Index: clang/test/CodeGen/asan-globals.cpp
===================================================================
--- clang/test/CodeGen/asan-globals.cpp
+++ clang/test/CodeGen/asan-globals.cpp
@@ -6,6 +6,7 @@
 // RUN: echo "src:%s" | sed -e 's/\\/\\\\/g' > %t.ignorelist-src
 // RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=address -fsanitize-ignorelist=%t.ignorelist-src -emit-llvm -o - %s | FileCheck %s --check-prefix=IGNORELIST-SRC
 // RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=kernel-address -fsanitize-ignorelist=%t.ignorelist-src -emit-llvm -o - %s | FileCheck %s --check-prefix=IGNORELIST-SRC
+// RUN: %clang_cc1 -include %t.extra-source.cpp -fsanitize=address -o - %s -S -triple x86_64-unknown-linux-gnu | FileCheck %s --check-prefix=ELF-SIZE
 
 int global;
 int dyn_init_global = global;
@@ -55,20 +56,20 @@
 // CHECK: ![[EXTRA_GLOBAL]] = !{{{.*}} ![[EXTRA_GLOBAL_LOC:[0-9]+]], !"extra_global", i1 false, i1 false}
 // CHECK: ![[EXTRA_GLOBAL_LOC]] = !{!"{{.*}}extra-source.cpp", i32 1, i32 5}
 // CHECK: ![[GLOBAL]] = !{{{.*}} ![[GLOBAL_LOC:[0-9]+]], !"global", i1 false, i1 false}
-// CHECK: ![[GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 10, i32 5}
+// CHECK: ![[GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 11, i32 5}
 // CHECK: ![[DYN_INIT_GLOBAL]] = !{{{.*}} ![[DYN_INIT_LOC:[0-9]+]], !"dyn_init_global", i1 true, i1 false}
-// CHECK: ![[DYN_INIT_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 11, i32 5}
+// CHECK: ![[DYN_INIT_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 12, i32 5}
 // CHECK: ![[ATTR_GLOBAL]] = !{{{.*attributed_global.*}}, null, null, i1 false, i1 true}
 // CHECK: ![[DISABLE_INSTR_GLOBAL]] = !{{{.*disable_instrumentation_global.*}}, null, null, i1 false, i1 true}
 // CHECK: ![[IGNORELISTED_GLOBAL]] = !{{{.*ignorelisted_global.*}}, null, null, i1 false, i1 true}
 // CHECK: ![[SECTIONED_GLOBAL]] = !{{{.*}} ![[SECTIONED_GLOBAL_LOC:[0-9]+]], !"sectioned_global", i1 false, i1 false}
-// CHECK: ![[SECTIONED_GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 16, i32 50}
+// CHECK: ![[SECTIONED_GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 17, i32 50}
 // CHECK: ![[SPECIAL_GLOBAL]] = !{{{.*}} ![[SPECIAL_GLOBAL_LOC:[0-9]+]], !"__special_global", i1 false, i1 false}
-// CHECK: ![[SPECIAL_GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 18, i32 5}
+// CHECK: ![[SPECIAL_GLOBAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 19, i32 5}
 // CHECK: ![[STATIC_VAR]] = !{{{.*}} ![[STATIC_LOC:[0-9]+]], !"static_var", i1 false, i1 false}
-// CHECK: ![[STATIC_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 22, i32 14}
+// CHECK: ![[STATIC_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 23, i32 14}
 // CHECK: ![[LITERAL]] = !{{{.*}} ![[LITERAL_LOC:[0-9]+]], !"<string literal>", i1 false, i1 false}
-// CHECK: ![[LITERAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 23, i32 25}
+// CHECK: ![[LITERAL_LOC]] = !{!"{{.*}}asan-globals.cpp", i32 24, i32 25}
 
 // IGNORELIST-SRC: !llvm.asan.globals = !{![[EXTRA_GLOBAL:[0-9]+]], ![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[ATTR_GLOBAL:[0-9]+]], ![[DISABLE_INSTR_GLOBAL:[0-9]+]], ![[IGNORELISTED_GLOBAL:[0-9]+]], ![[SECTIONED_GLOBAL:[0-9]+]], ![[SPECIAL_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]}
 // IGNORELIST-SRC: ![[EXTRA_GLOBAL]] = !{{{.*}} ![[EXTRA_GLOBAL_LOC:[0-9]+]], !"extra_global", i1 false, i1 false}
@@ -82,3 +83,9 @@
 // IGNORELIST-SRC: ![[SPECIAL_GLOBAL]] = !{{{.*}} null, null, i1 false, i1 true}
 // IGNORELIST-SRC: ![[STATIC_VAR]] = !{{{.*}} null, null, i1 false, i1 true}
 // IGNORELIST-SRC: ![[LITERAL]] = !{{{.*}} null, null, i1 false, i1 true}
+
+// ELF-SIZE: .globl global
+// ELF-SIZE-NEXT: .p2align 5
+// ELF-SIZE-NEXT: global:
+// ELF-SIZE-NEXT: .zero 32
+// ELF-SIZE-NEXT: .size global, 4
Index: llvm/include/llvm/IR/DerivedTypes.h
===================================================================
--- llvm/include/llvm/IR/DerivedTypes.h
+++ llvm/include/llvm/IR/DerivedTypes.h
@@ -226,6 +226,7 @@
   /// This is null if the type is an literal struct or if it is a identified
   /// type that has an empty name.
   void *SymbolTableEntry = nullptr;
+  llvm::Optional<uint64_t> ExplicitSize;
 
 public:
   StructType(const StructType &) = delete;
@@ -249,8 +250,9 @@
   }
 
   /// This static method is the primary way to create a literal StructType.
-  static StructType *get(LLVMContext &Context, ArrayRef<Type*> Elements,
-                         bool isPacked = false);
+  static StructType *get(LLVMContext &Context, ArrayRef<Type *> Elements,
+                         bool isPacked = false,
+                         llvm::Optional<uint64_t> ExplicitSize = {});
 
