Don't apply NRVO to over-aligned variables. The caller only
guarantees alignment up to the ABI alignment of the return type.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144364 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index a34d838..a424a8a 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -18,6 +18,7 @@
#include "clang/Sema/Lookup.h"
#include "clang/AST/APValue.h"
#include "clang/AST/ASTContext.h"
+#include "clang/AST/CharUnits.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
@@ -1650,14 +1651,29 @@
if (!VD)
return 0;
- if (VD->hasLocalStorage() && !VD->isExceptionVariable() &&
- !VD->getType()->isReferenceType() && !VD->hasAttr<BlocksAttr>() &&
- !VD->getType().isVolatileQualified() &&
- ((VD->getKind() == Decl::Var) ||
- (AllowFunctionParameter && VD->getKind() == Decl::ParmVar)))
- return VD;
+ // ...object (other than a function or catch-clause parameter)...
+ if (VD->getKind() != Decl::Var &&
+ !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar))
+ return 0;
+ if (VD->isExceptionVariable()) return 0;
- return 0;
+ // ...automatic...
+ if (!VD->hasLocalStorage()) return 0;
+
+ // ...non-volatile...
+ if (VD->getType().isVolatileQualified()) return 0;
+ if (VD->getType()->isReferenceType()) return 0;
+
+ // __block variables can't be allocated in a way that permits NRVO.
+ if (VD->hasAttr<BlocksAttr>()) return 0;
+
+ // Variables with higher required alignment than their type's ABI
+ // alignment cannot use NRVO.
+ if (VD->hasAttr<AlignedAttr>() &&
+ Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType()))
+ return 0;
+
+ return VD;
}
/// \brief Perform the initialization of a potentially-movable value, which
diff --git a/test/CodeGenCXX/nrvo.cpp b/test/CodeGenCXX/nrvo.cpp
index 57bf27a..4a117f1 100644
--- a/test/CodeGenCXX/nrvo.cpp
+++ b/test/CodeGenCXX/nrvo.cpp
@@ -147,3 +147,15 @@
}
}
#endif
+
+// rdar://problem/10430868
+// CHECK: define void @_Z5test6v
+X test6() {
+ X a __attribute__((aligned(8)));
+ return a;
+ // CHECK: [[A:%.*]] = alloca [[X:%.*]], align 8
+ // CHECK-NEXT: call void @_ZN1XC1Ev([[X]]* [[A]])
+ // CHECK-NEXT: call void @_ZN1XC1ERKS_([[X]]* {{%.*}}, [[X]]* [[A]])
+ // CHECK-NEXT: call void @_ZN1XD1Ev([[X]]* [[A]])
+ // CHECK-NEXT: ret void
+}