From 203f103b27d352b82b156a51f6309341432629d3 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Tue, 27 Nov 2018 21:20:42 +0000
Subject: [PATCH] [MS] Push outermost class DeclContexts only in
 -fdelayed-template-parsing

This is more or less a complete rewrite of r347627, and it fixes PR38460
I added a reduced test case to DelayedTemplateParsing.cpp.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@347713 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Parse/ParseTemplate.cpp            | 35 +++++++++++++++++---------
 test/Parser/DelayedTemplateParsing.cpp | 30 ++++++++++++++++++++++
 2 files changed, 53 insertions(+), 12 deletions(-)

diff --git a/lib/Parse/ParseTemplate.cpp b/lib/Parse/ParseTemplate.cpp
index 26709a5aaa..e0a7cc6e85 100644
--- a/lib/Parse/ParseTemplate.cpp
+++ b/lib/Parse/ParseTemplate.cpp
@@ -1381,26 +1381,37 @@ void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) {
 
   SmallVector<ParseScope*, 4> TemplateParamScopeStack;
 
-  // Get the list of DeclContexts to reenter.
-  SmallVector<DeclContext*, 4> DeclContextsToReenter;
+  // Get the list of DeclContexts to reenter. For inline methods, we only want
+  // to push the DeclContext of the outermost class. This matches the way the
+  // parser normally parses bodies of inline methods when the outermost class is
+  // complete.
+  struct ContainingDC {
+    ContainingDC(DeclContext *DC, bool ShouldPush) : Pair(DC, ShouldPush) {}
+    llvm::PointerIntPair<DeclContext *, 1, bool> Pair;
+    DeclContext *getDC() { return Pair.getPointer(); }
+    bool shouldPushDC() { return Pair.getInt(); }
+  };
+  SmallVector<ContainingDC, 4> DeclContextsToReenter;
   DeclContext *DD = FunD;
+  DeclContext *NextContaining = Actions.getContainingDC(DD);
   while (DD && !DD->isTranslationUnit()) {
-    DeclContextsToReenter.push_back(DD);
+    bool ShouldPush = DD == NextContaining;
+    DeclContextsToReenter.push_back({DD, ShouldPush});
+    if (ShouldPush)
+      NextContaining = Actions.getContainingDC(DD);
     DD = DD->getLexicalParent();
   }
 
   // Reenter template scopes from outermost to innermost.
-  SmallVectorImpl<DeclContext *>::reverse_iterator II =
-      DeclContextsToReenter.rbegin();
-  for (; II != DeclContextsToReenter.rend(); ++II) {
-    TemplateParamScopeStack.push_back(new ParseScope(this,
-          Scope::TemplateParamScope));
-    unsigned NumParamLists =
-      Actions.ActOnReenterTemplateScope(getCurScope(), cast<Decl>(*II));
+  for (ContainingDC CDC : reverse(DeclContextsToReenter)) {
+    TemplateParamScopeStack.push_back(
+        new ParseScope(this, Scope::TemplateParamScope));
+    unsigned NumParamLists = Actions.ActOnReenterTemplateScope(
+        getCurScope(), cast<Decl>(CDC.getDC()));
     CurTemplateDepthTracker.addDepth(NumParamLists);
-    if (*II != FunD) {
+    if (CDC.shouldPushDC()) {
       TemplateParamScopeStack.push_back(new ParseScope(this, Scope::DeclScope));
-      Actions.PushDeclContext(Actions.getCurScope(), *II);
+      Actions.PushDeclContext(Actions.getCurScope(), CDC.getDC());
     }
   }
 
diff --git a/test/Parser/DelayedTemplateParsing.cpp b/test/Parser/DelayedTemplateParsing.cpp
index 6ea245c2d4..c65e80b1f7 100644
--- a/test/Parser/DelayedTemplateParsing.cpp
+++ b/test/Parser/DelayedTemplateParsing.cpp
@@ -181,3 +181,33 @@ static void h() {
 }
 
 }
+
+struct PR38460 {
+  template <typename>
+  struct T {
+    static void foo() {
+      struct U {
+        void dummy() {
+          use_delayed_identifier();
+        }
+      };
+    }
+  };
+};
+void use_delayed_identifier();
+void trigger_PR38460() {
+  PR38460::T<int>::foo();
+}
+
+template <typename> struct PR38460_2 {
+  struct p {
+    struct G {
+      bool operator()(int) {}
+    };
+  };
+  static void as() {
+    typename p::G g;
+    g(0);
+  }
+};
+template struct PR38460_2<int>;
-- 
2.40.0