Clang: Workaround completion for make_unique/shared

Change unsaved file to provide constructor overloads
for std::make_unique, std::make_shared and
QSharedPointer::create

Example:
// Provide Foo constructor signatures at <Cursor>
std::make_unique<Foo>(<Cursor>

Task-number: QTCREATORBUG-18615
Change-Id: I87dd17085adf99ee498db969a3cdda5ebd973476
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/tools/clangbackend/ipcsource/clangcodemodelserver.cpp

@@ -212,6 +212,8 @@ void ClangCodeModelServer::completeCode(const ClangBackEnd::CompleteCodeMessage
         JobRequest jobRequest = processor.createJobRequest(JobRequest::Type::CompleteCode);
         jobRequest.line = message.line();
         jobRequest.column = message.column();
+        jobRequest.funcNameStartLine = message.funcNameStartLine();
+        jobRequest.funcNameStartColumn = message.funcNameStartColumn();
         jobRequest.ticketNumber = message.ticketNumber();
 
         processor.addJob(jobRequest);

src/tools/clangbackend/ipcsource/clangcompletecodejob.cpp

@@ -36,12 +36,15 @@ namespace ClangBackEnd {
 static CompleteCodeJob::AsyncResult runAsyncHelper(const TranslationUnit &translationUnit,
                                                    UnsavedFiles unsavedFiles,
                                                    quint32 line,
-                                                   quint32 column)
+                                                   quint32 column,
+                                                   qint32 funcNameStartLine,
+                                                   qint32 funcNameStartColumn)
 {
     TIME_SCOPE_DURATION("CompleteCodeJobRunner");
 
     const TranslationUnit::CodeCompletionResult results
-            = translationUnit.complete(unsavedFiles, line, column);
+            = translationUnit.complete(unsavedFiles, line, column,
+                                       funcNameStartLine, funcNameStartColumn);
 
     CompleteCodeJob::AsyncResult asyncResult;
     asyncResult.completions = results.completions;
@@ -63,8 +66,12 @@ IAsyncJob::AsyncPrepareResult CompleteCodeJob::prepareAsyncRun()
         const UnsavedFiles unsavedFiles = *context().unsavedFiles;
         const quint32 line = jobRequest.line;
         const quint32 column = jobRequest.column;
-        setRunner([translationUnit, unsavedFiles, line, column]() {
+        const qint32 funcNameStartLine = jobRequest.funcNameStartLine;
-            return runAsyncHelper(translationUnit, unsavedFiles, line, column);
+        const qint32 funcNameStartColumn = jobRequest.funcNameStartColumn;
+        setRunner([translationUnit, unsavedFiles, line, column,
+                  funcNameStartLine, funcNameStartColumn]() {
+            return runAsyncHelper(translationUnit, unsavedFiles, line, column,
+                                  funcNameStartLine, funcNameStartColumn);
         });
         return AsyncPrepareResult{translationUnit.id()};
 

src/tools/clangbackend/ipcsource/clangjobrequest.h

@@ -110,6 +110,8 @@ public:
     // Specific to some jobs
     quint32 line = 0;
     quint32 column = 0;
+    qint32 funcNameStartLine = -1;
+    qint32 funcNameStartColumn = -1;
     quint64 ticketNumber = 0;
     Utf8StringVector dependentFiles;
     bool resolveTarget = true;

src/tools/clangbackend/ipcsource/clangtranslationunit.cpp

@@ -119,11 +119,15 @@ bool TranslationUnit::suspend() const
 TranslationUnit::CodeCompletionResult TranslationUnit::complete(
         UnsavedFiles &unsavedFiles,
         uint line,
-        uint column) const
+        uint column,
+        int funcNameStartLine,
+        int funcNameStartColumn) const
 {
     CodeCompleter codeCompleter(*this, unsavedFiles);
 
-    const CodeCompletions completions = codeCompleter.complete(line, column);
+    const CodeCompletions completions = codeCompleter.complete(line, column,
+                                                               funcNameStartLine,
+                                                               funcNameStartColumn);
     const CompletionCorrection correction = codeCompleter.neededCorrection();
 
     return CodeCompletionResult{completions, correction};

src/tools/clangbackend/ipcsource/clangtranslationunit.h

@@ -75,7 +75,8 @@ public:
     TranslationUnitUpdateResult parse(const TranslationUnitUpdateInput &parseInput) const;
     TranslationUnitUpdateResult reparse(const TranslationUnitUpdateInput &parseInput) const;
 
