[scan-build-py] use subprocess wrapper

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@293396 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 89 insertions, 92 deletions

diff --git a/tools/scan-build-py/libscanbuild/__init__.py b/tools/scan-build-py/libscanbuild/__init__.py
index c020b4e434..f5adc86f78 100644
--- a/tools/scan-build-py/libscanbuild/__init__.py
+++ b/tools/scan-build-py/libscanbuild/__init__.py
@@ -3,10 +3,13 @@
 #
 # This file is distributed under the University of Illinois Open Source
 # License. See LICENSE.TXT for details.
-"""
-This module responsible to run the Clang static analyzer against any build
-and generate reports.
-"""
+""" This module is a collection of methods commonly used in this project. """
+import functools
+import logging
+import os
+import os.path
+import subprocess
+import sys
 
 
 def duplicate_check(method):
@@ -33,16 +36,35 @@ def duplicate_check(method):
 def tempdir():
     """ Return the default temorary directory. """
 
-    from os import getenv
-    return getenv('TMPDIR', getenv('TEMP', getenv('TMP', '/tmp')))
+    return os.getenv('TMPDIR', os.getenv('TEMP', os.getenv('TMP', '/tmp')))
+
+
+def run_command(command, cwd=None):
+    """ Run a given command and report the execution.
+
+    :param command: array of tokens
+    :param cwd: the working directory where the command will be executed
+    :return: output of the command
+    """
+    def decode_when_needed(result):
+        """ check_output returns bytes or string depend on python version """
+        return result.decode('utf-8') if isinstance(result, bytes) else result
+
+    try:
+        directory = os.path.abspath(cwd) if cwd else os.getcwd()
+        logging.debug('exec command %s in %s', command, directory)
+        output = subprocess.check_output(command,
+                                         cwd=directory,
+                                         stderr=subprocess.STDOUT)
+        return decode_when_needed(output).splitlines()
+    except subprocess.CalledProcessError as ex:
+        ex.output = decode_when_needed(ex.output).splitlines()
+        raise ex
 
 
 def initialize_logging(verbose_level):
     """ Output content controlled by the verbosity level. """
 
-    import sys
-    import os.path
-    import logging
     level = logging.WARNING - min(logging.WARNING, (10 * verbose_level))
 
     if verbose_level <= 3:
@@ -57,9 +79,6 @@ def initialize_logging(verbose_level):
 def command_entry_point(function):
     """ Decorator for command entry points. """
 
-    import functools
-    import logging
-
     @functools.wraps(function)
     def wrapper(*args, **kwargs):
 
diff --git a/tools/scan-build-py/libscanbuild/clang.py b/tools/scan-build-py/libscanbuild/clang.py
index 833e77d28b..192e708782 100644
--- a/tools/scan-build-py/libscanbuild/clang.py
+++ b/tools/scan-build-py/libscanbuild/clang.py
@@ -9,8 +9,7 @@ Since Clang command line interface is so rich, but this project is using only
 a subset of that, it makes sense to create a function specific wrapper. """
 
 import re
-import subprocess
-import logging
+from libscanbuild import run_command
 from libscanbuild.shell import decode
 
 __all__ = ['get_version', 'get_arguments', 'get_checkers']
@@ -25,8 +24,9 @@ def get_version(clang):
     :param clang:   the compiler we are using
     :return:        the version string printed to stderr """
 
-    output = subprocess.check_output([clang, '-v'], stderr=subprocess.STDOUT)
-    return output.decode('utf-8').splitlines()[0]
+    output = run_command([clang, '-v'])
+    # the relevant version info is in the first line
+    return output[0]
 
 
 def get_arguments(command, cwd):
@@ -38,12 +38,11 @@ def get_arguments(command, cwd):
 
     cmd = command[:]
     cmd.insert(1, '-###')
-    logging.debug('exec command in %s: %s', cwd, ' '.join(cmd))
 
