ClangCodeModel: Use the correct language type options for MSVC

This was broken by our compiler command line optimizations, resulting in
"-x" rather than "/T" appearing for MSVC/clang-cl toolchains and causing
clangd to assume C instead of C++ for some files.

Change-Id: Ib98db88ac90e4e45a7016a7edcb80a279df372aa
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdclient.cpp

@@ -845,9 +845,11 @@ static void addToCompilationDb(QJsonObject &cdb,
                                CppEditor::UsePrecompiledHeaders usePch,
                                const QJsonArray &projectPartOptions,
                                const Utils::FilePath &workingDir,
-                               const CppEditor::ProjectFile &sourceFile)
+                               const CppEditor::ProjectFile &sourceFile,
+                               bool clStyle)
 {
-    QJsonArray args = clangOptionsForFile(sourceFile, projectPart, projectPartOptions, usePch);
+    QJsonArray args = clangOptionsForFile(sourceFile, projectPart, projectPartOptions, usePch,
+                                          clStyle);
 
     // TODO: clangd seems to apply some heuristics depending on what we put here.
     //       Should we make use of them or keep using our own?
@@ -889,7 +891,8 @@ ClangdClient::ClangdClient(Project *project, const Utils::FilePath &jsonDbDir)
         const QJsonArray projectPartOptions = fullProjectPartOptions(
                     optionsBuilder, globalClangOptions());
         const QJsonArray clangOptions = clangOptionsForFile({}, optionsBuilder.projectPart(),
-                                                            projectPartOptions, usePch);
+                                                            projectPartOptions, usePch,
+                                                            optionsBuilder.isClStyle());
         initOptions.insert("fallbackFlags", clangOptions);
         setInitializationOptions(initOptions);
     }
@@ -1328,7 +1331,7 @@ void ClangdClient::updateParserConfig(const Utils::FilePath &filePath,
     const QJsonArray projectPartOptions = fullProjectPartOptions(
                 optionsBuilder, globalClangOptions());
     addToCompilationDb(cdbChanges, *projectPart, CppEditor::getPchUsage(), projectPartOptions,
-                       filePath.parentDir(), file);
+                       filePath.parentDir(), file, optionsBuilder.isClStyle());
     QJsonObject settings;
     addCompilationDb(settings, cdbChanges);
     DidChangeConfigurationParams configChangeParams;

src/plugins/clangcodemodel/clangutils.cpp

@@ -130,7 +130,8 @@ static QJsonObject createFileObject(const FilePath &buildDir,
                                     const ProjectFile &projFile,
                                     CompilationDbPurpose purpose,
                                     const QJsonArray &projectPartOptions,
-                                    UsePrecompiledHeaders usePch)
+                                    UsePrecompiledHeaders usePch,
+                                    bool clStyle)
 {
     QJsonObject fileObject;
     fileObject["file"] = projFile.path;
@@ -155,7 +156,7 @@ static QJsonObject createFileObject(const FilePath &buildDir,
                 args.append(langOptionPart);
         }
     } else {
-        args = clangOptionsForFile(projFile, projectPart, projectPartOptions, usePch);
+        args = clangOptionsForFile(projFile, projectPart, projectPartOptions, usePch, clStyle);
         args.prepend("clang"); // TODO: clang-cl for MSVC targets? Does it matter at all what we put here?
     }
 
@@ -200,7 +201,8 @@ GenerateCompilationDbResult generateCompilationDB(const CppEditor::ProjectInfo::
         }
         for (const ProjectFile &projFile : projectPart->files) {
             const QJsonObject json = createFileObject(baseDir, args, *projectPart, projFile,
-                                                      purpose, ppOptions, usePch);
+                                                      purpose, ppOptions, usePch,
+                                                      optionsBuilder.isClStyle());
             if (compileCommandsFile.size() > 1)
                 compileCommandsFile.write(",");
             compileCommandsFile.write('\n' + QJsonDocument(json).toJson().trimmed());
@@ -274,9 +276,11 @@ QString DiagnosticTextInfo::clazyCheckName(const QString &option)
 
 
 QJsonArray clangOptionsForFile(const ProjectFile &file, const ProjectPart &projectPart,
-                               const QJsonArray &generalOptions, UsePrecompiledHeaders usePch)
+                               const QJsonArray &generalOptions, UsePrecompiledHeaders usePch,
+                               bool clStyle)
 {
     CompilerOptionsBuilder optionsBuilder(projectPart);
+    optionsBuilder.setClStyle(clStyle);
     ProjectFile::Kind fileKind = file.kind;
     if (fileKind == ProjectFile::AmbiguousHeader) {
         fileKind = projectPart.languageVersion <= LanguageVersion::LatestC

src/plugins/clangcodemodel/clangutils.h

@@ -66,7 +66,7 @@ QJsonArray fullProjectPartOptions(const QJsonArray &projectPartOptions,
 QJsonArray clangOptionsForFile(const CppEditor::ProjectFile &file,
                                const CppEditor::ProjectPart &projectPart,
                                const QJsonArray &generalOptions,
-                               CppEditor::UsePrecompiledHeaders usePch);
+                               CppEditor::UsePrecompiledHeaders usePch, bool clStyle);
 
 CppEditor::ProjectPart::ConstPtr projectPartForFile(const QString &filePath);
 

src/plugins/cppeditor/compileroptionsbuilder.h

@@ -95,6 +95,7 @@ public:
 
     void evaluateCompilerFlags();
     bool isClStyle() const;
+    void setClStyle(bool clStyle) { m_clStyle = clStyle; }
 
     const ProjectPart &projectPart() const { return m_projectPart; }