circle: allow to annotate clang static analyzer false positives

https://bugs.llvm.org/show_bug.cgi?id=3888

clang analyzer doesn't know how to handle __attribute__(cleanup()).

There are only 2 warnings raised because the analyzer only look at the
current compilation unit for checking the malloc call. So only those
2 are detected by clang and then marked as memory leak.

This also means our current continuous integration doesn't check for
memory leaks.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

circle.yml

@@ -124,13 +124,13 @@ scan_build_run: &scan_build_run
     - *fedora_install
     - run:
         name: Install clang and find
-        command: dnf install -y clang-analyzer findutils
+        command: dnf install -y clang-analyzer findutils python3-beautifulsoup4
     - checkout
     - *ninja_scan_build
     - *export_logs
     - run:
         name: Check scan-build results
-        command: test ! -d ~/libratbag/build/meson-logs/scanbuild || test $(find ~/libratbag/build/meson-logs/scanbuild -maxdepth 0 ! -empty -exec echo "not empty" \; | wc -l) -eq 0 || (echo "Check scan-build results" && false)
+        command: python3 ~/libratbag/tools/check_scan_build.py ~/libratbag/build/meson-logs/scanbuild
 
 doc_build: &doc_build
   <<: *default_settings

src/hidpp20.c

@@ -2362,7 +2362,7 @@ hidpp20_onboard_profiles_parse(struct hidpp20_device *device,
 						  profiles->sector_size,
 						  data);
 	if (rc < 0)
-		return rc;
+		return rc; // ignore_clang_sa_mem_leak
 
 	crc_valid = hidpp20_onboard_profiles_is_sector_valid(device,
 							     profiles->sector_size,

src/libratbag-data.c

@@ -388,7 +388,7 @@ file_data_matches(struct ratbag *ratbag,
 	data->refcount = 1;
 	data->name = g_key_file_get_string(keyfile, GROUP_DEVICE, "Name", NULL);
 	if (!data->name) {
-		return false;
+		return false; // ignore_clang_sa_mem_leak
 	}
 
 	data->driver = g_key_file_get_string(keyfile, GROUP_DEVICE, "Driver", NULL);

tools/check_scan_build.py

@@ -0,0 +1,99 @@
+#!/bin/env python3
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+
+import bs4
+import os
+import re
+import sys
+
+
+class Bug(object):
+    def __init__(self):
+        self.line_number = None
+        self.cfile = None
+        self.sa_type = None
+        self.sa_descr = None
+
+
+def main(argv):
+    if len(argv) < 2:
+        print(f'usage {argv[0]} PATH')
+        sys.exit(1)
+
+    scanbuild_path = argv[1]
+
+    ignored = []
+    bugs = []
+
+    line_re = re.compile(r'line (\d+), column (\d+)')
+
+    for root, dirs, files in os.walk(scanbuild_path):
+        for filename in files:
+            if not filename.startswith('report'):
+                continue
+
+            with open(os.path.join(root, filename)) as f:
+                soup = bs4.BeautifulSoup(f, 'html.parser')
+
+                # the first table is the summary
+                summary = soup.table
+                bug = Bug()
+
+                # iterate over the table
+                for tr in summary('tr'):
+                    if 'File:' in tr.contents[0].string:
+                        bug.cfile = os.path.abspath(tr.contents[1].string)
+                    else:
+                        bug.sa_type = tr.contents[0].string.rstrip(':').lower()
+                        for s in tr.contents[1].strings:
+                            # retrieve the line number and the description
+                            m = line_re.match(s)
+                            if m is None:
+                                bug.sa_descr = s
+                            else:
+                                bug.line_number = int(m.group(1))
+
+                # retrieve the html line corresponding to the code
+                code = soup.find('td', id=f'LN{bug.line_number}').parent
+
+                # fetching any comments in this line
+                try:
+                    comments = code.find('span', class_='comment').string
+                except AttributeError:
+                    # no comments on the line
+                    bugs.append(bug)
+                else:
+                    if 'ignore_clang_sa_' in comments:
+                        ignored.append(bug)
+                    else:
+                        bugs.append(bug)
+
+    if len(ignored) > 0:
+        print(f'{len(ignored)} bugs are ignored:')
+        for b in ignored:
+            print(f'    {b.sa_type}: {b.sa_descr} at {b.cfile}:{b.line_number}')
+
+        if len(bugs) > 0:
+            print()
+
+    if len(bugs) > 0:
+        print(f'ERROR: {len(bugs)} bugs found:')
+        for b in bugs:
+            print(f'  * {b.sa_type.upper()}: {b.sa_descr} at {b.cfile}:{b.line_number}')
+        sys.exit(1)
+
+    sys.exit(0)
+
+
+if __name__ == '__main__':
+    main(sys.argv)