-    output = subprocess.check_output(cmd, cwd=cwd, stderr=subprocess.STDOUT)
+    output = run_command(cmd, cwd=cwd)
     # The relevant information is in the last line of the output.
     # Don't check if finding last line fails, would throw exception anyway.
-    last_line = output.decode('utf-8').splitlines()[-1]
+    last_line = output[-1]
     if re.search(r'clang(.*): error:', last_line):
         raise Exception(last_line)
     return decode(last_line)
@@ -141,9 +140,7 @@ def get_checkers(clang, plugins):
     load = [elem for plugin in plugins for elem in ['-load', plugin]]
     cmd = [clang, '-cc1'] + load + ['-analyzer-checker-help']
 
-    logging.debug('exec command: %s', ' '.join(cmd))
-    output = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
-    lines = output.decode('utf-8').splitlines()
+    lines = run_command(cmd)
 
     is_active_checker = is_active(get_active_checkers(clang, plugins))
 
diff --git a/tools/scan-build-py/libscanbuild/intercept.py b/tools/scan-build-py/libscanbuild/intercept.py
index 6a9f75349f..2aef79fe58 100644
--- a/tools/scan-build-py/libscanbuild/intercept.py
+++ b/tools/scan-build-py/libscanbuild/intercept.py
@@ -31,7 +31,7 @@ import argparse
 import logging
 import subprocess
 from libear import build_libear, TemporaryDirectory
-from libscanbuild import command_entry_point
+from libscanbuild import command_entry_point, run_command
 from libscanbuild import duplicate_check, tempdir, initialize_logging
 from libscanbuild.compilation import split_command
 from libscanbuild.shell import encode, decode
@@ -44,6 +44,7 @@ US = chr(0x1f)
 
 COMPILER_WRAPPER_CC = 'intercept-cc'
 COMPILER_WRAPPER_CXX = 'intercept-c++'
+WRAPPER_ONLY_PLATFORMS = frozenset({'win32', 'cygwin'})
 
 
 @command_entry_point
@@ -238,24 +239,21 @@ def is_preload_disabled(platform):
     the path and, if so, (2) whether the output of executing 'csrutil status'
     contains 'System Integrity Protection status: enabled'.
 
-    Same problem on linux when SELinux is enabled. The status query program
-    'sestatus' and the output when it's enabled 'SELinux status: enabled'. """
+    :param platform: name of the platform (returned by sys.platform),
+    :return: True if library preload will fail by the dynamic linker. """
 
-    if platform == 'darwin':
-        pattern = re.compile(r'System Integrity Protection status:\s+enabled')
+    if platform in WRAPPER_ONLY_PLATFORMS:
+        return True
+    elif platform == 'darwin':
         command = ['csrutil', 'status']
-    elif platform in {'linux', 'linux2'}:
-        pattern = re.compile(r'SELinux status:\s+enabled')
-        command = ['sestatus']
+        pattern = re.compile(r'System Integrity Protection status:\s+enabled')
+        try:
+            return any(pattern.match(line) for line in run_command(command))
+        except:
+            return False
     else:
         return False
 
-    try:
-        lines = subprocess.check_output(command).decode('utf-8')
-        return any((pattern.match(line) for line in lines.splitlines()))
-    except:
-        return False
-
 
 def entry_hash(entry):
     """ Implement unique hash method for compilation database entries. """
diff --git a/tools/scan-build-py/libscanbuild/runner.py b/tools/scan-build-py/libscanbuild/runner.py
index 72d02c85fe..014b872479 100644
--- a/tools/scan-build-py/libscanbuild/runner.py
+++ b/tools/scan-build-py/libscanbuild/runner.py
@@ -12,6 +12,7 @@ import tempfile
 import functools
 import subprocess
 import logging
+from libscanbuild import run_command
 from libscanbuild.compilation import classify_source, compiler_language
 from libscanbuild.clang import get_version, get_arguments
 from libscanbuild.shell import decode
@@ -100,7 +101,7 @@ def run(opts):
 
 
 @require(['clang', 'directory', 'flags', 'file', 'output_dir', 'language',
-          'error_type', 'error_output', 'exit_code'])
+          'error_output', 'exit_code'])
 def report_failure(opts):
     """ Create report when analyzer failed.
 
