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-rw-r--r--lib/AST/ExprConstant.cpp19
-rw-r--r--lib/AST/RecordLayoutBuilder.cpp29
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;
}
}