diff --git a/clang/test/Driver/flang/flang.f90 b/clang/test/Driver/flang/flang.f90
new file mode 100644
index 0000000000000..9d47c7c90225c
--- /dev/null
+++ b/clang/test/Driver/flang/flang.f90
@@ -0,0 +1,51 @@
+! Check that flang -fc1 is invoked when in --driver-mode=flang.
+
+! This is a copy of flang_ucase.F90 because the driver has logic in it which
+! differentiates between F90 and f90 files. Flang will not treat these files
+! differently.
+
+! Test various output types:
+! * -E
+! * -fsyntax-only
+! * -emit-llvm -S
+! * -emit-llvm
+! * -S
+! * (no type specified, resulting in an object file)
+
+! All invocations should begin with flang -fc1, consume up to here.
+! ALL-LABEL: "{{[^"]*}}flang" "-fc1"
+
+! Check that f90 files are not treated as "previously preprocessed"
+! ... in --driver-mode=flang.
+! RUN: %clang --driver-mode=flang -### -E                  %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-E %s
+! CHECK-E-NOT: previously preprocessed input
+! CHECK-E-DAG: "-E"
+! CHECK-E-DAG: "-o" "-"
+
+! RUN: %clang --driver-mode=flang -### -emit-ast           %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-AST %s
+! CHECK-EMIT-AST-DAG: "-triple"
+! CHECK-EMIT-AST-DAG: "-emit-ast"
+! CHECK-EMIT-AST-DAG: "-o" "{{[^"]*}}.ast"
+
+! RUN: %clang --driver-mode=flang -### -fsyntax-only       %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-SYNTAX-ONLY %s
+! CHECK-SYNTAX-ONLY-NOT: "-o"
+! CHECK-SYNTAX-ONLY-DAG: "-fsyntax-only"
+
+! RUN: %clang --driver-mode=flang -### -emit-llvm -S       %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-LLVM-IR %s
+! CHECK-EMIT-LLVM-IR-DAG: "-emit-llvm"
+! CHECK-EMIT-LLVM-IR-DAG: "-o" "{{[^"]*}}.ll"
+
+! RUN: %clang --driver-mode=flang -### -emit-llvm          %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-LLVM-BC %s
+! CHECK-EMIT-LLVM-BC-DAG: "-emit-llvm-bc"
+! CHECK-EMIT-LLVM-BC-DAG: "-o" "{{[^"]*}}.bc"
+
+! RUN: %clang --driver-mode=flang -### -S                  %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-S %s
+! CHECK-S-DAG: "-S"
+! CHECK-S-DAG: "-o" "{{[^"]*}}.s"
+
+! RUN: %clang --driver-mode=flang -###                     %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-OBJ %s
+! CHECK-EMIT-OBJ-DAG: "-emit-obj"
+! CHECK-EMIT-OBJ-DAG: "-o" "{{[^"]*}}.o"
+
+! Should end in the input file.
+! ALL: "{{.*}}flang.f90"{{$}}
diff --git a/clang/test/Driver/flang/flang_ucase.F90 b/clang/test/Driver/flang/flang_ucase.F90
new file mode 100644
index 0000000000000..323afb21dccf5
--- /dev/null
+++ b/clang/test/Driver/flang/flang_ucase.F90
@@ -0,0 +1,51 @@
+! Check that flang -fc1 is invoked when in --driver-mode=flang.
+
+! This is a copy of flang.f90 because the driver has logic in it which
+! differentiates between F90 and f90 files. Flang will not treat these files
+! differently.
+
+! Test various output types:
+! * -E
+! * -fsyntax-only
+! * -emit-llvm -S
+! * -emit-llvm
+! * -S
+! * (no type specified, resulting in an object file)
+
+! All invocations should begin with flang -fc1, consume up to here.
+! ALL-LABEL: "{{[^"]*}}flang" "-fc1"
+
+! Check that f90 files are not treated as "previously preprocessed"
+! ... in --driver-mode=flang.
+! RUN: %clang --driver-mode=flang -### -E                  %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-E %s
+! CHECK-E-NOT: previously preprocessed input
+! CHECK-E-DAG: "-E"
+! CHECK-E-DAG: "-o" "-"
+
+! RUN: %clang --driver-mode=flang -### -emit-ast           %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-AST %s
+! CHECK-EMIT-AST-DAG: "-triple"
+! CHECK-EMIT-AST-DAG: "-emit-ast"
+! CHECK-EMIT-AST-DAG: "-o" "{{[^"]*}}.ast"
+
+! RUN: %clang --driver-mode=flang -### -fsyntax-only       %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-SYNTAX-ONLY %s
+! CHECK-SYNTAX-ONLY-NOT: "-o"
+! CHECK-SYNTAX-ONLY-DAG: "-fsyntax-only"
+
+! RUN: %clang --driver-mode=flang -### -emit-llvm -S       %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-LLVM-IR %s
+! CHECK-EMIT-LLVM-IR-DAG: "-emit-llvm"
+! CHECK-EMIT-LLVM-IR-DAG: "-o" "{{[^"]*}}.ll"
+
+! RUN: %clang --driver-mode=flang -### -emit-llvm          %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-LLVM-BC %s
+! CHECK-EMIT-LLVM-BC-DAG: "-emit-llvm-bc"
+! CHECK-EMIT-LLVM-BC-DAG: "-o" "{{[^"]*}}.bc"
+
+! RUN: %clang --driver-mode=flang -### -S                  %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-S %s
+! CHECK-S-DAG: "-S"
+! CHECK-S-DAG: "-o" "{{[^"]*}}.s"
+
+! RUN: %clang --driver-mode=flang -###                     %s 2>&1 | FileCheck --check-prefixes=ALL,CHECK-EMIT-OBJ %s
+! CHECK-EMIT-OBJ-DAG: "-emit-obj"
+! CHECK-EMIT-OBJ-DAG: "-o" "{{[^"]*}}.o"
+
+! Should end in the input file.
+! ALL: "{{.*}}flang_ucase.F90"{{$}}