r256190 - Reapply "[CodeGen] Fix assignments of inline layouts into the byref structure"

[Vedant Kumar via cfe-commits]

Author: vedantk
Date: Mon Dec 21 14:21:15 2015
New Revision: 256190

URL: http://llvm.org/viewvc/llvm-project?rev=256190&view=rev
Log:
Reapply "[CodeGen] Fix assignments of inline layouts into the byref structure"

When using blocks, a byref structure is created to represent the
closure. The "byref.layout" field of this structure is an i8*. However,
some 'inline' layouts are represented as i64's, not i8*'s.

Prior to r246985 we cast the i64 'inline' layout to an i8* before
assigning it into the byref structure. This patch brings the cast back
and adds a regression test.

The original version of this patch was too invasive. This version only adds the
cast to BuildByrefLayout.

Differential Revision: http://reviews.llvm.org/D15674

rdar://23713871

Modified:
    cfe/trunk/lib/CodeGen/CGObjCMac.cpp
    cfe/trunk/lib/CodeGen/CGObjCRuntime.h
    cfe/trunk/test/CodeGenObjCXX/blocks.mm

Modified: cfe/trunk/lib/CodeGen/CGObjCMac.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCMac.cpp?rev=256190&r1=256189&r2=256190&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCMac.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjCMac.cpp Mon Dec 21 14:21:15 2015
@@ -2640,6 +2640,8 @@ llvm::Constant *CGObjCCommonMac::BuildBy
   if (const RecordType *record = T->getAs<RecordType>()) {
     BuildRCBlockVarRecordLayout(record, fieldOffset, hasUnion, true /*ByrefLayout */);
     llvm::Constant *Result = getBitmapBlockLayout(true);
+    if (isa<llvm::ConstantInt>(Result))
+      Result = llvm::ConstantExpr::getIntToPtr(Result, CGM.Int8PtrTy);
     return Result;
   }
   llvm::Constant *nullPtr = llvm::Constant::getNullValue(CGM.Int8PtrTy);

Modified: cfe/trunk/lib/CodeGen/CGObjCRuntime.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCRuntime.h?rev=256190&r1=256189&r2=256190&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCRuntime.h (original)
+++ cfe/trunk/lib/CodeGen/CGObjCRuntime.h Mon Dec 21 14:21:15 2015
@@ -275,8 +275,11 @@ public:
                                   const CodeGen::CGBlockInfo &blockInfo) = 0;
   virtual llvm::Constant *BuildRCBlockLayout(CodeGen::CodeGenModule &CGM,
                                   const CodeGen::CGBlockInfo &blockInfo) = 0;
+
+  /// Returns an i8* which points to the byref layout information.
   virtual llvm::Constant *BuildByrefLayout(CodeGen::CodeGenModule &CGM,
                                            QualType T) = 0;
+
   virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name,
                                                bool Weak = false) = 0;
 

Modified: cfe/trunk/test/CodeGenObjCXX/blocks.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjCXX/blocks.mm?rev=256190&r1=256189&r2=256190&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenObjCXX/blocks.mm (original)
+++ cfe/trunk/test/CodeGenObjCXX/blocks.mm Mon Dec 21 14:21:15 2015
@@ -68,3 +68,18 @@ class CaptureThisAndAnotherPointer {
     takeBlock(^{ useValues(ptr, this); });
   }
 };
+
+// rdar://problem/23713871
+// Check that we don't crash when using BLOCK_LAYOUT_STRONG.
+#pragma clang assume_nonnull begin
+ at interface NSUUID @end
+#pragma clang assume_nonnull end
+
+struct Wrapper1 { NSUUID *Ref; };
+struct Wrapper2 { Wrapper1 W1; };
+
+ at implementation B
+- (void) captureStrongRef {
+  __block Wrapper2 W2;
+}
+ at end