diff options
Diffstat (limited to 'lib/AST')
| -rw-r--r-- | lib/AST/ExprConstant.cpp | 19 | ||||
| -rw-r--r-- | lib/AST/RecordLayoutBuilder.cpp | 29 |
2 files changed, 40 insertions, 8 deletions
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp index 8d9b3c3bebc0..57bf2fca4eb7 100644 --- a/lib/AST/ExprConstant.cpp +++ b/lib/AST/ExprConstant.cpp @@ -61,14 +61,22 @@ namespace { static QualType getType(APValue::LValueBase B) { if (!B) return QualType(); - if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) + if (const ValueDecl *D = B.dyn_cast<const ValueDecl*>()) { // FIXME: It's unclear where we're supposed to take the type from, and - // this actually matters for arrays of unknown bound. Using the type of - // the most recent declaration isn't clearly correct in general. Eg: + // this actually matters for arrays of unknown bound. Eg: // // extern int arr[]; void f() { extern int arr[3]; }; // constexpr int *p = &arr[1]; // valid? - return cast<ValueDecl>(D->getMostRecentDecl())->getType(); + // + // For now, we take the array bound from the most recent declaration. + for (auto *Redecl = cast<ValueDecl>(D->getMostRecentDecl()); Redecl; + Redecl = cast_or_null<ValueDecl>(Redecl->getPreviousDecl())) { + QualType T = Redecl->getType(); + if (!T->isIncompleteArrayType()) + return T; + } + return D->getType(); + } const Expr *Base = B.get<const Expr*>(); @@ -8535,9 +8543,6 @@ bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { (LHSValue.Base && isZeroSized(RHSValue))) return Error(E); // Pointers with different bases cannot represent the same object. - // (Note that clang defaults to -fmerge-all-constants, which can - // lead to inconsistent results for comparisons involving the address - // of a constant; this generally doesn't matter in practice.) return Success(E->getOpcode() == BO_NE, E); } diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp index a9d43dfa80c5..de38bc9b64dd 100644 --- a/lib/AST/RecordLayoutBuilder.cpp +++ b/lib/AST/RecordLayoutBuilder.cpp @@ -1751,7 +1751,34 @@ void ItaniumRecordLayoutBuilder::LayoutField(const FieldDecl *D, QualType T = Context.getBaseElementType(D->getType()); if (const BuiltinType *BTy = T->getAs<BuiltinType>()) { CharUnits TypeSize = Context.getTypeSizeInChars(BTy); - if (TypeSize > FieldAlign) + + if (!llvm::isPowerOf2_64(TypeSize.getQuantity())) { + assert( + !Context.getTargetInfo().getTriple().isWindowsMSVCEnvironment() && + "Non PowerOf2 size in MSVC mode"); + // Base types with sizes that aren't a power of two don't work + // with the layout rules for MS structs. This isn't an issue in + // MSVC itself since there are no such base data types there. + // On e.g. x86_32 mingw and linux, long double is 12 bytes though. + // Any structs involving that data type obviously can't be ABI + // compatible with MSVC regardless of how it is laid out. + + // Since ms_struct can be mass enabled (via a pragma or via the + // -mms-bitfields command line parameter), this can trigger for + // structs that don't actually need MSVC compatibility, so we + // need to be able to sidestep the ms_struct layout for these types. + + // Since the combination of -mms-bitfields together with structs + // like max_align_t (which contains a long double) for mingw is + // quite comon (and GCC handles it silently), just handle it + // silently there. For other targets that have ms_struct enabled + // (most probably via a pragma or attribute), trigger a diagnostic + // that defaults to an error. + if (!Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) + Diag(D->getLocation(), diag::warn_npot_ms_struct); + } + if (TypeSize > FieldAlign && + llvm::isPowerOf2_64(TypeSize.getQuantity())) FieldAlign = TypeSize; } } |