[llvm-mc] Better error handling in ENOENT case + test.

This is a follow up to r247518.
As a general note, I think we could do a much better job testing for
error conditions in tools. I already anticipated in a previous mail,
but while implementing this I noticed that the code coverage we have
for error checking is pretty low. I can arbitrarily remove checks from
several tools and the suite still passes.

Differential Revision:	 http://reviews.llvm.org/D12846

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247582 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/tools/llvm-mc/basic.test b/test/tools/llvm-mc/basic.test
new file mode 100644 (file)
index 0000000..69d8f31
--- /dev/null
+++ b/test/tools/llvm-mc/basic.test
@@ -0,0 +1,2 @@
+# RUN: not llvm-mc %t.blah -o %t2 2>&1 | FileCheck --check-prefix=ENOENT %s
+# ENOENT: {{.*}}.blah: {{[Nn]}}o such file or directory

diff --git a/tools/llvm-mc/llvm-mc.cpp b/tools/llvm-mc/llvm-mc.cpp
index 678ad3603300f887811eda6e55dc12d89707ffa4..6e6b748c3d29d7d44cd3f46c2afa06bc8397812e 100644 (file)
--- a/tools/llvm-mc/llvm-mc.cpp
+++ b/tools/llvm-mc/llvm-mc.cpp
@@ -395,15 +395,10 @@ int main(int argc, char **argv) {
   // construct the Triple object.
   Triple TheTriple(TripleName);
 
-  if (InputFilename != "-" && !sys::fs::exists(InputFilename)) {
-    errs() << ProgName << ": '" << InputFilename << "': "
-           << "No such file\n";
-    return 1;
-  }
   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr =
       MemoryBuffer::getFileOrSTDIN(InputFilename);
   if (std::error_code EC = BufferPtr.getError()) {
-    errs() << ProgName << ": " << EC.message() << '\n';
+    errs() << InputFilename << ": " << EC.message() << '\n';
     return 1;
   }
   MemoryBuffer *Buffer = BufferPtr->get();