diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp --- a/clang/lib/AST/ASTContext.cpp +++ b/clang/lib/AST/ASTContext.cpp @@ -2478,11 +2478,16 @@ return ABIAlign; if (const auto *RT = T->getAs()) { - if (TI.AlignIsRequired || RT->getDecl()->isInvalidDecl()) + const RecordDecl *RD = RT->getDecl(); + + // When used as part of a typedef, or together with a 'packed' attribute, + // the 'aligned' attribute can be used to decrease alignment. + if ((TI.AlignIsRequired && T->getAs() != nullptr) || + RD->isInvalidDecl()) return ABIAlign; unsigned PreferredAlign = static_cast( - toBits(getASTRecordLayout(RT->getDecl()).PreferredAlignment)); + toBits(getASTRecordLayout(RD).PreferredAlignment)); assert(PreferredAlign >= ABIAlign && "PreferredAlign should be at least as large as ABIAlign."); return PreferredAlign; diff --git a/clang/test/Layout/aix-alignof-align-and-pack-attr.cpp b/clang/test/Layout/aix-alignof-align-and-pack-attr.cpp new file mode 100644 --- /dev/null +++ b/clang/test/Layout/aix-alignof-align-and-pack-attr.cpp @@ -0,0 +1,29 @@ +// RUN: %clang_cc1 -triple powerpc-ibm-aix-xcoff -S -emit-llvm -x c++ < %s | \ +// RUN: FileCheck %s + +// RUN: %clang_cc1 -triple powerpc64-ibm-aix-xcoff -S -emit-llvm -x c++ < %s | \ +// RUN: FileCheck %s + +namespace test1 { +struct __attribute__((__aligned__(2))) C { + double x; +} c; + +// CHECK: @{{.*}}test1{{.*}}c{{.*}} = global %"struct.test1::C" zeroinitializer, align 8 +} // namespace test1 + +namespace test2 { +struct __attribute__((__aligned__(2), packed)) C { + double x; +} c; + +// CHECK: @{{.*}}test2{{.*}}c{{.*}} = global %"struct.test2::C" zeroinitializer, align 2 +} // namespace test2 + +namespace test3 { +struct __attribute__((__aligned__(16))) C { + double x; +} c; + +// CHECK: @{{.*}}test3{{.*}}c{{.*}} = global %"struct.test3::C" zeroinitializer, align 16 +} // namespace test3