[CodeComplete] Add code completion after function equals

Summary:
Provide `default` and `delete` completion after the function equals.

Reviewers: kadircet, sammccall

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82548

1 files changed, 49 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 26d127e..0a8a270 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -24,11 +24,13 @@
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/CharInfo.h"
+#include "clang/Basic/OperatorKinds.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/MacroInfo.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Sema/CodeCompleteConsumer.h"
+#include "clang/Sema/DeclSpec.h"
 #include "clang/Sema/Designator.h"
 #include "clang/Sema/Lookup.h"
 #include "clang/Sema/Overload.h"
@@ -6266,6 +6268,53 @@ void Sema::CodeCompleteLambdaIntroducer(Scope *S, LambdaIntroducer &Intro,
                             Results.data(), Results.size());
 }
 
+void Sema::CodeCompleteAfterFunctionEquals(Declarator &D) {
+  if (!LangOpts.CPlusPlus11)
+    return;
+  ResultBuilder Results(*this, CodeCompleter->getAllocator(),
+                        CodeCompleter->getCodeCompletionTUInfo(),
+                        CodeCompletionContext::CCC_Other);
+  auto ShouldAddDefault = [&D, this]() {
+    if (!D.isFunctionDeclarator())
+      return false;
+    auto &Id = D.getName();
+    if (Id.getKind() == UnqualifiedIdKind::IK_DestructorName)
+      return true;
+    // FIXME(liuhui): Ideally, we should check the constructor parameter list to
+    // verify that it is the default, copy or move constructor?
+    if (Id.getKind() == UnqualifiedIdKind::IK_ConstructorName &&
+        D.getFunctionTypeInfo().NumParams <= 1)
+      return true;
+    if (Id.getKind() == UnqualifiedIdKind::IK_OperatorFunctionId) {
+      auto Op = Id.OperatorFunctionId.Operator;
+      // FIXME(liuhui): Ideally, we should check the function parameter list to
+      // verify that it is the copy or move assignment?
+      if (Op == OverloadedOperatorKind::OO_Equal)
+        return true;
+      if (LangOpts.CPlusPlus20 &&
+          (Op == OverloadedOperatorKind::OO_EqualEqual ||
+           Op == OverloadedOperatorKind::OO_ExclaimEqual ||
+           Op == OverloadedOperatorKind::OO_Less ||
+           Op == OverloadedOperatorKind::OO_LessEqual ||
+           Op == OverloadedOperatorKind::OO_Greater ||
+           Op == OverloadedOperatorKind::OO_GreaterEqual ||
+           Op == OverloadedOperatorKind::OO_Spaceship))
+        return true;
+    }
+    return false;
+  };
+
+  Results.EnterNewScope();
+  if (ShouldAddDefault())
+    Results.AddResult("default");
+  // FIXME(liuhui): Ideally, we should only provide `delete` completion for the
+  // first function declaration.
+  Results.AddResult("delete");
+  Results.ExitScope();
+  HandleCodeCompleteResults(this, CodeCompleter, Results.getCompletionContext(),
+                            Results.data(), Results.size());
+}
+
 /// Macro that optionally prepends an "@" to the string literal passed in via
 /// Keyword, depending on whether NeedAt is true or false.
 #define OBJC_AT_KEYWORD_NAME(NeedAt, Keyword) ((NeedAt) ? "@" Keyword : Keyword)