From e12013e04251f0be7232a484c31a80f4c8a128d7 Mon Sep 17 00:00:00 2001
From: firewave <firewave@users.noreply.github.com>
Date: Tue, 25 Mar 2025 14:12:57 +0100
Subject: [PATCH] cleaned up and test some `enforcedLang` handling

---
 lib/cppcheck.cpp              | 24 +++++------
 lib/cppcheck.h                |  4 +-
 test/cli/clang-import_test.py |  1 -
 test/cli/dumpfile_test.py     | 75 ++++++++++++++++++++++++++++++++++-
 4 files changed, 85 insertions(+), 19 deletions(-)

diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
index 7024969117a..aeb7a420efa 100644
--- a/lib/cppcheck.cpp
+++ b/lib/cppcheck.cpp
@@ -366,9 +366,11 @@ static void createDumpFile(const Settings& settings,
         std::ofstream fout(getCtuInfoFileName(dumpFile));
     }
 
-    // TODO: enforcedLang should be already applied in FileWithDetails object
     std::string language;
-    switch (settings.enforcedLang) {
+
+    assert(file.lang() != Standards::Language::None);
+
+    switch (file.lang()) {
     case Standards::Language::C:
         language = " language=\"c\"";
         break;
@@ -376,17 +378,8 @@ static void createDumpFile(const Settings& settings,
         language = " language=\"cpp\"";
         break;
     case Standards::Language::None:
-    {
-        // TODO: get language from FileWithDetails object
-        // TODO: error out on unknown language?
-        const Standards::Language lang = Path::identify(file.spath(), settings.cppHeaderProbe);
-        if (lang == Standards::Language::CPP)
-            language = " language=\"cpp\"";
-        else if (lang == Standards::Language::C)
-            language = " language=\"c\"";
         break;
     }
-    }
 
     fdump << "<?xml version=\"1.0\"?>\n";
     fdump << "<dumps" << language << ">\n";
@@ -619,13 +612,12 @@ std::string CppCheck::getLibraryDumpData() const {
     return out;
 }
 
-std::string CppCheck::getClangFlags(Standards::Language fileLang) const {
+std::string CppCheck::getClangFlags(Standards::Language lang) const {
     std::string flags;
 
-    const Standards::Language lang = mSettings.enforcedLang != Standards::None ? mSettings.enforcedLang : fileLang;
+    assert(lang != Standards::Language::None);
 
     switch (lang) {
-    case Standards::Language::None:
     case Standards::Language::C:
         flags = "-x c ";
         if (!mSettings.standards.stdValueC.empty())
@@ -636,6 +628,8 @@ std::string CppCheck::getClangFlags(Standards::Language fileLang) const {
         if (!mSettings.standards.stdValueCPP.empty())
             flags += "-std=" + mSettings.standards.stdValueCPP + " ";
         break;
+    case Standards::Language::None:
+        break;
     }
 
     for (const std::string &i: mSettings.includePaths)
@@ -674,7 +668,7 @@ unsigned int CppCheck::checkClang(const FileWithDetails &file)
 #endif
 
     const std::string args2 = "-fsyntax-only -Xclang -ast-dump -fno-color-diagnostics " +
-                              getClangFlags(Path::identify(file.spath(), mSettings.cppHeaderProbe)) +
+                              getClangFlags(file.lang()) +
                               file.spath();
     const std::string redirect2 = clangStderr.empty() ? "2>&1" : ("2> " + clangStderr);
     if (mSettings.verbose && !mSettings.quiet) {
diff --git a/lib/cppcheck.h b/lib/cppcheck.h
index ea7feeebd55..1b33a2d83f2 100644
--- a/lib/cppcheck.h
+++ b/lib/cppcheck.h
@@ -153,10 +153,10 @@ class CPPCHECKLIB CppCheck {
 
