ClangFormat: Use relevant settings for each file

Existing Clang Format settings may not follow the
project/global pattern but can be expected to be used
for the indentation/formatting.

So let's proceed with UI for global/project settings
but use global settings only if there's no configuration
found for the current file.

Change-Id: I87c25ab3feb7e2e3deb0290848088657783cf972
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

5 files changed, 54 insertions, 48 deletions

diff --git a/src/plugins/clangformat/clangformatconfigwidget.cpp b/src/plugins/clangformat/clangformatconfigwidget.cpp
index ea439a0f43..6d81bde972 100644
--- a/src/plugins/clangformat/clangformatconfigwidget.cpp
+++ b/src/plugins/clangformat/clangformatconfigwidget.cpp
@@ -139,7 +139,7 @@ void ClangFormatConfigWidget::initialize()
 
         connect(m_ui->createFileButton, &QPushButton::clicked,
                 this, [this]() {
-            createStyleFileIfNeeded(m_project->projectDirectory(), false);
+            createStyleFileIfNeeded(false);
             initialize();
         });
         return;
@@ -160,8 +160,7 @@ void ClangFormatConfigWidget::initialize()
                     tr("Current project has its own .clang-format file "
                        "and can be configured in Projects > Clang Format."));
         }
-        const QString settingsDir = Core::ICore::userResourcePath();
-        createStyleFileIfNeeded(Utils::FileName::fromString(settingsDir), true);
+        createStyleFileIfNeeded(true);
         m_ui->applyButton->hide();
     }
 
diff --git a/src/plugins/clangformat/clangformatconstants.h b/src/plugins/clangformat/clangformatconstants.h
index 1024341c22..7b616f74f6 100644
--- a/src/plugins/clangformat/clangformatconstants.h
+++ b/src/plugins/clangformat/clangformatconstants.h
@@ -27,4 +27,6 @@
 
 namespace ClangFormat {
 static const char SETTINGS_FILE_NAME[] = ".clang-format";
+static const char SETTINGS_FILE_ALT_NAME[] = "_clang-format";
+static const char SAMPLE_FILE_NAME[] = "test.cpp";
 }
diff --git a/src/plugins/clangformat/clangformatindenter.cpp b/src/plugins/clangformat/clangformatindenter.cpp
index ddd786fc22..0d93059152 100644
--- a/src/plugins/clangformat/clangformatindenter.cpp
+++ b/src/plugins/clangformat/clangformatindenter.cpp
@@ -164,13 +164,14 @@ void modifyToIndentEmptyLines(QByteArray &buffer, int &offset, int &length, cons
 
 static const int kMaxLinesFromCurrentBlock = 200;
 
-Replacements replacements(QByteArray buffer,
+Replacements replacements(const Utils::FileName &fileName,
+                          QByteArray buffer,
                           int utf8Offset,
                           int utf8Length,
                           const QTextBlock *block = nullptr,
                           const QChar &typedChar = QChar::Null)
 {
-    FormatStyle style = currentStyle();
+    FormatStyle style = styleForFile(fileName);
 
     int extraOffset = 0;
     if (block) {
@@ -198,10 +199,8 @@ Replacements replacements(QByteArray buffer,
                                static_cast<unsigned int>(utf8Length)}};
     FormattingAttemptStatus status;
 
-    Utils::FileName stylePath = currentStyleConfigPath();
-    const std::string assumedFilePath
-            = stylePath.appendPath("test.cpp").toString().toStdString();
-    Replacements replacements = reformat(style, buffer.data(), ranges, assumedFilePath, &status);
+    Replacements replacements = reformat(style, buffer.data(), ranges,
+                                         fileName.toString().toStdString(), &status);
 
