Index: cfe/trunk/lib/CodeGen/CGBlocks.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGBlocks.cpp
+++ cfe/trunk/lib/CodeGen/CGBlocks.cpp
@@ -161,6 +161,9 @@
 
   std::string TypeAtEncoding =
       CGM.getContext().getObjCEncodingForBlock(BlockInfo.getBlockExpr());
+  /// Replace occurrences of '@' with '\1'. '@' is reserved on ELF platforms as
+  /// a separator between symbol name and symbol version.
+  std::replace(TypeAtEncoding.begin(), TypeAtEncoding.end(), '@', '\1');
   Name += "e" + llvm::to_string(TypeAtEncoding.size()) + "_" + TypeAtEncoding;
   Name += "l" + CGM.getObjCRuntime().getRCBlockLayoutStr(CGM, BlockInfo);
   return Name;
Index: cfe/trunk/test/CodeGenObjC/block-desc-str.m
===================================================================
--- cfe/trunk/test/CodeGenObjC/block-desc-str.m
+++ cfe/trunk/test/CodeGenObjC/block-desc-str.m
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-freebsd -emit-llvm -fobjc-runtime=gnustep-1.7 -fblocks -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm -fobjc-runtime=gcc -fblocks -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple=x86_64-apple-darwin10 -emit-llvm -fblocks -o - %s | FileCheck %s
+
+// Test that descriptor symbol names don't include '@'.
+
+// CHECK: @[[STR:.*]] = private unnamed_addr constant [6 x i8] c"v8@?0\00"
+// CHECK: @"__block_descriptor_40_8_32o_e5_v8\01?0l" = linkonce_odr hidden unnamed_addr constant { i64, i64, i8*, i8*, i8*, {{.*}} } { i64 0, i64 40, i8* bitcast ({{.*}} to i8*), i8* bitcast ({{.*}} to i8*), i8* getelementptr inbounds ([6 x i8], [6 x i8]* @[[STR]], i32 0, i32 0), {{.*}} }, align 8
+
+typedef void (^BlockTy)(void);
+
+void test(id a) {
+  BlockTy b = ^{ (void)a; };
+}
Index: cfe/trunk/test/CodeGenObjCXX/block-nested-in-lambda.mm
===================================================================
--- cfe/trunk/test/CodeGenObjCXX/block-nested-in-lambda.mm
+++ cfe/trunk/test/CodeGenObjCXX/block-nested-in-lambda.mm
@@ -35,7 +35,7 @@
 // CHECK-LABEL: define void @_ZN18CaptureByReference5test0Ev(
 // CHECK-LABEL: define internal void @"_ZZN18CaptureByReference5test0EvENK3$_1clEv"(
 // CHECK: %[[BLOCK_DESCRIPTOR:.*]] = getelementptr inbounds <{ i8*, i32, i32, i8*, %[[STRUCT_BLOCK_DESCRIPTOR]]*, i8** }>, <{ i8*, i32, i32, i8*, %[[STRUCT_BLOCK_DESCRIPTOR]]*, i8** }>* %{{.*}}, i32 0, i32 4
-// CHECK: store %[[STRUCT_BLOCK_DESCRIPTOR]]* bitcast ({ i64, i64, i8*, i64 }* @"__block_descriptor_40_e5_v8@?0ls32l8" to %[[STRUCT_BLOCK_DESCRIPTOR]]*), %[[STRUCT_BLOCK_DESCRIPTOR]]** %[[BLOCK_DESCRIPTOR]], align 8
+// CHECK: store %[[STRUCT_BLOCK_DESCRIPTOR]]* bitcast ({ i64, i64, i8*, i64 }* @"__block_descriptor_40_e5_v8\01?0ls32l8" to %[[STRUCT_BLOCK_DESCRIPTOR]]*), %[[STRUCT_BLOCK_DESCRIPTOR]]** %[[BLOCK_DESCRIPTOR]], align 8
 
 void test0() {
   id a = getObj();
@@ -48,7 +48,7 @@
 // CHECK-LABEL: define void @_ZN18CaptureByReference5test1Ev(
 // CHECK-LABEL: define internal void @"_ZZN18CaptureByReference5test1EvENK3$_2clEv"(
 // CHECK: %[[BLOCK_DESCRIPTOR:.*]] = getelementptr inbounds <{ i8*, i32, i32, i8*, %[[STRUCT_BLOCK_DESCRIPTOR]]*, i8*, i8*, i8** }>, <{ i8*, i32, i32, i8*, %[[STRUCT_BLOCK_DESCRIPTOR]]*, i8*, i8*, i8** }>* %{{.*}}, i32 0, i32 4
-// CHECK: store %[[STRUCT_BLOCK_DESCRIPTOR]]* bitcast ({ i64, i64, i8*, i8*, i8*, i64 }* @"__block_descriptor_56_8_32s40s_e5_v8@?0l" to %[[STRUCT_BLOCK_DESCRIPTOR]]*), %[[STRUCT_BLOCK_DESCRIPTOR]]** %[[BLOCK_DESCRIPTOR]], align 8
+// CHECK: store %[[STRUCT_BLOCK_DESCRIPTOR]]* bitcast ({ i64, i64, i8*, i8*, i8*, i64 }* @"__block_descriptor_56_8_32s40s_e5_v8\01?0l" to %[[STRUCT_BLOCK_DESCRIPTOR]]*), %[[STRUCT_BLOCK_DESCRIPTOR]]** %[[BLOCK_DESCRIPTOR]], align 8
 
 // CHECK-LABEL: define linkonce_odr hidden void @__copy_helper_block_8_32s40s(
 // CHECK-NOT: call void @llvm.objc.storeStrong(