[CodeGen] Emit destructor calls to destruct compound literals

[ahatanak]

Summary

This patch fixes a bug in IRGen where it wasn't calling the destructors to destruct compound literals.

I've split out the changes needed to emit destructor calls for non-trivial C structs returned by function calls and loaded from volatile objects (https://reviews.llvm.org/D66094).

rdar://problem/51867864

[ahatanak]

lib/CodeGen/CGExprAgg.cpp

248 ↗

(On Diff #208863)

This change wasn't needed to fix the bugs, but I think isExternallyDestructed instead of isIgnored should be called to determine whether the returned value requires destruction.

[rjmccall]

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

Unfortunately, the lifetime of compound literals in C is not this simple; they're like blocks in that they're destroyed at the end of the enclosing scope rather than at the end of the current statement. (The cleanup here will be popped at the end of the full-expression if we've entered an ExprWithCleanups.) And the l-value case is exactly the case where this matters.

I think you need to do something like what we do with blocks, where we record all the blocks in the full-expression on the ExprWithCleanups so that we can push an inactive cleanup for them and then activate it when we emit the block.

lib/CodeGen/CGExprAgg.cpp

248 ↗

(On Diff #208863)

Agreed.

668 ↗

(On Diff #208863)

The cleanup shouldn't be pushed until after you've finished evaluating the initializer.

[ahatanak]

• Emit member access, compound literal, and call expressions as subexpressions of ExprWithCleanups if the expressions are of C struct types that require non-trivial destruction. This fixes the bug in IRGen where it was destructing the function return at the end of the enclosing scope rather than at the end of the full expression (see the changes made in test/CodeGenObjC/arc.m).
• Add compound literal expressions with automatic storage duration to the list of cleanup objects of ExprWithCleanups if the expressions have C struct types requiring non-trivial destruction. This enables IRGen to destruct the compound literals at the end of their enclosing scopes.

[rjmccall]

include/clang/AST/ExprCXX.h

3220 ↗

(On Diff #212942)

Might be worth spelling out and block-scoped compound literals here.

include/clang/Basic/DiagnosticSemaKinds.td

5171 ↗

(On Diff #212942)

Ah, good catch.

include/clang/Sema/Sema.h

587 ↗

(On Diff #212942)

I think the second sentence in this comment is no longer useful; you can just strike it.

lib/CodeGen/CGBlocks.cpp

863 ↗

(On Diff #212942)

This comment is no longer accurate. If you want to move the function, please do so in a separate commit, though.

lib/CodeGen/CGCleanup.cpp

1283 ↗

(On Diff #212942)

Please include in the comment here that this doesn't apply in C++, where the compound literal has temporary lifetime.

Can we clarify that we're talking about block-scope literals in all the new method names?

lib/CodeGen/CGDecl.cpp

555 ↗

(On Diff #212942)

It'd be nice to not shadow the enclosing variable.

lib/CodeGen/CGExpr.cpp

4647 ↗

(On Diff #212942)

Does EmitCallExpr not enter a cleanup when it returns an aggregate that's not into an externally-destructed slot? That seems wrong and dangerous.

4100 ↗

(On Diff #208863)

Can we make the check here something like (1) this is a block-scope compound literal and (2) it has a non-trivially-destructed type (of any kind)? That way we're not conflating two potentially unrelated elements, the lifetime of the object and the kinds of types that can be constructed by the literal.

Oh, actually, there's a concrete reason to do this: C99 compound literals are not required to have struct type; they can have any object type, including arrays but also scalars. So we could, even without non-trivial C structs, have a block-scope compound of type __strong id[]; I guess we've always just gotten this wrong. Please add tests for this case. :)

[ahatanak]

lib/CodeGen/CGExpr.cpp

4647 ↗

(On Diff #212942)

I'm going to split this patch into two parts, one for compound literals and the other for everything else. The patch is getting too large and I also found another bug: a cleanup isn't pushed for ObjC message send.

[martong]

test/Import/objc-arc/Inputs/cleanup-objects.m

6 ↗

(On Diff #212942)

Perhaps then this patch depends on another patch which implements the import of a BlockExpr?
Or maybe the branch if (auto *BD = From.dyn_cast<BlockDecl *>()) should be left out from the ASTImporter code, and this way BlockExpr and BlockDecl would be implemented later in another patch.

[ahatanak]

Address review comments:

• Destruct compound literals of ObjC array types too.
• Use pushLifetimeExtendedDestroy to extend the lifetime of compound literals to the end of the surrounding block. This simplifies the changes made in IRGen, but I was wondering whether we should do what we do to extend lifetime of block captures instead.

[ahatanak]

test/Import/objc-arc/Inputs/cleanup-objects.m

6 ↗

(On Diff #212942)

Yes, I removed it from ASTImporter::Import and left a FIXME comment there.

[ahatanak]

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

There is a check E->isFileScope() above this. Is that sufficient to check for block-scoped compound literals?

[martong]

clang/lib/AST/ASTImporter.cpp

7918

I think

return make_error<ImportError(ImportError::UnsupportedConstruct);

would be more appropriate here as this expresses that we do not support every aspect yet.

On the other hand a nullptr could be dereferenced later and thus could cause an unwanted crash.

[ahatanak]

Return make_error<ImportError> instead of a nullptr.

[rjmccall]

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

That plus the C/C++ difference; compound literals in C++ are just temporaries.

