diff options
| -rw-r--r-- | clang/lib/AST/RecordLayoutBuilder.cpp | 7 | ||||
| -rw-r--r-- | clang/test/SemaCXX/alignment-of-derived-class.cpp | 41 |
2 files changed, 45 insertions, 3 deletions
diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp index 51b1c062e0d..5df372639da 100644 --- a/clang/lib/AST/RecordLayoutBuilder.cpp +++ b/clang/lib/AST/RecordLayoutBuilder.cpp @@ -1532,18 +1532,19 @@ CharUnits RecordLayoutBuilder::LayoutBase(const BaseSubobjectInfo *Base) { } } + CharUnits UnpackedBaseAlign = Layout.getNonVirtualAlign(); + CharUnits BaseAlign = (Packed) ? CharUnits::One() : UnpackedBaseAlign; + // If we have an empty base class, try to place it at offset 0. if (Base->Class->isEmpty() && (!HasExternalLayout || Offset == CharUnits::Zero()) && EmptySubobjects->CanPlaceBaseAtOffset(Base, CharUnits::Zero())) { setSize(std::max(getSize(), Layout.getSize())); + UpdateAlignment(BaseAlign, UnpackedBaseAlign); return CharUnits::Zero(); } - CharUnits UnpackedBaseAlign = Layout.getNonVirtualAlign(); - CharUnits BaseAlign = (Packed) ? CharUnits::One() : UnpackedBaseAlign; - // The maximum field alignment overrides base align. if (!MaxFieldAlignment.isZero()) { BaseAlign = std::min(BaseAlign, MaxFieldAlignment); diff --git a/clang/test/SemaCXX/alignment-of-derived-class.cpp b/clang/test/SemaCXX/alignment-of-derived-class.cpp new file mode 100644 index 00000000000..28c1fa9144b --- /dev/null +++ b/clang/test/SemaCXX/alignment-of-derived-class.cpp @@ -0,0 +1,41 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11 +// expected-no-diagnostics + +// Test that the alignment of a empty direct base class is correctly +// inherited by the derived class. + +struct A { +} __attribute__ ((aligned(16))); + +static_assert(__alignof(A) == 16, "A should be aligned to 16 bytes"); + +struct B1 : public A { +}; + +static_assert(__alignof(B1) == 16, "B1 should be aligned to 16 bytes"); + +struct B2 : public A { +} __attribute__ ((aligned(2))); + +static_assert(__alignof(B2) == 16, "B2 should be aligned to 16 bytes"); + +struct B3 : public A { +} __attribute__ ((aligned(4))); + +static_assert(__alignof(B3) == 16, "B3 should be aligned to 16 bytes"); + +struct B4 : public A { +} __attribute__ ((aligned(8))); + +static_assert(__alignof(B4) == 16, "B4 should be aligned to 16 bytes"); + +struct B5 : public A { +} __attribute__ ((aligned(16))); + +static_assert(__alignof(B5) == 16, "B5 should be aligned to 16 bytes"); + +struct B6 : public A { +} __attribute__ ((aligned(32))); + +static_assert(__alignof(B6) == 32, "B6 should be aligned to 32 bytes"); + |
