[CodeCompletion] Code complete the missing C++11 keywords

This commit adds context sensitive code completion support for the C++11
keywords that currently don't have completion results.

The following keywords are supported by this patch:

alignas
constexpr
static_assert
noexcept (as a function/method qualifier)
thread_local

The following special identifiers are also supported:

final (as a method qualifier or class qualifier)
override

rdar://29219185

Differential Revision: https://reviews.llvm.org/D28286

llvm-svn: 295001
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 5f65df2..0056b11 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -1370,6 +1370,21 @@
   // in C++0x as a type specifier.
   Results.AddResult(Result("extern"));
   Results.AddResult(Result("static"));
+
+  if (LangOpts.CPlusPlus11) {
+    CodeCompletionAllocator &Allocator = Results.getAllocator();
+    CodeCompletionBuilder Builder(Allocator, Results.getCodeCompletionTUInfo());
+
+    // alignas
+    Builder.AddTypedTextChunk("alignas");
+    Builder.AddChunk(CodeCompletionString::CK_LeftParen);
+    Builder.AddPlaceholderChunk("expression");
+    Builder.AddChunk(CodeCompletionString::CK_RightParen);
+    Results.AddResult(Result(Builder.TakeString()));
+
+    Results.AddResult(Result("constexpr"));
+    Results.AddResult(Result("thread_local"));
+  }
 }
 
 static void AddFunctionSpecifiers(Sema::ParserCompletionContext CCC,
@@ -1527,6 +1542,21 @@
   Results.AddResult(CodeCompletionResult(Builder.TakeString()));
 }
 
+static void AddStaticAssertResult(CodeCompletionBuilder &Builder,
+                                  ResultBuilder &Results,
+                                  const LangOptions &LangOpts) {
+  if (!LangOpts.CPlusPlus11)
+    return;
+
+  Builder.AddTypedTextChunk("static_assert");
+  Builder.AddChunk(CodeCompletionString::CK_LeftParen);
+  Builder.AddPlaceholderChunk("expression");
+  Builder.AddChunk(CodeCompletionString::CK_Comma);
+  Builder.AddPlaceholderChunk("message");
+  Builder.AddChunk(CodeCompletionString::CK_RightParen);
+  Results.AddResult(CodeCompletionResult(Builder.TakeString()));
+}
+
 /// \brief Add language constructs that show up for "ordinary" names.
 static void AddOrdinaryNameResults(Sema::ParserCompletionContext CCC,
                                    Scope *S,
@@ -1611,6 +1641,8 @@
         Results.AddResult(Result(Builder.TakeString()));
       }
 
+      AddStaticAssertResult(Builder, Results, SemaRef.getLangOpts());
+
       if (CCC == Sema::PCC_Class) {
         AddTypedefResult(Results);
 
@@ -1824,6 +1856,8 @@
     Builder.AddChunk(CodeCompletionString::CK_HorizontalSpace);
     Builder.AddPlaceholderChunk("identifier");
     Results.AddResult(Result(Builder.TakeString()));
+
+    AddStaticAssertResult(Builder, Results, SemaRef.getLangOpts());
   }
 
   // Fall through (for statement expressions).
@@ -3483,6 +3517,11 @@
     Results.AddResult(Result("restrict"));
 
   if (getLangOpts().CPlusPlus) {
+    if (getLangOpts().CPlusPlus11 &&
+        (DS.getTypeSpecType() == DeclSpec::TST_class ||
+         DS.getTypeSpecType() == DeclSpec::TST_struct))
+      Results.AddResult("final");
+
     if (AllowNonIdentifiers) {
       Results.AddResult(Result("operator")); 
     }
@@ -4013,30 +4052,54 @@
                             Results.data(),Results.size());
 }
 
+static void AddTypeQualifierResults(DeclSpec &DS, ResultBuilder &Results,
+                                    const LangOptions &LangOpts) {
+  if (!(DS.getTypeQualifiers() & DeclSpec::TQ_const))
+    Results.AddResult("const");
+  if (!(DS.getTypeQualifiers() & DeclSpec::TQ_volatile))
+    Results.AddResult("volatile");
+  if (LangOpts.C99 && !(DS.getTypeQualifiers() & DeclSpec::TQ_restrict))
+    Results.AddResult("restrict");
+  if (LangOpts.C11 && !(DS.getTypeQualifiers() & DeclSpec::TQ_atomic))
+    Results.AddResult("_Atomic");
+  if (LangOpts.MSVCCompat && !(DS.getTypeQualifiers() & DeclSpec::TQ_unaligned))
+    Results.AddResult("__unaligned");
+}
+
 void Sema::CodeCompleteTypeQualifiers(DeclSpec &DS) {
   ResultBuilder Results(*this, CodeCompleter->getAllocator(),
                         CodeCompleter->getCodeCompletionTUInfo(),
                         CodeCompletionContext::CCC_TypeQualifiers);
   Results.EnterNewScope();
-  if (!(DS.getTypeQualifiers() & DeclSpec::TQ_const))
-    Results.AddResult("const");
-  if (!(DS.getTypeQualifiers() & DeclSpec::TQ_volatile))
-    Results.AddResult("volatile");
-  if (getLangOpts().C99 &&
-      !(DS.getTypeQualifiers() & DeclSpec::TQ_restrict))
-    Results.AddResult("restrict");
-  if (getLangOpts().C11 &&
-      !(DS.getTypeQualifiers() & DeclSpec::TQ_atomic))
-    Results.AddResult("_Atomic");
-  if (getLangOpts().MSVCCompat &&
-      !(DS.getTypeQualifiers() & DeclSpec::TQ_unaligned))
-    Results.AddResult("__unaligned");
+  AddTypeQualifierResults(DS, Results, LangOpts);
   Results.ExitScope();
   HandleCodeCompleteResults(this, CodeCompleter, 
                             Results.getCompletionContext(),
                             Results.data(), Results.size());
 }
 
+void Sema::CodeCompleteFunctionQualifiers(DeclSpec &DS, Declarator &D,
+                                          const VirtSpecifiers *VS) {
+  ResultBuilder Results(*this, CodeCompleter->getAllocator(),
+                        CodeCompleter->getCodeCompletionTUInfo(),
+                        CodeCompletionContext::CCC_TypeQualifiers);
+  Results.EnterNewScope();
+  AddTypeQualifierResults(DS, Results, LangOpts);
+  if (LangOpts.CPlusPlus11) {
+    Results.AddResult("noexcept");
+    if (D.getContext() == Declarator::MemberContext && !D.isCtorOrDtor() &&
+        !D.isStaticMember()) {
+      if (!VS || !VS->isFinalSpecified())
+        Results.AddResult("final");
+      if (!VS || !VS->isOverrideSpecified())
+        Results.AddResult("override");
+    }
+  }
+  Results.ExitScope();
+  HandleCodeCompleteResults(this, CodeCompleter, Results.getCompletionContext(),
+                            Results.data(), Results.size());
+}
+
 void Sema::CodeCompleteBracketDeclarator(Scope *S) {
   CodeCompleteExpression(S, QualType(getASTContext().getSizeType()));
 }