   /// Create an empty structure type.
   static StructType *get(LLVMContext &Context, bool isPacked = false);
@@ -308,6 +310,12 @@
     setBody(ArrayRef<Type *>({elt1, elts...}));
   }
 
+  llvm::Optional<uint64_t> getExplicitSize() const { return ExplicitSize; }
+
+  void setExplicitSize(llvm::Optional<uint64_t> NewExplicitSize) {
+    ExplicitSize = NewExplicitSize;
+  }
+
   /// Return true if the specified type is valid as a element type.
   static bool isValidElementType(Type *ElemTy);
 
Index: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -690,10 +690,14 @@
 
   emitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
 
-  if (MAI->hasDotTypeDotSizeDirective())
+  if (MAI->hasDotTypeDotSizeDirective()) {
+    if (const auto *Struct = dyn_cast<StructType>(GV->getValueType()))
+      if (llvm::Optional<uint64_t> ExplicitSize = Struct->getExplicitSize())
+        Size = *ExplicitSize;
     // .size foo, 42
     OutStreamer->emitELFSize(EmittedInitSym,
                              MCConstantExpr::create(Size, OutContext));
+  }
 
   OutStreamer->AddBlankLine();
 }
Index: llvm/lib/IR/LLVMContextImpl.h
===================================================================
--- llvm/lib/IR/LLVMContextImpl.h
+++ llvm/lib/IR/LLVMContextImpl.h
@@ -92,8 +92,11 @@
   struct KeyTy {
     ArrayRef<Type *> ETypes;
     bool isPacked;
+    Optional<uint64_t> ExplicitSize;
 
-    KeyTy(const ArrayRef<Type *> &E, bool P) : ETypes(E), isPacked(P) {}
+    KeyTy(const ArrayRef<Type *> &E, bool P,
+          Optional<uint64_t> ExplicitSize = {})
+        : ETypes(E), isPacked(P), ExplicitSize(ExplicitSize) {}
 
     KeyTy(const StructType *ST)
         : ETypes(ST->elements()), isPacked(ST->isPacked()) {}
@@ -103,7 +106,7 @@
         return false;
       if (ETypes != that.ETypes)
         return false;
-      return true;
+      return ExplicitSize == that.ExplicitSize;
     }
     bool operator!=(const KeyTy &that) const { return !this->operator==(that); }
   };
Index: llvm/lib/IR/Type.cpp
===================================================================
--- llvm/lib/IR/Type.cpp
+++ llvm/lib/IR/Type.cpp
@@ -403,10 +403,11 @@
 
 // Primitive Constructors.
 
-StructType *StructType::get(LLVMContext &Context, ArrayRef<Type*> ETypes,
-                            bool isPacked) {
+StructType *StructType::get(LLVMContext &Context, ArrayRef<Type *> ETypes,
+                            bool isPacked,
+                            llvm::Optional<uint64_t> ExplicitSize) {
   LLVMContextImpl *pImpl = Context.pImpl;
-  const AnonStructTypeKeyInfo::KeyTy Key(ETypes, isPacked);
+  AnonStructTypeKeyInfo::KeyTy Key(ETypes, isPacked, ExplicitSize);
 
   StructType *ST;
   // Since we only want to allocate a fresh struct type in case none is found
@@ -421,6 +422,7 @@
     ST = new (Context.pImpl->Alloc) StructType(Context);
     ST->setSubclassData(SCDB_IsLiteral);  // Literal struct.
     ST->setBody(ETypes, isPacked);
+    ST->setExplicitSize(ExplicitSize);
     *Insertion.first = ST;
   } else {
     // The struct type was found. Just return it.
@@ -518,7 +520,7 @@
 }
 
 StructType *StructType::get(LLVMContext &Context, bool isPacked) {
-  return get(Context, None, isPacked);
+  return get(Context, None, isPacked, {});
 }
 
 StructType *StructType::create(LLVMContext &Context, ArrayRef<Type*> Elements,
Index: llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -2475,11 +2475,13 @@
         /*AllowMerging*/ true, kAsanGenPrefix);
 
     Type *Ty = G->getValueType();
+    uint64_t Size = G->getParent()->getDataLayout().getTypeAllocSize(Ty);
     const uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
     const uint64_t RightRedzoneSize = getRedzoneSizeForGlobal(SizeInBytes);
     Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
 
-    StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
+    StructType *NewTy =
+        StructType::get(Ty->getContext(), {Ty, RightRedZoneTy}, false, Size);
     Constant *NewInitializer = ConstantStruct::get(
         NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));