     if (!status.FormatComplete)
         Replacements();
@@ -337,6 +336,10 @@ void ClangFormatIndenter::indent(QTextDocument *doc,
                                  bool autoTriggered)
 {
     if (typedChar == QChar::Null && (cursor.hasSelection() || !autoTriggered)) {
+        TextEditorWidget *editor = TextEditorWidget::currentTextEditorWidget();
+        if (!editor)
+            return;
+        const Utils::FileName fileName = editor->textDocument()->filePath();
         int utf8Offset;
         int utf8Length;
         const QByteArray buffer = doc->toPlainText().toUtf8();
@@ -349,7 +352,7 @@ void ClangFormatIndenter::indent(QTextDocument *doc,
             applyReplacements(start,
                               utf8Offset,
                               buffer,
-                              replacements(buffer, utf8Offset, utf8Length));
+                              replacements(fileName,  buffer, utf8Offset, utf8Length));
         } else {
             const QTextBlock block = cursor.block();
             utf8Offset = Utils::Text::utf8NthLineOffset(doc, buffer, block.blockNumber() + 1);
@@ -358,7 +361,7 @@ void ClangFormatIndenter::indent(QTextDocument *doc,
             applyReplacements(block,
                               utf8Offset,
                               buffer,
-                              replacements(buffer, utf8Offset, utf8Length));
+                              replacements(fileName,  buffer, utf8Offset, utf8Length));
         }
     } else {
         indentBlock(doc, cursor.block(), typedChar, tabSettings);
@@ -383,6 +386,7 @@ void ClangFormatIndenter::indentBlock(QTextDocument *doc,
     if (!editor)
         return;
 
+    const Utils::FileName fileName = editor->textDocument()->filePath();
     trimFirstNonEmptyBlock(block);
     const QByteArray buffer = doc->toPlainText().toUtf8();
     const int utf8Offset = Utils::Text::utf8NthLineOffset(doc, buffer, block.blockNumber() + 1);
@@ -392,7 +396,7 @@ void ClangFormatIndenter::indentBlock(QTextDocument *doc,
     applyReplacements(block,
                       utf8Offset,
                       buffer,
-                      replacements(buffer, utf8Offset, utf8Length, &block, typedChar));
+                      replacements(fileName, buffer, utf8Offset, utf8Length, &block, typedChar));
 }
 
 int ClangFormatIndenter::indentFor(const QTextBlock &block, const TextEditor::TabSettings &)
@@ -401,6 +405,7 @@ int ClangFormatIndenter::indentFor(const QTextBlock &block, const TextEditor::Ta
     if (!editor)
         return -1;
 
+    const Utils::FileName fileName = editor->textDocument()->filePath();
     trimFirstNonEmptyBlock(block);
     const QTextDocument *doc = block.document();
     const QByteArray buffer = doc->toPlainText().toUtf8();
@@ -408,7 +413,7 @@ int ClangFormatIndenter::indentFor(const QTextBlock &block, const TextEditor::Ta
     QTC_ASSERT(utf8Offset >= 0, return 0;);
     const int utf8Length = block.text().toUtf8().size();
 
-    Replacements toReplace = replacements(buffer, utf8Offset, utf8Length, &block);
+    Replacements toReplace = replacements(fileName, buffer, utf8Offset, utf8Length, &block);
 
     if (toReplace.empty())
         return -1;
@@ -423,7 +428,7 @@ int ClangFormatIndenter::indentFor(const QTextBlock &block, const TextEditor::Ta
 
 TabSettings ClangFormatIndenter::tabSettings() const
 {
-    FormatStyle style = currentStyle();
+    FormatStyle style = currentProjectStyle();
     TabSettings tabSettings;
 
     switch (style.UseTab) {
diff --git a/src/plugins/clangformat/clangformatutils.cpp b/src/plugins/clangformat/clangformatutils.cpp
index f0e5f78557..76af9956c0 100644
--- a/src/plugins/clangformat/clangformatutils.cpp
+++ b/src/plugins/clangformat/clangformatutils.cpp
@@ -92,7 +92,7 @@ static void applyCppCodeStyleSettings(clang::format::FormatStyle &style,
             : - static_cast<int>(style.IndentWidth);
 }
 
-static Utils::FileName projectStylePath()
+static Utils::FileName projectPath()
 {
     const Project *project = SessionManager::startupProject();
     if (project)
@@ -101,18 +101,18 @@ static Utils::FileName projectStylePath()
     return Utils::FileName();
 }
 
-static Utils::FileName globalStylePath()
+static Utils::FileName globalPath()
 {
     return Utils::FileName::fromString(Core::ICore::userResourcePath());
 }
 
