ClangFormat: Change the logic how configuration is picked

Let's use by default the configuration that clang-format picks itself
for the source file. The Qt Creator configuration will now only
override the default one with global or project settings and can be
turned off with the checkbox.

This behavior is clearer than always picking some configuration
which Qt Creator prefers best.

Change-Id: If5ed3d67eb6b4b47a6d0fd5259f7efbb608914d1
Reviewed-by: Marco Bubke <marco.bubke@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

src/plugins/clangformat/clangformatutils.cpp

@@ -26,6 +26,7 @@
 #include "clangformatutils.h"
 
 #include "clangformatconstants.h"
+#include "clangformatsettings.h"
 
 #include <coreplugin/icore.h>
 #include <cpptools/cppcodestylesettings.h>
@@ -33,6 +34,8 @@
 #include <projectexplorer/project.h>
 #include <projectexplorer/session.h>
 
+#include <QCryptographicHash>
+
 using namespace clang;
 using namespace format;
 using namespace llvm;
@@ -92,13 +95,26 @@ static void applyCppCodeStyleSettings(clang::format::FormatStyle &style,
             : - static_cast<int>(style.IndentWidth);
 }
 
-static Utils::FileName projectPath()
+static bool useGlobalOverriddenSettings()
+{
+    return ClangFormatSettings::instance().overrideDefaultFile();
+}
+
+QString currentProjectUniqueId()
 {
     const Project *project = SessionManager::startupProject();
-    if (project)
-        return project->projectDirectory();
+    if (!project)
+        return QString();
 
-    return Utils::FileName();
+    return QString::fromUtf8(QCryptographicHash::hash(project->projectFilePath().toString().toUtf8(),
+                                                      QCryptographicHash::Md5)
+                                 .toHex(0));
+}
+
+static bool useProjectOverriddenSettings()
+{
+    const Project *project = SessionManager::startupProject();
+    return project ? project->namedSettings(Constants::OVERRIDE_FILE_ID).toBool() : false;
 }
 
 static Utils::FileName globalPath()
@@ -106,25 +122,40 @@ static Utils::FileName globalPath()
     return Utils::FileName::fromString(Core::ICore::userResourcePath());
 }
 
-static QString configForFile(Utils::FileName fileName)
+static Utils::FileName projectPath()
 {
-    Utils::FileName topProjectPath = projectPath();
-    if (topProjectPath.isEmpty())
-        return QString();
+    const Project *project = SessionManager::startupProject();
+    if (project)
+        return globalPath().appendPath("clang-format").appendPath(currentProjectUniqueId());
 
-    QDir projectDir(fileName.parentDir().toString());
-    while (!projectDir.exists(Constants::SETTINGS_FILE_NAME)
-           && !projectDir.exists(Constants::SETTINGS_FILE_ALT_NAME)) {
-        if (projectDir.path() == topProjectPath.toString()
-            || !Utils::FileName::fromString(projectDir.path()).isChildOf(topProjectPath)
-            || !projectDir.cdUp()) {
-            return QString();
-        }
+    return Utils::FileName();
+}
+
+static QString configForFile(Utils::FileName fileName, bool checkForSettings)
+{
+    QDir overrideDir;
+    if (!checkForSettings || useProjectOverriddenSettings()) {
+        overrideDir = projectPath().toString();
+        if (!overrideDir.isEmpty() && overrideDir.exists(Constants::SETTINGS_FILE_NAME))
+            return overrideDir.filePath(Constants::SETTINGS_FILE_NAME);
     }
 
-    if (projectDir.exists(Constants::SETTINGS_FILE_NAME))
-        return projectDir.filePath(Constants::SETTINGS_FILE_NAME);
-    return projectDir.filePath(Constants::SETTINGS_FILE_ALT_NAME);
+    if (!checkForSettings || useGlobalOverriddenSettings()) {
+        overrideDir = globalPath().toString();
+        if (!overrideDir.isEmpty() && overrideDir.exists(Constants::SETTINGS_FILE_NAME))
+            return overrideDir.filePath(Constants::SETTINGS_FILE_NAME);
+    }
+
+    QDir parentDir(fileName.parentDir().toString());
+    while (!parentDir.exists(Constants::SETTINGS_FILE_NAME)
+           && !parentDir.exists(Constants::SETTINGS_FILE_ALT_NAME)) {
+        if (!parentDir.cdUp())
+            return QString();
+    }
+
+    if (parentDir.exists(Constants::SETTINGS_FILE_NAME))
+        return parentDir.filePath(Constants::SETTINGS_FILE_NAME);
+    return parentDir.filePath(Constants::SETTINGS_FILE_ALT_NAME);
 }
 
 static clang::format::FormatStyle constructStyle(bool isGlobal,
@@ -169,6 +200,7 @@ void createStyleFileIfNeeded(bool isGlobal)
     if (QFile::exists(configFile))
         return;
 
+    QDir().mkpath(path.parentDir().toString());
     std::fstream newStyleFile(configFile.toStdString(), std::fstream::out);
     if (newStyleFile.is_open()) {
         newStyleFile << clang::format::configurationAsText(constructStyle(isGlobal));
@@ -198,16 +230,11 @@ static QByteArray configBaseStyleName(const QString &configFile)
         .trimmed();
 }
 
-clang::format::FormatStyle styleForFile(Utils::FileName fileName)
+static clang::format::FormatStyle styleForFile(Utils::FileName fileName, bool checkForSettings)
 {
-    bool isGlobal = false;
-    QString configFile = configForFile(fileName);
-    if (configFile.isEmpty()) {
-        Utils::FileName path = fileName = globalPath();
-        fileName.appendPath(Constants::SAMPLE_FILE_NAME);
-        createStyleFileIfNeeded(true);
-        configFile = path.appendPath(Constants::SETTINGS_FILE_NAME).toString();
-    }
+    QString configFile = configForFile(fileName, checkForSettings);
+    if (configFile.isEmpty())
+        return constructStyle(true);
 
     Expected<FormatStyle> style = format::getStyle("file",
                                                    fileName.toString().toStdString(),
@@ -219,17 +246,22 @@ clang::format::FormatStyle styleForFile(Utils::FileName fileName)
         // do nothing
     });
 
-    return constructStyle(isGlobal, configBaseStyleName(configFile));
+    return constructStyle(true, configBaseStyleName(configFile));
+}
+
+clang::format::FormatStyle styleForFile(Utils::FileName fileName)
+{
+    return styleForFile(fileName, true);
 }
 
 clang::format::FormatStyle currentProjectStyle()
 {
-    return styleForFile(projectPath().appendPath(Constants::SAMPLE_FILE_NAME));
+    return styleForFile(projectPath().appendPath(Constants::SAMPLE_FILE_NAME), false);
 }
 
 clang::format::FormatStyle currentGlobalStyle()
 {
-    return styleForFile(globalPath().appendPath(Constants::SAMPLE_FILE_NAME));
+    return styleForFile(globalPath().appendPath(Constants::SAMPLE_FILE_NAME), false);
 }
 
 }