[rjmccall]

This patch looks good except for that C/C++ semantic difference. A compound literal temporary can be lifetime-extended in C++, but only in the standard way of binding a reference to it.

[ahatanak]

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

I haven't been able to come up with a piece of C++ code that executes EmitCompoundLiteralLValue. The following code gets rejected because you can't take the address of a temporary object in C++:

StrongSmall *p = &(StrongSmall){ 1, 0 };

If a bind a reference to it, AggExprEmitter::VisitCompoundLiteralExpr is called.

[rjmccall]

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

That makes sense; they're not gl-values in C++. It would be reasonable to assert that. But the C++ point does apply elsewhere.

[ahatanak]

Don't try to push a cleanup in C++.

[ahatanak]

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

It turns out this function is called in C++ when the compound literal is a vector type, so I've just added a check for C++ instead of an assert.

[rjmccall]

clang/lib/CodeGen/CGBlocks.cpp

869

I wonder if we could just switch blocks to the same thing.

clang/lib/Sema/SemaExpr.cpp

6271

This should all be conditional on C++ (but you should leave a comment explaining why).

clang/lib/Serialization/ASTWriterStmt.cpp

1729

Will this just serialize a second copy of the compound literal expression?

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

Really? Is the expression actually an l-value in this case somehow?

[martong]

Looks good from the ASTImporter's point of view. I don't have the competence to review the rest, so I am resigning.

[ahatanak]

Address review comments

[ahatanak]

clang/lib/CodeGen/CGBlocks.cpp

869

I think we can, but I haven't tried. We can fix it in a separate patch.

clang/lib/CodeGen/CGExprAgg.cpp

664

I fixed the way IsExternallyDestructed is used based on the comment in the other review.

clang/lib/Serialization/ASTWriterStmt.cpp

1729

This should emit a serialization::STMT_REF_PTR record, which is a reference to the previously serialized compound literal (see ASTWriter::WriteSubStmt).

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

I see this function being called when ScalarExprEmitter::VisitCompoundLiteralExpr calls EmitLoadOfLValue.

[rjmccall]

Minor comments; otherwise LGTM.

clang/lib/Sema/SemaExpr.cpp

6256

Probably add "in C; in C++, they're just temporaries".

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

Okay. As a general rule, nothing should be calling EmitLValue on an expression that isn't actually an l-value. It's a little more reasonable here because it's more like a helper routine. If this is the cleanest way to handle this in C++, it's okay, but please leave a comment explaining that here.

[ahatanak]

lib/CodeGen/CGExpr.cpp

4100 ↗

(On Diff #208863)

I added a comment in ScalarExprEmitter::VisitCompoundLiteralExpr.

clang/include/clang/AST/ASTImporter.h

 
 #include "clang/AST/DeclBase.h"
 #include "clang/AST/DeclarationName.h"
+#include "clang/AST/ExprCXX.h"
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/TemplateName.h"
 #include "clang/AST/Type.h"

       return ToOrErr.takeError();
     }
 
+    /// Import cleanup objects owned by ExprWithCleanup.
+    llvm::Expected<ExprWithCleanups::CleanupObject>
+    Import(ExprWithCleanups::CleanupObject From);
+
     /// Import the given type from the "from" context into the "to"
     /// context. A null type is imported as a null type (no error).
     ///

clang/include/clang/AST/ExprCXX.h

 /// literal is the extent of the enclosing scope.
 class ExprWithCleanups final
     : public FullExpr,
-      private llvm::TrailingObjects<ExprWithCleanups, BlockDecl *> {
+      private llvm::TrailingObjects<
+          ExprWithCleanups,
+          llvm::PointerUnion<BlockDecl *, CompoundLiteralExpr *>> {
 public:
   /// The type of objects that are kept in the cleanup.
-  /// It's useful to remember the set of blocks;  we could also
-  /// remember the set of temporaries, but there's currently
-  /// no need.
-  using CleanupObject = BlockDecl *;
+  /// It's useful to remember the set of blocks and block-scoped compound
+  /// literals; we could also remember the set of temporaries, but there's
+  /// currently no need.
+  using CleanupObject = llvm::PointerUnion<BlockDecl *, CompoundLiteralExpr *>;
 
 private:
   friend class ASTStmtReader;

clang/include/clang/AST/TextNodeDumper.h

   void dumpBareDeclRef(const Decl *D);
   void dumpName(const NamedDecl *ND);
   void dumpAccessSpecifier(AccessSpecifier AS);
+  void dumpCleanupObject(const ExprWithCleanups::CleanupObject &C);
 
   void dumpDeclRef(const Decl *D, StringRef Label = {});
 

clang/include/clang/Basic/DiagnosticSemaKinds.td

 def note_enters_block_captures_non_trivial_c_struct : Note<
   "jump enters lifetime of block which captures a C struct that is non-trivial "
   "to destroy">;
+def note_enters_compound_literal_scope : Note<
+  "jump enters lifetime of a compound literal that is non-trivial to destruct">;
 
 def note_exits_cleanup : Note<
   "jump exits scope of variable with __attribute__((cleanup))">;

 def note_exits_block_captures_non_trivial_c_struct : Note<
   "jump exits lifetime of block which captures a C struct that is non-trivial "
   "to destroy">;
+def note_exits_compound_literal_scope : Note<
+  "jump exits lifetime of a compound literal that is non-trivial to destruct">;
 
 def err_func_returning_qualified_void : ExtWarn<
   "function cannot return qualified void type %0">,

clang/include/clang/Sema/Sema.h

   CleanupInfo Cleanup;
 
