ProcessExecutor: do not modify mutable objects from parent in forked process

cli/processexecutor.cpp

@@ -342,6 +342,12 @@ unsigned int ProcessExecutor::check()
         return v + p.size();
     });
 
+    // pass unmodified suppressions to forked process so we only transfer back the actual changes done by the fork
+    // and do not see the changes which have already been transferred back
+    Suppressions supprs;
+    supprs.nomsg.addSuppressions(mSuppressions.nomsg.getSuppressions());
+    supprs.nofail.addSuppressions(mSuppressions.nofail.getSuppressions());
+
     std::list<int> rpipes;
     std::map<pid_t, std::string> childFile;
     std::map<int, std::string> pipeFile;
@@ -380,13 +386,13 @@ unsigned int ProcessExecutor::check()
 #endif
                 close(pipes[0]);
 
-                // reset so we do not have the data which has already been transferred back
+                // create a separate result object so we do not get the results which have already been transferred back
+                std::unique_ptr<TimerResults> timerResults;
                 if (mTimerResults)
-                    mTimerResults->reset();
-                // TODO: how to "reset" mSuppressions?
+                    timerResults.reset(new TimerResults);
 
                 PipeWriter pipewriter(pipes[1], mSettings.debugipc);
-                CppCheck fileChecker(mSettings, mSuppressions, pipewriter, mTimerResults, false, mExecuteCommand);
+                CppCheck fileChecker(mSettings, supprs, pipewriter, timerResults.get(), false, mExecuteCommand);
                 unsigned int resultOfCheck = 0;
 
                 if (iFileSettings != mFileSettings.end()) {
@@ -396,9 +402,9 @@ unsigned int ProcessExecutor::check()
                     resultOfCheck = fileChecker.check(*iFile);
                 }
 
-                pipewriter.writeSuppr(mSuppressions.nomsg);
+                pipewriter.writeSuppr(supprs.nomsg);
 
-                pipewriter.writeTimer(mTimerResults);
+                pipewriter.writeTimer(timerResults.get());
 
                 pipewriter.writeEnd(std::to_string(resultOfCheck));
                 std::exit(EXIT_SUCCESS);

test/cli/other_test.py

@@ -4657,4 +4657,96 @@ def test_ipc(tmp_path):
         'writeToPipe - 5 - 0',
         'handleRead - 5 - 0'
     ]
+    assert stderr.splitlines() == []
+
+
+@pytest.mark.skipif(sys.platform == 'win32', reason="requires ProcessExecutor")
+def test_ipc_suppressions(tmp_path):
+    test1_file = tmp_path / 'test1.c'
+    with open(test1_file, "w") as f:
+        f.write('void f() {}')
+
+    test2_file = tmp_path / 'test2.c'
+    with open(test2_file, "w") as f:
+        f.write('void f() {}')
+
+    test3_file = tmp_path / 'test3.c'
+    with open(test3_file, "w") as f:
+        f.write('void f() {}')
+
+    args = [
+        '-q',
+        '--debug-ipc',
+        '-j2',
+        '--executor=process',
+        '--no-cppcheck-build-dir',
+        '--suppress=id0:test1.c',
+        str(tmp_path)
+    ]
+
+    exitcode, stdout, stderr = cppcheck(args)
+    assert exitcode == 0
+    # sort the lines since the order is not fixed
+    stdout_exp = [
+        'writeToPipe - 4 - id0:test1.c;0;1;0;',
+        'handleRead - 4 - id0:test1.c;0;1;0;',
+        'writeToPipe - 5 - 0',
+        'handleRead - 5 - 0',
+        'writeToPipe - 5 - 0',
+        'handleRead - 5 - 0',
+        'writeToPipe - 5 - 0',
+        'handleRead - 5 - 0'
+    ]
+    stdout_exp.sort()
+    stdout_lines = stdout.splitlines()
+    stdout_lines.sort()
+    assert stdout_lines == stdout_exp
+    assert stderr.splitlines() == []
+
+
+@pytest.mark.skipif(sys.platform == 'win32', reason="requires ProcessExecutor")
+def test_ipc_inline_suppressions(tmp_path):
+    test1_file = tmp_path / 'test1.c'
+    with open(test1_file, "w") as f:
+        f.write('void f() {} // cppcheck-suppress id1')
+
+    test2_file = tmp_path / 'test2.c'
+    with open(test2_file, "w") as f:
+        f.write('void f() {} // cppcheck-suppress id2')
+
+    test3_file = tmp_path / 'test3.c'
+    with open(test3_file, "w") as f:
+        f.write('void f() {} // cppcheck-suppress id3')
+
+    args = [
+        '-q',
+        '--debug-ipc',
+        '-j2',
+        '--executor=process',
+        '--no-cppcheck-build-dir',
+        '--inline-suppr',
+        str(tmp_path)
+    ]
+
+    exitcode, stdout, stderr = cppcheck(args)
+    assert exitcode == 0
+    # sort the lines since the order is not fixed
+    stdout_exp = [
+        f'writeToPipe - 3 - id1:{test1_file}:1;13;1;0;',
+        f'handleRead - 3 - id1:{test1_file}:1;13;1;0;',
+        'writeToPipe - 5 - 0',
+        'handleRead - 5 - 0',
+        f'writeToPipe - 3 - id2:{test2_file}:1;13;1;0;',
+        f'handleRead - 3 - id2:{test2_file}:1;13;1;0;',
+        'writeToPipe - 5 - 0',
+        'handleRead - 5 - 0',
+        f'writeToPipe - 3 - id3:{test3_file}:1;13;1;0;',
+        f'handleRead - 3 - id3:{test3_file}:1;13;1;0;',
+        'writeToPipe - 5 - 0',
+        'handleRead - 5 - 0'
+    ]
+    stdout_exp.sort()
+    stdout_lines = stdout.splitlines()
+    stdout_lines.sort()
+    assert stdout_lines == stdout_exp
     assert stderr.splitlines() == []