r312780 - Fix templated type alias completion when using global completion cache

[Erik Verbruggen via cfe-commits]

Author: erikjv
Date: Fri Sep  8 02:31:13 2017
New Revision: 312780

URL: http://llvm.org/viewvc/llvm-project?rev=312780&view=rev
Log:
Fix templated type alias completion when using global completion cache

When we have enabled cache for global completions we did not have
diagnostics for Bar and could not complete Ba as in provided code
example.

template <typename T>
struct Foo { T member; };

template<typename T> using Bar = Foo<T>;

int main() {
   Ba
}

(This is the fixed version of r 311442, which was reverted in r311445.)

Patch by Ivan Donchevskii!

Differential Revision: https://reviews.llvm.org/D35355

Modified:
    cfe/trunk/lib/Frontend/ASTUnit.cpp
    cfe/trunk/lib/Parse/ParseTemplate.cpp
    cfe/trunk/test/Index/code-completion.cpp

Modified: cfe/trunk/lib/Frontend/ASTUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/ASTUnit.cpp?rev=312780&r1=312779&r2=312780&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/ASTUnit.cpp (original)
+++ cfe/trunk/lib/Frontend/ASTUnit.cpp Fri Sep  8 02:31:13 2017
@@ -243,7 +243,8 @@ static unsigned getDeclShowContexts(cons
   
   uint64_t Contexts = 0;
   if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND) || 
-      isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND)) {
+      isa<ClassTemplateDecl>(ND) || isa<TemplateTemplateParmDecl>(ND) ||
+      isa<TypeAliasTemplateDecl>(ND)) {
     // Types can appear in these contexts.
     if (LangOpts.CPlusPlus || !isa<TagDecl>(ND))
       Contexts |= (1LL << CodeCompletionContext::CCC_TopLevel)

Modified: cfe/trunk/lib/Parse/ParseTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseTemplate.cpp?rev=312780&r1=312779&r2=312780&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseTemplate.cpp (original)
+++ cfe/trunk/lib/Parse/ParseTemplate.cpp Fri Sep  8 02:31:13 2017
@@ -197,10 +197,11 @@ Parser::ParseSingleDeclarationAfterTempl
   MaybeParseCXX11Attributes(prefixAttrs);
 
   if (Tok.is(tok::kw_using)) {
-    // FIXME: We should return the DeclGroup to the caller.
-    ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd,
-                                     prefixAttrs);
-    return nullptr;
+    auto usingDeclPtr = ParseUsingDirectiveOrDeclaration(Context, TemplateInfo, DeclEnd,
+                                                         prefixAttrs);
+    if (!usingDeclPtr || !usingDeclPtr.get().isSingleDecl())
+      return nullptr;
+    return usingDeclPtr.get().getSingleDecl();
   }
 
   // Parse the declaration specifiers, stealing any diagnostics from

Modified: cfe/trunk/test/Index/code-completion.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Index/code-completion.cpp?rev=312780&r1=312779&r2=312780&view=diff
==============================================================================
--- cfe/trunk/test/Index/code-completion.cpp (original)
+++ cfe/trunk/test/Index/code-completion.cpp Fri Sep  8 02:31:13 2017
@@ -37,6 +37,16 @@ Z::operator int() const {
   return 0;
 }
 
+template <typename T>
+struct Foo { T member; };
+
+template<typename T> using Bar = Foo<T>;
+
+void test_template_alias() {
+  // RUN: env CINDEXTEST_COMPLETION_CACHING=1 c-index-test -code-completion-at=%s:47:1 %s | FileCheck -check-prefix=CHECK-TEMPLATE-ALIAS %s
+
+}
+
 // CHECK-MEMBER: FieldDecl:{ResultType double}{TypedText member}
 // CHECK-MEMBER: FieldDecl:{ResultType int}{Text X::}{TypedText member}
 // CHECK-MEMBER: FieldDecl:{ResultType float}{Text Y::}{TypedText member}
@@ -88,3 +98,5 @@ Z::operator int() const {
 // CHECK-EXPR-NEXT: Class name
 // CHECK-EXPR-NEXT: Nested name specifier
 // CHECK-EXPR-NEXT: Objective-C interface
+
+// CHECK-TEMPLATE-ALIAS: AliasTemplateDecl:{TypedText Bar}{LeftAngle <}{Placeholder typename T}{RightAngle >} (50)