   /// ExprCleanupObjects - This is the stack of objects requiring
-  /// cleanup that are created by the current full expression.  The
-  /// element type here is ExprWithCleanups::Object.
-  SmallVector<BlockDecl*, 8> ExprCleanupObjects;
+  /// cleanup that are created by the current full expression.
+  SmallVector<ExprWithCleanups::CleanupObject, 8> ExprCleanupObjects;
 
   /// Store a set of either DeclRefExprs or MemberExprs that contain a reference
   /// to a variable (constant) that may or may not be odr-used in this Expr, and

clang/include/clang/Serialization/ASTBitCodes.h

       CTOR_INITIALIZER_INDIRECT_MEMBER
     };
 
+    /// Kinds of cleanup objects owned by ExprWithCleanups.
+    enum CleanupObjectKind { COK_Block, COK_CompoundLiteral };
+
     /// Describes the redeclarations of a declaration.
     struct LocalRedeclarationsInfo {
       // The ID of the first declaration

clang/lib/AST/ASTImporter.cpp

   MapImported(FromD, ToD);
 }
 
+llvm::Expected<ExprWithCleanups::CleanupObject>
+ASTImporter::Import(ExprWithCleanups::CleanupObject From) {
+  if (auto *CLE = From.dyn_cast<CompoundLiteralExpr *>()) {
+    if (Expected<Expr *> R = Import(CLE))
+      return ExprWithCleanups::CleanupObject(cast<CompoundLiteralExpr>(*R));
+  }
+
+  // FIXME: Handle BlockDecl when we implement importing BlockExpr in
+  //        ASTNodeImporter.
+  return make_error<ImportError>(ImportError::UnsupportedConstruct);
+}
+
 Expected<QualType> ASTImporter::Import(QualType FromT) {
   if (FromT.isNull())
     return QualType{};

clang/lib/AST/JSONNodeDumper.cpp

   if (EWC->getNumObjects()) {
     JOS.attributeArray("cleanups", [this, EWC] {
       for (const ExprWithCleanups::CleanupObject &CO : EWC->getObjects())
-        JOS.value(createBareDeclRef(CO));
+        if (auto *BD = CO.dyn_cast<BlockDecl *>()) {
+          JOS.value(createBareDeclRef(BD));
+        } else if (auto *CLE = CO.dyn_cast<CompoundLiteralExpr *>()) {
+          llvm::json::Object Obj;
+          Obj["id"] = createPointerRepresentation(CLE);
+          Obj["kind"] = CLE->getStmtClassName();
+          JOS.value(std::move(Obj));
+        } else {
+          llvm_unreachable("unexpected cleanup object type");
+        }
     });
   }
 }

clang/lib/AST/TextNodeDumper.cpp

   }
 }
 
+void TextNodeDumper::dumpCleanupObject(
+    const ExprWithCleanups::CleanupObject &C) {
+  if (auto *BD = C.dyn_cast<BlockDecl *>())
+    dumpDeclRef(BD, "cleanup");
+  else if (auto *CLE = C.dyn_cast<CompoundLiteralExpr *>())
+    AddChild([=] {
+      OS << "cleanup ";
+      {
+        ColorScope Color(OS, ShowColors, StmtColor);
+        OS << CLE->getStmtClassName();
+      }
+      dumpPointer(CLE);
+    });
+  else
+    llvm_unreachable("unexpected cleanup type");
+}
+
 void TextNodeDumper::dumpDeclRef(const Decl *D, StringRef Label) {
   if (!D)
     return;

 
 void TextNodeDumper::VisitExprWithCleanups(const ExprWithCleanups *Node) {
   for (unsigned i = 0, e = Node->getNumObjects(); i != e; ++i)
-    dumpDeclRef(Node->getObject(i), "cleanup");
+    dumpCleanupObject(Node->getObject(i));
 }
 
 void TextNodeDumper::VisitSizeOfPackExpr(const SizeOfPackExpr *Node) {

clang/lib/CodeGen/CGBlocks.cpp

 }
 
 /// Enter a full-expression with a non-trivial number of objects to
-/// clean up.  This is in this file because, at the moment, the only
-/// kind of cleanup object is a BlockDecl*.
+/// clean up.
 void CodeGenFunction::enterNonTrivialFullExpression(const FullExpr *E) {
   if (const auto EWC = dyn_cast<ExprWithCleanups>(E)) {
     assert(EWC->getNumObjects() != 0);
     for (const ExprWithCleanups::CleanupObject &C : EWC->getObjects())
-      enterBlockScope(*this, C);
+      if (auto *BD = C.dyn_cast<BlockDecl *>())
+        enterBlockScope(*this, BD);
   }
 }
 

clang/lib/CodeGen/CGExpr.cpp

   EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
                    /*Init*/ true);
 
+  if (QualType::DestructionKind DtorKind = E->getType().isDestructedType())
+    pushLifetimeExtendedDestroy(getCleanupKind(DtorKind), DeclPtr, E->getType(),
+                                getDestroyer(DtorKind), DtorKind & EHCleanup);
+
   return Result;
 }
 

clang/lib/CodeGen/CGExprAgg.cpp

   }
 
   AggValueSlot Slot = EnsureSlot(E->getType());
+
   CGF.EmitAggExpr(E->getInitializer(), Slot);
+
+  if (!Slot.isExternallyDestructed())
+    if (QualType::DestructionKind DtorKind = E->getType().isDestructedType()) {
+      CGF.pushLifetimeExtendedDestroy(
+          CGF.getCleanupKind(DtorKind), Slot.getAddress(), E->getType(),
+          CGF.getDestroyer(DtorKind), DtorKind & EHCleanup);
+      Slot.setExternallyDestructed();
+    }
 }
 