     /**
      * @brief Get the clang command line flags using the Settings
-     * @param fileLang language guessed from filename
+     * @param lang language guessed from filename
      * @return Clang command line flags
      */
-    std::string getClangFlags(Standards::Language fileLang) const;
+    std::string getClangFlags(Standards::Language lang) const;
 
 private:
 #ifdef HAVE_RULES
diff --git a/test/cli/clang-import_test.py b/test/cli/clang-import_test.py
index 168a31bb45f..42e5f7ecb93 100644
--- a/test/cli/clang-import_test.py
+++ b/test/cli/clang-import_test.py
@@ -174,7 +174,6 @@ def test_cmd_cpp(tmp_path):
 
 
 # files with unknown extensions are treated as C++
-@pytest.mark.xfail(strict=True)
 def test_cmd_unk(tmp_path):
     __test_cmd(tmp_path, 'test.cplusplus', [], '-x c++')
 
diff --git a/test/cli/dumpfile_test.py b/test/cli/dumpfile_test.py
index 89842fc9924..9593e2a1660 100644
--- a/test/cli/dumpfile_test.py
+++ b/test/cli/dumpfile_test.py
@@ -1,9 +1,10 @@
-
 # python -m pytest dumpfile_test.py
 
 import os
+import pathlib
 
 from testutils import cppcheck
+import xml.etree.ElementTree as ET
 
 
 def test_libraries(tmpdir):  #13701
@@ -20,3 +21,75 @@ def test_libraries(tmpdir):  #13701
         dump = f.read()
     assert '<library lib="posix"/>' in dump
     assert dump.find('<library lib="posix"/>') < dump.find('<dump cfg=')
+
+
+def __test_language(tmp_path, file_ext, exp_lang, force_lang=None):
+    test_file = tmp_path / ('test.' + file_ext)
+    with open(test_file, 'wt'):
+        pass
+
+    args = [
+        '--dump',
+        str(test_file)
+    ]
+    if force_lang:
+        args += ['--language=' + force_lang]
+
+    exitcode, stdout, stderr = cppcheck(args)
+    assert exitcode == 0, stdout if stdout else stderr
+
+    dump_s = pathlib.Path(str(test_file) + '.dump').read_text()
+
+    dump_xml = ET.fromstring(dump_s)
+    assert 'language' in dump_xml.attrib
+    assert dump_xml.attrib['language'] == exp_lang
+
+
+def test_language_c(tmp_path):
+    __test_language(tmp_path, 'c', exp_lang='c')
+
+
+def test_language_c_force_c(tmp_path):
+    __test_language(tmp_path, 'c', force_lang='c', exp_lang='c')
+
+
+def test_language_c_force_cpp(tmp_path):
+    __test_language(tmp_path, 'c', force_lang='c++', exp_lang='cpp')
+
+
+def test_language_cpp(tmp_path):
+    __test_language(tmp_path, 'cpp', exp_lang='cpp')
+
+
+def test_language_cpp_force_cpp(tmp_path):
+    __test_language(tmp_path, 'cpp', force_lang='c++', exp_lang='cpp')
+
+
+def test_language_cpp_force_c(tmp_path):
+    __test_language(tmp_path, 'cpp', force_lang='c', exp_lang='c')
+
+
+# headers default to C
+def test_language_h(tmp_path):
+    __test_language(tmp_path, 'h', exp_lang='c')
+
+
+def test_language_h_force_c(tmp_path):
+    __test_language(tmp_path, 'h', force_lang='c', exp_lang='c')
+
+
+def test_language_h_force_cpp(tmp_path):
+    __test_language(tmp_path, 'h', force_lang='c++', exp_lang='cpp')
+
+
+# files with unknown extensions default to C++
+def test_language_unk(tmp_path):
+    __test_language(tmp_path, 'src', exp_lang='cpp')
+
+
+def test_language_unk_force_c(tmp_path):
+    __test_language(tmp_path, 'src', force_lang='c', exp_lang='c')
+
+
+def test_language_unk_force_cpp(tmp_path):
+    __test_language(tmp_path, 'src', force_lang='c++', exp_lang='cpp')
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