>>>  I had a look at the GCC STL implementation and unfortunately
>>>> is is impossible for me to implement (a) since I can't accomplish
>>>> what I want by deriving std::ifstream/ofstream due to the access
>>>> specifiers on the necessary member variables and the fact that
>>>> the open() function is not declared virtual.
>>>>
>>>>>>
>>>>>> b. overload open() to use the gcc extension like this:
>>>>>> __gnu_cxx::stdio_filebuf buf( _wopen ( utf8_filename, _O_RDONLY ) );
>>>>>> std::istream mystream ( &buf );
>>>>>
>>>>> If this is portable, than I'm file with this as well but on the surface
>>>>> it looks gcc specific.  If that is the case, then I would rather got
>>>>> with option a.
>>>>>
>>>>
>>>> Even solution (a), which I now know is not possible, would have been
>>>> a gcc-specific hack.
>>>>
>>>> The solution I'm working on at the moment requires the replacement of
>>>>
>>>> std::ifstream X;
>>>> X.open( filename, ... );
>>>> X.close();
>>>>
>>>> with
>>>>
>>>> OPEN_ISTREAM( X, filename );
>>>> CLOSE_STREAM( X );
>>>>
>>>> On builds which are not MinGW the helper macros generate exactly
>>>> the same code as before. On MinGW builds, the helper macros
>>>> create an extra class which creates an i/ostream and cleans up
>>>> where required on destruction. The only caveat in MinGW is that
>>>> rather than an explicit ifstream/ofstream the object which is actually
>>>> created is an istream/ostream, but this is not a difficult thing to handle.
>>>> The good thing about preserving the use of std::iostream is that I
>>>> can eliminate some of the locale switching code and simply use
>>>> imbue() on the open streams to avoid unintended effects on other
>>>> code.
>>>
>>> I'm not sure at this point why you wouldn't just use FILE_LINE_READER or
>>> wxFFileInputStream which we know both work with utf8 file names.  It
>>> seems a bit like reinventing the wheel.  I realize this doesn't solve
>>> the oce issue but for KiCad's file parsing usage, I think it makes more
>>> sense.  I'm not saying your solution isn't valid, it just seems like
>>> unnecessary work.
>>>
>>
>> The std::stream objects have modular localization support which we need
>> to force "C" locale for VRML and IDF output and of course the '<<' and '>>'
>> stream operators. The code which needs to be reworked already uses
>> streams, so this gcc-specific hack is the easiest way to fix the UTF8
>> issue within KiCad (but of course not for external libs like OCE). This
>> change is already a 1600+ lines patch + a few hundred lines for the
>> additional files. Changing the modules to use FILE_LINE_READER
>> means that we need to perform app-wide locale changes just to input/
>> output a file since wx does not implement stream locale settings, plus
>> I would need to change the many hundreds (possibly a few thousand)
>> lines with streaming ops.
>
> Please fix it this way.  I'm not sure I really like it but it sounds
> like you've programmed yourself into a hole.  I try to avoid the stream
> << and >> operators just because of these issues.
>

Hi Wayne,

  Do you mean use the wxStreams instead of std::stream?

- Cirilo

>>
>>
>>>>
>>>> I still need to look into how the issue with OCE can be tackled then
>>>> see if the devs are willing to make changes. This UTF8 filename
>>>> problem has come up on the MinGW list many times and a number
>>>> of users had suggested various changes over the years but this
>>>> really seems to be a "won't fix" issue.
>>>
>>> I spent about an hour the other day looking through the opencascade
>>> documentation and the oce source code and I couldn't find the code for
>>> the file parsers.  Could you point me to the source file where the base
>>> file parser code lives so I can take a look at it.  We can open utf-8
>>> file names just fine in mingw.  I don't understand why oce cannot open
>>> them on mingw as well.
>>>
>>
>> The OpenCascade source is easily grepped for FILE, fstream and so on.
>> The vast bulk of OpenCascade modules make use of defined classes to
>> handle I/O in various 'FSD' files, to to find all relevant files:
>>
>> find . -name "*FSD*"
>>
>> You can see the use of "_wopen" in those classes to open filestreams;
>> this is a Microsoft extension which is available in MSVC but not in
>> MinGW since the STL is different.  Other directories of interest are:
>>
>> src/STEPControl
>> src/IGESControl
>> src/STEPCAFControl
>> src/IGESCAFControl
>
> Thanks for the info.  I'll take a look at it when I can.
>
>>
>> - Cirilo
>>
>>
>>>>
>>>> If we use anything other than gcc on Windows we can tackle the
>>>> other issues then.
>>>>
>>>> - Cirilo
>>>>
>>>>>>
>>>>>> 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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>