Re: [O] Org Babel C/C++

[Daimrod]

Michael Hannon <address@hidden> writes:

> On Wednesday, March 28, 2012 at 4:01 PM Daimrod wrote:
>
>> Eric Schulte <address@hidden> writes:
>>
>>> Applied, Thanks!
>>>
>>> Daimrod <address@hidden> writes:
>>>
>>>> Hi,
>>>>
>>>> I've made a small patch to ob-C.el so it now includes the current
>>>> directory to the list of directories to be searched for header files.
>>>> Without this, I cannot include a local header file because the
>>>> compilation happens in /tmp and thus gcc or g++ doesn't search for
>>>> header files in the directory I currently work.
>>>>
>>>> diff --git a/lisp/ob-C.el b/lisp/ob-C.el
>>>> index f1525aa..4f33fc4 100644
>>>> --- a/lisp/ob-C.el
>>>> +++ b/lisp/ob-C.el
>>>> @@ -96,15 +96,14 @@ or `org-babel-execute:C++'."
>>>>         (progn
>>>>           (with-temp-file tmp-src-file (insert full-body))
>>>>           (org-babel-eval
>>>> -        (format "%s -o %s %s %s -I
>> \"%s\""
>>>> +        (format "%s -o %s %s %s"
>>>>               (cond
>>>>                 ((equal org-babel-c-variant 'c)
>> org-babel-C-compiler)
>>>>                 ((equal org-babel-c-variant 'cpp)
>> org-babel-C++-compiler))
>>>>               (org-babel-process-file-name tmp-bin-file)
>>>>               (mapconcat 'identity
>>>>                   (if (listp flags) flags (list flags)) " ")
>>>> -            (org-babel-process-file-name tmp-src-file)
>>>> -            (file-name-directory (expand-file-name
>> (buffer-file-name)))) ""))))
>>>> +            (org-babel-process-file-name tmp-src-file))
>> ""))))
>>>>       ((lambda (results)
>>>>         (org-babel-reassemble-table
>>>>       (if (member "vector" (cdr (assoc :result-params
>> params)))
>>
>> Hum, I'm quite embarrassed, this doesn't work when the block is executed
>> during an export. I didn't track it down yet, but (buffer-file-name)
>> returns nil during the export probably because the buffer changes.
>>
>> A workaround would be to use the :flags header argument though it's a
>> bit tedious because it doesn't seem possible to eval elisp during the
>> export.
>>
>> i.e.
>>
>> #+BEGIN_SRC cpp :flags -I (file-name-directory (buffer-file-name))
>> ...
>> #+END_SRC
>>
>
> I ran into this problem a few months ago.  I don't have the elisp skills to
> patch Org mode, but I found something that worked for me:
>
>     http://article.gmane.org/gmane.emacs.orgmode/49356/
>
> -- Mike

This won't work if you use different directories, you'll have to set the
variable org-babel-C++-compiler every time.

IMHO a good solution would be to be able to specify the directory used
to compile, or maybe I should just use a Makefile.