Handle dependent types/exprs in static_assert expressions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66997 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 273b5ed..e34412e 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -1044,6 +1044,7 @@
 }
 
 static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
+  assert(!E->isValueDependent() && "Should not see value dependent exprs!");
   if (!E->getType()->isIntegralType()) {
     return ICEDiag(2, E->getLocStart());
   }
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 57a6c62..37035b9 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -2243,20 +2243,23 @@
   StringLiteral *AssertMessage = 
     cast<StringLiteral>((Expr *)assertmessageexpr.get());
 
-  llvm::APSInt Value(32);
-  if (!AssertExpr->isIntegerConstantExpr(Value, Context)) {
-    Diag(AssertLoc, diag::err_static_assert_expression_is_not_constant) <<
-      AssertExpr->getSourceRange();
-    return 0;
-  }
+  if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
+    llvm::APSInt Value(32);
+    if (!AssertExpr->isIntegerConstantExpr(Value, Context)) {
+      Diag(AssertLoc, diag::err_static_assert_expression_is_not_constant) <<
+        AssertExpr->getSourceRange();
+      return 0;
+    }
 
+    if (Value == 0) {
+      std::string str(AssertMessage->getStrData(), 
+                      AssertMessage->getByteLength());
+      Diag(AssertLoc, diag::err_static_assert_failed) << str;
+    }
+  }
+  
   Decl *Decl = StaticAssertDecl::Create(Context, CurContext, AssertLoc, 
                                         AssertExpr, AssertMessage);
-  if (Value == 0) {
-    std::string str(AssertMessage->getStrData(), 
-                    AssertMessage->getByteLength());
-    Diag(AssertLoc, diag::err_static_assert_failed) << str;
-  }
   
   CurContext->addDecl(Decl);
   return Decl;
diff --git a/test/SemaCXX/static-assert.cpp b/test/SemaCXX/static-assert.cpp
index a2b0b52..94ffff8 100644
--- a/test/SemaCXX/static-assert.cpp
+++ b/test/SemaCXX/static-assert.cpp
@@ -13,3 +13,12 @@
 class C {
     static_assert(false, "false is false"); // expected-error {{static_assert failed "false is false"}}
 };
+
+template<int N> struct T {
+    static_assert(N == 2, "N is not 2!");
+};
+
+template<typename T> struct S {
+    static_assert(sizeof(T) > sizeof(char), "Type not big enough!");
+};
+