Clang: Do not show global completions after comma

Handle the case when we try to show the function hint but
do not find any completion. Do not fall back to the normal
code completion in such case.

Fixes: QTCREATORBUG-21624
Change-Id: I147d71b8970c18d49947f68786347a9db97736bb
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

2 files changed, 14 insertions, 0 deletions

diff --git a/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp b/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
index db34c904d4..6f1397c487 100644
--- a/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
+++ b/src/plugins/clangcodemodel/clangcompletionassistprocessor.cpp
@@ -214,6 +214,9 @@ void ClangCompletionAssistProcessor::handleAvailableCompletions(const CodeComple
             setAsyncProposalAvailable(createFunctionHintProposal(completions));
             return;
         }
+
+        if (!m_fallbackToNormalCompletion)
+            return;
         // else: Proceed with a normal completion in case:
         // 1) it was not a function call, but e.g. a function declaration like "void f("
         // 2) '{' meant not a constructor call.
@@ -286,6 +289,14 @@ static QByteArray modifyInput(QTextDocument *doc, int endOfExpression) {
     return modifiedInput;
 }
 
+static QChar lastPrecedingNonWhitespaceChar(const ClangCompletionAssistInterface *interface)
+{
+    int pos = interface->position();
+    while (pos >= 0 && interface->characterAt(pos).isSpace())
+        --pos;
+    return pos >= 0 ? interface->characterAt(pos) : QChar::Null;
+}
+
 IAssistProposal *ClangCompletionAssistProcessor::startCompletionHelper()
 {
     ClangCompletionContextAnalyzer analyzer(m_interface.data(), m_interface->languageFeatures());
@@ -323,6 +334,8 @@ IAssistProposal *ClangCompletionAssistProcessor::startCompletionHelper()
     }
     case ClangCompletionContextAnalyzer::PassThroughToLibClangAfterLeftParen: {
         m_sentRequestType = FunctionHintCompletion;
+        if (lastPrecedingNonWhitespaceChar(m_interface.data()) == ',')
+            m_fallbackToNormalCompletion = false;
         m_requestSent = sendCompletionRequest(analyzer.positionForClang(), QByteArray(),
                                               analyzer.functionNameStart());
         break;
diff --git a/src/plugins/clangcodemodel/clangcompletionassistprocessor.h b/src/plugins/clangcodemodel/clangcompletionassistprocessor.h
index 03711f0fa8..5e8c772235 100644
--- a/src/plugins/clangcodemodel/clangcompletionassistprocessor.h
+++ b/src/plugins/clangcodemodel/clangcompletionassistprocessor.h
@@ -97,6 +97,7 @@ private:
     CompletionRequestType m_sentRequestType = NormalCompletion;
     bool m_requestSent = false;
     bool m_addSnippets = false; // For type == Type::NormalCompletion
+    bool m_fallbackToNormalCompletion = true;
 };
 
 } // namespace Internal