stevewan updated this revision to Diff 368716.
stevewan marked an inline comment as done.
stevewan added a comment.
Avoid unannotated fall-through between cases
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D107394/new/
https://reviews.llvm.org/D107394
Files:
clang/lib/AST/RecordLayoutBuilder.cpp
clang/test/Layout/aix-alignof-align-and-pack-attr.cpp
clang/test/Layout/aix-power-alignment-typedef.cpp
clang/test/Layout/aix-type-align-and-pack-attr.cpp
Index: clang/test/Layout/aix-type-align-and-pack-attr.cpp
===================================================================
--- /dev/null
+++ clang/test/Layout/aix-type-align-and-pack-attr.cpp
@@ -0,0 +1,59 @@
+// 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))) S {
+ double d;
+};
+
+S s;
+
+// CHECK: @{{.*}}test1{{.*}}s{{.*}} = global %"struct.test1::S" zeroinitializer, align 8
+} // namespace test1
+
+namespace test2 {
+struct __attribute__((__aligned__(2), packed)) S {
+ double d;
+};
+
+S s;
+
+// CHECK: @{{.*}}test2{{.*}}s{{.*}} = global %"struct.test2::S" zeroinitializer, align 2
+} // namespace test2
+
+namespace test3 {
+struct __attribute__((__aligned__(16))) S {
+ double d;
+};
+
+S s;
+
+// CHECK: @{{.*}}test3{{.*}}s{{.*}} = global %"struct.test3::S" zeroinitializer, align 16
+} // namespace test3
+
+namespace test4 {
+struct __attribute__((aligned(2))) SS {
+ double d;
+};
+
+struct S {
+ struct SS ss;
+} s;
+
+// CHECK: @{{.*}}test4{{.*}}s{{.*}} = global %"struct.test4::S" zeroinitializer, align 8
+} // namespace test4
+
+namespace test5 {
+struct __attribute__((aligned(2), packed)) SS {
+ double d;
+};
+
+struct S {
+ struct SS ss;
+} s;
+
+// CHECK: @{{.*}}test5{{.*}}s{{.*}} = global %"struct.test5::S" zeroinitializer, align 2
+} // namespace test5
Index: clang/test/Layout/aix-power-alignment-typedef.cpp
===================================================================
--- clang/test/Layout/aix-power-alignment-typedef.cpp
+++ clang/test/Layout/aix-power-alignment-typedef.cpp
@@ -37,3 +37,39 @@
// CHECK-NEXT: | nvsize=2, nvalign=2, preferrednvalign=2]
} // namespace test2
+
+namespace test3 {
+typedef double DblArr[] __attribute__((__aligned__(2)));
+
+union U {
+ DblArr da;
+ char x;
+};
+
+int x = sizeof(U);
+
+// CHECK: 0 | union test3::U
+// CHECK-NEXT: 0 | test3::DblArr da
+// CHECK-NEXT: 0 | char x
+// CHECK-NEXT: | [sizeof=2, dsize=2, align=2, preferredalign=2,
+// CHECK-NEXT: | nvsize=2, nvalign=2, preferrednvalign=2]
+
+} // namespace test3
+
+namespace test4 {
+typedef double Dbl __attribute__((__aligned__(2)));
+
+union U {
+ Dbl DblArr[];
+ char x;
+};
+
+int x = sizeof(U);
+
+// CHECK: 0 | union test4::U
+// CHECK-NEXT: 0 | test4::Dbl [] DblArr
+// CHECK-NEXT: 0 | char x
+// CHECK-NEXT: | [sizeof=2, dsize=2, align=2, preferredalign=2,
+// CHECK-NEXT: | nvsize=2, nvalign=2, preferrednvalign=2]
+
+} // namespace test4
Index: clang/test/Layout/aix-alignof-align-and-pack-attr.cpp
===================================================================
--- clang/test/Layout/aix-alignof-align-and-pack-attr.cpp
+++ /dev/null
@@ -1,29 +0,0 @@
-// 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
Index: clang/lib/AST/RecordLayoutBuilder.cpp
===================================================================
--- clang/lib/AST/RecordLayoutBuilder.cpp
+++ clang/lib/AST/RecordLayoutBuilder.cpp
@@ -1978,8 +1978,144 @@
// and zero-width bit-fields count as prior members; members of empty class
// types marked `no_unique_address` are not considered to be prior members.
CharUnits PreferredAlign = FieldAlign;
- if (DefaultsToAIXPowerAlignment && !AlignIsRequired &&
+ if (DefaultsToAIXPowerAlignment &&
(FoundFirstNonOverlappingEmptyFieldForAIX || IsNaturalAlign)) {
+ auto checkTypeIsTypedef = [](auto &&checkTypeIsTypedef,
+ const auto Ty) -> bool {
+ bool isTypedef = false;
+ switch (Ty->getTypeClass()) {
+ case Type::Typedef: {
+ isTypedef = true;
+ break;
+ }
+ // Recursively check if a type can be unwound to a typedef.
