[clang-cl] Check that we are in clang cl mode before enabling support for the CL environment variable.

[pgousseau]

Summary

Checking for the type of the command line tokenizer should not be the criteria to enable support for the CL environment variable, this change checks that we are in clang-cl mode instead.

[pgousseau]

Ping!

[majnemer]

LGTM

cfe/trunk/test/Driver/cl-options.c

 // STDCXXLATEST: -std=c++1z
 
 // RUN: env CL="/Gy" %clang_cl -### -- %s 2>&1 | FileCheck -check-prefix=ENV-CL %s
 // ENV-CL: "-ffunction-sections"
 
 // RUN: env CL="/Gy" _CL_="/Gy- -- %s" %clang_cl -### 2>&1 | FileCheck -check-prefix=ENV-_CL_ %s
 // ENV-_CL_-NOT: "-ffunction-sections"
 
+// RUN: env CL="%s" _CL_="%s" not %clang --rsp-quoting=windows -c
+
 // Accept "core" clang options.
 // (/Zs is for syntax-only, -Werror makes it fail hard on unknown options)
 // RUN: %clang_cl \
 // RUN:     --driver-mode=cl \
 // RUN:     -fcolor-diagnostics \
 // RUN:     -fno-color-diagnostics \
 // RUN:     -fdiagnostics-color \
 // RUN:     -fno-diagnostics-color \

cfe/trunk/tools/driver/driver.cpp

for (int i = 1, size = argv.size(); i < size; ++i) {
     if (StringRef(argv[i]) == "-no-canonical-prefixes") {
       CanonicalPrefixes = false;
       break;
     }
   }
 
   // Handle CL and _CL_ which permits additional command line options to be
   // prepended or appended.
-  if (Tokenizer == &llvm::cl::TokenizeWindowsCommandLine) {
+  if (ClangCLMode) {
     // Arguments in "CL" are prepended.
     llvm::Optional<std::string> OptCL = llvm::sys::Process::GetEnv("CL");
     if (OptCL.hasValue()) {
       SmallVector<const char *, 8> PrependedOpts;
       getCLEnvVarOptions(OptCL.getValue(), Saver, PrependedOpts);
 
       // Insert right after the program name to prepend to the argument list.
       argv.insert(argv.begin() + 1, PrependedOpts.begin(), PrependedOpts.end());