diff options
| -rw-r--r-- | include/clang/AST/Expr.h | 5 | ||||
| -rw-r--r-- | lib/AST/Expr.cpp | 38 | ||||
| -rw-r--r-- | test/CodeGenCXX/global-init.cpp | 18 |
3 files changed, 35 insertions, 26 deletions
diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h index bb66e710ae..29e3649a27 100644 --- a/include/clang/AST/Expr.h +++ b/include/clang/AST/Expr.h @@ -510,9 +510,8 @@ public: bool isEvaluatable(const ASTContext &Ctx) const; /// HasSideEffects - This routine returns true for all those expressions - /// which must be evaluated each time and must not be optimized away - /// or evaluated at compile time. Example is a function call, volatile - /// variable read. + /// which have any effect other than producing a value. Example is a function + /// call, volatile variable read, or throwing an exception. bool HasSideEffects(const ASTContext &Ctx) const; /// \brief Determine whether this expression involves a call to any function diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp index faba404b9a..9df850d6bd 100644 --- a/lib/AST/Expr.cpp +++ b/lib/AST/Expr.cpp @@ -2643,6 +2643,8 @@ bool Expr::HasSideEffects(const ASTContext &Ctx) const { case SubstNonTypeTemplateParmPackExprClass: llvm_unreachable("shouldn't see dependent / unresolved nodes here"); + case DeclRefExprClass: + case ObjCIvarRefExprClass: case PredefinedExprClass: case IntegerLiteralClass: case FloatingLiteralClass: @@ -2696,16 +2698,10 @@ bool Expr::HasSideEffects(const ASTContext &Ctx) const { case MemberExprClass: case ConditionalOperatorClass: case BinaryConditionalOperatorClass: - case ImplicitCastExprClass: - case CStyleCastExprClass: case CompoundLiteralExprClass: case ExtVectorElementExprClass: case DesignatedInitExprClass: case ParenListExprClass: - case CXXStaticCastExprClass: - case CXXReinterpretCastExprClass: - case CXXConstCastExprClass: - case CXXFunctionalCastExprClass: case CXXPseudoDestructorExprClass: case SubstNonTypeTemplateParmExprClass: case MaterializeTemporaryExprClass: @@ -2714,24 +2710,16 @@ bool Expr::HasSideEffects(const ASTContext &Ctx) const { // These have a side-effect if any subexpression does. break; - case UnaryOperatorClass: { - const UnaryOperator *UO = cast<UnaryOperator>(this); - if (UO->isIncrementDecrementOp()) - return true; - if (UO->getOpcode() == UO_Deref && UO->getType().isVolatileQualified()) + case UnaryOperatorClass: + if (cast<UnaryOperator>(this)->isIncrementDecrementOp()) return true; break; - } case BinaryOperatorClass: if (cast<BinaryOperator>(this)->isAssignmentOp()) return true; break; - case DeclRefExprClass: - case ObjCIvarRefExprClass: - return getType().isVolatileQualified(); - case InitListExprClass: // FIXME: The children for an InitListExpr doesn't include the array filler. if (const Expr *E = cast<InitListExpr>(this)->getArrayFiller()) @@ -2755,7 +2743,17 @@ bool Expr::HasSideEffects(const ASTContext &Ctx) const { if (DCE->getTypeAsWritten()->isReferenceType() && DCE->getCastKind() == CK_Dynamic) return true; - // Also has side-effects if the subexpression does. + } // Fall through. + case ImplicitCastExprClass: + case CStyleCastExprClass: + case CXXStaticCastExprClass: + case CXXReinterpretCastExprClass: + case CXXConstCastExprClass: + case CXXFunctionalCastExprClass: { + const CastExpr *CE = cast<CastExpr>(this); + if (CE->getCastKind() == CK_LValueToRValue && + CE->getSubExpr()->getType().isVolatileQualified()) + return true; break; } @@ -2779,10 +2777,10 @@ bool Expr::HasSideEffects(const ASTContext &Ctx) const { case CXXConstructExprClass: case CXXTemporaryObjectExprClass: { const CXXConstructExpr *CE = cast<CXXConstructExpr>(this); - if (!CE->isElidable() && !CE->getConstructor()->isTrivial()) + if (!CE->getConstructor()->isTrivial()) return true; - // An elidable or trivial constructor does not add any side-effects of its - // own. Just look at its arguments. + // A trivial constructor does not add any side-effects of its own. Just look + // at its arguments. break; } diff --git a/test/CodeGenCXX/global-init.cpp b/test/CodeGenCXX/global-init.cpp index da5467ac3f..2a53ad9e3e 100644 --- a/test/CodeGenCXX/global-init.cpp +++ b/test/CodeGenCXX/global-init.cpp @@ -129,6 +129,14 @@ namespace test6 { const std::type_info *const t = &typeid(p); // CHECK-NOT: @_ZN5test6L1tE + extern B *volatile v; + // CHECK: store {{.*}} @_ZN5test6L1wE + B *const w = dynamic_cast<B*>(v); + + // CHECK: load volatile + // CHECK: store {{.*}} @_ZN5test6L1xE + const int x = *(volatile int*)0x1234; + namespace { int a = int(); volatile int b = int(); @@ -145,7 +153,7 @@ namespace test6 { namespace test7 { struct A { A(); }; struct B { ~B(); int n; }; - struct C { C() = default; C(const C&); }; + struct C { C() = default; C(const C&); int n; }; struct D {}; // CHECK: call void @_ZN5test71AC1Ev({{.*}}@_ZN5test7L1aE) @@ -161,8 +169,12 @@ namespace test7 { // CHECK-NOT: @_ZN5test7L2c1E // CHECK: @_ZN5test7L2c2E - const C c1 = C(); // elidable copy - const C c2 = static_cast<C&&>(C()); // non-elidable copy + // CHECK-NOT: @_ZN5test7L2c3E + // CHECK: @_ZN5test7L2c4E + const C c1 = C(); + const C c2 = static_cast<const C&>(C()); + const int c3 = C().n; + const int c4 = C(C()).n; // CHECK-NOT: @_ZN5test7L1dE const D d = D(); |