From 2f36dae5c01d46c8c71af594601f125a604226a1 Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Sun, 28 Oct 2012 06:18:02 +0000
Subject: [PATCH] When determining whether to try evaluating the initializer of
 a variable, check whether the initializer is value-dependent rather than
 whether we are in a dependent context. This allows us to detect some errors
 sooner, and fixes a crash-on-invalid if a dependent type leaks out to a
 non-dependent context in error recovery.

llvm-svn: 166898
---
 clang/lib/Sema/SemaDecl.cpp                      |  2 +-
 clang/test/SemaCXX/constant-expression-cxx11.cpp |  9 ++++++++-
 clang/test/SemaCXX/cxx11-crashes.cpp             | 12 ++++++++++++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 3576190..6eef427 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -7201,7 +7201,7 @@ void Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
   Expr *Init = var->getInit();
   bool IsGlobal = var->hasGlobalStorage() && !var->isStaticLocal();
 
-  if (!var->getDeclContext()->isDependentContext() && Init) {
+  if (Init && !Init->isValueDependent()) {
     if (IsGlobal && !var->isConstexpr() &&
         getDiagnostics().getDiagnosticLevel(diag::warn_global_constructor,
                                             var->getLocation())
diff --git a/clang/test/SemaCXX/constant-expression-cxx11.cpp b/clang/test/SemaCXX/constant-expression-cxx11.cpp
index 9ce5b85..9a9746e 100644
--- a/clang/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/clang/test/SemaCXX/constant-expression-cxx11.cpp
@@ -521,12 +521,19 @@ namespace DependentValues {
 
 struct I { int n; typedef I V[10]; };
 I::V x, y;
-template<bool B> struct S {
+int g(); // expected-note {{here}}
+template<bool B, typename T> struct S : T {
   int k;
   void f() {
     I::V &cells = B ? x : y;
     I &i = cells[k];
     switch (i.n) {}
+
+    constexpr int n = g(); // \
+    // expected-error {{must be initialized by a constant expression}} \
+    // expected-note {{non-constexpr function 'g'}}
+
+    constexpr int m = this->g(); // ok, could be constexpr
   }
 };
 
diff --git a/clang/test/SemaCXX/cxx11-crashes.cpp b/clang/test/SemaCXX/cxx11-crashes.cpp
index 66b182b..bd51af1 100644
--- a/clang/test/SemaCXX/cxx11-crashes.cpp
+++ b/clang/test/SemaCXX/cxx11-crashes.cpp
@@ -62,3 +62,15 @@ void foobar()
 }
 
 }
+
+namespace b6981007 {
+  struct S {}; // expected-note 3{{candidate}}
+  void f() {
+    S s(1, 2, 3); // expected-error {{no matching}}
+    for (auto x : s) {
+      // We used to attempt to evaluate the initializer of this variable,
+      // and crash because it has an undeduced type.
+      const int &n(x);
+    }
+  }
+}
-- 
2.7.4