+#define TYPE(Class, Base)
+#define ABSTRACT_TYPE(Class, Base)
+#define NON_CANONICAL_TYPE(Class, Base)
+#define DEPENDENT_TYPE(Class, Base) case Type::Class:
+#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) \
+ case Type::Class: \
+ assert(!Ty->isDependentType() && "should not see dependent types here"); \
+ return checkTypeIsTypedef(checkTypeIsTypedef, \
+ cast<Class##Type>(Ty)->desugar().getTypePtr());
+#include "clang/AST/TypeNodes.inc"
+ llvm_unreachable("Should not see dependent types");
+ case Type::IncompleteArray:
+ case Type::VariableArray:
+ case Type::ConstantArray: {
+ isTypedef = checkTypeIsTypedef(checkTypeIsTypedef,
+ cast<ArrayType>(Ty)->getElementType());
+ break;
+ }
+ case Type::ExtVector:
+ case Type::Vector: {
+ isTypedef = checkTypeIsTypedef(checkTypeIsTypedef,
+ cast<VectorType>(Ty)->getElementType());
+ break;
+ }
+ case Type::ConstantMatrix: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef, cast<ConstantMatrixType>(Ty)->getElementType());
+ break;
+ }
+ case Type::Complex: {
+ isTypedef = checkTypeIsTypedef(checkTypeIsTypedef,
+ cast<ComplexType>(Ty)->getElementType());
+ break;
+ }
+ case Type::ObjCObject: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<ObjCObjectType>(Ty)->getBaseType().getTypePtr());
+ break;
+ }
+ case Type::Adjusted:
+ case Type::Decayed: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<AdjustedType>(Ty)->getAdjustedType().getTypePtr());
+ break;
+ }
+ case Type::Enum: {
+ const auto *TT = cast<TagType>(Ty);
+
+ if (TT->getDecl()->isInvalidDecl())
+ break;
+ if (const auto *ET = dyn_cast<EnumType>(TT)) {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ ET->getDecl()->getIntegerType()->getUnqualifiedDesugaredType());
+ }
+ break;
+ }
+ case Type::SubstTemplateTypeParm: {
+ isTypedef = checkTypeIsTypedef(checkTypeIsTypedef,
+ cast<SubstTemplateTypeParmType>(Ty)
+ ->getReplacementType()
+ .getTypePtr());
+ break;
+ }
+ case Type::Auto:
+ case Type::DeducedTemplateSpecialization: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<DeducedType>(Ty)->getDeducedType().getTypePtr());
+ break;
+ }
+ case Type::Paren: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<ParenType>(Ty)->getInnerType().getTypePtr());
+ break;
+ }
+ case Type::MacroQualified: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<MacroQualifiedType>(Ty)->getUnderlyingType().getTypePtr());
+ break;
+ }
+ case Type::ObjCTypeParam: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<ObjCTypeParamType>(Ty)->desugar().getTypePtr());
+ break;
+ }
+ case Type::Elaborated: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<ElaboratedType>(Ty)->getNamedType().getTypePtr());
+ break;
+ }
+ case Type::Attributed: {
+ isTypedef = checkTypeIsTypedef(
+ checkTypeIsTypedef,
+ cast<AttributedType>(Ty)->getEquivalentType().getTypePtr());
+ break;
+ }
+ case Type::Atomic: {
+ isTypedef = checkTypeIsTypedef(checkTypeIsTypedef,
+ cast<AtomicType>(Ty)->getValueType());
+ break;
+ }
+ // Account for the rest of the types.
+ case Type::FunctionNoProto:
+ case Type::FunctionProto:
+ case Type::Builtin:
+ case Type::ObjCObjectPointer:
+ case Type::BlockPointer:
+ case Type::LValueReference:
+ case Type::RValueReference:
+ case Type::Pointer:
+ case Type::MemberPointer:
+ case Type::ObjCInterface:
+ case Type::ExtInt:
+ case Type::Record:
+ case Type::Pipe:
+ break;
+ }
+ return isTypedef;
+ };
+
auto performBuiltinTypeAlignmentUpgrade = [&](const BuiltinType *BTy) {
if (BTy->getKind() == BuiltinType::Double ||
BTy->getKind() == BuiltinType::LongDouble) {
@@ -1989,16 +2125,25 @@
}
};
- const Type *Ty = D->getType()->getBaseElementTypeUnsafe();
- if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
- performBuiltinTypeAlignmentUpgrade(CTy->getElementType()->castAs<BuiltinType>());
- } else if (const BuiltinType *BTy = Ty->getAs<BuiltinType>()) {
- performBuiltinTypeAlignmentUpgrade(BTy);
- } else if (const RecordType *RT = Ty->getAs<RecordType>()) {
- const RecordDecl *RD = RT->getDecl();
- assert(RD && "Expected non-null RecordDecl.");
- const ASTRecordLayout &FieldRecord = Context.getASTRecordLayout(RD);
- PreferredAlign = FieldRecord.getPreferredAlignment();
+ const Type *Ty = D->getType().getTypePtr();
+ const Type *BaseTy = Ty->getBaseElementTypeUnsafe();
+ // When used as part of a typedef, or together with a 'packed' attribute,
+ // the 'aligned' attribute can be used to decrease alignment. In that case,
+ // it overrides any computed alignment we have, and there is no need to
+ // upgrade the alignment.
+ if (!(AlignIsRequired &&
+ (checkTypeIsTypedef(checkTypeIsTypedef, Ty) || FieldPacked))) {
+ if (const ComplexType *CTy = BaseTy->getAs<ComplexType>()) {
+ performBuiltinTypeAlignmentUpgrade(
+ CTy->getElementType()->castAs<BuiltinType>());
+ } else if (const BuiltinType *BTy = BaseTy->getAs<BuiltinType>()) {
+ performBuiltinTypeAlignmentUpgrade(BTy);
+ } else if (const RecordType *RT = BaseTy->getAs<RecordType>()) {
+ const RecordDecl *RD = RT->getDecl();
+ assert(RD && "Expected non-null RecordDecl.");
+ const ASTRecordLayout &FieldRecord = Context.getASTRecordLayout(RD);
+ PreferredAlign = FieldRecord.getPreferredAlignment();
+ }
}
}
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