ClangCodeModel: Fix usage type of constructors in "Find References"

In particular, in a variable definition, the (invisible) reference to the
constructor is *not* a declaration (but an implicit call).

Change-Id: Ic1f29a4da360959e81ec536efbf1175924ea34d7
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdfindreferences.cpp

@@ -75,6 +75,7 @@ public:
     QList<MessageId> pendingAstRequests;
     QPointer<SearchResult> search;
     std::optional<ReplacementData> replacementData;
+    QString searchTerm;
     bool canceled = false;
     bool categorize = false;
 };
@@ -85,6 +86,7 @@ ClangdFindReferences::ClangdFindReferences(ClangdClient *client, TextDocument *d
     : QObject(client), d(new ClangdFindReferences::Private(this))
 {
     d->categorize = categorize;
+    d->searchTerm = searchTerm;
     if (replacement) {
         ReplacementData replacementData;
         replacementData.oldSymbolName = searchTerm;
@@ -286,7 +288,7 @@ void ClangdFindReferences::Private::reportAllSearchResultsAndFinish()
     finishSearch();
 }
 
-static Usage::Tags getUsageType(const ClangdAstPath &path);
+static Usage::Tags getUsageType(const ClangdAstPath &path, const QString &searchTerm);
 
 void ClangdFindReferences::Private::addSearchResultsForFile(const FilePath &file,
                                                             const ReferencesFileData &fileData)
@@ -296,7 +298,7 @@ void ClangdFindReferences::Private::addSearchResultsForFile(const FilePath &file
     for (const auto &rangeWithText : fileData.rangesAndLineText) {
         const Range &range = rangeWithText.first;
         const ClangdAstPath astPath = getAstPath(fileData.ast, range);
-        const Usage::Tags usageType = fileData.ast.isValid() ? getUsageType(astPath)
+        const Usage::Tags usageType = fileData.ast.isValid() ? getUsageType(astPath, searchTerm)
                                                              : Usage::Tags();
 
         SearchResultItem item;
@@ -349,11 +351,14 @@ std::optional<QString> ClangdFindReferences::Private::getContainingFunctionName(
     return containingFuncNode->detail();
 }
 
-static Usage::Tags getUsageType(const ClangdAstPath &path)
+static Usage::Tags getUsageType(const ClangdAstPath &path, const QString &searchTerm)
 {
     bool potentialWrite = false;
     bool isFunction = false;
     const bool symbolIsDataType = path.last().role() == "type" && path.last().kind() == "Record";
+    QString invokedConstructor;
+    if (path.last().role() == "expression" && path.last().kind() == "CXXConstruct")
+        invokedConstructor = path.last().detail().value_or(QString());
     const auto isPotentialWrite = [&] { return potentialWrite && !isFunction; };
     for (auto pathIt = path.rbegin(); pathIt != path.rend(); ++pathIt) {
         if (pathIt->arcanaContains("non_odr_use_unevaluated"))
@@ -386,6 +391,8 @@ static Usage::Tags getUsageType(const ClangdAstPath &path)
         if (pathIt->role() == "declaration") {
             if (symbolIsDataType)
                 return {};
+            if (!invokedConstructor.isEmpty() && invokedConstructor == searchTerm)
+                return {};
             if (pathIt->arcanaContains("cinit")) {
                 if (pathIt == path.rbegin())
                     return {Usage::Tag::Declaration, Usage::Tag::Write};

src/plugins/clangcodemodel/test/clangdtests.cpp

@@ -261,6 +261,13 @@ void ClangdTestFindReferences::test_data()
         makeItem(58, 10, Usage::Tag::Read), makeItem(58, 22, Usage::Tag::Read),
         makeItem(59, 4, Usage::Tag::Write), makeItem(59, 21, Usage::Tag::Read)};
 
+    QTest::newRow("struct type 2") << "defs.h" << 450 << ItemList{
+        makeItem(20, 7, Usage::Tag::Declaration), makeItem(5, 4, Usage::Tags()),
+        makeItem(13, 21, Usage::Tags()), makeItem(32, 8, Usage::Tags())};
+
+    QTest::newRow("constructor") << "defs.h" << 627 << ItemList{
+        makeItem(31, 4, Usage::Tag::Declaration), makeItem(36, 7, Usage::Tags())};
+
     QTest::newRow("subclass") << "defs.h" << 450 << ItemList{
         makeItem(20, 7, Usage::Tag::Declaration), makeItem(5, 4, Usage::Tags()),
         makeItem(13, 21, Usage::Tags()), makeItem(32, 8, Usage::Tags())};

src/plugins/clangcodemodel/test/data/find-usages/defs.h

@@ -26,3 +26,12 @@ void func2(const int &);
 void func3(int *);
 void func4(const int *);
 void func5(int);
+
+struct S3 {
+    S3();
+};
+
+void s3Use()
+{
+    S3 s3;
+}