 /// Attempt to look through various unimportant expressions to find a

clang/lib/Sema/JumpDiagnostics.cpp

   void BuildScopeInformation(Decl *D, unsigned &ParentScope);
   void BuildScopeInformation(VarDecl *D, const BlockDecl *BDecl,
                              unsigned &ParentScope);
+  void BuildScopeInformation(CompoundLiteralExpr *CLE, unsigned &ParentScope);
   void BuildScopeInformation(Stmt *S, unsigned &origParentScope);
 
   void VerifyJumps();

   }
 }
 
+/// Build scope information for compound literals of C struct types that are
+/// non-trivial to destruct.
+void JumpScopeChecker::BuildScopeInformation(CompoundLiteralExpr *CLE,
+                                             unsigned &ParentScope) {
+  unsigned InDiag = diag::note_enters_compound_literal_scope;
+  unsigned OutDiag = diag::note_exits_compound_literal_scope;
+  Scopes.push_back(GotoScope(ParentScope, InDiag, OutDiag, CLE->getExprLoc()));
+  ParentScope = Scopes.size() - 1;
+}
+
 /// BuildScopeInformation - The statements from CI to CE are known to form a
 /// coherent VLA scope with a specified parent node.  Walk through the
 /// statements, adding any labels or gotos to LabelAndGotoScopes and recursively

     // implementable but a lot of work which we haven't felt up to doing.
     ExprWithCleanups *EWC = cast<ExprWithCleanups>(S);
     for (unsigned i = 0, e = EWC->getNumObjects(); i != e; ++i) {
-      const BlockDecl *BDecl = EWC->getObject(i);
+      if (auto *BDecl = EWC->getObject(i).dyn_cast<BlockDecl *>())
         for (const auto &CI : BDecl->captures()) {
           VarDecl *variable = CI.getVariable();
           BuildScopeInformation(variable, BDecl, origParentScope);
         }
+      else if (auto *CLE = EWC->getObject(i).dyn_cast<CompoundLiteralExpr *>())
+        BuildScopeInformation(CLE, origParentScope);
+      else
+        llvm_unreachable("unexpected cleanup object type");
     }
     break;
   }

clang/lib/Sema/SemaExpr.cpp

     checkNonTrivialCUnionInInitializer(E->getInitializer(),
                                        E->getInitializer()->getExprLoc());
 
+  if (!isFileScope && literalType.isDestructedType()) {
+    Cleanup.setExprNeedsCleanups(true);
+    ExprCleanupObjects.push_back(E);
+    getCurFunction()->setHasBranchProtectedScope();
+  }
+
   return MaybeBindToTemporary(E);
 }
 

clang/lib/Serialization/ASTReaderStmt.cpp

 
   unsigned NumObjects = Record.readInt();
   assert(NumObjects == E->getNumObjects());
-  for (unsigned i = 0; i != NumObjects; ++i)
-    E->getTrailingObjects<BlockDecl *>()[i] =
-        readDeclAs<BlockDecl>();
+  for (unsigned i = 0; i != NumObjects; ++i) {
+    unsigned CleanupKind = Record.readInt();
+    ExprWithCleanups::CleanupObject Obj;
+    if (CleanupKind == COK_Block)
+      Obj = readDeclAs<BlockDecl>();
+    else if (CleanupKind == COK_CompoundLiteral)
+      Obj = cast<CompoundLiteralExpr>(Record.readSubExpr());
+    else
+      llvm_unreachable("unexpected cleanup object type");
+    E->getTrailingObjects<ExprWithCleanups::CleanupObject>()[i] = Obj;
+  }
 
   E->ExprWithCleanupsBits.CleanupsHaveSideEffects = Record.readInt();
   E->SubExpr = Record.readSubExpr();

clang/lib/Serialization/ASTWriterStmt.cpp

 void ASTStmtWriter::VisitExprWithCleanups(ExprWithCleanups *E) {
   VisitExpr(E);
   Record.push_back(E->getNumObjects());
-  for (unsigned i = 0, e = E->getNumObjects(); i != e; ++i)
-    Record.AddDeclRef(E->getObject(i));
+  for (auto &Obj : E->getObjects()) {
+    if (auto *BD = Obj.dyn_cast<BlockDecl *>()) {
+      Record.push_back(serialization::COK_Block);
+      Record.AddDeclRef(BD);
+    } else if (auto *CLE = Obj.dyn_cast<CompoundLiteralExpr *>()) {
+      Record.push_back(serialization::COK_CompoundLiteral);
+      Record.AddStmt(CLE);
+    }
+  }
 
