refs #14304/#14242 - fixed active checkers with UNUSEDFUNCTION_ONLY hack

cli/singleexecutor.cpp

@@ -67,6 +67,7 @@ unsigned int SingleExecutor::check()
             reportStatus(c, mFileSettings.size(), c, mFileSettings.size());
     }
 
+    // TODO: CppCheckExecutor::check_internal() is also invoking the whole program analysis - is it run twice?
     if (mCppcheck.analyseWholeProgram())
         result++;
 

lib/checkersreport.cpp

@@ -143,9 +143,13 @@ void CheckersReport::countCheckers()
         ++mAllCheckersCount;
     }
     if (mSettings.premiumArgs.find("misra-c-") != std::string::npos || mSettings.addons.count("misra")) {
+        const bool doUnusedFunctionOnly = Settings::unusedFunctionOnly();
         for (const checkers::MisraInfo& info: checkers::misraC2012Rules) {
             const std::string rule = std::to_string(info.a) + "." + std::to_string(info.b);
-            const bool active = isMisraRuleActive(mActiveCheckers, rule);
+            // this will return some rules as always active even if they are not in the active checkers.
+            // this leads to a difference in the shown count and in the checkers stored in the builddir
+            // TODO: fix this?
+            const bool active = !doUnusedFunctionOnly && isMisraRuleActive(mActiveCheckers, rule);
             if (active)
                 ++mActiveCheckersCount;
             ++mAllCheckersCount;

lib/cppcheck.cpp

@@ -1495,7 +1495,7 @@ void CppCheck::executeAddons(const std::string& dumpFile, const FileWithDetails&
 
 void CppCheck::executeAddons(const std::vector<std::string>& files, const std::string& file0)
 {
-    if (mSettings.addons.empty() || files.empty())
+    if (mSettings.addons.empty() || files.empty() || Settings::unusedFunctionOnly())
         return;
 
     const bool isCtuInfo = endsWith(files[0], ".ctu-info");
@@ -1807,22 +1807,25 @@ void CppCheck::analyseClangTidy(const FileSettings &fileSettings)
 bool CppCheck::analyseWholeProgram()
 {
     bool errors = false;
-    // Analyse the tokens
-    CTU::FileInfo ctu;
-    if (mSettings.useSingleJob() || !mSettings.buildDir.empty())
-    {
-        for (const Check::FileInfo *fi : mFileInfo) {
-            const auto *fi2 = dynamic_cast<const CTU::FileInfo *>(fi);
-            if (fi2) {
-                ctu.functionCalls.insert(ctu.functionCalls.end(), fi2->functionCalls.cbegin(), fi2->functionCalls.cend());
-                ctu.nestedCalls.insert(ctu.nestedCalls.end(), fi2->nestedCalls.cbegin(), fi2->nestedCalls.cend());
+
+    if (!Settings::unusedFunctionOnly()) {
+        // Analyse the tokens
+        CTU::FileInfo ctu;
+        if (mSettings.useSingleJob() || !mSettings.buildDir.empty())
+        {
+            for (const Check::FileInfo *fi : mFileInfo) {
+                const auto *fi2 = dynamic_cast<const CTU::FileInfo *>(fi);
+                if (fi2) {
+                    ctu.functionCalls.insert(ctu.functionCalls.end(), fi2->functionCalls.cbegin(), fi2->functionCalls.cend());
+                    ctu.nestedCalls.insert(ctu.nestedCalls.end(), fi2->nestedCalls.cbegin(), fi2->nestedCalls.cend());
+                }
             }
         }
-    }
 
-    // cppcheck-suppress shadowFunction - TODO: fix this
-    for (Check *check : Check::instances())
-        errors |= check->analyseWholeProgram(ctu, mFileInfo, mSettings, mErrorLogger);  // TODO: ctu
+        // cppcheck-suppress shadowFunction - TODO: fix this
+        for (Check *check : Check::instances())
+            errors |= check->analyseWholeProgram(ctu, mFileInfo, mSettings, mErrorLogger);  // TODO: ctu
+    }
 
     if (mUnusedFunctionsCheck)
         errors |= mUnusedFunctionsCheck->check(mSettings, mErrorLogger);
@@ -1832,9 +1835,16 @@ bool CppCheck::analyseWholeProgram()
 
