Compile with coverage support optionally

Author: rhpvorderman

pyproject.toml

@@ -1,3 +1,6 @@
 [build-system]
 requires = ["setuptools>=51", "cython>=0.29", "wheel"]
 build-backend = "setuptools.build_meta"
+
+[tool.coverage.run]
+plugins = ["Cython.Coverage"]

setup.py

@@ -25,6 +25,8 @@
 import tempfile
 from pathlib import Path
 
+from Cython.Build import cythonize
+
 from setuptools import Extension, find_packages, setup
 from setuptools.command.build_ext import build_ext
 
@@ -62,6 +64,17 @@ def build_extension(self, ext):
             ext.extra_objects = [
                 os.path.join(isa_l_prefix_dir, "lib", "libisal.a")]
 
+        if os.getenv("CYTHON_COVERAGE") is not None:
+            # Add cython directives and macros for coverage support.
+            cythonized_exts = cythonize(ext, compiler_directives=dict(
+                linetrace=True
+            ))
+            for cython_ext in cythonized_exts:
+                cython_ext.define_macros = [("CYTHON_TRACE_NOGIL", "1")]
+                cython_ext._needs_stub = False
+                super().build_extension(cython_ext)
+            return
+
         super().build_extension(ext)
 
 

tox.ini

@@ -3,10 +3,13 @@
 # python3 interpreter of the user.
 envlist=py3
 [testenv]
-deps=coverage
+deps=coverage[toml]
+     cython
      pytest
 passenv=
     PYTHON_ISAL_LINK_DYNAMIC
+setenv=
+    CYTHON_COVERAGE=true
 commands =
     # Create HTML coverage report for humans and xml coverage report for external services.
     coverage run --source={envsitepackagesdir}/isal -m py.test -v tests