--- a/checker.py	Mon Jul 04 16:04:14 2016 +0800
+++ b/checker.py	Mon Jul 04 16:35:41 2016 +0800
@@ -77,106 +77,103 @@
         print("# C&O checker doesn't support {} yet.".format(config['scm']))
         ok = False
 
-    if not ok:
-        print('# C&O job failed')
-
     return ok
 
 
-def execute(config):
+def execute(tmp, config):
+    if not prevalidate(config):
+        return False
+
+    os.chdir(tmp)
+    source = './source'
+
+    print('# C&O task: clone')
+    print('# C&O project URL: {}'.format(config['url']))
+    os.environ['HGPLAIN'] = '1'
+
+    if not run(['hg', 'clone', config['url'], source]):
+        return False
+
+    print('$ cd {}'.format(source))
+    os.chdir(source)
+
+    if not run(['hg', 'sum']):
+        return False
+
+    template = (r'# C&O commit: {rev}:{node}\n'
+                r'# C&O commit branch: {branch}\n'
+                r'# C&O commit date: {date|isodatesec}\n'
+                r'# C&O commit author: {author|person}\n'
+                r'# C&O commit message: {desc|firstline}\n')
+    if not run(['hg', 'log', '-r', '.', '-T', template], silent=True):
+        return False
+
+    print('# C&O task: setup')
+
+    to_install = [l['name'] for l in config.get('linters', []) if 'name' in l]
+    print('# C&O linters to install: {}'.format(' '.join(to_install)))
+
+    linter_config = {}
+
+    for linter in config.get('linters', []):
+        if 'name' not in linter:
+            continue
+
+        name = linter['name']
+        if name in linter_config:
+            continue
+
+        lc = read_linter_config(name)
+        if lc is None or 'exec' not in lc:
+            continue
+
+        linter_config[name] = lc
+
+        for item in lc.get('setup', []):
+            if not run(item):
+                return False
+
+        if 'version' in lc and not run(lc['exec'] + lc['version']):
+            return False
+
+    print('# C&O linters installed: {}'.format(' '.join(linter_config.keys())))
+
+    print('# C&O task: checks')
+    for linter in config.get('linters', []):
+        if 'name' not in linter or 'include' not in linter:
+            continue
+
+        if linter['name'] not in linter_config:
+            continue
+
+        cmd = ['hg', 'files']
+        for pat in linter['include']:
+            cmd.extend(('-I', pat))
+        for pat in linter.get('exclude', []):
+            cmd.extend(('-X', pat))
+        files = run(cmd, silent=True, get_output=True, ignore_codes=(1,))
+        if files is False:
+            return False
+
+        lc = linter_config[linter['name']]
+
+        for f in files.splitlines():
+            cmd = lc['exec']
+            flags = lc.get('flags', []) + linter.get('flags', [])
+            pf = lc.get('post_flags', []) + linter.get('post_flags', [])
+            codes = lc.get('codes', (1,))
+            if not run(cmd + flags + [f] + pf, ignore_codes=codes):
+                return False
+
+    return True
+
+
+def wrapper(config):
     print('# C&O job started: {}'.format(now()))
     tmp = mkdtemp(prefix='candolint.')
-    os.chdir(tmp)
 
-    source = './source'
-    ok = prevalidate(config)
-
-    if ok:
-        print('# C&O task: clone')
-        print('# C&O project URL: {}'.format(config['url']))
-        os.environ['HGPLAIN'] = '1'
-
-    if ok and not run(['hg', 'clone', config['url'], source]):
-        ok = False
-
-    if ok:
-        print('$ cd {}'.format(source))
-        os.chdir(source)
-
-    if ok and not run(['hg', 'sum']):
-        ok = False
-
-    if ok:
-        template = (r'# C&O commit: {rev}:{node}\n'
-                    r'# C&O commit branch: {branch}\n'
-                    r'# C&O commit date: {date|isodatesec}\n'
-                    r'# C&O commit author: {author|person}\n'
-                    r'# C&O commit message: {desc|firstline}\n')
-        if not run(['hg', 'log', '-r', '.', '-T', template], silent=True):
-            ok = False
-
-    if ok:
-        print('# C&O task: setup')
-
-        to_install = [l['name'] for l in config.get('linters', []) if 'name' in l]
-        print('# C&O linters to install: {}'.format(' '.join(to_install)))
-
-        linter_config = {}
-
-        for linter in config.get('linters', []):
-            if 'name' not in linter:
-                continue
-
-            name = linter['name']
-            if name in linter_config:
-                continue
-
-            lc = read_linter_config(name)
-            if lc is None or 'exec' not in lc:
-                continue
-
-            linter_config[name] = lc
-
-            for item in lc.get('setup', []):
-                if not run(item):
-                    ok = False
-                    break
-
-            if 'version' in lc and not run(lc['exec'] + lc['version']):
-                ok = False
-                break
-
-        print('# C&O linters installed: {}'.format(' '.join(linter_config.keys())))
-
-    if ok:
-        print('# C&O task: checks')
-        for linter in config.get('linters', []):
-            if 'name' not in linter or 'include' not in linter:
-                continue
-
-            if linter['name'] not in linter_config:
-                continue
-
-            cmd = ['hg', 'files']
-            for pat in linter['include']:
-                cmd.extend(('-I', pat))
-            for pat in linter.get('exclude', []):
-                cmd.extend(('-X', pat))
-            files = run(cmd, silent=True, get_output=True, ignore_codes=(1,))
-            if files is False:
-                ok = False
-                break
-
-            lc = linter_config[linter['name']]
-
-            for f in files.splitlines():
-                cmd = lc['exec']
-                flags = lc.get('flags', []) + linter.get('flags', [])
-                pf = lc.get('post_flags', []) + linter.get('post_flags', [])
-                codes = lc.get('codes', (1,))
-                if not run(cmd + flags + [f] + pf, ignore_codes=codes):
-                    ok = False
-                    break
+    if not execute(tmp, config):
+        print('# C&O job failed')
 
     print('# C&O task: cleanup')
     rmtree(tmp)
@@ -196,7 +193,7 @@
     args = parser.parse_args()
     config = yaml.safe_load(args.config)
     try:
-        execute(config)
+        wrapper(config)
     except:
         bad_exit()