Re: [patch, libgfortran] Part 2: PR105456 Child I/O does not propage iostat

[Jerry D <jvdelisle2@gmail.com>]

On 2/29/24 10:13 AM, Steve Kargl wrote:
> On Thu, Feb 29, 2024 at 09:36:43AM -0800, Jerry D wrote:
>> On 2/29/24 1:47 AM, Bernhard Reutner-Fischer wrote:
>>
>>> And, just for my own education, the length limitation of iomsg to 255
>>> chars is not backed by the standard AFAICS, right? It's just our
>>> STRERR_MAXSZ?
>>
>> Yes, its what we have had for a long lone time. Once you throw an error
>> things get very processor dependent. I found MSGLEN set to 100 and IOMSG_len
>> to 256. Nothing magic about it.
>>
> 
> There is no restriction on the length for the iomsg-variable
> that receives the generated error message.  In fact, if the
> iomsg-variable has a deferred-length type parameter, then
> (re)-allocation to the exact length is expected.
> 
>    F2023
> 
>    12.11.6 IOMSG= specifier
> 
>    If an error, end-of-file, or end-of-record condition occurs during
>    execution of an input/output statement, iomsg-variable is assigned
>    an explanatory message, as if by intrinsic assignment. If no such
>    condition occurs, the definition status and value of iomsg-variable
>    are unchanged.
>   
> character(len=23) emsg
> read(fd,*,iomsg=emsg)
> 
> Here, the generated iomsg is either truncated to a length of 23
> or padded with blanks to a length of 23.
> 
> character(len=:), allocatable :: emsg
> read(fd,*,iomsg=emsg)
> 
> Here, emsg should have the length of whatever error message was
> generated.
>   
> HTH
> 

Well, currently, if someone uses a larger string than 256 we are going 
to chop it off.

Do we want to process this differently now?

Jerry