Clang: Fix adding completion snippets after {

...e.g. as in "void f() {".

The criteria whether to change snippets got invalidated with

    commit 8d0391a4f9
    Clang: Treat brace initialization as constructor completion

as the completion operator might be T_LBRACE now instead of T_EOF_SYMBOL
for normal completions.

This fixes the plugin test ClangCodeCompletionTest::testCompleteGlobals.

Add also unit tests.

Change-Id: I85cf522b9b307359c5c3e25198dd228cbb68ded0
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp

@@ -262,6 +262,7 @@ IAssistProposal *ClangCompletionAssistProcessor::startCompletionHelper()
     analyzer.analyze();
     m_completionOperator = analyzer.completionOperator();
     m_positionForProposal = analyzer.positionForProposal();
+    m_addSnippets = analyzer.addSnippets();
 
     QByteArray modifiedFileContent;
 
@@ -285,7 +286,6 @@ IAssistProposal *ClangCompletionAssistProcessor::startCompletionHelper()
                                           analyzer.positionEndOfExpression());
         Q_FALLTHROUGH();
     case ClangCompletionContextAnalyzer::PassThroughToLibClang: {
-        m_addSnippets = m_completionOperator == T_EOF_SYMBOL;
         m_sentRequestType = NormalCompletion;
         m_requestSent = sendCompletionRequest(analyzer.positionForClang(),
                                               modifiedFileContent);

src/plugins/clangcodemodel/clangcompletioncontextanalyzer.cpp

@@ -169,6 +169,7 @@ void ClangCompletionContextAnalyzer::handleFunctionCall(int afterOperatorPositio
                                           m_positionForProposal,
                                           functionNameStart);
             } else { // e.g. "(" without any function name in front
+                m_addSnippets = true;
                 m_positionForProposal = afterOperatorPosition;
                 setActionAndClangPosition(PassThroughToLibClang, afterOperatorPosition);
             }
@@ -179,6 +180,8 @@ void ClangCompletionContextAnalyzer::handleFunctionCall(int afterOperatorPositio
 bool ClangCompletionContextAnalyzer::handleNonFunctionCall(int position)
 {
     if (isTokenForPassThrough(m_completionOperator)) {
+        if (m_completionOperator == T_EOF_SYMBOL)
+            m_addSnippets = true;
         setActionAndClangPosition(PassThroughToLibClang, position);
         return true;
     } else if (m_completionOperator == T_DOXY_COMMENT) {

src/plugins/clangcodemodel/clangcompletioncontextanalyzer.h

@@ -58,6 +58,7 @@ public:
     int positionForClang() const { return m_positionForClang; }
     int functionNameStart() const { return m_functionNameStart; }
     int positionEndOfExpression() const { return m_positionEndOfExpression; }
+    bool addSnippets() const { return m_addSnippets; }
 
 private:
     ClangCompletionContextAnalyzer();
@@ -84,6 +85,7 @@ private:
     int m_positionForClang = -1;
     int m_functionNameStart = -1;
     int m_positionEndOfExpression = -1;
+    bool m_addSnippets = false;
 };
 
 } // namespace Internal