From: David Majnemer <david.majnemer@gmail.com>
Date: Fri, 18 Jul 2014 20:00:13 +0000 (+0000)
Subject: Revert "CodeGen: Properly null-check typeid expressions"
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=15bbd9f4769b7734fe33d5517d9a4e0b9faba3b5;p=clang

Revert "CodeGen: Properly null-check typeid expressions"

This reverts commit r213401, r213402, r213403, and r213404.

I accidently committed these changes instead of updating the
differential.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213405 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 5c4e1f1266..47dc9fbbc7 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -1615,35 +1615,6 @@ void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
   EmitBlock(DeleteEnd);
 }
 
-static bool isGLValueFromPointerDeref(const Expr *E) {
-  E = E->IgnoreParens();
-
-  if (const auto *CE = dyn_cast<CastExpr>(E)) {
-    if (!CE->getSubExpr()->isGLValue())
-      return false;
-    return isGLValueFromPointerDeref(CE->getSubExpr());
-  }
-
-  if (const auto *BO = dyn_cast<BinaryOperator>(E))
-    if (BO->getOpcode() == BO_Comma)
-      return isGLValueFromPointerDeref(BO->getRHS());
-
-  if (const auto *ACO = dyn_cast<AbstractConditionalOperator>(E))
-    return isGLValueFromPointerDeref(ACO->getTrueExpr()) ||
-           isGLValueFromPointerDeref(ACO->getFalseExpr());
-
-  // C++11 [expr.sub]p1:
-  //   The expression E1[E2] is identical (by definition) to *((E1)+(E2))
-  if (isa<ArraySubscriptExpr>(E))
-    return true;
-
-  if (const auto *UO = dyn_cast<UnaryOperator>(E))
-    if (UO->getOpcode() == UO_Deref)
-      return true;
-
-  return false;
-}
-
 static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
                                          llvm::Type *StdTypeInfoPtrTy) {
   // Get the vtable pointer.
@@ -1653,13 +1624,13 @@ static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E,
   //   If the glvalue expression is obtained by applying the unary * operator to
   //   a pointer and the pointer is a null pointer value, the typeid expression
   //   throws the std::bad_typeid exception.
-  //
-  // However, this paragraph's intent is not clear.  We choose a very generous
-  // interpretation which implores us to consider comma operators, conditional
-  // operators, parentheses and other such constructs.
+  bool IsDeref = false;
+  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParens()))
+    if (UO->getOpcode() == UO_Deref)
+      IsDeref = true;
+
   QualType SrcRecordTy = E->getType();
-  if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(
-          isGLValueFromPointerDeref(E), SrcRecordTy)) {
+  if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(IsDeref, SrcRecordTy)) {
     llvm::BasicBlock *BadTypeidBlock =
         CGF.createBasicBlock("typeid.bad_typeid");
     llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end");
diff --git a/test/CodeGenCXX/typeid-should-throw.cpp b/test/CodeGenCXX/typeid-should-throw.cpp
deleted file mode 100644
index 8b3f2ac0bb..0000000000
--- a/test/CodeGenCXX/typeid-should-throw.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-// RUN: %clang_cc1 %s -triple %itanium_abi_triple -Wno-unused-value -emit-llvm -o - -std=c++11 | FileCheck %s
-namespace std {
-struct type_info;
-}
-
-struct A {
-  virtual ~A();
-  operator bool();
-};
-struct B : A {};
-
-void f1(A *x) { typeid(false, *x); }
-// CHECK-LABEL: define void @_Z2f1P1A
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f2(bool b, A *x, A *y) { typeid(b ? *x : *y); }
-// CHECK-LABEL: define void @_Z2f2bP1AS0_
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f3(bool b, A *x, A &y) { typeid(b ? *x : y); }
-// CHECK-LABEL: define void @_Z2f3bP1ARS_
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f4(bool b, A &x, A *y) { typeid(b ? x : *y); }
-// CHECK-LABEL: define void @_Z2f4bR1APS_
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f5(volatile A *x) { typeid(*x); }
-// CHECK-LABEL: define void @_Z2f5PV1A
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f6(A *x) { typeid((B &)*(B *)x); }
-// CHECK-LABEL: define void @_Z2f6P1A
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f7(A *x) { typeid((*x)); }
-// CHECK-LABEL: define void @_Z2f7P1A
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f8(A *x) { typeid(x[0]); }
-// CHECK-LABEL: define void @_Z2f8P1A
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f9(A *x) { typeid(0[x]); }
-// CHECK-LABEL: define void @_Z2f9P1A
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f10(A *x, A *y) { typeid(*y ?: *x); }
-// CHECK-LABEL: define void @_Z3f10P1AS0_
-// CHECK:       icmp eq {{.*}}, null
-// CHECK-NEXT:  br i1
-
-void f11(A *x) { typeid((const A &)(A)*x); }
-// CHECK-LABEL: define void @_Z3f11P1A
-// CHECK-NOT:   icmp eq {{.*}}, null
-
-void f12(A *x) { typeid((A &&)*(A *)nullptr); }
-// CHECK-LABEL: define void @_Z3f12P1A
-// CHECK-NOT:   icmp eq {{.*}}, null