[clang] 0342bbf - Revert "Anonymous unions should be transparent wrt `[[clang::trivial_abi]]`."
Nico Weber via cfe-commits
cfe-commits at lists.llvm.org
Mon Aug 7 12:48:49 PDT 2023
Author: Nico Weber
Date: 2023-08-07T15:48:23-04:00
New Revision: 0342bbf223fa12701a0570a23f9eac433b8b341c
URL: https://github.com/llvm/llvm-project/commit/0342bbf223fa12701a0570a23f9eac433b8b341c
DIFF: https://github.com/llvm/llvm-project/commit/0342bbf223fa12701a0570a23f9eac433b8b341c.diff
LOG: Revert "Anonymous unions should be transparent wrt `[[clang::trivial_abi]]`."
This reverts commit bddaa35177861545fc329123e55b6a3b34549507.
Reverting as requested at https://reviews.llvm.org/D155895#4566945
(for breaking tests on Windows).
Added:
Modified:
clang/include/clang/Basic/LangOptions.h
clang/lib/Frontend/CompilerInvocation.cpp
clang/lib/Sema/SemaDeclCXX.cpp
clang/test/SemaCXX/attr-trivial-abi.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index d926cfcd4d8665..3ef68ca8af6685 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -230,12 +230,6 @@ class LangOptions : public LangOptionsBase {
/// - consider classes with defaulted special member functions non-pod.
Ver15,
- /// Attempt to be ABI-compatible with code generated by Clang 17.0.x.
- /// This causes clang to:
- /// - Treat `[[clang::trivial_abi]]` as ill-formed and ignore it if any
- /// field is an anonymous union and/or struct.
- Ver17,
-
/// Conform to the underlying platform's C and C++ ABIs as closely
/// as we can.
Latest
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 699b315269deb3..be53ce3e472659 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3474,8 +3474,6 @@ void CompilerInvocation::GenerateLangArgs(const LangOptions &Opts,
GenerateArg(Consumer, OPT_fclang_abi_compat_EQ, "14.0");
else if (Opts.getClangABICompat() == LangOptions::ClangABI::Ver15)
GenerateArg(Consumer, OPT_fclang_abi_compat_EQ, "15.0");
- else if (Opts.getClangABICompat() == LangOptions::ClangABI::Ver17)
- GenerateArg(Consumer, OPT_fclang_abi_compat_EQ, "17.0");
if (Opts.getSignReturnAddressScope() ==
LangOptions::SignReturnAddressScopeKind::All)
@@ -3961,8 +3959,6 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
Opts.setClangABICompat(LangOptions::ClangABI::Ver14);
else if (Major <= 15)
Opts.setClangABICompat(LangOptions::ClangABI::Ver15);
- else if (Major <= 17)
- Opts.setClangABICompat(LangOptions::ClangABI::Ver17);
} else if (Ver != "latest") {
Diags.Report(diag::err_drv_invalid_value)
<< A->getAsString(Args) << A->getValue();
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 6c29efc03a4b78..2c2c9dc8147437 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -45,7 +45,6 @@
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallString.h"
-#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/SaveAndRestore.h"
#include <map>
@@ -10414,35 +10413,21 @@ void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) {
}
}
- llvm::SmallVector<const FieldDecl *> FieldsToCheck{RD.fields()};
- while (!FieldsToCheck.empty()) {
- const FieldDecl *FD = FieldsToCheck.pop_back_val();
-
- // Ill-formed if the field is an ObjectiveC pointer.
+ for (const auto *FD : RD.fields()) {
+ // Ill-formed if the field is an ObjectiveC pointer or of a type that is
+ // non-trivial for the purpose of calls.
QualType FT = FD->getType();
if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) {
PrintDiagAndRemoveAttr(4);
return;
}
- if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
- // Check the fields of anonymous structs (and/or or unions) instead of
- // checking the type of the anonynous struct itself.
