CppEditor: Improve "definition from declaration" for templates

- Make sure the template parameters are included in the definition.
- Find the correct insertion location when using an already-defined
  template member function as an anchor.

Fixes: QTCREATORBUG-24848
Change-Id: I1272ba36403904e7aed81bcef48745793c5e2217
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

3 files changed, 25 insertions, 8 deletions

diff --git a/src/plugins/cppeditor/cppquickfix_test.cpp b/src/plugins/cppeditor/cppquickfix_test.cpp
index 793f3113a89..5dd19adbf3b 100644
--- a/src/plugins/cppeditor/cppquickfix_test.cpp
+++ b/src/plugins/cppeditor/cppquickfix_test.cpp
@@ -3740,20 +3740,25 @@ void CppEditorPlugin::test_quickfix_InsertDefFromDecl_templateClass()
         "template<class T>\n"
         "class Foo\n"
         "{\n"
-        "    void fun@c();\n"
-        "};\n";
+        "    void fun@c1();\n"
+        "    void func2();\n"
+        "};\n\n"
+        "template<class T>\n"
+        "void Foo<T>::func2() {}\n";
     QByteArray expected =
         "template<class T>\n"
         "class Foo\n"
         "{\n"
-        "    void fun@c();\n"
-        "};\n"
-        "\n"
+        "    void func1();\n"
+        "    void func2();\n"
+        "};\n\n"
         "template<class T>\n"
-        "void Foo::func()\n" // Should really be Foo<T>::func()
+        "void Foo<T>::func1()\n"
         "{\n"
         "\n"
-        "}\n";
+        "}\n\n"
+        "template<class T>\n"
+        "void Foo<T>::func2() {}\n";
 
     InsertDefFromDecl factory;
     QuickFixOperationTest(singleDocument(original, expected), &factory);
@@ -3775,7 +3780,7 @@ void CppEditorPlugin::test_quickfix_InsertDefFromDecl_templateFunction()
         "};\n"
         "\n"
         "template<class T>\n"
-        "void Foo::func()\n"
+        "void Foo::func<T>()\n"
         "{\n"
         "\n"
         "}\n";
diff --git a/src/plugins/cppeditor/cppquickfixes.cpp b/src/plugins/cppeditor/cppquickfixes.cpp
index 15bdd1e92b9..94bfef1a84e 100644
--- a/src/plugins/cppeditor/cppquickfixes.cpp
+++ b/src/plugins/cppeditor/cppquickfixes.cpp
@@ -3040,6 +3040,7 @@ public:
         oo.showReturnTypes = true;
         oo.showArgumentNames = true;
         oo.showEnclosingTemplate = true;
+        oo.showTemplateParameters = true;
 
         if (defPos == DefPosInsideClass) {
             const int targetPos = targetFile->position(loc.line(), loc.column());
diff --git a/src/plugins/cpptools/insertionpointlocator.cpp b/src/plugins/cpptools/insertionpointlocator.cpp
index e0063567948..228d5344306 100644
--- a/src/plugins/cpptools/insertionpointlocator.cpp
+++ b/src/plugins/cpptools/insertionpointlocator.cpp
@@ -32,6 +32,7 @@
 
 #include <coreplugin/icore.h>
 
+#include <cplusplus/ASTPath.h>
 #include <cplusplus/LookupContext.h>
 
 #include <utils/qtcassert.h>
@@ -545,6 +546,16 @@ static InsertionLocation nextToSurroundingDefinitions(Symbol *declaration,
             return noResult;
 
         targetFile->cppDocument()->translationUnit()->getTokenStartPosition(functionDefinition->firstToken(), &line, &column);
+        const QList<AST *> path = ASTPath(targetFile->cppDocument())(line, column);
+        for (auto it = path.rbegin(); it != path.rend(); ++it) {
+            if (const auto templateDecl = (*it)->asTemplateDeclaration()) {
+                if (templateDecl->declaration == functionDefinition) {
+                    targetFile->cppDocument()->translationUnit()->getTokenStartPosition(
+                                templateDecl->firstToken(), &line, &column);
+                }
+                break;
+            }
+        }
     }
 
     return InsertionLocation(QString::fromUtf8(definitionFunction->fileName()), prefix, suffix, line, column);