diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -5880,7 +5880,7 @@
       Arg->render(Args, OriginalArgs);
 
     SmallString<256> Flags;
-    Flags += Exec;
+    EscapeSpacesAndBackslashes(Exec, Flags);
     for (const char *OriginalArg : OriginalArgs) {
       SmallString<128> EscapedArg;
       EscapeSpacesAndBackslashes(OriginalArg, EscapedArg);
@@ -6788,7 +6788,7 @@
 
     SmallString<256> Flags;
     const char *Exec = getToolChain().getDriver().getClangProgramPath();
-    Flags += Exec;
+    EscapeSpacesAndBackslashes(Exec, Flags);
     for (const char *OriginalArg : OriginalArgs) {
       SmallString<128> EscapedArg;
       EscapeSpacesAndBackslashes(OriginalArg, EscapedArg);