[clang] 0fe88f9 - [PS4/PS5] Don't inherit base class alignment

[Paul Robinson via cfe-commits]

Author: Paul Robinson
Date: 2022-06-10T13:15:17-07:00
New Revision: 0fe88f9679ff6df5a7cce7e89038602c35a5e272

URL: https://github.com/llvm/llvm-project/commit/0fe88f9679ff6df5a7cce7e89038602c35a5e272
DIFF: https://github.com/llvm/llvm-project/commit/0fe88f9679ff6df5a7cce7e89038602c35a5e272.diff

LOG: [PS4/PS5] Don't inherit base class alignment

Added: 
    

Modified: 
    clang/lib/AST/RecordLayoutBuilder.cpp
    clang/test/SemaCXX/alignment-of-derived-class.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/RecordLayoutBuilder.cpp b/clang/lib/AST/RecordLayoutBuilder.cpp
index 6e775baed147f..6f3ede2ce42a7 100644
--- a/clang/lib/AST/RecordLayoutBuilder.cpp
+++ b/clang/lib/AST/RecordLayoutBuilder.cpp
@@ -1261,7 +1261,9 @@ ItaniumRecordLayoutBuilder::LayoutBase(const BaseSubobjectInfo *Base) {
       (!HasExternalLayout || Offset == CharUnits::Zero()) &&
       EmptySubobjects->CanPlaceBaseAtOffset(Base, CharUnits::Zero())) {
     setSize(std::max(getSize(), Layout.getSize()));
-    UpdateAlignment(BaseAlign, UnpackedAlignTo, PreferredBaseAlign);
+    // On PS4/PS5, don't update the alignment, to preserve compatibility.
+    if (!Context.getTargetInfo().getTriple().isPS())
+      UpdateAlignment(BaseAlign, UnpackedAlignTo, PreferredBaseAlign);
 
     return CharUnits::Zero();
   }

diff  --git a/clang/test/SemaCXX/alignment-of-derived-class.cpp b/clang/test/SemaCXX/alignment-of-derived-class.cpp
index 28c1fa9144b78..ab28bc0a235f1 100644
--- a/clang/test/SemaCXX/alignment-of-derived-class.cpp
+++ b/clang/test/SemaCXX/alignment-of-derived-class.cpp
@@ -2,7 +2,7 @@
 // expected-no-diagnostics
 
 // Test that the alignment of a empty direct base class is correctly
-// inherited by the derived class.
+// inherited by the derived class, and correctly not inherited on PS4/PS5.
 
 struct A {
 } __attribute__ ((aligned(16)));
@@ -12,22 +12,38 @@ static_assert(__alignof(A) == 16, "A should be aligned to 16 bytes");
 struct B1 : public A {
 };
 
+#if defined(__SCE__)
+static_assert(__alignof(B1) == 1, "B1 should be aligned to 1 byte");
+#else
 static_assert(__alignof(B1) == 16, "B1 should be aligned to 16 bytes");
+#endif
 
 struct B2 : public A {
 } __attribute__ ((aligned(2)));
 
+#if defined(__SCE__)
+static_assert(__alignof(B2) == 2, "B2 should be aligned to 2 bytes");
+#else
 static_assert(__alignof(B2) == 16, "B2 should be aligned to 16 bytes");
+#endif
 
 struct B3 : public A {
 } __attribute__ ((aligned(4)));
 
+#if defined(__SCE__)
+static_assert(__alignof(B3) == 4, "B3 should be aligned to 4 bytes");
+#else
 static_assert(__alignof(B3) == 16, "B3 should be aligned to 16 bytes");
+#endif
 
 struct B4 : public A {
 } __attribute__ ((aligned(8)));
 
+#if defined(__SCE__)
+static_assert(__alignof(B4) == 8, "B4 should be aligned to 8 bytes");
+#else
 static_assert(__alignof(B4) == 16, "B4 should be aligned to 16 bytes");
+#endif
 
 struct B5 : public A {
 } __attribute__ ((aligned(16)));