[WIP] Python interface generated by SWIG

Makefile.am

@@ -179,6 +179,16 @@ cppcheck.out: $(trexio_h)
 	  --language=c --std=c99 -rp --platform=unix64  \
 	  -I../include *.c *.h 2>../$@
 
+
+python: $(ORG_FILES) src/pytrexio.i 
+	cd src/ && \
+	swig -python -o pytrexio_wrap.c pytrexio.i && \
+	$(CC) $(CPPFLAGS) -I/usr/include/python3.8 \
+		-fPIC -c trexio.c trexio_hdf5.c trexio_text.c pytrexio_wrap.c && \
+	$(CC) -shared trexio.o trexio_hdf5.o trexio_text.o pytrexio_wrap.o \
+		-L/usr/lib/x86_64-linux-gnu/hdf5/serial/ -lz -lm -lhdf5 -lhdf5_hl -o _pytrexio.so
+
+
 .PHONY: cppcheck
 
 endif

src/pytrexio.i

@@ -0,0 +1,89 @@
+%module pytrexio
+/* Define SWIGWORDSIZE in order to properly align long integers on 64-bit system */
+#define SWIGWORDSIZE64
+%{
+/* Include the headers in the wrapper code */
+#include "trexio.h"
+#include "trexio_s.h"
+#include "trexio_private.h"
+#include "trexio_text.h"
+#include "trexio_hdf5.h"
+%}
+
+/* Include stdint to recognize types from stdint.h */
+%include <stdint.i>
+/* Include carrays to work with C-like arrays */
+%include "carrays.i"
+/* Include classes that correspond to integer and float arrays */
+%array_class(double, doubleArray);
+%array_class(float, floatArray);
+%array_class(int32_t, int32Array);
+%array_class(int64_t, int64Array);
+/* Include typemaps to play with input/output re-casting 
+   Useful when working with C pointers
+*/
+%include typemaps.i
+/* Redefine the int32_t* and int64_t* num to be output 
+   Useful for TREXIO read_num functions where the 
+   num variable is modified by address
+*/
+%apply int *OUTPUT { int32_t* const num};
+%apply int *OUTPUT { int64_t* const num};
+/* Does not work for arrays (SIGSEGV)
+%apply double *OUTPUT { double* const dataset };
+*/
+/* TODO: Redefine trexio_exit_code and back_end_t types to gain access to the list 
+   of back ends and exit codes. Currently: hard-coded back ends
+*/
+/*%typemap(out) back_end_t {
+  // $1 is what we got from our C or C++ call
+  $result = PyInt_FromLong((long) $1);
+  // $result is what gets given back to Python and we are responsible for setting it
+}*/
+%constant int TREXIO_HDF5 = 0;
+%constant int TREXIO_TEXT = 1;
+
+/* This tells SWIG to treat char ** as a special case */
+%typemap(in) char ** {
+  /* Check if is a list */
+  if (PyList_Check($input)) {
+    int size = PyList_Size($input);
+    Py_ssize_t i = 0;
+    $1 = (char **) malloc((size+1)*sizeof(char *));
+    for (i = 0; i < size; i++) {
+      PyObject *o = PyList_GetItem($input, i);
+      if (PyUnicode_Check(o)) {
+        $1[i] = PyUnicode_AsUTF8(PyList_GetItem($input,i));
+      } else {
+        PyErr_Format(PyExc_TypeError, "list must contain strings. %d/%d element was not string.", i, size);
+        free($1);
+        return NULL;
+      }
+    }
+    $1[i] = 0;
+  } else {
+    PyErr_SetString(PyExc_TypeError, "not a list");
+    return NULL;
+  }
+}
+/* This cleans up the char ** array we malloc-ed before */
+%typemap(freearg) char ** {
+  free((char *) $1);
+}
+/* Now a test function
+%inline %{
+int print_args(char ** argv) {
+  int i = 0;
+  while (argv[i]) {
+    printf("argv[%d] = %s\n", i, argv[i]);
+    i++;
+  }
+  return i;
+}
+%}*/
+/* Parse the header files to generate wrappers */
+%include "trexio.h"
+%include "trexio_s.h"
+%include "trexio_private.h"
+%include "trexio_text.h"
+%include "trexio_hdf5.h"