From 50801485f046a4bdcc8596edefa771a172d5d06a Mon Sep 17 00:00:00 2001
From: Douglas Stebila <dstebila@uwaterloo.ca>
Date: Mon, 25 Feb 2019 23:28:37 -0500
Subject: [PATCH] Add test to check that every .c / .h file triggers a library
 rebuild

---
 test/helpers.py                    |  3 +-
 test/pqclean.py                    |  3 ++
 test/test_makefile_dependencies.py | 63 ++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 test/test_makefile_dependencies.py

diff --git a/test/helpers.py b/test/helpers.py
index 0ad50da9..6b558e7e 100644
--- a/test/helpers.py
+++ b/test/helpers.py
@@ -1,7 +1,7 @@
 import subprocess
 
 
-def run_subprocess(command, working_dir, expected_returncode=0):
+def run_subprocess(command, working_dir='.', expected_returncode=0):
     """
     Helper function to run a shell command and report success/failure
     depending on the exit status of the shell command.
@@ -15,6 +15,7 @@ def run_subprocess(command, working_dir, expected_returncode=0):
         stderr=subprocess.STDOUT,
         cwd=working_dir
     )
+    print(working_dir + " > " + " ".join(command))
     print(result.stdout.decode('utf-8'))
     assert(result.returncode == expected_returncode)
     return result.stdout.decode('utf-8')
diff --git a/test/pqclean.py b/test/pqclean.py
index 6a0e9e3a..ee63d821 100644
--- a/test/pqclean.py
+++ b/test/pqclean.py
@@ -69,6 +69,9 @@ class Implementation:
     def path(self, base='..') -> str:
         return os.path.join(self.scheme.path(), self.name)
 
+    def libname(self) -> str:
+        return "lib{}_{}.a".format(self.scheme.name, self.name)
+
     @staticmethod
     def by_name(scheme_name, implementation_name):
         scheme = Scheme.by_name(scheme_name)
diff --git a/test/test_makefile_dependencies.py b/test/test_makefile_dependencies.py
new file mode 100644
index 00000000..fd2a888d
--- /dev/null
+++ b/test/test_makefile_dependencies.py
@@ -0,0 +1,63 @@
+"""
+Checks that every .c and .h file in an implementation is present as a
+dependency of that scheme's Makefile.
+"""
+
+import hashlib
+import os
+import pqclean
+import helpers
+import subprocess
+import glob
+
+
+def test_makefile_dependencies():
+    for scheme in pqclean.Scheme.all_schemes():
+        for implementation in scheme.implementations:
+            # initial build - want to have all files in place at beginning
+            helpers.run_subprocess(['make', 'clean'], implementation.path())
+            helpers.run_subprocess(['make'], implementation.path())
+            # test case for each candidate file
+            cfiles = glob.glob(os.path.join(implementation.path(), '*.c'))
+            hfiles = glob.glob(os.path.join(implementation.path(), '*.h'))
+            for file in cfiles + hfiles:
+                yield check_makefile_dependencies, scheme.name, implementation.name, file
+
+def check_makefile_dependencies(scheme_name, implementation_name, file):
+    scheme = pqclean.Scheme.by_name(scheme_name)
+    implementation = pqclean.Implementation.by_name(scheme_name, implementation_name)
+    
+    cfiles = glob.glob(os.path.join(implementation.path(), '*.c'))
+    hfiles = glob.glob(os.path.join(implementation.path(), '*.h'))
+    ofiles = glob.glob(os.path.join(implementation.path(), '*.o'))
+
+    libfile = os.path.join(implementation.path(), implementation.libname())
+
+    # modification time-based calculations is tricky on a sub-second basis
+    # so we reset all the modification times to a known and "sensible" order
+    helpers.run_subprocess(['touch'] + cfiles + hfiles + ofiles)
+    helpers.run_subprocess(['touch', libfile])
+    helpers.run_subprocess(['touch', '-A', '-15', '-m'] + cfiles + hfiles)
+    helpers.run_subprocess(['touch', '-A', '-10', '-m'] + ofiles)
+    helpers.run_subprocess(['touch', '-A', '-05', '-m', libfile])
+    mtime_lib_orig = os.stat(libfile).st_mtime_ns
+
+    # touch the candidate .c / .h file
+    helpers.run_subprocess(['touch', '-A', '15', '-m', file])
+
+    # rebuild
+    helpers.run_subprocess(['make'], implementation.path())
+
+    # make sure the libfile's modification time changed
+    mtime_lib_upd = os.stat(libfile).st_mtime_ns
+    if (mtime_lib_orig == mtime_lib_upd):
+        print("ERROR: Library was not updated after touching {}".format(file))
+    assert(mtime_lib_orig != mtime_lib_upd)
+
+if __name__ == '__main__':
+    try:
+        import nose2
+        nose2.main()
+    except ImportError:
+        import nose
+        nose.runmodule()