- if (getLangOpts().getClangABICompat() > LangOptions::ClangABI::Ver17 &&
- RT->getDecl()->isAnonymousStructOrUnion()) {
- FieldsToCheck.append(RT->getDecl()->field_begin(),
- RT->getDecl()->field_end());
- continue;
- }
-
- // Ill-formed if the field is of a type that is non-trivial for the
- // purpose of calls.
+ if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>())
if (!RT->isDependentType() &&
!cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) {
PrintDiagAndRemoveAttr(5);
return;
}
- }
}
}
diff --git a/clang/test/SemaCXX/attr-trivial-abi.cpp b/clang/test/SemaCXX/attr-trivial-abi.cpp
index accac42c25cf5f..c215f90eb124ce 100644
--- a/clang/test/SemaCXX/attr-trivial-abi.cpp
+++ b/clang/test/SemaCXX/attr-trivial-abi.cpp
@@ -1,5 +1,4 @@
// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++11
-// RUN: %clang_cc1 -fsyntax-only -fclang-abi-compat=17 -verify %s -std=c++11 -DCLANG_ABI_COMPAT=17
void __attribute__((trivial_abi)) foo(); // expected-warning {{'trivial_abi' attribute only applies to classes}}
@@ -170,115 +169,3 @@ static_assert(!__is_trivially_relocatable(S20), "");
static_assert(__is_trivially_relocatable(S20), "");
#endif
} // namespace deletedCopyMoveConstructor
-
-namespace anonymousUnionsAndStructs {
- // Test helper:
- struct [[clang::trivial_abi]] Trivial {
- Trivial() {}
- Trivial(Trivial&& other) {}
- Trivial& operator=(Trivial&& other) { return *this; }
- ~Trivial() {}
- };
- static_assert(__is_trivially_relocatable(Trivial), "");
-
- // Test helper:
- struct Nontrivial {
- Nontrivial() {}
- Nontrivial(Nontrivial&& other) {}
- Nontrivial& operator=(Nontrivial&& other) { return *this; }
- ~Nontrivial() {}
- };
- static_assert(!__is_trivially_relocatable(Nontrivial), "");
-
- // Basic smoke test, not yet related to anonymous unions or structs:
- struct [[clang::trivial_abi]] BasicStruct {
- BasicStruct(BasicStruct&& other) {}
- BasicStruct& operator=(BasicStruct&& other) { return *this; }
- ~BasicStruct() {}
- Trivial field;
- };
- static_assert(__is_trivially_relocatable(BasicStruct), "");
-
- // `StructWithAnonymousUnion` is like `BasicStruct`, but `field` is wrapped in
- // an anonymous union, and thus trivial relocatability of `BasicStruct` and
- // `StructWithAnonymousUnion` should be the same).
- //
- // It's impossible to declare a constructor for an anonymous unions so to
- // support applying `[[clang::trivial_abi]]` to structs containing anonymous
- // unions, and therefore when processing fields of the struct containing the
- // anonymous union, the trivial relocatability of the *union* is ignored and
- // instead the union's fields are recursively inspected in
- // `checkIllFormedTrivialABIStruct`.
- struct [[clang::trivial_abi]] StructWithAnonymousUnion {
-#if defined(CLANG_ABI_COMPAT) && CLANG_ABI_COMPAT <= 17
- // expected-warning at -2 {{'trivial_abi' cannot be applied to 'StructWithAnonymousUnion'}}
- // expected-note at -3 {{trivial_abi' is disallowed on 'StructWithAnonymousUnion' because it has a field of a non-trivial class type}}
-#endif
- StructWithAnonymousUnion(StructWithAnonymousUnion&& other) {}
- StructWithAnonymousUnion& operator=(StructWithAnonymousUnion&& other) { return *this; }
- ~StructWithAnonymousUnion() {}
- union { Trivial field; };
- };
-#if defined(CLANG_ABI_COMPAT) && CLANG_ABI_COMPAT <= 17
- static_assert(!__is_trivially_relocatable(StructWithAnonymousUnion), "");
-#else
- static_assert(__is_trivially_relocatable(StructWithAnonymousUnion), "");
-#endif
-
- // `StructWithAnonymousStruct` is like `StructWithAnonymousUnion` but uses an
- // anonymous `struct` rather than an anonymous `union. The same expectations
- // can be applied to CLANG_ABI_COMPAT <= 17 and 18+, because the anonymous
- // `struct` does have move constructors in the test below (unlike the
- // anonymous `union` in the previous `StructWithAnonymousUnion` test).
