do not crash when pygments crashes

Summary:
When syntax highlighting the source excerpts that Infer prints on stdout, we
would crash if `pygments.lexers` did not find a suitable class given the name
of the source file. Instead, do not colorize when that's the case.

Reviewed By: martinoluca

Differential Revision: D3358115

fbshipit-source-id: ccb9b41

infer/lib/python/inferlib/colorize.py

@@ -55,7 +55,11 @@ def syntax_highlighting(source_name, mode, s):
     if pygments is None or mode == PLAIN_FORMATTER:
         return s
 
-    lexer = pygments.lexers.get_lexer_for_filename(source_name)
+    try:
+        lexer = pygments.lexers.get_lexer_for_filename(source_name)
+    except pygments.lexers.ClassNotFound:
+        return s
+
     formatter = None
     if mode == TERMINAL_FORMATTER:
         if not sys.stdout.isatty():

infer/tests/build_systems/build_integration_tests.py

@@ -63,6 +63,7 @@ ALL_TESTS = [
     'javac',
     'locale',
     'make',
+    'unknown_ext',
     'utf8_in_pwd',
     'waf',
 ]
@@ -375,7 +376,7 @@ class BuildIntegrationTest(unittest.TestCase):
             return
         print('\nRunning utf8_in_pwd integration test')
 
-        utf8_in_pwd_path = os.path.join(CODETOANALYZE_DIR, 'utf8_ιn_pwd')
+        utf8_in_pwd_path = os.path.join(CODETOANALYZE_DIR, u'utf8_\u03B9n_pwd')
 
         # copy non-unicode dir to one with unicode in it
         shutil.rmtree(utf8_in_pwd_path, True) # remove just in case
@@ -400,6 +401,22 @@ class BuildIntegrationTest(unittest.TestCase):
             report_name='utf8_in_pwd_make_report.json')
         shutil.rmtree(utf8_in_pwd_path, True) # remove copied dir
 
+    def test_unknown_extension(self):
+        if 'unknown_ext' not in to_test:
+            print('\nSkipping unknown extension integration test')
+            return
+
+        print('\nRunning unknown extension integration test')
+        root = CODETOANALYZE_DIR
+        errors = run_analysis(
+            root,
+            [],
+            [['clang', '-x', 'c', '-c', 'hello.unknown_ext']],
+            INFER_EXECUTABLE)
+        original = os.path.join(EXPECTED_OUTPUTS_DIR,
+                                'unknown_ext_report.json')
+        do_test(errors, original)
+
 
 if __name__ == '__main__':
     # hackish capturing of the arguments after '--'

infer/tests/build_systems/codetoanalyze/hello.unknown_ext

@@ -0,0 +1 @@
+../../../../examples/hello.c

infer/tests/build_systems/expected_outputs/unknown_ext_report.json

@@ -0,0 +1,7 @@
+[
+  {
+    "bug_type": "NULL_DEREFERENCE",
+    "file": "hello.unknown_ext",
+    "procedure": "test"
+  }
+]