-    CodeCompletionResult complete(UnsavedFiles &unsavedFiles, uint line, uint column) const;
+    CodeCompletionResult complete(UnsavedFiles &unsavedFiles, uint line, uint column,
+                                  int funcNameStartLine, int funcNameStartColumn) const;
 
     void extractDiagnostics(DiagnosticContainer &firstHeaderErrorDiagnostic,
                             QVector<DiagnosticContainer> &mainFileDiagnostics) const;

src/tools/clangbackend/ipcsource/codecompleter.cpp

@@ -81,11 +81,22 @@ CodeCompleter::CodeCompleter(const TranslationUnit &translationUnit,
 {
 }
 
-CodeCompletions CodeCompleter::complete(uint line, uint column)
+CodeCompletions CodeCompleter::complete(uint line, uint column,
+                                        int funcNameStartLine,
+                                        int funcNameStartColumn)
 {
     neededCorrection_ = CompletionCorrection::NoCorrection;
 
-    ClangCodeCompleteResults results = completeHelper(line, column);
+    // Check if we have a smart pointer completion and get proper constructor signatures in results.
+    // Results are empty when it's not a smart pointer or this completion failed.
+    ClangCodeCompleteResults results = completeSmartPointerCreation(line,
+                                                                    column,
+                                                                    funcNameStartLine,
+                                                                    funcNameStartColumn);
+
+    if (results.isNull() || results.isEmpty())
+        results = completeHelper(line, column);
+
     filterUnknownContextResults(results, unsavedFile(), line, column);
     tryDotArrowCorrectionIfNoResults(results, line, column);
 
@@ -97,6 +108,62 @@ CompletionCorrection CodeCompleter::neededCorrection() const
     return neededCorrection_;
 }
 
+// For given "make_unique<T>" / "make_shared<T>" / "QSharedPointer<T>::create" return "new T("
+// Otherwize return empty QString
+static QString tweakName(const QString &oldName)
+{
+    QString fullName = oldName.trimmed();
+    if (!fullName.contains('>'))
+        return QString();
+
+    if (!fullName.endsWith('>')) {
+        // This is the class<type>::method case - remove ::method part
+        if (!fullName.endsWith("create") || !fullName.contains("QSharedPointer"))
+            return QString();
+        fullName = fullName.mid(0, fullName.lastIndexOf(':') - 1);
+    } else if (!fullName.contains("make_unique") && !fullName.contains("make_shared")) {
+        return QString();
+    }
+    int templateStart = fullName.indexOf('<');
+    QString name = fullName.mid(0, templateStart);
+    QString templatePart = fullName.mid(templateStart + 1,
+                                        fullName.length() - templateStart - 2);
+    return "new " + templatePart + "(";
+}
+
+ClangCodeCompleteResults CodeCompleter::completeSmartPointerCreation(uint line,
+                                                                     uint column,
+                                                                     int funcNameStartLine,
+                                                                     int funcNameStartColumn)
+{
+    if (column <= 1 || funcNameStartLine == -1)
+        return ClangCodeCompleteResults();
+
+    UnsavedFile &file = unsavedFiles.unsavedFile(translationUnit.filePath());
+    if (!file.hasCharacterAt(line, column - 1, '('))
+        return ClangCodeCompleteResults();
+
+    bool ok;
+    const uint startPos = file.toUtf8Position(funcNameStartLine, funcNameStartColumn, &ok);
+    const uint endPos = file.toUtf8Position(line, column - 1, &ok);
+
+    Utf8String content = file.fileContent();
+    const QString oldName = content.mid(startPos, endPos - startPos);
+    const QString updatedName = tweakName(oldName);
+    if (updatedName.isEmpty())
+        return ClangCodeCompleteResults();
+
+    column += updatedName.length();
+    file.replaceAt(endPos + 1, 0, updatedName);
+
+    ClangCodeCompleteResults results = completeHelper(line, column);
+    if (results.isEmpty()) {
+        column -= updatedName.length();
+        file.replaceAt(endPos + 1, updatedName.length(), QString());
+    }
+    return results;
+}
+
 ClangCodeCompleteResults CodeCompleter::completeHelper(uint line, uint column)
 {
     const Utf8String nativeFilePath = FilePath::toNativeSeparators(translationUnit.filePath());

src/tools/clangbackend/ipcsource/codecompleter.h

@@ -43,7 +43,9 @@ public:
     CodeCompleter(const TranslationUnit &translationUnit,
                   const UnsavedFiles &unsavedFiles);
 
