[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 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(

clang/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']))
 

clang/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)

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 @@ Assertions are picked up by the static analyzer to prune infeasible paths, which
 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