Re: Document PR 84073 change in /gcc-8/porting_to.html

[Andre Vehreschild]

Hi Thomas,

looks ok to me.

- Andre

On Thu, 10 May 2018 17:19:39 +0200
Thomas König  wrote:

> Am 10.05.2018 um 14:20 schrieb Thomas Koenig:
> > Am 10.05.2018 um 12:33 schrieb Jonathan Wakely:
> >> Should the fix for PR 84073 be documented, so that users whose code is
> >> now rejected understand why, and how to fix it?
> >>
> >> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84073
> >> https://gcc.gnu.org/gcc-8/porting_to.html#fortran
> > 
> > Sounds like a good idea.
> > 
> > Since I introduced this, I'll do it within a few days (unless, of
> > course, somebody beats me to it, which I won't mind :-)
> 
> OK, not a few days, but a few hours :-)
> 
> Here is the diff.  OK to commit to gcc-docs?
> 
> Regards
> 
>   Thomas
> 
> 


-- 
Andre Vehreschild * Email: vehre ad gmx dot de 

Re: Document PR 84073 change in /gcc-8/porting_to.html

[Thomas König]

Am 10.05.2018 um 14:20 schrieb Thomas Koenig:

Am 10.05.2018 um 12:33 schrieb Jonathan Wakely:

Should the fix for PR 84073 be documented, so that users whose code is
now rejected understand why, and how to fix it?

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84073
https://gcc.gnu.org/gcc-8/porting_to.html#fortran


Sounds like a good idea.

Since I introduced this, I'll do it within a few days (unless, of
course, somebody beats me to it, which I won't mind :-)


OK, not a few days, but a few hours :-)

Here is the diff.  OK to commit to gcc-docs?

Regards

Thomas


Index: porting_to.html
===
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-8/porting_to.html,v
retrieving revision 1.6
diff -u -r1.6 porting_to.html
--- porting_to.html	4 May 2018 06:35:39 -	1.6
+++ porting_to.html	10 May 2018 15:16:57 -
@@ -196,7 +196,31 @@
   void foo_ (char*, int*, fortran_charlen_t);
   
 
+
+  Versions of gfortran prior to 8.1 wrongly accepted CHARACTER
+  variables with a length type parameter other than one as C
+  interoperable. For example, the code
+  
+  module mod
+use iso_c_binding
+type, bind(C) :: a
+  character(len=2,kind=c_char) :: b ! Wrong
+end type a
+character(len=2), bind(C) :: c ! Also wrong
+  end module mod
+  
+  was accepted.  To achieve similar functionality, an array of
+  LEN=1 characters can be used, for example
+  
+  module mod
+use iso_c_binding
+type, bind(C) :: a
+  character(kind=c_char) :: b(2)
+end type a
+character(kind=c_char), bind(C) :: c(2)
+  end module mod
+  
+
 Links
-