 unsigned int CppCheck::analyseWholeProgram(const std::string &buildDir, const std::list<FileWithDetails> &files, const std::list<FileSettings>& fileSettings, const std::string& ctuInfo)
 {
-    executeAddonsWholeProgram(files, fileSettings, ctuInfo);
     if (mSettings.checks.isEnabled(Checks::unusedFunction))
         CheckUnusedFunctions::analyseWholeProgram(mSettings, mErrorLogger, buildDir);
+
+    if (mUnusedFunctionsCheck)
+        mUnusedFunctionsCheck->check(mSettings, mErrorLogger);
+
+    if (Settings::unusedFunctionOnly())
+        return mLogger->exitcode();
+
+    executeAddonsWholeProgram(files, fileSettings, ctuInfo);
     std::list<Check::FileInfo*> fileInfoList;
     CTU::FileInfo ctuFileInfo;
 
@@ -1885,9 +1895,6 @@ unsigned int CppCheck::analyseWholeProgram(const std::string &buildDir, const st
     for (Check *check : Check::instances())
         check->analyseWholeProgram(ctuFileInfo, fileInfoList, mSettings, mErrorLogger);
 
-    if (mUnusedFunctionsCheck)
-        mUnusedFunctionsCheck->check(mSettings, mErrorLogger);
-
     for (Check::FileInfo *fi : fileInfoList)
         delete fi;
 

test/cli/other_test.py

@@ -4051,4 +4051,71 @@ def test_no_valid_configuration_check_config(tmp_path):
     assert stderr.splitlines() == [
         '{}:1:2: error: No header in #include [syntaxError]'.format(test_file),
         '{}:1:2: error: No header in #include [syntaxError]'.format(test_file)
-    ]
+    ]
+
+
+def __test_active_checkers(tmp_path, active_cnt, total_cnt, use_misra=False, use_unusedfunction_only=False, checkers_exp=None):
+    test_file = tmp_path / 'test.c'
+    with open(test_file, 'w') as f:
+        f.write('int i;')
+
+    build_dir = None
+    if checkers_exp is not None:
+        build_dir = tmp_path / 'b1'
+        os.makedirs(build_dir)
+
+    args = [
+        '-q',
+        '--enable=information',
+        '-j1',
+        str(test_file)
+    ]
+
+    if use_misra:
+        args += ['--addon=misra']
+    if build_dir:
+        args += ['--cppcheck-build-dir={}'.format(build_dir)]
+    else:
+        args += ['--no-cppcheck-build-dir']
+
+    env = {}
+    if use_unusedfunction_only:
+        env = {'UNUSEDFUNCTION_ONLY': '1'}
+        args += ['--enable=unusedFunction']
+    exitcode, stdout, stderr, _ = cppcheck_ex(args, remove_checkers_report=False, env=env)
+    assert exitcode == 0, stdout
+    assert stdout.splitlines() == []
+    assert stderr.splitlines() == [
+        f'nofile:0:0: information: Active checkers: {active_cnt}/{total_cnt} (use --checkers-report=<filename> to see details) [checkersReport]',
+        ''  # TODO: get rid of extra newline
+    ]
+
+    if build_dir:
+        checkers_file = build_dir / 'checkers.txt'
+        with open(checkers_file, 'r') as f:
+            checkers = f.read().splitlines()
+
+        assert checkers == checkers_exp
+        assert len(checkers) == active_cnt
+
+
+def test_active_unusedfunction_only(tmp_path):
+    __test_active_checkers(tmp_path, 1, 966, use_unusedfunction_only=True)
+
+
+def test_active_unusedfunction_only_builddir(tmp_path):
+    checkers_exp = [
+        'CheckUnusedFunctions::check'
+    ]
+    __test_active_checkers(tmp_path, 1, 966, use_unusedfunction_only=True, checkers_exp=checkers_exp)
+
+
+def test_active_unusedfunction_only_misra(tmp_path):
+    __test_active_checkers(tmp_path, 1, 1166, use_unusedfunction_only=True, use_misra=True)
+
+
+def test_active_unusedfunction_only_misra_builddir(tmp_path):
+    checkers_exp = [
+        'CheckUnusedFunctions::check'
+    ]
+    __test_active_checkers(tmp_path, 1, 1166, use_unusedfunction_only=True, use_misra=True, checkers_exp=checkers_exp)