org-babel C math.h issue

[Oz Ben-Ami <ozzieba@gmail.com>]

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Hi,

I'm a new org user, and I'm sorry if I'm missing something obvious. When
executing a C code snippet with org-babel, that contains a math function, I
get the famous "undefined reference" errors. I tried adding ":flags -lm",
but that doesn't help. Looking at the code, it seems the -lm flag is
inserted in the wrong place, before the source file. An easy change would
be in line 147 of ob-C.el version 8.3.4-634, moving "flags" to after the
source file. This seems to work, but I don't know if it would break
anything else.

A minimal working example, attached, includes the following snippet:

#+BEGIN_SRC C :includes '(<math.h> <stdio.h>) :flags -lm
int i=9;
printf("%d\n",(int)sqrt(i));
#+END_SRC

Note the issue disappears if constants are directly used rather than
variables, presumably because the function call is optimized away entirely.

Any thoughts are appreciated.

Oz

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#+BEGIN_SRC elisp
(custom-set-variables
 '(org-babel-load-languages
   (quote
    ((emacs-lisp . t)
     (C . t)))))
#+END_SRC

#+RESULTS:


#+BEGIN_SRC C :includes '(<math.h> <stdio.h>) :flags -lm
int i=9;
printf("%d\n",(int)sqrt(pow(i,i)));
#+END_SRC

#+RESULTS: