llc: Add ability to parse mir from stdin

- Add -x <language> option to switch between IR and MIR inputs.
- Change MIR parser to read from stdin when filename is '-'.
- Add a simple mir roundtrip test.

llvm-svn: 304825

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index cdeba007458..78b57f35778 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -869,7 +869,7 @@ bool MIRParser::parseMachineFunctions(Module &M, MachineModuleInfo &MMI) {
 std::unique_ptr<MIRParser> llvm::createMIRParserFromFile(StringRef Filename,
                                                          SMDiagnostic &Error,
                                                          LLVMContext &Context) {
-  auto FileOrErr = MemoryBuffer::getFile(Filename);
+  auto FileOrErr = MemoryBuffer::getFileOrSTDIN(Filename);
   if (std::error_code EC = FileOrErr.getError()) {
     Error = SMDiagnostic(Filename, SourceMgr::DK_Error,
                          "Could not open input file: " + EC.message());