@@ -108,30 +109,36 @@ def report_failure(opts):
     randomly. The compiler output also captured into '.stderr.txt' file.
     And some more execution context also saved into '.info.txt' file. """
 
-    def extension(opts):
+    def extension():
         """ Generate preprocessor file extension. """
 
         mapping = {'objective-c++': '.mii', 'objective-c': '.mi', 'c++': '.ii'}
         return mapping.get(opts['language'], '.i')
 
-    def destination(opts):
+    def destination():
         """ Creates failures directory if not exits yet. """
 
-        name = os.path.join(opts['output_dir'], 'failures')
-        if not os.path.isdir(name):
-            os.makedirs(name)
-        return name
-
-    error = opts['error_type']
-    (handle, name) = tempfile.mkstemp(suffix=extension(opts),
+        failures_dir = os.path.join(opts['output_dir'], 'failures')
+        if not os.path.isdir(failures_dir):
+            os.makedirs(failures_dir)
+        return failures_dir
+
+    # Classify error type: when Clang terminated by a signal it's a 'Crash'.
+    # (python subprocess Popen.returncode is negative when child terminated
+    # by signal.) Everything else is 'Other Error'.
+    error = 'crash' if opts['exit_code'] < 0 else 'other_error'
+    # Create preprocessor output file name. (This is blindly following the
+    # Perl implementation.)
+    (handle, name) = tempfile.mkstemp(suffix=extension(),
                                       prefix='clang_' + error + '_',
-                                      dir=destination(opts))
+                                      dir=destination())
     os.close(handle)
+    # Execute Clang again, but run the syntax check only.
     cwd = opts['directory']
-    cmd = get_arguments([opts['clang'], '-fsyntax-only', '-E'] +
-                        opts['flags'] + [opts['file'], '-o', name], cwd)
-    logging.debug('exec command in %s: %s', cwd, ' '.join(cmd))
-    subprocess.call(cmd, cwd=cwd)
+    cmd = get_arguments(
+        [opts['clang'], '-fsyntax-only', '-E'
+         ] + opts['flags'] + [opts['file'], '-o', name], cwd)
+    run_command(cmd, cwd=cwd)
     # write general information about the crash
     with open(name + '.info.txt', 'w') as handle:
         handle.write(opts['file'] + os.linesep)
@@ -144,11 +151,6 @@ def report_failure(opts):
     with open(name + '.stderr.txt', 'w') as handle:
         handle.writelines(opts['error_output'])
         handle.close()
-    # return with the previous step exit code and output
-    return {
-        'error_output': opts['error_output'],
-        'exit_code': opts['exit_code']
-    }
 
 
 @require(['clang', 'directory', 'flags', 'direct_args', 'file', 'output_dir',
@@ -158,7 +160,7 @@ def run_analyzer(opts, continuation=report_failure):
     output of the analysis and returns with it. If failure reports are
     requested, it calls the continuation to generate it. """
 
-    def output():
+    def target():
         """ Creates output file name for reports. """
         if opts['output_format'] in {'plist', 'plist-html'}:
             (handle, name) = tempfile.mkstemp(prefix='report-',
@@ -168,30 +170,20 @@ def run_analyzer(opts, continuation=report_failure):
             return name
         return opts['output_dir']
 