   Record.push_back(E->cleanupsHaveSideEffects());
   Record.AddStmt(E->getSubExpr());

clang/test/AST/ast-dump-objc-arc-json.m

+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -x objective-c -fobjc-arc -ast-dump=json -ast-dump-filter Test %s | FileCheck %s
+
+typedef struct {
+  id f;
+} S;
+
+id TestCompoundLiteral(id a) {
+  return ((S){ .f = a }).f;
+}
+
+// CHECK:  "kind": "ExprWithCleanups",
+// CHECK-NEXT:  "range": {
+// CHECK-NEXT:   "begin": {
+// CHECK-NEXT:    "offset": 202,
+// CHECK-NEXT:    "col": 10,
+// CHECK-NEXT:    "tokLen": 1
+// CHECK-NEXT:   },
+// CHECK-NEXT:   "end": {
+// CHECK-NEXT:    "offset": 218,
+// CHECK-NEXT:    "col": 26,
+// CHECK-NEXT:    "tokLen": 1
+// CHECK-NEXT:   }
+// CHECK-NEXT:  },
+// CHECK-NEXT:  "type": {
+// CHECK-NEXT:   "desugaredQualType": "id",
+// CHECK-NEXT:   "qualType": "id",
+// CHECK-NEXT:   "typeAliasDeclId": "0x{{.*}}"
+// CHECK-NEXT:  },
+// CHECK-NEXT:  "valueCategory": "rvalue",
+// CHECK-NEXT:  "cleanupsHaveSideEffects": true,
+// CHECK-NEXT:  "cleanups": [
+// CHECK-NEXT:   {
+// CHECK-NEXT:    "id": "0x{{.*}}",
+// CHECK-NEXT:    "kind": "CompoundLiteralExpr"
+// CHECK-NEXT:   }
+// CHECK-NEXT:  ],

clang/test/AST/ast-dump-stmt.m

-// RUN: %clang_cc1 -Wno-unused -fblocks -fobjc-exceptions -ast-dump -ast-dump-filter Test %s | FileCheck -strict-whitespace %s
+// RUN: %clang_cc1 -Wno-unused -fobjc-arc -fblocks -fobjc-exceptions -ast-dump -ast-dump-filter Test %s | FileCheck -strict-whitespace %s
 
 void TestBlockExpr(int x) {
   ^{ x; };

 // CHECK-NEXT:   ObjCAtCatchStmt{{.*}} catch all
 // CHECK-NEXT:     CompoundStmt
 // CHECK-NEXT:   ObjCAtFinallyStmt
+
+typedef struct {
+  id f;
+} S;
+
+id TestCompoundLiteral(id a) {
+  return ((S){ .f = a }).f;
+}
+
+// CHECK:     FunctionDecl{{.*}}TestCompoundLiteral
+// CHECK:       ExprWithCleanups
+// CHECK-NEXT:    cleanup CompoundLiteralExpr
+// CHECK:           CompoundLiteralExpr{{.*}}'S':'S' lvalue

clang/test/CodeGenObjC/arc-ternary-op.m

 // RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -O2 -disable-llvm-passes -o - %s | FileCheck %s
 
+id g0, g1;
+
 void test0(_Bool cond) {
   id test0_helper(void) __attribute__((ns_returns_retained));
 

