PGO and LTO in clang-cl

build/pgo/test_llvm_pgo.py

@@ -0,0 +1,139 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+import unittest
+from distutils.spawn import find_executable
+
+from llvm_pgo import LLVMProfile
+
+
+class LLVMProfileTest(unittest.TestCase):
+    def setUp(self):
+        self.directory = tempfile.mkdtemp(prefix='llvm pgo test ')
+        self.profile = LLVMProfile(self.directory, sys.executable)
+        self.check_call = subprocess.check_call
+
+    def tearDown(self):
+        subprocess.check_call = self.check_call
+        shutil.rmtree(self.directory)
+
+    def write(self, path, data):
+        with open(path, 'w') as stream:
+            stream.write(data)
+
+    def test_missing_tool(self):
+        with self.assertRaises(RuntimeError):
+            LLVMProfile(self.directory, None)
+
+    def test_prepare_isolates_runs(self):
+        self.write(self.profile.output, 'stale merged profile')
+        env = {}
+        self.profile.prepare(env)
+        first = self.profile.directory
+        self.write(os.path.join(first, 'stale.profraw'), 'stale raw profile')
+        self.profile.prepare(env)
+        self.assertNotEqual(first, self.profile.directory)
+        self.assertFalse(os.path.exists(self.profile.output))
+        self.assertEqual(env['LLVM_PROFILE_FILE'],
+                         os.path.join(self.profile.directory, '%m-%p.profraw'))
+        with self.assertRaises(RuntimeError):
+            self.profile.merge()
+
+    def test_empty_profiles(self):
+        self.profile.prepare({})
+        self.write(os.path.join(self.profile.directory, 'empty.profraw'), '')
+        with self.assertRaises(RuntimeError):
+            self.profile.merge()
+
+    def test_merge_uses_input_list(self):
+        self.profile.prepare({})
+        raw = os.path.join(self.profile.directory, 'module-process.profraw')
+        self.write(raw, 'raw profile')
+        def merge(args):
+            self.assertEqual(args[:4], [sys.executable, 'merge', '-o',
+                                       self.profile.output])
+            self.assertEqual(args[4], '-f')
+            with open(args[5]) as stream:
+                self.assertEqual(stream.read().splitlines(), [raw])
+            self.write(self.profile.output, 'merged profile')
+        subprocess.check_call = merge
+        self.profile.merge()
+
+    def test_merge_failure_propagates(self):
+        self.profile.prepare({})
+        self.write(os.path.join(self.profile.directory, 'bad.profraw'), 'bad')
+        def fail(args):
+            raise subprocess.CalledProcessError(1, args)
+        subprocess.check_call = fail
+        with self.assertRaises(subprocess.CalledProcessError):
+            self.profile.merge()
+
+    def test_merge_requires_output(self):
+        self.profile.prepare({})
+        self.write(os.path.join(self.profile.directory, 'data.profraw'), 'raw')
+        subprocess.check_call = lambda args: None
+        with self.assertRaises(RuntimeError):
+            self.profile.merge()
+
+
+class PGOConfigurationTest(unittest.TestCase):
+    def setUp(self):
+        self.make = (os.environ.get('MAKE') or find_executable('mozmake') or
+                     find_executable('make'))
+        if not self.make:
+            self.skipTest('GNU make is required')
+        self.directory = tempfile.mkdtemp(prefix='pgo configuration ')
+        config = os.path.join(os.path.dirname(__file__), '..', '..',
+                              'config', 'config.mk')
+        with open(config) as stream:
+            source = stream.read()
+        start = source.index('# Reject stale Windows PGO configuration')
+        end = source.index('# Enable profile-based feedback', start)
+        self.makefile = os.path.join(self.directory, 'Makefile')
+        with open(self.makefile, 'w') as stream:
+            stream.write(source[start:end] + '\nall:;\n')
+
+    def tearDown(self):
+        if hasattr(self, 'directory'):
+            shutil.rmtree(self.directory)
+
+    def run_make(self, *variables):
+        process = subprocess.Popen([self.make, '-f', self.makefile] +
+                                   list(variables), stdout=subprocess.PIPE,
+                                   stderr=subprocess.STDOUT)
+        output = process.communicate()[0].decode('utf-8')
+        return process.returncode, output
+
+    def test_missing_profdata_fails_before_build(self):
+        code, output = self.run_make('MOZ_PGO=1', 'CLANG_CL=1', 'LLVM_PROFDATA=')
+        self.assertNotEqual(code, 0)
+        self.assertIn('requires LLVM_PROFDATA', output)
+
+    def test_msvc_flags_rejected_for_clang(self):
+        code, output = self.run_make('MOZ_PGO=1', 'CLANG_CL=1',
+                                    'LLVM_PROFDATA=llvm-profdata.exe',
+                                    'PROFILE_GEN_CFLAGS=-GL')
+        self.assertNotEqual(code, 0)
+        self.assertIn('requires LLVM instrumentation flags', output)
+
+    def test_llvm_configuration_accepted(self):
+        code, output = self.run_make('MOZ_PGO=1', 'CLANG_CL=1',
+                                    'LLVM_PROFDATA=llvm-profdata.exe',
+                                    'PROFILE_GEN_CFLAGS=-clang:-fprofile-instr-generate')
+        self.assertEqual(code, 0, output)
+
+    def test_non_pgo_and_msvc_unaffected(self):
+        for variables in [('MOZ_PGO=', 'CLANG_CL=1'),
+                          ('MOZ_PGO=1', 'CLANG_CL=')]:
+            code, output = self.run_make(*variables)
+            self.assertEqual(code, 0, output)
+
+
+if __name__ == '__main__':
+    unittest.main()