+// thread safe statics are off for versions < 19.
+// RUN: %clang_cl /c -### -- %s 2>&1 | FileCheck -check-prefix=NoThreadSafeStatics %s
+// RUN: %clang_cl /Zc:threadSafeInit /Zc:threadSafeInit- /c -### -- %s 2>&1 | FileCheck -check-prefix=NoThreadSafeStatics %s
+// NoThreadSafeStatics: "-fno-threadsafe-statics"
+
+// RUN: %clang_cl /Zc:threadSafeInit /c -### -- %s 2>&1 | FileCheck -check-prefix=ThreadSafeStatics %s
+// ThreadSafeStatics-NOT: "-fno-threadsafe-statics"
+
+// RUN: %clang_cl /Zi /c -### -- %s 2>&1 | FileCheck -check-prefix=Zi %s
+// Zi: "-gcodeview"
+// Zi: "-debug-info-kind=line-tables-only"
+
+// RUN: %clang_cl /Z7 /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7 %s
+// Z7: "-gcodeview"
+// Z7: "-debug-info-kind=line-tables-only"
+
+// This test was super sneaky: "/Z7" means "line-tables", but "-gdwarf" occurs
+// later on the command line, so it should win. Interestingly the cc1 arguments
+// came out right, but had wrong semantics, because an invariant assumed by
+// CompilerInvocation was violated: it expects that at most one of {gdwarfN,
+// line-tables-only} appear. If you assume that, then you can safely use
+// Args.hasArg to test whether a boolean flag is present without caring
+// where it appeared. And for this test, it appeared to the left of -gdwarf
+// which made it "win". This test could not detect that bug.
+// RUN: %clang_cl /Z7 -gdwarf /c -### -- %s 2>&1 | FileCheck -check-prefix=Z7_gdwarf %s
+// Z7_gdwarf: "-gcodeview"
+// Z7_gdwarf: "-debug-info-kind=limited"
+// Z7_gdwarf: "-dwarf-version=4"
+
+// RUN: %clang_cl -fmsc-version=1800 -TP -### -- %s 2>&1 | FileCheck -check-prefix=CXX11 %s
+// CXX11: -std=c++11
+
+// RUN: %clang_cl -fmsc-version=1900 -TP -### -- %s 2>&1 | FileCheck -check-prefix=CXX14 %s
+// CXX14: -std=c++14
+
+// 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"
+