[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

llvm-svn: 261204

clang/tools/scan-build-py/libscanbuild/analyze.py

@@ -106,7 +106,8 @@ def exclude(filename):
         '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(

clang/tools/scan-build-py/libscanbuild/runner.py

@@ -41,6 +41,7 @@ def wrapper(*args, **kwargs):
 
 @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']))
 

clang/tools/scan-build-py/tests/unit/test_runner.py

@@ -211,3 +211,14 @@ def test_method_with_expecteds(self):
 
     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)

clang/tools/scan-build/bin/scan-build

@@ -69,7 +69,8 @@ my %Options = (
   MaxLoop => 0,
   PluginsToLoad => [],
   AnalyzerDiscoveryMethod => undef,
-  OverrideCompiler => 0      # The flag corresponding to the --override-compiler command line option.
+  OverrideCompiler => 0,      # The flag corresponding to the --override-compiler command line option.
+  ForceAnalyzeDebugCode => 0
 );
 lock_keys(%Options);
 
@@ -951,7 +952,8 @@ sub SetEnv {
                    'CCC_CC',
                    'CCC_CXX',
                    'CCC_REPORT_FAILURES',
-                   'CLANG_ANALYZER_TARGET') {
+                   'CLANG_ANALYZER_TARGET',
+                   'CCC_ANALYZER_FORCE_ANALYZE_DEBUG_CODE') {
     my $x = $EnvVars->{$var};
     if (defined $x) { $ENV{$var} = $x }
   }
@@ -1118,6 +1120,11 @@ OPTIONS:
    Also analyze functions in #included files.  By default, such functions
    are skipped unless they are called by functions within the main source file.
 
+ --force-analyze-debug-code
+
+   Tells analyzer to enable assertions in code even if they were disabled
+   during compilation to enable more precise results.
+
  -o <output location>
 
    Specifies the output directory for analyzer reports. Subdirectories will be
@@ -1681,6 +1688,12 @@ sub ProcessArgs {
       next;
     }
 
+    if ($arg eq "--force-analyze-debug-code") {
+      shift @$Args;
+      $Options{ForceAnalyzeDebugCode} = 1;
+      next;
+    }
+
     DieDiag("unrecognized option '$arg'\n") if ($arg =~ /^-/);
 
     $NumArgs--;
@@ -1796,7 +1809,8 @@ my %EnvVars = (
   'CCC_ANALYZER_CONSTRAINTS_MODEL' => $Options{ConstraintsModel},
   'CCC_ANALYZER_INTERNAL_STATS' => $Options{InternalStats},
   'CCC_ANALYZER_OUTPUT_FORMAT' => $Options{OutputFormat},
-  'CLANG_ANALYZER_TARGET' => $Options{AnalyzerTarget}
+  'CLANG_ANALYZER_TARGET' => $Options{AnalyzerTarget},
+  'CCC_ANALYZER_FORCE_ANALYZE_DEBUG_CODE' => $Options{ForceAnalyzeDebugCode}
 );
 
 # Run the build.

clang/tools/scan-build/libexec/ccc-analyzer

@@ -492,6 +492,9 @@ if (defined $ENV{'CCC_ANALYZER_LOG'}) { $Verbose = 2; }
 # Get the HTML output directory.
 my $HtmlDir = $ENV{'CCC_ANALYZER_HTML'};
 
+# Get force-analyze-debug-code option.
+my $ForceAnalyzeDebugCode = $ENV{'CCC_ANALYZER_FORCE_ANALYZE_DEBUG_CODE'};
+
 my %DisabledArchs = ('ppc' => 1, 'ppc64' => 1);
 my %ArchsSeen;
 my $HadArch = 0;
@@ -682,6 +685,11 @@ foreach (my $i = 0; $i < scalar(@ARGV); ++$i) {
   }
 }
 
+# Forcedly enable debugging if requested by user.
+if ($ForceAnalyzeDebugCode) {
+  push @CompileOpts, '-UNDEBUG';
+}
+
 # If we are on OSX and have an installation where the
 # default SDK is inferred by xcrun use xcrun to infer
 # the SDK.

clang/www/analyzer/scan-build.html

@@ -226,6 +226,9 @@ <h3 id="recommended_debug">ALWAYS analyze a project in its &quot;debug&quot; con
 in some cases can greatly reduce the number of false positives (bogus error
 reports) emitted by the tool.</p>
 
+<p>Another option is to use <tt>--force-analyze-debug-code</tt> flag of
+<b>scan-build</b> tool which would enable assertions automatically.</p>
+
 <h3 id="recommend_verbose">Use verbose output when debugging scan-build</h3>
 
 <p><tt>scan-build</tt> takes a <b>-v</b> option to emit verbose output about