1 files changed, 87 insertions, 0 deletions
diff --git a/ot/helpers/pre_build_helpers.py b/ot/helpers/pre_build_helpers.py
new file mode 100644
index 0000000..93ecd6a
--- /dev/null
+++ b/ot/helpers/pre_build_helpers.py
@@ -0,0 +1,87 @@
+"""Helpers to check build environment before actual build of POT"""
+
+import os
+import sys
+import glob
+import tempfile
+import setuptools  # noqa
+import subprocess
+
+from distutils.dist import Distribution
+from distutils.sysconfig import customize_compiler
+from numpy.distutils.ccompiler import new_compiler
+from numpy.distutils.command.config_compiler import config_cc
+
+
+def _get_compiler():
+    """Get a compiler equivalent to the one that will be used to build POT
+    Handles compiler specified as follows:
+        - python setup.py build_ext --compiler=<compiler>
+        - CC=<compiler> python setup.py build_ext
+    """
+    dist = Distribution({'script_name': os.path.basename(sys.argv[0]),
+                         'script_args': sys.argv[1:],
+                         'cmdclass': {'config_cc': config_cc}})
+
+    cmd_opts = dist.command_options.get('build_ext')
+    if cmd_opts is not None and 'compiler' in cmd_opts:
+        compiler = cmd_opts['compiler'][1]
+    else:
+        compiler = None
+
+    ccompiler = new_compiler(compiler=compiler)
+    customize_compiler(ccompiler)
+
+    return ccompiler
+
+
+def compile_test_program(code, extra_preargs=[], extra_postargs=[]):
+    """Check that some C code can be compiled and run"""
+    ccompiler = _get_compiler()
+
+    # extra_(pre/post)args can be a callable to make it possible to get its
+    # value from the compiler
+    if callable(extra_preargs):
+        extra_preargs = extra_preargs(ccompiler)
+    if callable(extra_postargs):
+        extra_postargs = extra_postargs(ccompiler)
+
+    start_dir = os.path.abspath('.')
+
+    with tempfile.TemporaryDirectory() as tmp_dir:
+        try:
+            os.chdir(tmp_dir)
+
+            # Write test program
+            with open('test_program.c', 'w') as f:
+                f.write(code)
+
+            os.mkdir('objects')
+
+            # Compile, test program
+            ccompiler.compile(['test_program.c'], output_dir='objects',
+                              extra_postargs=extra_postargs)
+
+            # Link test program
+            objects = glob.glob(
+                os.path.join('objects', '*' + ccompiler.obj_extension))
+            ccompiler.link_executable(objects, 'test_program',
+                                      extra_preargs=extra_preargs,
+                                      extra_postargs=extra_postargs)
+
+            if "PYTHON_CROSSENV" not in os.environ:
+                # Run test program if not cross compiling
+                # will raise a CalledProcessError if return code was non-zero
+                output = subprocess.check_output('./test_program')
+                output = output.decode(
+                    sys.stdout.encoding or 'utf-8').splitlines()
+            else:
+                # Return an empty output if we are cross compiling
+                # as we cannot run the test_program
+                output = []
+        except Exception:
+            raise
+        finally:
+            os.chdir(start_dir)
+
+    return output, extra_postargs