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

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

[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

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

[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 :-)

Regards

	Thomas

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

[Thomas König]

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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



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[-- Type: text/x-patch, Size: 1159 bytes --]

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 -0000	1.6
+++ porting_to.html	10 May 2018 15:16:57 -0000
@@ -196,7 +196,31 @@
       void foo_ (char*, int*, fortran_charlen_t);
   </code></pre>
 
+<p>
+  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
+  <pre><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
+  </code></pre>
+  was accepted.  To achieve similar functionality, an array of
+  LEN=1 characters can be used, for example
+  <pre><code>
+  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
+  </code></pre>
+</p>
 <h2 id="links">Links</h2>
-
 </body>
 </html>

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 <tk@tkoenig.net> 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