Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -4918,7 +4918,7 @@
     if (Triple.isX86() && Triple.isOSBinFormatELF()) {
       StringRef Val = A->getValue();
       if (Val != "all" && Val != "labels" && Val != "none" &&
-          !(Val.startswith("list=") && llvm::sys::fs::exists(Val.substr(5))))
+          !Val.startswith("list="))
         D.Diag(diag::err_drv_invalid_value)
             << A->getAsString(Args) << A->getValue();
       else
Index: clang/test/Driver/fbasic-block-sections.c
===================================================================
--- clang/test/Driver/fbasic-block-sections.c
+++ clang/test/Driver/fbasic-block-sections.c
@@ -4,9 +4,14 @@
 // RUN: %clang -### -target x86_64 -fbasic-block-sections=labels %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-LABELS %s
 // RUN: not %clang -c -target arm-unknown-linux -fbasic-block-sections=all %s -S 2>&1 | FileCheck -check-prefix=CHECK-TRIPLE %s
 // RUN: not %clang -c -target x86_64-apple-darwin10 -fbasic-block-sections=all %s -S 2>&1 | FileCheck -check-prefix=CHECK-TRIPLE %s
+// RUN: %clang -### -target x86_64 -fbasic-block-sections=alll %s -S 2>&1 | FileCheck -check-prefix=CHECK-INVALID-VALUE %s
+// RUN: %clang -### -target x86_64 -fbasic-block-sections=list %s -S 2>&1 | FileCheck -check-prefix=CHECK-INVALID-VALUE %s
+// RUN: %clang -### -target x86_64 -fbasic-block-sections=list= %s -S 2>&1 | FileCheck -check-prefix=CHECK-OPT-NULL-LIST %s
 //
 // CHECK-OPT-NONE:   "-fbasic-block-sections=none"
 // CHECK-OPT-ALL:    "-fbasic-block-sections=all"
 // CHECK-OPT-LIST:   "-fbasic-block-sections={{[^ ]*}}fbasic-block-sections.c"
 // CHECK-OPT-LABELS: "-fbasic-block-sections=labels"
 // CHECK-TRIPLE:     error: unsupported option '-fbasic-block-sections=all' for target
+// CHECK-INVALID-VALUE: error: invalid value {{[^ ]*}} in '-fbasic-block-sections={{.*}}'
+// CHECK-OPT-NULL-LIST: "-fbasic-block-sections=list="
Index: clang/test/Frontend/fbasic-block-sections.c
===================================================================
--- /dev/null
+++ clang/test/Frontend/fbasic-block-sections.c
@@ -0,0 +1,3 @@
+// RUN: not %clang_cc1 -fbasic-block-sections=list= -emit-obj %s 2>&1 | FileCheck %s
+//
+// CHECK: error:  unable to load basic block sections function list: 'No such file or directory'