[CodeCompletion] Enable signature help when initializing class/struct/union members.

Summary:
Factors out member decleration gathering and uses it in parsing to call signature
help. Doesn't support signature help for base class constructors, the code was too
coupled with diagnostic handling, but still can be factored out but just needs
more afford.

Reviewers: sammccall, ilya-biryukov, ioeric

Reviewed By: ilya-biryukov

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D51917

llvm-svn: 341949

1 files changed, 19 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index addddd8a849..4af36db2e56 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -4586,6 +4586,25 @@ QualType Sema::ProduceConstructorSignatureHelp(Scope *S, QualType Type,
   return ProduceSignatureHelp(*this, S, Results, Args.size(), OpenParLoc);
 }
 
+QualType Sema::ProduceCtorInitMemberSignatureHelp(
+    Scope *S, Decl *ConstructorDecl, CXXScopeSpec SS, ParsedType TemplateTypeTy,
+    ArrayRef<Expr *> ArgExprs, IdentifierInfo *II, SourceLocation OpenParLoc) {
+  if (!CodeCompleter)
+    return QualType();
+
+  CXXConstructorDecl *Constructor =
+      dyn_cast<CXXConstructorDecl>(ConstructorDecl);
+  if (!Constructor)
+    return QualType();
+  // FIXME: Add support for Base class constructors as well.
+  if (ValueDecl *MemberDecl = tryLookupCtorInitMemberDecl(
+          Constructor->getParent(), SS, TemplateTypeTy, II))
+    return ProduceConstructorSignatureHelp(getCurScope(), MemberDecl->getType(),
+                                           MemberDecl->getLocation(), ArgExprs,
+                                           OpenParLoc);
+  return QualType();
+}
+
 void Sema::CodeCompleteInitializer(Scope *S, Decl *D) {
   ValueDecl *VD = dyn_cast_or_null<ValueDecl>(D);
   if (!VD) {