From 0c9a3d744105f172bc5de627936ea574d60ae00d Mon Sep 17 00:00:00 2001
From: Michael Ekstrand <md@ekstrandom.net>
Date: Mon, 4 Mar 2024 09:36:23 -0500
Subject: [PATCH] Support coverage of Cython code

---
 .coveragerc    |  0
 pyproject.toml |  3 +++
 setup.py       | 16 ++++++++++++++--
 3 files changed, 17 insertions(+), 2 deletions(-)
 delete mode 100644 .coveragerc

diff --git a/.coveragerc b/.coveragerc
deleted file mode 100644
index e69de29bb..000000000
diff --git a/pyproject.toml b/pyproject.toml
index ac2ed2adf..be5a69f79 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -157,3 +157,6 @@ exclude = [
 ]
 reportMissingImports = true
 reportMissingTypeStubs = false
+
+[tool.coverage.run]
+plugins = ["Cython.Coverage"]
diff --git a/setup.py b/setup.py
index c62f019b3..8b53a6d34 100644
--- a/setup.py
+++ b/setup.py
@@ -1,3 +1,5 @@
+import os
+
 from setuptools import Extension, setup
 
 try:
@@ -7,8 +9,17 @@
 except ImportError:
     USE_CYTHON = False
 
+
+COVERAGE = os.environ.get("BUILD_FOR_COVER", None)
 EXT_SPECS = {"lenskit.util.kvp": None}
 
+CYTHON_OPTIONS = {}
+C_DEFINES = []
+if COVERAGE:
+    print("enabling tracing")
+    CYTHON_OPTIONS["linetrace"] = True
+    C_DEFINES.append(("CYTHON_TRACE_NOGIL", "1"))
+
 
 def _make_extension(name: str, opts: None) -> Extension:
     path = name.replace(".", "/")
@@ -16,10 +27,11 @@ def _make_extension(name: str, opts: None) -> Extension:
         path += ".pyx"
     else:
         path += ".c"
-    return Extension(name, [path])
+    return Extension(name, [path], define_macros=C_DEFINES)
 
 
 EXTENSIONS = [_make_extension(ext, opts) for (ext, opts) in EXT_SPECS.items()]
 if USE_CYTHON:
-    EXTENSIONS = cythonize(EXTENSIONS)
+    EXTENSIONS = cythonize(EXTENSIONS, compiler_directives=CYTHON_OPTIONS)
+print(EXTENSIONS[0].__dict__)
 setup(ext_modules=EXTENSIONS)