-    cwd = opts['directory']
-    cmd = get_arguments([opts['clang'], '--analyze'] + opts['direct_args'] +
-                        opts['flags'] + [opts['file'], '-o', output()],
-                        cwd)
-    logging.debug('exec command in %s: %s', cwd, ' '.join(cmd))
-    child = subprocess.Popen(cmd,
-                             cwd=cwd,
-                             universal_newlines=True,
-                             stdout=subprocess.PIPE,
-                             stderr=subprocess.STDOUT)
-    output = child.stdout.readlines()
-    child.stdout.close()
-    # do report details if it were asked
-    child.wait()
-    if opts.get('output_failures', False) and child.returncode:
-        error_type = 'crash' if child.returncode & 127 else 'other_error'
-        opts.update({
-            'error_type': error_type,
-            'error_output': output,
-            'exit_code': child.returncode
-        })
-        return continuation(opts)
-    # return the output for logging and exit code for testing
-    return {'error_output': output, 'exit_code': child.returncode}
+    try:
+        cwd = opts['directory']
+        cmd = get_arguments([opts['clang'], '--analyze'] +
+                            opts['direct_args'] + opts['flags'] +
+                            [opts['file'], '-o', target()],
+                            cwd)
+        output = run_command(cmd, cwd=cwd)
+        return {'error_output': output, 'exit_code': 0}
+    except subprocess.CalledProcessError as ex:
+        result = {'error_output': ex.output, 'exit_code': ex.returncode}
+        if opts.get('output_failures', False):
+            opts.update(result)
+            continuation(opts)
+        return result
 
 
 @require(['flags', 'force_debug'])
diff --git a/tools/scan-build-py/tests/unit/test_intercept.py b/tools/scan-build-py/tests/unit/test_intercept.py
index 5b6ed2cee1..583d1c3da9 100644
--- a/tools/scan-build-py/tests/unit/test_intercept.py
+++ b/tools/scan-build-py/tests/unit/test_intercept.py
@@ -65,11 +65,10 @@ class InterceptUtilTest(unittest.TestCase):
         DISABLED = 'disabled'
 
         OSX = 'darwin'
-        LINUX = 'linux'
 
         with libear.TemporaryDirectory() as tmpdir:
+            saved = os.environ['PATH']
             try:
-                saved = os.environ['PATH']
                 os.environ['PATH'] = tmpdir + ':' + saved
 
                 create_csrutil(tmpdir, ENABLED)
@@ -77,21 +76,14 @@ class InterceptUtilTest(unittest.TestCase):
 
                 create_csrutil(tmpdir, DISABLED)
                 self.assertFalse(sut.is_preload_disabled(OSX))
-
-                create_sestatus(tmpdir, ENABLED)
-                self.assertTrue(sut.is_preload_disabled(LINUX))
-
-                create_sestatus(tmpdir, DISABLED)
-                self.assertFalse(sut.is_preload_disabled(LINUX))
             finally:
                 os.environ['PATH'] = saved
 
+        saved = os.environ['PATH']
         try:
-            saved = os.environ['PATH']
             os.environ['PATH'] = ''
             # shall be false when it's not in the path
             self.assertFalse(sut.is_preload_disabled(OSX))
-            self.assertFalse(sut.is_preload_disabled(LINUX))
 
             self.assertFalse(sut.is_preload_disabled('unix'))
         finally:
diff --git a/tools/scan-build-py/tests/unit/test_runner.py b/tools/scan-build-py/tests/unit/test_runner.py
index 2d09062233..4b51e65284 100644
--- a/tools/scan-build-py/tests/unit/test_runner.py
+++ b/tools/scan-build-py/tests/unit/test_runner.py
@@ -150,7 +150,6 @@ class RunAnalyzerTest(unittest.TestCase):
     def test_run_analyzer_crash_and_forwarded(self):
         content = "int div(int n, int d) { return n / d }"
         (_, fwds) = RunAnalyzerTest.run_analyzer(content, True)
-        self.assertEqual('crash', fwds['error_type'])
         self.assertEqual(1, fwds['exit_code'])
         self.assertTrue(len(fwds['error_output']) > 0)