Re: [ft-devel] Testing PIC mode code (Re: Fixes for some compile and link errors when using FT_CONFIG_OPTION_PIC)

[David Turner]

Forgot to reply on-list, sorry

2012/2/1 David Turner <address@hidden>

2012/1/28 suzuki toshiya <address@hidden>

Also I've checked ANSI C (C89) spec draft, available on:
http://flash-gordon.me.uk/ansi.c.txt
In the description of sizeof operator, I could not find explicit
permission to pass the variable (not the type) to sizeof operator,

The sizeof operator can take a "unary _expression_" as its argument, which includes simple variable designators.

The only constraint is that the _expression_ must have a known type at compile time, so "sizeof varname" is completely legal.

The parenthesis are only needed for "sizeof (typename)"

 

but I could find examples doing such:

        extern void *alloc();
        double *dp = alloc(sizeof *dp);

or

        sizeof array / sizeof array[0]

I think prohibiting the first example and rewriting it as
"double* dp = alloc(sizeof(double));" does not make the maintainability
worse,

It does make maintainability worse because it prevents handy macros like FT_NEW or FT_NEW_ARRAY from working properly.

Besides, it's not forbidden in any way by the standard.

 

but prohibiting the second example will make the maintainability
worse. The second example is refused by BREW "official" compiler?

The second example is refused because the first sizeof operator gets the _expression_ "array / sizeof array[0]" which isn't valid.

It should work if written as:

    (sizeof array)/(sizeof array[0])

or

    sizeof(array)/sizeof(array[0])

 

I think the second example is quite widely used, and some consideration
is needed.

I understand that many companies in embedded system market are selling
stubborn SDKs whose compilers are not conforming to C89 and the companies
had already lost how to maintain their SDKs, but I don't know appropriate
& well-defined subset of C89 to modify FreeType2 to fit it.

Regards,
mpsuzuki

>> Regarding testing of the PIC mode, yes you can test it on Linux even
>> though PIC isn't normally required there. The linker that has issues
>> with strings and array initializations like in ftobjs.c is for the Brew
>> platform.
>
> Thanks. I heard that BREW's official SDK is based on ARM RVCT
> compiler in Microsoft Visual C++ IDE. I don't have MSVC IDE,
> but I will check if there is any free-charged version of RVCT
> compiler.
>
> Regards,
> mpsuzuki
>
>> On Tue, 17 Jan 2012 07:54:40 +0100, suzuki toshiya
>> <address@hidden> wrote:
>>
>>> During the overhaul for PIC build, I found that cache subsystem
>>> of FreeType2 is not ready for PIC build, thus the demo programs
>>> doing rasterization (e.g. ftview, ftbench) cannot be built.
>>> Thus I can check if the code is compilable, but cannot check
>>> if the code is working. Maybe most expected direction is the
>>> porting of the cache subsystem for PIC build (even if there is
>>> no real user of it on embedded system), but extending some demo
>>> programs for FreeType2 without cache subsystem would be easier
>>> first step.
>>>
>>> # I assume FreeType2 built in PIC mode will work in the operating
>>> # system that PIC mode is NOT required (e.g. Linux). If it's
>>> # misunderstanding, please let me know.
>>>
>>> Any comments?
>>>
>>> Regards,
>>> mpsuzuki
>>>
>>> suzuki toshiya wrote:
>>>> Dear Erik,
>>>>
>>>> I have made some overhaul for PIC build, and, your patch to
>>>> modify resource fork support for PIC build is applied with
>>>> some coding style changing. Please check whether GIT head
>>>> works on your platform.
>>>>
>>>> BTW,
>>>>
>>>> diff --git a/src/base/ftobjs.c b/src/base/ftobjs.c
>>>> index 1a5a327..fc687f5 100644
>>>> --- a/src/base/ftobjs.c
>>>> +++ b/src/base/ftobjs.c
>>>> @@ -4533,7 +4533,9 @@
>>>>       */
>>>>      {
>>>>        FT_UInt      m, n;
>>>> -      const char*  driver_name[] = { "type42", NULL };
>>>> +      const char*  driver_name[2];
>>>> +         driver_name[0] = "type42";
>>>> +         driver_name[1] = NULL;
>>>>
>>>>
>>>>        for ( m = 0;
>>>>
>>>> is not committed yet, because I want to know which linker complains
>>>> about such initialization. If possible, please let me know 1 example
>>>> to be documented in ChangeLog. I'm not saying "there should not be
>>>> such linker", just I want to know 1 example, for good documentation.
>>>> Sorry for troubling you.
>>>>
>>>> Regards,
>>>> mpsuzuki
>>>>
>>>> suzuki toshiya wrote:
>>>>> Dear Erik,
>>>>>
>>>>> Sorry for your trouble and thank you for providing a patch,
>>>>> I will check it in this weekend. Please give me a few days.
>>>>>
>>>>> Regards,
>>>>> mpsuzuki
>>>>>
>>>>> Werner LEMBERG wrote:
>>>>>>> The commits in question are both dealing with compilation of
>>>>>>> 'complex' structures and static globals.
>>>>>> Thanks for the patch.  Toshiya-san, can you have a look and take care
>>>>>> of it, please?
>>>>>>
>>>>>>
>>>>>>     Werner
>>
>
>
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