Index: lld/test/COFF/directives.s
===================================================================
--- /dev/null
+++ lld/test/COFF/directives.s
@@ -0,0 +1,46 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -triple=x86_64-windows %s -filetype=obj -o %t.obj
+
+# RUN: lld-link -dll -out:%t.dll -entry:entry %t.obj -subsystem:console
+# RUN: llvm-objdump -p %t.dll | FileCheck %s
+
+# CHECK:      Export Table:
+# CHECK:      DLL name: directives.s.tmp.dll
+# CHECK:      Ordinal      RVA  Name
+# CHECK-NEXT:       0        0
+# CHECK-NEXT:       1   0x1000  exportfn1
+# CHECK-NEXT:       2   0x1000  exportfn2
+# CHECK-NEXT:       3   0x1000  exportfn3
+# CHECK-NEXT:       4   0x1000  exportfn4
+# CHECK-NEXT:       5   0x1000  exportfn5
+# CHECK-NEXT:       6   0x1000  exportfn6
+
+  .global entry
+  .global exportfn1
+  .global exportfn2
+  .global exportfn3
+  .global exportfn4
+  .global exportfn5
+  .global exportfn6
+  .text
+entry:
+exportfn1:
+exportfn2:
+exportfn3:
+exportfn4:
+exportfn5:
+exportfn6:
+  ret
+  .section .drectve
+# Test that directive strings can be separated by any combination of
+# spaces and null bytes.
+  .ascii "-export:exportfn1 "
+  .asciz "-export:exportfn2"
+  .asciz "-export:exportfn3"
+  .asciz "-export:exportfn4 "
+  .byte 0
+  .ascii " "
+  .byte 0
+  .asciz "-export:exportfn5"
+  .asciz " -export:exportfn6"
Index: llvm/lib/Support/CommandLine.cpp
===================================================================
--- llvm/lib/Support/CommandLine.cpp
+++ llvm/lib/Support/CommandLine.cpp
@@ -693,6 +693,10 @@
   return C == ' ' || C == '\t' || C == '\r' || C == '\n';
 }
 
+static bool isWhitespaceOrNull(char C) {
+  return isWhitespace(C) || C == '\0';
+}
+
 static bool isQuote(char C) { return C == '\"' || C == '\''; }
 
 void cl::TokenizeGNUCommandLine(StringRef Src, StringSaver &Saver,
@@ -808,7 +812,7 @@
     // INIT state indicates that the current input index is at the start of
     // the string or between tokens.
     if (State == INIT) {
-      if (isWhitespace(C)) {
+      if (isWhitespaceOrNull(C)) {
         // Mark the end of lines in response files
         if (MarkEOLs && C == '\n')
           NewArgv.push_back(nullptr);
@@ -832,7 +836,7 @@
     // quotes.
     if (State == UNQUOTED) {
       // Whitespace means the end of the token.
-      if (isWhitespace(C)) {
+      if (isWhitespaceOrNull(C)) {
         NewArgv.push_back(Saver.save(StringRef(Token)).data());
         Token.clear();
         State = INIT;