r316723 - [CodeGen] Add support for IncompleteArrayType in Obj-C ivars.

[Volodymyr Sapsai via cfe-commits]

Author: vsapsai
Date: Thu Oct 26 17:56:23 2017
New Revision: 316723

URL: http://llvm.org/viewvc/llvm-project?rev=316723&view=rev
Log:
[CodeGen] Add support for IncompleteArrayType in Obj-C ivars.

Fixes an assertion failure when ivar is a struct containing incomplete
array. Also completes support for direct flexible array members.

rdar://problem/21054495

Reviewers: rjmccall, theraven

Reviewed By: rjmccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D38774


Added:
    cfe/trunk/test/CodeGenObjC/ivar-layout-flexible-array.m
Modified:
    cfe/trunk/lib/CodeGen/CGObjCMac.cpp

Modified: cfe/trunk/lib/CodeGen/CGObjCMac.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCMac.cpp?rev=316723&r1=316722&r2=316723&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCMac.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjCMac.cpp Thu Oct 26 17:56:23 2017
@@ -5084,6 +5084,11 @@ void IvarLayoutBuilder::visitField(const
 
   // Drill down into arrays.
   uint64_t numElts = 1;
+  if (auto arrayType = CGM.getContext().getAsIncompleteArrayType(fieldType)) {
+    numElts = 0;
+    fieldType = arrayType->getElementType();
+  }
+  // Unlike incomplete arrays, constant arrays can be nested.
   while (auto arrayType = CGM.getContext().getAsConstantArrayType(fieldType)) {
     numElts *= arrayType->getSize().getZExtValue();
     fieldType = arrayType->getElementType();

Added: cfe/trunk/test/CodeGenObjC/ivar-layout-flexible-array.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjC/ivar-layout-flexible-array.m?rev=316723&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenObjC/ivar-layout-flexible-array.m (added)
+++ cfe/trunk/test/CodeGenObjC/ivar-layout-flexible-array.m Thu Oct 26 17:56:23 2017
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -Wno-objc-root-class -fobjc-arc -emit-llvm -o - %s | FileCheck %s
+
+// rdar://problem/21054495
+ at interface FlexibleArrayMember {
+  char flexible_array[][4][2];
+}
+ at end
+ at implementation FlexibleArrayMember
+ at end
+// CHECK: @OBJC_METH_VAR_NAME_{{.*}} = private unnamed_addr constant {{.*}} c"flexible_array\00"
+// CHECK-NEXT: @OBJC_METH_VAR_TYPE_{{.*}} = private unnamed_addr constant {{.*}} c"^[4[2c]]\00"
+
+
+typedef char FlexibleArray[];
+
+struct Packet {
+  int size;
+  FlexibleArray data;
+};
+
+ at interface VariableSizeIvar {
+  struct Packet flexible_struct;
+}
+ at end
+ at implementation VariableSizeIvar
+ at end
+// CHECK: @OBJC_METH_VAR_NAME_{{.*}} = private unnamed_addr constant {{.*}} c"flexible_struct\00"
+// CHECK-NEXT: @OBJC_METH_VAR_TYPE_{{.*}} = private unnamed_addr constant {{.*}} c"{Packet=\22size\22i\22data\22[0c]}\00"