From e2a115b35e151ece7fefd0e095a73d478e2268f6 Mon Sep 17 00:00:00 2001
From: Daniel Garcia Moreno <daniel.garcia@suse.com>
Date: Mon, 14 Nov 2022 12:56:32 +0100
Subject: [PATCH] Make clib build reproducible by sorting sources

Fix https://github.com/pypa/setuptools/issues/3678
---
 changelog.d/3678.change.rst                 |  1 +
 setuptools/_distutils/command/build_clib.py |  2 +-
 setuptools/command/build_clib.py            |  2 +-
 setuptools/tests/test_build_clib.py         | 28 +++++++++++++++++++++
 4 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 changelog.d/3678.change.rst

diff --git a/changelog.d/3678.change.rst b/changelog.d/3678.change.rst
new file mode 100644
index 00000000000..9893f99fc84
--- /dev/null
+++ b/changelog.d/3678.change.rst
@@ -0,0 +1 @@
+Make clib builds reproducible by sorting sources -- by :user:`danigm`
diff --git a/setuptools/_distutils/command/build_clib.py b/setuptools/_distutils/command/build_clib.py
index 50bb9bbabb7..7d5f8c51349 100644
--- a/setuptools/_distutils/command/build_clib.py
+++ b/setuptools/_distutils/command/build_clib.py
@@ -183,7 +183,7 @@ def build_libraries(self, libraries):
                     "'sources' must be present and must be "
                     "a list of source filenames" % lib_name
                 )
-            sources = list(sources)
+            sources = sorted(list(sources))
 
             log.info("building '%s' library", lib_name)
 
diff --git a/setuptools/command/build_clib.py b/setuptools/command/build_clib.py
index 67ce2444ea6..09483e69e5b 100644
--- a/setuptools/command/build_clib.py
+++ b/setuptools/command/build_clib.py
@@ -28,7 +28,7 @@ def build_libraries(self, libraries):
                     "in 'libraries' option (library '%s'), "
                     "'sources' must be present and must be "
                     "a list of source filenames" % lib_name)
-            sources = list(sources)
+            sources = sorted(list(sources))
 
             log.info("building '%s' library", lib_name)
 
diff --git a/setuptools/tests/test_build_clib.py b/setuptools/tests/test_build_clib.py
index af9e7c6dc39..2d9273cdcab 100644
--- a/setuptools/tests/test_build_clib.py
+++ b/setuptools/tests/test_build_clib.py
@@ -2,6 +2,7 @@
 
 import pytest
 
+import random
 from distutils.errors import DistutilsSetupError
 from setuptools.command.build_clib import build_clib
 from setuptools.dist import Distribution
@@ -56,3 +57,30 @@ def test_build_libraries(self, mock_newer):
         cmd.build_libraries(libs)
         assert cmd.compiler.compile.call_count == 1
         assert cmd.compiler.create_static_lib.call_count == 1
+
+    @mock.patch(
+        'setuptools.command.build_clib.newer_pairwise_group')
+    def test_build_libraries_reproducible(self, mock_newer):
+        dist = Distribution()
+        cmd = build_clib(dist)
+
+        # with that out of the way, let's see if the crude dependency
+        # system works
+        cmd.compiler = mock.MagicMock(spec=cmd.compiler)
+        mock_newer.return_value = ([], [])
+
+        original_sources = ['a-example.c', 'example.c']
+        sources = original_sources
+
+        obj_deps = {'': ('global.h',), 'example.c': ('example.h',)}
+        libs = [('example', {'sources': sources, 'obj_deps': obj_deps})]
+
+        cmd.build_libraries(libs)
+        computed_call_args = mock_newer.call_args[0]
+
+        while sources == original_sources:
+            sources = random.sample(original_sources, len(original_sources))
+        libs = [('example', {'sources': sources, 'obj_deps': obj_deps})]
+
+        cmd.build_libraries(libs)
+        assert computed_call_args == mock_newer.call_args[0]