-    CodeCompletions complete(uint line, uint column);
+    CodeCompletions complete(uint line, uint column,
+                             int funcNameStartLine = -1,
+                             int funcNameStartColumn = -1);
 
     CompletionCorrection neededCorrection() const;
 
@@ -56,6 +58,10 @@ private:
                                           uint column);
 
     ClangCodeCompleteResults completeHelper(uint line, uint column);
+    ClangCodeCompleteResults completeSmartPointerCreation(uint line,
+                                                          uint column,
+                                                          int funcNameStartLine,
+                                                          int funcNameStartColumn);
     ClangCodeCompleteResults completeWithArrowInsteadOfDot(uint line,
                                                            uint column,
                                                            uint dotPosition);

tests/unit/unittest/codecompleter-test.cpp

@@ -188,6 +188,12 @@ protected:
         readFileContent(QStringLiteral("/complete_withGlobalCompletionAfterForwardDeclaredClassPointer.cpp")),
         true
     };
+    ClangBackEnd::FileContainer smartPointerCompletion{
+        Utf8StringLiteral(TESTDATA_DIR"/complete_smartpointer.cpp"),
+        projectPart.projectPartId(),
+        readFileContent(QStringLiteral("/complete_smartpointer.cpp")),
+        true
+    };
 };
 
 using CodeCompleterSlowTest = CodeCompleter;
@@ -297,6 +303,33 @@ TEST_F(CodeCompleterSlowTest, FunctionInIncludedHeader)
                                           CodeCompletion::FunctionCompletionKind)));
 }
 
+TEST_F(CodeCompleterSlowTest, UniquePointerCompletion)
+{
+    auto myCompleter = setupCompleter(smartPointerCompletion);
+
+    ASSERT_THAT(myCompleter.complete(55, 54, 55, 32),
+                Contains(IsCodeCompletion(Utf8StringLiteral("Bar"),
+                                          CodeCompletion::ConstructorCompletionKind)));
+}
+
+TEST_F(CodeCompleterSlowTest, SharedPointerCompletion)
+{
+    auto myCompleter = setupCompleter(smartPointerCompletion);
+
+    ASSERT_THAT(myCompleter.complete(56, 55, 56, 33),
+                Contains(IsCodeCompletion(Utf8StringLiteral("Bar"),
+                                          CodeCompletion::ConstructorCompletionKind)));
+}
+
+TEST_F(CodeCompleterSlowTest, QSharedPointerCompletion)
+{
+    auto myCompleter = setupCompleter(smartPointerCompletion);
+
+    ASSERT_THAT(myCompleter.complete(57, 60, 57, 32),
+                Contains(IsCodeCompletion(Utf8StringLiteral("Bar"),
+                                          CodeCompletion::ConstructorCompletionKind)));
+}
+
 TEST_F(CodeCompleterSlowTest, FunctionInUnsavedIncludedHeader)
 {
     unsavedFiles.createOrUpdate({unsavedTargetHeaderFileContainer});

tests/unit/unittest/data/complete_smartpointer.cpp

@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+namespace std {
+template<class Type, class... Args>
+class unique_ptr {};
+
+template<class Type, class... Args>
+class shared_ptr {};
+
+template<class Type, class... Args>
+unique_ptr<Type> make_unique(Args&&... args);
+
+template<class Type, class... Args>
+shared_ptr<Type> make_shared(Args&&... args);
+} // namespace std
+
+template<class Type>
+class QSharedPointer
+{
+public:
+    template<class... Args>
+    static QSharedPointer<Type> create(Args&&... args);
+};
+
+class Bar
+{
+public:
+    Bar();
+    Bar(int, int);
+};
+void f2()
+{
+    std::unique_ptr<Bar> bar = std::make_unique<Bar>();
+    std::shared_ptr<Bar> bar2 = std::make_shared<Bar>();
+    QSharedPointer<Bar> bar3 = QSharedPointer<Bar>::create();
+}