   // CHECK:      call void @llvm.objc.release(i8* [[RESULT]])
 }
 
+void test3(int cond) {
+  __strong id *p = cond ? (__strong id[]){g0, g1} : (__strong id[]){g1, g0};
+  test2(cond);
+
+  // CHECK: define void @test3(
+  // CHECK: %[[P:.*]] = alloca i8**, align 8
+  // CHECK: %[[_COMPOUNDLITERAL:.*]] = alloca [2 x i8*], align 8
+  // CHECK: %[[CLEANUP_COND:.*]] = alloca i1, align 1
+  // CHECK: %[[_COMPOUNDLITERAL1:.*]] = alloca [2 x i8*], align 8
+  // CHECK: %[[CLEANUP_COND4:.*]] = alloca i1, align 1
+
+  // CHECK: %[[ARRAYINIT_BEGIN:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[_COMPOUNDLITERAL]], i64 0, i64 0
+  // CHECK: %[[V2:.*]] = load i8*, i8** @g0, align 8
+  // CHECK: %[[V3:.*]] = call i8* @llvm.objc.retain(i8* %[[V2]])
+  // CHECK: store i8* %[[V3]], i8** %[[ARRAYINIT_BEGIN]], align 8
+  // CHECK: %[[ARRAYINIT_ELEMENT:.*]] = getelementptr inbounds i8*, i8** %[[ARRAYINIT_BEGIN]], i64 1
+  // CHECK: %[[V4:.*]] = load i8*, i8** @g1, align 8
+  // CHECK: %[[V5:.*]] = call i8* @llvm.objc.retain(i8* %[[V4]])
+  // CHECK: store i8* %[[V5]], i8** %[[ARRAYINIT_ELEMENT]], align 8
+  // CHECK: store i1 true, i1* %[[CLEANUP_COND]], align 1
+  // CHECK: %[[ARRAYDECAY:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[_COMPOUNDLITERAL]], i64 0, i64 0
+
+  // CHECK: %[[ARRAYINIT_BEGIN2:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[_COMPOUNDLITERAL1]], i64 0, i64 0
+  // CHECK: %[[V6:.*]] = load i8*, i8** @g1, align 8
+  // CHECK: %[[V7:.*]] = call i8* @llvm.objc.retain(i8* %[[V6]])
+  // CHECK: store i8* %[[V7]], i8** %[[ARRAYINIT_BEGIN2]], align 8
+  // CHECK: %[[ARRAYINIT_ELEMENT3:.*]] = getelementptr inbounds i8*, i8** %[[ARRAYINIT_BEGIN2]], i64 1
+  // CHECK: %[[V8:.*]] = load i8*, i8** @g0, align 8
+  // CHECK: %[[V9:.*]] = call i8* @llvm.objc.retain(i8* %[[V8]])
+  // CHECK: store i8* %[[V9]], i8** %[[ARRAYINIT_ELEMENT3]], align 8
+  // CHECK: store i1 true, i1* %[[CLEANUP_COND4]], align 1
+  // CHECK: %[[ARRAYDECAY5:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[_COMPOUNDLITERAL1]], i64 0, i64 0
+
+  // CHECK: %[[COND6:.*]] = phi i8** [ %[[ARRAYDECAY]], %{{.*}} ], [ %[[ARRAYDECAY5]], %{{.*}} ]
+  // CHECK: store i8** %[[COND6]], i8*** %[[P]], align 8
+  // CHECK: call void @test2(
+
+  // CHECK: %[[ARRAY_BEGIN:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[_COMPOUNDLITERAL1]], i32 0, i32 0
+  // CHECK: %[[V11:.*]] = getelementptr inbounds i8*, i8** %[[ARRAY_BEGIN]], i64 2
+
+  // CHECK: %[[ARRAYDESTROY_ELEMENTPAST:.*]] = phi i8** [ %[[V11]], %{{.*}} ], [ %[[ARRAYDESTROY_ELEMENT:.*]], %{{.*}} ]
+  // CHECK: %[[ARRAYDESTROY_ELEMENT]] = getelementptr inbounds i8*, i8** %[[ARRAYDESTROY_ELEMENTPAST]], i64 -1
+  // CHECK: %[[V12:.*]] = load i8*, i8** %[[ARRAYDESTROY_ELEMENT]], align 8
+  // CHECK: call void @llvm.objc.release(i8* %[[V12]])
+
+  // CHECK: %[[ARRAY_BEGIN10:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[_COMPOUNDLITERAL]], i32 0, i32 0
+  // CHECK: %[[V13:.*]] = getelementptr inbounds i8*, i8** %[[ARRAY_BEGIN10]], i64 2
+
+  // CHECK: %[[ARRAYDESTROY_ELEMENTPAST12:.*]] = phi i8** [ %[[V13]], %{{.*}} ], [ %[[ARRAYDESTROY_ELEMENT13:.*]], %{{.*}} ]
+  // CHECK: %[[ARRAYDESTROY_ELEMENT13]] = getelementptr inbounds i8*, i8** %[[ARRAYDESTROY_ELEMENTPAST12]], i64 -1
+  // CHECK: %[[V14:.*]] = load i8*, i8** %[[ARRAYDESTROY_ELEMENT13]], align 8
+  // CHECK: call void @llvm.objc.release(i8* %[[V14]])
+}
+
 // CHECK: attributes [[NUW]] = { nounwind }

clang/test/CodeGenObjC/arc.m

   getAggDtor();
 }
 
+// Check that no extra release calls are emitted to detruct the compond literal.
+
+// CHECK: define void @test72(i8* %[[A:.*]], i8* %[[B:.*]])
+// CHECK: %[[A_ADDR:.*]] = alloca i8*, align 8
+// CHECK: %[[B_ADDR:.*]] = alloca i8*, align 8
+// CHECK: %[[T:.*]] = alloca [2 x i8*], align 16
+// CHECK: %[[V0:.*]] = call i8* @llvm.objc.retain(i8* %[[A]])
+// CHECK: %[[V1:.*]] = call i8* @llvm.objc.retain(i8* %[[B]]) #2
+// CHECK: %[[ARRAYINIT_BEGIN:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[T]], i64 0, i64 0
+// CHECK: %[[V3:.*]] = load i8*, i8** %[[A_ADDR]], align 8, !tbaa !7
+// CHECK: %[[V4:.*]] = call i8* @llvm.objc.retain(i8* %[[V3]]) #2
+// CHECK: store i8* %[[V4]], i8** %[[ARRAYINIT_BEGIN]], align 8, !tbaa !7
+// CHECK: %[[ARRAYINIT_ELEMENT:.*]] = getelementptr inbounds i8*, i8** %[[ARRAYINIT_BEGIN]], i64 1
+// CHECK: %[[V5:.*]] = load i8*, i8** %[[B_ADDR]], align 8, !tbaa !7
+// CHECK: %[[V6:.*]] = call i8* @llvm.objc.retain(i8* %[[V5]]) #2
+// CHECK: store i8* %[[V6]], i8** %[[ARRAYINIT_ELEMENT]], align 8, !tbaa !7
+// CHECK: %[[ARRAY_BEGIN:.*]] = getelementptr inbounds [2 x i8*], [2 x i8*]* %[[T]], i32 0, i32 0
+// CHECK: %[[V7:.*]] = getelementptr inbounds i8*, i8** %[[ARRAY_BEGIN]], i64 2
+
+// CHECK-NOT: call void @llvm.objc.release
+
+// CHECK: %[[ARRAYDESTROY_ELEMENTPAST:.*]] = phi i8** [ %[[V7]], %{{.*}} ], [ %[[ARRAYDESTROY_ELEMENT:.*]], %{{.*}} ]
+// CHECK: %[[ARRAYDESTROY_ELEMENT]] = getelementptr inbounds i8*, i8** %[[ARRAYDESTROY_ELEMENTPAST]], i64 -1
+// CHECK: %[[V8:.*]] = load i8*, i8** %[[ARRAYDESTROY_ELEMENT]], align 8
+// CHECK: call void @llvm.objc.release(i8* %[[V8]]) #2, !clang.imprecise_release !10
+
+// CHECK-NOT: call void @llvm.objc.release
+
+// CHECK: %[[V10:.*]] = load i8*, i8** %[[B_ADDR]], align 8
+// CHECK: call void @llvm.objc.release(i8* %[[V10]]) #2, !clang.imprecise_release !10
+// CHECK: %[[V11:.*]] = load i8*, i8** %[[A_ADDR]], align 8
+// CHECK: call void @llvm.objc.release(i8* %[[V11]]) #2, !clang.imprecise_release !10
+
+void test72(id a, id b) {
+  __strong id t[] = (__strong id[]){a, b};
+}
+
 // ARC-ALIEN: attributes [[NLB]] = { nonlazybind }
 // ARC-NATIVE: attributes [[NLB]] = { nonlazybind }
 // CHECK: attributes [[NUW]] = { nounwind }

