[analyzer] Add --force-analyze-debug-code option to scan-build

to force debug build and hopefully enable more precise warnings.

Static Analyzer is much more efficient when built in debug mode
(-UNDEBUG) so we advice users to enable it manually. This may be
inconvenient in case of large complex projects (think about Linux
distros e.g. Android or Tizen). This patch adds a flag to scan-build
which inserts -UNDEBUG automatically.

Differential Revision: http://reviews.llvm.org/D16200


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@261204 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 34 insertions, 4 deletions

diff --git a/tools/scan-build-py/libscanbuild/analyze.py b/tools/scan-build-py/libscanbuild/analyze.py
index 0d3547befe..9b00d04fc0 100644
--- a/tools/scan-build-py/libscanbuild/analyze.py
+++ b/tools/scan-build-py/libscanbuild/analyze.py
@@ -106,7 +106,8 @@ def run_analyzer(args, output_dir):
         'output_dir': output_dir,
         'output_format': args.output_format,
         'output_failures': args.output_failures,
-        'direct_args': analyzer_params(args)
+        'direct_args': analyzer_params(args),
+        'force_analyze_debug_code' : args.force_analyze_debug_code
     }
 
     logging.debug('run analyzer against compilation database')
@@ -138,7 +139,9 @@ def setup_environment(args, destination, bin_dir):
         'ANALYZE_BUILD_REPORT_DIR': destination,
         'ANALYZE_BUILD_REPORT_FORMAT': args.output_format,
         'ANALYZE_BUILD_REPORT_FAILURES': 'yes' if args.output_failures else '',
-        'ANALYZE_BUILD_PARAMETERS': ' '.join(analyzer_params(args))
+        'ANALYZE_BUILD_PARAMETERS': ' '.join(analyzer_params(args)),
+        'ANALYZE_BUILD_FORCE_ANALYZE_DEBUG_CODE'
+            : 'yes' if args.force_analyze_debug_code else ''
     })
     return environment
 
@@ -168,6 +171,8 @@ def analyze_build_wrapper(cplusplus):
             'output_failures': os.getenv('ANALYZE_BUILD_REPORT_FAILURES'),
             'direct_args': os.getenv('ANALYZE_BUILD_PARAMETERS',
                                      '').split(' '),
+            'force_analyze_debug_code':
+                os.getenv('ANALYZE_BUILD_FORCE_ANALYZE_DEBUG_CODE'),
             'directory': os.getcwd(),
         }
         # get relevant parameters from command line arguments
@@ -450,6 +455,13 @@ def create_parser(from_build_command):
                 Could be usefull when project contains 3rd party libraries.
                 The directory path shall be absolute path as file names in
                 the compilation database.""")
+    advanced.add_argument(
+        '--force-analyze-debug-code',
+        dest='force_analyze_debug_code',
+        action='store_true',
+        help="""Tells analyzer to enable assertions in code even if they were
+                disabled during compilation, enabling more precise
+                results.""")
 
     plugins = parser.add_argument_group('checker options')
     plugins.add_argument(
diff --git a/tools/scan-build-py/libscanbuild/runner.py b/tools/scan-build-py/libscanbuild/runner.py
index 248ca90ad3..63b9f74369 100644
--- a/tools/scan-build-py/libscanbuild/runner.py
+++ b/tools/scan-build-py/libscanbuild/runner.py
@@ -41,6 +41,7 @@ def require(required):
 
 @require(['command', 'directory', 'file',  # an entry from compilation database
           'clang', 'direct_args',  # compiler name, and arguments from command
+          'force_analyze_debug_code',  # preprocessing options
           'output_dir', 'output_format', 'output_failures'])
 def run(opts):
     """ Entry point to run (or not) static analyzer against a single entry
@@ -164,9 +165,13 @@ def set_analyzer_output(opts, continuation=run_analyzer):
         opts.update({'output': ['-o', opts['output_dir']]})
         return continuation(opts)
 
+def force_analyze_debug_code(cmd):
+    """ Enable assert()'s by undefining NDEBUG. """
+    cmd.append('-UNDEBUG')
 
-@require(['file', 'directory', 'clang', 'direct_args', 'language',
-          'output_dir', 'output_format', 'output_failures'])
+@require(['file', 'directory', 'clang', 'direct_args',
+          'force_analyze_debug_code', 'language', 'output_dir',
+          'output_format', 'output_failures'])
 def create_commands(opts, continuation=set_analyzer_output):
     """ Create command to run analyzer or failure report generation.
 
@@ -178,6 +183,8 @@ def create_commands(opts, continuation=set_analyzer_output):
     if 'arch' in opts:
         common.extend(['-arch', opts.pop('arch')])
     common.extend(opts.pop('compile_options', []))
+    if opts['force_analyze_debug_code']:
+        force_analyze_debug_code(common)
     common.extend(['-x', opts['language']])
     common.append(os.path.relpath(opts['file'], opts['directory']))
 
diff --git a/tools/scan-build-py/tests/unit/test_runner.py b/tools/scan-build-py/tests/unit/test_runner.py
index ea10051d85..de15d23692 100644
--- a/tools/scan-build-py/tests/unit/test_runner.py
+++ b/tools/scan-build-py/tests/unit/test_runner.py
@@ -211,3 +211,14 @@ class RequireDecoratorTest(unittest.TestCase):
 
     def test_method_exception_not_caught(self):
         self.assertRaises(Exception, method_exception_from_inside, dict())
+
+class ForceAnalyzeDebugTest(unittest.TestCase):
+
+    def test_force_analyze_debug_code(self):
+        for a, b in [
+                ([], ['-UNDEBUG']),
+                (['-O2'], ['-O2', '-UNDEBUG']),
+                (['-Dkey=val'], ['-Dkey=val', '-UNDEBUG']),
+                (['-D', 'NDEBUG'], ['-D', 'NDEBUG', '-UNDEBUG']) ]:
+            sut.force_analyze_debug_code(a)
+            self.assertEqual(a, b)