Allow -MF to be used in combination with -E -M or -E -MM.

Fixes PR13851. Patch by Dimitry Andric!

llvm-svn: 164717

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index f77d8ee..12564b4 100644 (file)
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -219,11 +219,11 @@ void Clang::AddPreprocessingOptions(Compilation &C,
       (A = Args.getLastArg(options::OPT_MMD))) {
     // Determine the output location.
     const char *DepFile;
-    if (Output.getType() == types::TY_Dependencies) {
-      DepFile = Output.getFilename();
-    } else if (Arg *MF = Args.getLastArg(options::OPT_MF)) {
+    if (Arg *MF = Args.getLastArg(options::OPT_MF)) {
       DepFile = MF->getValue(Args);
       C.addFailureResultFile(DepFile);
+    } else if (Output.getType() == types::TY_Dependencies) {
+      DepFile = Output.getFilename();
     } else if (A->getOption().matches(options::OPT_M) ||
                A->getOption().matches(options::OPT_MM)) {
       DepFile = "-";

diff --git a/clang/test/Preprocessor/pr13851.c b/clang/test/Preprocessor/pr13851.c
new file mode 100644 (file)
index 0000000..537594d
--- /dev/null
+++ b/clang/test/Preprocessor/pr13851.c
@@ -0,0 +1,11 @@
+// Check that -E -M -MF does not cause an "argument unused" error, by adding
+// -Werror to the clang invocation.  Also check the dependency output, if any.
+// RUN: %clang -Werror -E -M -MF %t-M.d %s
+// RUN: FileCheck --input-file=%t-M.d %s
+// CHECK: pr13851.o:
+// CHECK: pr13851.c
+
+// Check that -E -MM -MF does not cause an "argument unused" error, by adding
+// -Werror to the clang invocation.  Also check the dependency output, if any.
+// RUN: %clang -Werror -E -MM -MF %t-MM.d %s
+// RUN: FileCheck --input-file=%t-MM.d %s