clang/test/CodeGenObjC/strong-in-c-struct.m

   VolatileArray t = *a;
 }
 
+// CHECK: define void @test_compound_literal0(
+// CHECK: %[[P:.*]] = alloca %[[STRUCT_STRONGSMALL]]*, align 8
+// CHECK: %[[_COMPOUNDLITERAL:.*]] = alloca %[[STRUCT_STRONGSMALL]], align 8
+// CHECK: %[[CLEANUP_COND:.*]] = alloca i1, align 1
+// CHECK: %[[_COMPOUNDLITERAL1:.*]] = alloca %[[STRUCT_STRONGSMALL]], align 8
+// CHECK: %[[CLEANUP_COND4:.*]] = alloca i1, align 1
+
+// CHECK: %[[I:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL]], i32 0, i32 0
+// CHECK: store i32 1, i32* %[[I]], align 8
+// CHECK: %[[F1:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL]], i32 0, i32 1
+// CHECK: store i8* null, i8** %[[F1]], align 8
+// CHECK: store i1 true, i1* %[[CLEANUP_COND]], align 1
+
+// CHECK: %[[I2:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL1]], i32 0, i32 0
+// CHECK: store i32 2, i32* %[[I2]], align 8
+// CHECK: %[[F13:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL1]], i32 0, i32 1
+// CHECK: store i8* null, i8** %[[F13]], align 8
+// CHECK: store i1 true, i1* %[[CLEANUP_COND4]], align 1
+
+// CHECK: %[[COND:.*]] = phi %[[STRUCT_STRONGSMALL]]* [ %[[_COMPOUNDLITERAL]], %{{.*}} ], [ %[[_COMPOUNDLITERAL1]], %{{.*}} ]
+// CHECK: store %[[STRUCT_STRONGSMALL]]* %[[COND]], %[[STRUCT_STRONGSMALL]]** %[[P]], align 8
+// CHECK: call void @func(
+
+// CHECK: %[[V1:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL1]] to i8**
+// CHECK: call void @__destructor_8_s8(i8** %[[V1]])
+
+// CHECK: %[[V2:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL]] to i8**
+// CHECK: call void @__destructor_8_s8(i8** %[[V2]])
+
+void test_compound_literal0(int c) {
+  StrongSmall *p = c ? &(StrongSmall){ 1, 0 } : &(StrongSmall){ 2, 0 };
+  func(0);
+}
+
+// Check that there is only one destructor call, which destructs 't'.
+
+// CHECK: define void @test_compound_literal1(
+// CHECK: %[[T:.*]] = alloca %[[STRUCT_STRONGSMALL]], align 8
+
+// CHECK: %[[I:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[T]], i32 0, i32 0
+// CHECK: store i32 1, i32* %[[I]], align 8
+// CHECK: %[[F1:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[T]], i32 0, i32 1
+// CHECK: store i8* null, i8** %[[F1]], align 8
+
+// CHECK: %[[I1:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[T]], i32 0, i32 0
+// CHECK: store i32 2, i32* %[[I1]], align 8
+// CHECK: %[[F12:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[T]], i32 0, i32 1
+// CHECK: store i8* null, i8** %[[F12]], align 8
+
+// CHECK: call void @func(
+// CHECK-NOT: call void
+// CHECK: %[[V1:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[T]] to i8**
+// CHECK: call void @__destructor_8_s8(i8** %[[V1]])
+// CHECK-NOT: call void
+
+void test_compound_literal1(int c) {
+  StrongSmall t = c ? (StrongSmall){ 1, 0 } : (StrongSmall){ 2, 0 };
+  func(0);
+}
+
+// CHECK: define void @test_compound_literal2(
+// CHECK: %[[P_ADDR:.*]] = alloca %[[STRUCT_STRONGSMALL]]*, align 8
+// CHECK: %[[_COMPOUNDLITERAL:.*]] = alloca %[[STRUCT_STRONGSMALL]], align 8
+// CHECK: %[[CLEANUP_COND:.*]] = alloca i1, align 1
+// CHECK: %[[_COMPOUNDLITERAL1:.*]] = alloca %[[STRUCT_STRONGSMALL]], align 8
+// CHECK: %[[CLEANUP_COND4:.*]] = alloca i1, align 1
+// CHECK: %[[V0:.*]] = load %[[STRUCT_STRONGSMALL]]*, %[[STRUCT_STRONGSMALL]]** %[[P_ADDR]], align 8
+
+// CHECK: %[[I:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL]], i32 0, i32 0
+// CHECK: store i32 1, i32* %[[I]], align 8
+// CHECK: %[[F1:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL]], i32 0, i32 1
+// CHECK: store i8* null, i8** %[[F1]], align 8
+// CHECK: store i1 true, i1* %[[CLEANUP_COND]], align 1
+// CHECK: %[[V2:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[V0]] to i8**
+// CHECK: %[[V3:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL]] to i8**
+// CHECK: call void @__copy_assignment_8_8_t0w4_s8(i8** %[[V2]], i8** %[[V3]])
+
+// CHECK: %[[I2:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL1]], i32 0, i32 0
+// CHECK: store i32 2, i32* %[[I2]], align 8
+// CHECK: %[[F13:.*]] = getelementptr inbounds %[[STRUCT_STRONGSMALL]], %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL1]], i32 0, i32 1
+// CHECK: store i8* null, i8** %[[F13]], align 8
+// CHECK: store i1 true, i1* %[[CLEANUP_COND4]], align 1
+// CHECK: %[[V4:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[V0]] to i8**
+// CHECK: %[[V5:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL1]] to i8**
+// CHECK: call void @__copy_assignment_8_8_t0w4_s8(i8** %[[V4]], i8** %[[V5]])
+
+// CHECK: call void @func(
+
+// CHECK: %[[V6:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL1]] to i8**
+// CHECK: call void @__destructor_8_s8(i8** %[[V6]])
+
+// CHECK: %[[V7:.*]] = bitcast %[[STRUCT_STRONGSMALL]]* %[[_COMPOUNDLITERAL]] to i8**
+// CHECK: call void @__destructor_8_s8(i8** %[[V7]])
+
+void test_compound_literal2(int c, StrongSmall *p) {
+  *p = c ? (StrongSmall){ 1, 0 } : (StrongSmall){ 2, 0 };
+  func(0);
+}
+
 #endif /* USESTRUCT */

