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Re: [Patch, libgfortran] Pass mode in "open" for O_CREAT and on VxWorks
On Wed, May 16, 2012 at 1:03 PM, Tobias Burnus <burnus@net-b.de> wrote:
> Dear Janne,
>
>
> On 05/16/2012 08:45 AM, Janne Blomqvist wrote:
>>
>> IMHO it would be cleaner if you instead somewhere in the beginning of
>> unix.c did
>>
>> #ifdef __VXWORKS__
>> /* open is not a variadic function on vxworks (or something...) */
>> #define open(path, flags) open(path, flags, 0666)
>> #endif
>>
>> Untested, but AFAICS it should work (unless I'm missing something wrt
>> macro expansion, which of course is quite possible).
>
>
> Testing shows that CPP does not like it:
>
> $ cpp
> #define a(x,y) a(x,y,0666)
> a(1,2)
> a(1,2,3)
> # 1 "<stdin>"
> # 1 "<command-line>"
> # 1 "<stdin>"
>
> a(1,2,0666)
> <stdin>:3:8: error: macro "a" passed 3 arguments, but takes just 2
Ah, bummer. We have something roughly similiar for snprintf (see
libgfortran.h), but it seems that it works slightly differently due to
using a variadic macro etc. So it seems this idea will not work,
sorry.
> However, I was told that VxWorks 6.6 *does* have access() [1] and it is
> defined in unistd.h of 6.3. (Recall that fallback_access does not get
> complied if HAS_ACCESS is true.) He didn't know whether it is available in
> all versions of VxWorks, however. Additionally, he has heard about gfortran
> issues (but has no experience with them); and he promised to compile
> everything to see whether everything works.
>
> [1]
> http://www-ad.fnal.gov/controls/micro_p/manuals/vxworks_application_api_reference_6.6.pdf
Interestingly, according to that document open() also has the POSIXly
correct varargs prototype. So apparently the old 3-argument prototype
was used only in some older vxworks version? Since the document above
is from 2007, one wonders how long ago did the prototype change, and
how much new development is done on these older vxworks versions?
> In light of the CPP issue and the HAS_ACCESAS: Shall I only commit the
> second part or also the VxWorks part?
IMHO lets do only the second part now, and wait for someone with
vxworks experience to pop in and explain what changes are necessary,
and which vxworks versions are worth considering to support.
--
Janne Blomqvist