From 6f750292da7ccc66cffd6d51767d7f135bbc8392 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Wed, 13 Apr 2016 19:36:04 +0000
Subject: [PATCH] LibDriver: Silently do nothing when provided no inputs.

This behavior is strange, but it matches lib.exe. Based on a patch by
Nico Weber.

Fixes PR27335.

llvm-svn: 266236
---
 lib/LibDriver/LibDriver.cpp   | 4 ++--
 test/LibDriver/no-inputs.test | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)
 create mode 100644 test/LibDriver/no-inputs.test

diff --git a/lib/LibDriver/LibDriver.cpp b/lib/LibDriver/LibDriver.cpp
index 3ae54346074..671cc73c576 100644
--- a/lib/LibDriver/LibDriver.cpp
+++ b/lib/LibDriver/LibDriver.cpp
@@ -122,8 +122,8 @@ int llvm::libDriverMain(llvm::ArrayRef<const char*> ArgsArr) {
     llvm::errs() << "ignoring unknown argument: " << Arg->getSpelling() << "\n";
 
   if (Args.filtered_begin(OPT_INPUT) == Args.filtered_end()) {
-    llvm::errs() << "no input files.\n";
-    return 1;
+    // No input files.  To match lib.exe, silently do nothing.
+    return 0;
   }
 
   std::vector<StringRef> SearchPaths = getSearchPaths(&Args, Saver);
diff --git a/test/LibDriver/no-inputs.test b/test/LibDriver/no-inputs.test
new file mode 100644
index 00000000000..95d6555d58c
--- /dev/null
+++ b/test/LibDriver/no-inputs.test
@@ -0,0 +1,2 @@
+RUN: llvm-lib -out:%t.a
+RUN: test ! -e %t.a