Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp
+++ lib/CodeGen/CodeGenModule.cpp
@@ -2430,6 +2430,12 @@
       EmitGlobalVarDefinition(D);
     }
 
+    // Emit section information for extern variables.
+    if (D->hasExternalStorage() && !D->isThisDeclarationADefinition()) {
+      if (const SectionAttr *SA = D->getAttr<SectionAttr>())
+        GV->setSection(SA->getName());
+    }
+
     // Handle XCore specific ABI requirements.
     if (getTriple().getArch() == llvm::Triple::xcore &&
         D->getLanguageLinkage() == CLanguageLinkage &&
Index: test/CodeGenCXX/extern-section-attribute.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/extern-section-attribute.cpp
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=i386-pc-linux-gnu | FileCheck %s --check-prefix=CHECK-LIN
+// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=x86_64-pc-linux-gnu | FileCheck %s --check-prefix=CHECK-LIN
+// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=i386-pc-win32 | FileCheck %s --check-prefix=CHECK-WIN
+// RUN: %clang_cc1 -emit-llvm %s -o - -ffreestanding -triple=x86_64-pc-win32 | FileCheck %s  --check-prefix=CHECK-WIN
+
+extern int aa __attribute__((section(".sdata")));
+// CHECK-LIN-DAG: @aa = external global i32, section ".sdata", align 4
+// CHECK-WIN-DAG: @"\01?aa@@3HA" = external global i32, section ".sdata", align 4
+
+extern int bb __attribute__((section(".sdata"))) = 1;
+// CHECK-LIN-DAG: @bb = global i32 1, section ".sdata", align 4
+// CHECK-WIN-DAG: @"\01?bb@@3HA" = global i32 1, section ".sdata", align 4
+
+int foo() {
+  return aa + bb;
+}