CPlusPlus: Add new usage tag "Template"

For use in follow-up patch.

Change-Id: I49c057280be9b09862a89fa385a7396f1b1093bb
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/libs/cplusplus/FindUsages.cpp

@@ -274,6 +274,10 @@ public:
                         }
                     }
                 }
+                for (auto it2 = it; it2 != m_astPath.rend(); ++it2) {
+                    if ((*it2)->asTemplateDeclaration())
+                        return tags |= Usage::Tag::Template;
+                }
                 return tags;
             }
             if (const auto retStmt = (*it)->asReturnStatement()) {

src/libs/cplusplus/FindUsages.h

@@ -24,6 +24,7 @@ public:
         WritableRef = 1 << 3,
         Override = 1 << 4,
         MocInvokable = 1 << 5,
+        Template = 1 << 6,
     };
     using Tags = QFlags<Tag>;
 

src/plugins/clangcodemodel/clangdfindreferences.cpp

@@ -360,6 +360,22 @@ static Usage::Tags getUsageType(const ClangdAstPath &path, const QString &search
     if (path.last().role() == "expression" && path.last().kind() == "CXXConstruct")
         invokedConstructor = path.last().detail().value_or(QString());
     const auto isPotentialWrite = [&] { return potentialWrite && !isFunction; };
+    const auto isSomeSortOfTemplate = [&](auto declPathIt) {
+        if (declPathIt->kind() == "Function") {
+            const auto children = declPathIt->children().value_or(QList<ClangdAstNode>());
+            for (const ClangdAstNode &child : children) {
+                if (child.role() == "template argument")
+                    return true;
+            }
+        }
+        for (; declPathIt != path.rend(); ++declPathIt) {
+            if (declPathIt->kind() == "FunctionTemplate" || declPathIt->kind() == "ClassTemplate"
+                    || declPathIt->kind() == "ClassTemplatePartialSpecialization") {
+                return true;
+            }
+        }
+        return false;
+    };
     for (auto pathIt = path.rbegin(); pathIt != path.rend(); ++pathIt) {
         if (pathIt->arcanaContains("non_odr_use_unevaluated"))
             return {};
@@ -414,6 +430,8 @@ static Usage::Tags getUsageType(const ClangdAstPath &path, const QString &search
                         tags |= Usage::Tag::MocInvokable;
                 }
             }
+            if (isSomeSortOfTemplate(pathIt))
+                tags |= Usage::Tag::Template;
             return tags;
         }
         if (pathIt->kind() == "MemberInitializer")

tests/auto/cplusplus/findusages/tst_findusages.cpp

@@ -1134,7 +1134,7 @@ void tst_FindUsages::templateClassParameters()
     findUsages(templArgument);
     QCOMPARE(findUsages.usages().size(), 5);
     QCOMPARE(findUsages.usages().at(0).tags, Usage::Tag::Declaration);
-    QCOMPARE(findUsages.usages().at(1).tags, Usage::Tags());
+    QCOMPARE(findUsages.usages().at(1).tags, Usage::Tag::Template);
     QCOMPARE(findUsages.usages().at(2).tags, Usage::Tags());
     QCOMPARE(findUsages.usages().at(3).tags, Usage::Tags());
     QCOMPARE(findUsages.usages().at(4).tags, Usage::Tags());
@@ -1221,7 +1221,7 @@ void tst_FindUsages::templateFunctionParameters()
     QCOMPARE(findUsages.usages().size(), 4);
     QCOMPARE(findUsages.usages().at(0).tags, Usage::Tag::Declaration);
     QCOMPARE(findUsages.usages().at(1).tags, Usage::Tags());
-    QCOMPARE(findUsages.usages().at(2).tags, Usage::Tags());
+    QCOMPARE(findUsages.usages().at(2).tags, Usage::Tag::Template);
     QCOMPARE(findUsages.usages().at(3).tags, Usage::Tags());
 }
 
@@ -1253,7 +1253,8 @@ void tst_FindUsages::templatedFunction_QTCREATORBUG9749()
     FindUsages findUsages(src, doc, snapshot, true);
     findUsages(func);
     QCOMPARE(findUsages.usages().size(), 2);
-    QCOMPARE(findUsages.usages().at(0).tags, Usage::Tag::Declaration);
+    QCOMPARE(findUsages.usages().at(0).tags,
+             (Usage::Tags{Usage::Tag::Declaration, Usage::Tag::Template}));
     QCOMPARE(findUsages.usages().at(1).tags, Usage::Tags());
 }
 
@@ -1458,7 +1459,8 @@ void tst_FindUsages::memberAccessAsTemplate()
         FindUsages find(src, doc, snapshot, true);
         find(f);
         QCOMPARE(find.usages().size(), 2);
-        QCOMPARE(find.usages()[0].tags, Usage::Tag::Declaration);
+        QCOMPARE(find.usages()[0].tags,
+                (Usage::Tags{Usage::Tag::Declaration, Usage::Tag::Template}));
         QCOMPARE(find.usages()[0].line, 4);
         QCOMPARE(find.usages()[0].col, 7);
         QCOMPARE(find.usages()[1].tags, Usage::Tags());