clang/test/Import/objc-arc/Inputs/cleanup-objects.m

+typedef struct {
+  id x;
+} S;
+
+id getObj(int c, id a) {
+  // Commenting out the following line because AST importer crashes when trying
+  // to import a BlockExpr.
+  // return c ? ^{ return a; }() : ((S){ .x = a }).x;
+  return ((S){ .x = a }).x;
+}

clang/test/Import/objc-arc/test-cleanup-object.m

+// RUN: clang-import-test -x objective-c -objc-arc -import %S/Inputs/cleanup-objects.m -dump-ast -expression %s | FileCheck %s
+
+// CHECK: FunctionDecl {{.*}} getObj '
+// CHECK: ExprWithCleanups
+// CHECK-NEXT: cleanup CompoundLiteralExpr
+
+void test(int c, id a) {
+  (void)getObj(c, a);
+}
+

clang/test/PCH/non-trivial-c-compound-literal.m

+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -x objective-c -fobjc-arc -emit-pch -o %t %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -x objective-c -fobjc-arc -include-pch %t -emit-llvm -o - %s | FileCheck %s
+
+#ifndef HEADER
+#define HEADER
+
+typedef struct {
+  id f;
+} S;
+
+static inline id getObj(id a) {
+  S *p = &(S){ .f = a };
+  return p->f;
+}
+
+#else
+
+// CHECK: %[[STRUCT_S:.*]] = type { i8* }
+
+// CHECK: define internal i8* @getObj(
+// CHECK: %[[_COMPOUNDLITERAL:.*]] = alloca %[[STRUCT_S]],
+// CHECK: %[[V5:.*]] = bitcast %[[STRUCT_S]]* %[[_COMPOUNDLITERAL]] to i8**
+// CHECK: call void @__destructor_8_s0(i8** %[[V5]])
+
+id test(id a) {
+  return getObj(a);
+}
+
+#endif

clang/test/SemaObjC/strong-in-c-struct.m

   func(^{ func2(x); });
   goto *ips; // expected-error {{cannot jump}}
 }
+
+void test_compound_literal0(int cond, id x) {
+  switch (cond) {
+  case 0:
+    (void)(Strong){ .a = x }; // expected-note {{jump enters lifetime of a compound literal that is non-trivial to destruct}}
+    break;
+  default: // expected-error {{cannot jump from switch statement to this case label}}
+    break;
+  }
+}
+
+void test_compound_literal1(id x) {
+  static void *ips[] = { &&L0 };
+L0:  // expected-note {{possible target of indirect goto}}
+  ;
+  (void)(Strong){ .a = x }; // expected-note {{jump exits lifetime of a compound literal that is non-trivial to destruct}}
+  goto *ips; // expected-error {{cannot jump}}
+}

clang/tools/clang-import-test/clang-import-test.cpp

           llvm::cl::desc("The language to parse (default: c++)"),
           llvm::cl::init("c++"));
 
+static llvm::cl::opt<bool>
+    ObjCARC("objc-arc", llvm::cl::init(false),
+            llvm::cl::desc("Emable ObjC ARC"));
+
 static llvm::cl::opt<bool> DumpAST("dump-ast", llvm::cl::init(false),
                                    llvm::cl::desc("Dump combined AST"));
 

       Inv->getLangOpts()->ObjC = 1;
     }
   }
+  Inv->getLangOpts()->ObjCAutoRefCount = ObjCARC;
+
   Inv->getLangOpts()->Bool = true;
   Inv->getLangOpts()->WChar = true;
   Inv->getLangOpts()->Blocks = true;