nonstopf2py.py

"""
   An non-stop f2py. When the fortran program calls stop, it is trapped with a long jmp,
   and the error is converted to a python error. 

   A lot of inspiration came from patch_f2py.py in James Kermode's quippy 
     (http://www.jrkermode.co.uk/quippy)
   
   currently supported fortran runtimes are:
    ifcore (intel)
    gfortran (gnu)

   For new runtimes, compile a small f90 that uses stop 

   boo.f90:
      program boo
          stop "boo the dog stops here"
      end program boo

   and
     
     objdump -t a.o

   to find the function to override.

  -- Yu Feng <yfeng1@cmu.edu> @ McWilliam Center, Carnegie Mellon 2012

"""

from numpy import f2py

# trap the fortran STOP methods.
# luckily they are not builtin/inlined.
# we do not need to free 'message'. it appears to be staticly allocated
# by the compiler.

f2py.rules.module_rules['modulebody'] = f2py.rules.module_rules['modulebody'].replace(
      '#includes0#\n', 
    r"""#includes0#
        #include <setjmp.h>
        static char * _error;
        static jmp_buf _env;
        void for_stop_core(char * message, int len) {
          _error = strndup(message, len);
          longjmp(_env, 1);
        }
        void _gfortran_stop_string(char * message, int len) {
          _error = strndup(message, len);
          longjmp(_env, 1);
        }
     """)

# here we fight the leak as f2py will no longer always return.
# the easiest way is to first construct the return tuple, 
# then free them all
f2py.rules.routine_rules['body'] = f2py.rules.routine_rules['body'].replace(
"""\t\tif (f2py_success) {
#pyobjfrom#
/*end of pyobjfrom*/
\t\tCFUNCSMESS(\"Building return value.\\n\");
\t\tcapi_buildvalue = Py_BuildValue(\"#returnformat#\"#return#);
/*closepyobjfrom*/
#closepyobjfrom#
\t\t} /*if (f2py_success) after callfortranroutine*/""",

"""\t\t{
#pyobjfrom#
/*end of pyobjfrom*/
\t\tCFUNCSMESS(\"Building return value.\\n\");
\t\tcapi_buildvalue = Py_BuildValue(\"#returnformat#\"#return#);
/*closepyobjfrom*/
#closepyobjfrom#
\t\tif(!f2py_success) {
\t\t\tPy_XDECREF(capi_buildvalue);
\t\t\tcapi_buildvalue = NULL;
\t\t}
\t\t}
/*if (f2py_success) after callfortranroutine*/
"""
)

# the actual function call. free _error as PyErr_SetString will copy it.
f2py.rules.routine_rules['body'] = f2py.rules.routine_rules['body'].replace(
   '#callfortranroutine#\n', 
   r"""
       if(setjmp(_env)) {
         PyErr_SetString(PyExc_RuntimeError, _error);
         free(_error);
       } else { 
         #callfortranroutine# 
       }
   """)