-Utils::FileName currentStyleConfigPath()
-{
-    Utils::FileName path = projectStylePath();
-    if (!path.isEmpty())
-        return path;
-
-    return globalStylePath();
+static bool configForFileExists(Utils::FileName fileName) {
+    QDir projectDir(fileName.parentDir().toString());
+    while (!projectDir.exists(SETTINGS_FILE_NAME) && !projectDir.exists(SETTINGS_FILE_ALT_NAME)) {
+        if (!projectDir.cdUp())
+            return false;
+    }
+    return true;
 }
 
 static clang::format::FormatStyle constructStyle(bool isGlobal)
@@ -134,9 +134,11 @@ static clang::format::FormatStyle constructStyle(bool isGlobal)
     return style;
 }
 
-void createStyleFileIfNeeded(Utils::FileName styleConfigPath, bool isGlobal)
+void createStyleFileIfNeeded(bool isGlobal)
 {
-    const QString configFile = styleConfigPath.appendPath(SETTINGS_FILE_NAME).toString();
+    Utils::FileName path = isGlobal ? globalPath() : projectPath();
+    const QString configFile = path.appendPath(SETTINGS_FILE_NAME).toString();
+
     if (QFile::exists(configFile))
         return;
 
@@ -147,13 +149,23 @@ void createStyleFileIfNeeded(Utils::FileName styleConfigPath, bool isGlobal)
     }
 }
 
-static clang::format::FormatStyle currentStyle(bool isGlobal)
+clang::format::FormatStyle styleForFile(Utils::FileName fileName)
 {
-    Utils::FileName styleConfigPath = isGlobal ? globalStylePath() : projectStylePath();
-    createStyleFileIfNeeded(styleConfigPath, isGlobal);
+    bool isGlobal = false;
+    if (!configForFileExists(fileName)) {
+        if (fileName.isChildOf(projectPath()) && CppCodeStyleSettings::currentProjectCodeStyle()) {
+            fileName = projectPath();
+        } else {
+            fileName = globalPath();
+            isGlobal = true;
+        }
+        fileName.appendPath(SAMPLE_FILE_NAME);
+        createStyleFileIfNeeded(isGlobal);
+    }
 
-    Expected<FormatStyle> style = format::getStyle(
-                "file", styleConfigPath.appendPath("test.cpp").toString().toStdString(), "LLVM");
+    Expected<FormatStyle> style = format::getStyle("file",
+                                                   fileName.toString().toStdString(),
+                                                   "none");
     if (style)
         return *style;
 
@@ -166,25 +178,12 @@ static clang::format::FormatStyle currentStyle(bool isGlobal)
 
 clang::format::FormatStyle currentProjectStyle()
 {
-    return currentStyle(false);
+    return styleForFile(projectPath().appendPath(SAMPLE_FILE_NAME));
 }
 
 clang::format::FormatStyle currentGlobalStyle()
 {
-    return currentStyle(true);
-}
-
-static bool isCurrentStyleGlobal()
-{
-    Utils::FileName path = projectStylePath();
-    if (path.appendPath(SETTINGS_FILE_NAME).exists())
-        return false;
-    return !CppCodeStyleSettings::currentProjectCodeStyle().has_value();
-}
-
-clang::format::FormatStyle currentStyle()
-{
-    return currentStyle(isCurrentStyleGlobal());
+    return styleForFile(globalPath().appendPath(SAMPLE_FILE_NAME));
 }
 
 }
diff --git a/src/plugins/clangformat/clangformatutils.h b/src/plugins/clangformat/clangformatutils.h
index 8634685971..41e2b5611f 100644
--- a/src/plugins/clangformat/clangformatutils.h
+++ b/src/plugins/clangformat/clangformatutils.h
@@ -34,12 +34,13 @@
 
 namespace ClangFormat {
 
-void createStyleFileIfNeeded(Utils::FileName styleConfigPath, bool isGlobal);
+// Creates the style for the current project or the global style if needed.
+void createStyleFileIfNeeded(bool isGlobal);
 
 clang::format::FormatStyle currentProjectStyle();
 clang::format::FormatStyle currentGlobalStyle();
 
-Utils::FileName currentStyleConfigPath();
-clang::format::FormatStyle currentStyle();
+// Is the style from the matching .clang-format file or global one if it's not found.
+clang::format::FormatStyle styleForFile(Utils::FileName fileName);
 
 }