- struct [[clang::trivial_abi]] StructWithAnonymousStruct {
- StructWithAnonymousStruct(StructWithAnonymousStruct&& other) {}
- StructWithAnonymousStruct& operator=(StructWithAnonymousStruct&& other) { return *this; }
- ~StructWithAnonymousStruct() {}
- struct { Trivial field; };
- };
- static_assert(__is_trivially_relocatable(StructWithAnonymousStruct), "");
-
- // `TrivialAbiAttributeAppliedToAnonymousUnion` is like
- // `StructWithAnonymousUnion` but with `[[clang::trivial_abi]]` also applied
- // to the anonymous union.
- //
- // The example below shows that it is still *not* okay to explicitly apply
- // `[[clang::trivial_abi]]` to anonymous unions. Handling this would require
- // relaxing the `HasNonDeletedCopyOrMoveConstructor` check when
- // `isAnonymousStructOrUnion` in `checkIllFormedTrivialABIStruct` but when
- // that check runs `setAnonymousStructOrUnion` hasn't been called yet (i.e. at
- // this point it's not possible to rely on `RD->isAnonymousStructOrUnion()`).
- struct [[clang::trivial_abi]] TrivialAbiAttributeAppliedToAnonymousUnion {
-#if defined(CLANG_ABI_COMPAT) && CLANG_ABI_COMPAT <= 17
- // expected-warning at -2 {{'trivial_abi' cannot be applied to 'TrivialAbiAttributeAppliedToAnonymousUnion'}}
- // expected-note at -3 {{trivial_abi' is disallowed on 'TrivialAbiAttributeAppliedToAnonymousUnion' because it has a field of a non-trivial class type}}
-#endif
- TrivialAbiAttributeAppliedToAnonymousUnion(TrivialAbiAttributeAppliedToAnonymousUnion&& other) {}
- TrivialAbiAttributeAppliedToAnonymousUnion& operator=(TrivialAbiAttributeAppliedToAnonymousUnion&& other) { return *this; }
- ~TrivialAbiAttributeAppliedToAnonymousUnion() {}
- union [[clang::trivial_abi]] { // expected-warning {{'trivial_abi' cannot be applied to '(unnamed union}} expected-note {{copy constructors and move constructors are all deleted}}
- Trivial field;
- };
- };
-#if defined(CLANG_ABI_COMPAT) && CLANG_ABI_COMPAT <= 17
- static_assert(!__is_trivially_relocatable(TrivialAbiAttributeAppliedToAnonymousUnion), "");
-#else
- static_assert(__is_trivially_relocatable(TrivialAbiAttributeAppliedToAnonymousUnion), "");
-#endif
-
- // Like `StructWithAnonymousUnion`, but the field of the anonymous union is
- // *not* trivial.
- struct [[clang::trivial_abi]] StructWithAnonymousUnionWithNonTrivialField {
- // expected-warning at -1 {{'trivial_abi' cannot be applied to 'StructWithAnonymousUnionWithNonTrivialField'}}
- // expected-note at -2 {{trivial_abi' is disallowed on 'StructWithAnonymousUnionWithNonTrivialField' because it has a field of a non-trivial class type}}
- StructWithAnonymousUnionWithNonTrivialField(StructWithAnonymousUnionWithNonTrivialField&& other) {}
- StructWithAnonymousUnionWithNonTrivialField& operator=(StructWithAnonymousUnionWithNonTrivialField&& other) { return *this; }
- ~StructWithAnonymousUnionWithNonTrivialField() {}
- union {
- Nontrivial field;
- };
- };
- static_assert(!__is_trivially_relocatable(StructWithAnonymousUnionWithNonTrivialField), "");
-
-} // namespace anonymousStructsAndUnions
-
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