fix rdar://9204520 - Accept int(0.85 * 10) as an initializer in a class member

as an extension.

llvm-svn: 132980

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -3542,6 +3542,9 @@ def ext_in_class_initializer_float_type : ExtWarn<
 def err_in_class_initializer_non_constant : Error<
   "in-class initializer is not a constant expression">;
 
+def ext_in_class_initializer_non_constant : Extension<
+ "in-class initializer is not a constant expression, accepted as an extension">;
+
 // C++ anonymous unions and GNU anonymous structs/unions
 def ext_anonymous_union : Extension<
   "anonymous unions are a GNU extension in C">, InGroup<GNU>;

clang/lib/Sema/SemaDecl.cpp

@@ -5369,15 +5369,23 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
 
     // We allow integer constant expressions in all cases.
     } else if (T->isIntegralOrEnumerationType()) {
-      if (!Init->isValueDependent()) {
-        // Check whether the expression is a constant expression.
-        llvm::APSInt Value;
-        SourceLocation Loc;
-        if (!Init->isIntegerConstantExpr(Value, Context, &Loc)) {
-          Diag(Loc, diag::err_in_class_initializer_non_constant)
-            << Init->getSourceRange();
-          VDecl->setInvalidDecl();
-        }
+      // Check whether the expression is a constant expression.
+      SourceLocation Loc;
+      if (Init->isValueDependent())
+        ; // Nothing to check.
+      else if (Init->isIntegerConstantExpr(Context, &Loc))
+        ; // Ok, it's an ICE!
+      else if (Init->isEvaluatable(Context)) {
+        // If we can constant fold the initializer through heroics, accept it,
+        // but report this as a use of an extension for -pedantic.
+        Diag(Loc, diag::ext_in_class_initializer_non_constant)
+          << Init->getSourceRange();
+      } else {
+        // Otherwise, this is some crazy unknown case.  Report the issue at the
+        // location provided by the isIntegerConstantExpr failed check.
+        Diag(Loc, diag::err_in_class_initializer_non_constant)
+          << Init->getSourceRange();
+        VDecl->setInvalidDecl();
       }
 
     // We allow floating-point constants as an extension in C++03, and

clang/test/SemaCXX/i-c-e-cxx.cpp

@@ -42,3 +42,16 @@ namespace pr6206 {
 void pr6373(const unsigned x = 0) {
   unsigned max = 80 / x;
 }
+
+
+// rdar://9204520
+namespace rdar9204520 {
+  
+struct A {
+  static const int B = int(0.75 * 1000 * 1000);
+};
+
+int foo() { return A::B; }
+}
+
+