[clang] 0f5099c - Opting out of Clang 16 ABI Changes for AIX and z/OS
Hubert Tong via cfe-commits
cfe-commits at lists.llvm.org
Mon Jan 23 22:14:10 PST 2023
Author: Nicole Rabjohn
Date: 2023-01-24T01:14:05-05:00
New Revision: 0f5099cd94226479fe30b4fc2d6a9743ebe2b12b
URL: https://github.com/llvm/llvm-project/commit/0f5099cd94226479fe30b4fc2d6a9743ebe2b12b
DIFF: https://github.com/llvm/llvm-project/commit/0f5099cd94226479fe30b4fc2d6a9743ebe2b12b.diff
LOG: Opting out of Clang 16 ABI Changes for AIX and z/OS
There is already a GCC compatibility gap on AIX, & GCC compatibility is
not a concern on z/OS. GCC compatibility is not sufficient motivation
for breaking ABI on AIX and z/OS. This opts out of changes introduced in
https://reviews.llvm.org/D119051. For AIX only, also opt out of D117616
(which z/OS had picked up at the time ABI stabilization occurred).
Differential Revision: https://reviews.llvm.org/D142358
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/lib/AST/RecordLayoutBuilder.cpp
clang/lib/Basic/Targets/OSTargets.h
clang/test/SemaCXX/class-layout.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index f7a68a64df325..7d356e53547bf 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -838,13 +838,14 @@ ABI Changes in Clang
- GCC doesn't pack non-POD members in packed structs unless the packed
attribute is also specified on the member. Clang historically did perform
- such packing. Clang now matches the gcc behavior (except on Darwin and PS4).
+ such packing. Clang now matches the gcc behavior
+ (except on Darwin, PS4 and AIX).
You can switch back to the old ABI behavior with the flag:
``-fclang-abi-compat=15.0``.
- GCC allows POD types to have defaulted special members. Clang historically
classified such types as non-POD (for the purposes of Itanium ABI). Clang now
- matches the gcc behavior (except on Darwin and PS4). You can switch back to
- the old ABI behavior with the flag: ``-fclang-abi-compat=15.0``.
+ matches the gcc behavior (except on Darwin, PS4, AIX and z/OS). You can switch
+ back to the old ABI behavior with the flag: ``-fclang-abi-compat=15.0``.
OpenMP Support in Clang
-----------------------
diff --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
index da27f73ea94e2..2f546398338c4 100644
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -1968,7 +1968,8 @@ void ItaniumRecordLayoutBuilder::LayoutField(const FieldDecl *D,
FieldClass->hasAttr<PackedAttr>() ||
Context.getLangOpts().getClangABICompat() <=
LangOptions::ClangABI::Ver15 ||
- Target.isPS() || Target.isOSDarwin())) ||
+ Target.isPS() || Target.isOSDarwin() ||
+ Target.isOSAIX())) ||
D->hasAttr<PackedAttr>();
// When used as part of a typedef, or together with a 'packed' attribute, the
diff --git a/clang/lib/Basic/Targets/OSTargets.h b/clang/lib/Basic/Targets/OSTargets.h
index a1b1f917931b2..fd372cb12df2b 100644
--- a/clang/lib/Basic/Targets/OSTargets.h
+++ b/clang/lib/Basic/Targets/OSTargets.h
@@ -773,6 +773,10 @@ class AIXTargetInfo : public OSTargetInfo<Target> {
}
bool defaultsToAIXPowerAlignment() const override { return true; }
+
+ bool areDefaultedSMFStillPOD(const LangOptions &) const override {
+ return false;
+ }
};
// z/OS target
@@ -831,6 +835,10 @@ class LLVM_LIBRARY_VISIBILITY ZOSTargetInfo : public OSTargetInfo<Target> {
this->UseLeadingZeroLengthBitfield = false;
this->ZeroLengthBitfieldBoundary = 32;
}
+
+ bool areDefaultedSMFStillPOD(const LangOptions &) const override {
+ return false;
+ }
};
void addWindowsDefines(const llvm::Triple &Triple, const LangOptions &Opts,
diff --git a/clang/test/SemaCXX/class-layout.cpp b/clang/test/SemaCXX/class-layout.cpp
index 3d710dc5a5200..3ccd0ad25d7e7 100644
--- a/clang/test/SemaCXX/class-layout.cpp
+++ b/clang/test/SemaCXX/class-layout.cpp
@@ -7,8 +7,17 @@
// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=14 -DCLANG_ABI_COMPAT=14
// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=16 -DCLANG_ABI_COMPAT=16
+// RUN: %clang_cc1 -triple powerpc-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple powerpc-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple powerpc64-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple powerpc64-ibm-aix7.3.0.0 %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
+// RUN: %clang_cc1 -triple s390x-none-zos %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base
+// RUN: %clang_cc1 -triple s390x-none-zos %s -fsyntax-only -verify -std=c++11 -Wno-inaccessible-base -fclang-abi-compat=15 -DCLANG_ABI_COMPAT=15
+
// expected-no-diagnostics
+#if !defined(__MVS__) && !defined(_AIX)
+
#define SA(n, p) int a##n[(p) ? 1 : -1]
struct A {
@@ -611,6 +620,8 @@ namespace PR37275 {
#pragma pack(pop)
}
+#endif // !defined(__MVS__) && !defined(__AIX__)
+
namespace non_pod {
struct t1 {
protected:
@@ -670,11 +681,15 @@ struct t1 {
struct t2 {
t1 v1;
} __attribute__((packed));
+#if (defined(CLANG_ABI_COMPAT) && CLANG_ABI_COMPAT <= 15) || !defined(__MVS__)
_Static_assert(_Alignof(t2) == 1, "");
+#else
+_Static_assert(_Alignof(t2) == 4, "");
+#endif
struct t3 : t1 {
char c;
};
-#if defined(CLANG_ABI_COMPAT) && CLANG_ABI_COMPAT <= 15
+#if (defined(CLANG_ABI_COMPAT) && CLANG_ABI_COMPAT <= 15) || defined(__MVS__)
_Static_assert(sizeof(t3) == 8, "");
#else
_Static_assert(sizeof(t3) == 12, "");
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