[MinGW] Implement the -v and --version flags for the MinGW driver

Differential Revision: https://reviews.llvm.org/D62030

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@361016 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 2 deletions

diff --git a/MinGW/Driver.cpp b/MinGW/Driver.cpp
index 28ce49d6e..36dde8d05 100644
--- a/MinGW/Driver.cpp
+++ b/MinGW/Driver.cpp
@@ -30,6 +30,7 @@
 
 #include "lld/Common/Driver.h"
 #include "lld/Common/ErrorHandler.h"
+#include "lld/Common/Version.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringExtras.h"
@@ -139,6 +140,21 @@ bool mingw::link(ArrayRef<const char *> ArgsArr, raw_ostream &Diag) {
     return true;
   }
 
+  // A note about "compatible with GNU linkers" message: this is a hack for
+  // scripts generated by GNU Libtool 2.4.6 (released in February 2014 and
+  // still the newest version in March 2017) or earlier to recognize LLD as
+  // a GNU compatible linker. As long as an output for the -v option
+  // contains "GNU" or "with BFD", they recognize us as GNU-compatible.
+  if (Args.hasArg(OPT_v) || Args.hasArg(OPT_version))
+    message(getLLDVersion() + " (compatible with GNU linkers)");
+
+  // The behavior of -v or --version is a bit strange, but this is
+  // needed for compatibility with GNU linkers.
+  if (Args.hasArg(OPT_v) && !Args.hasArg(OPT_INPUT) && !Args.hasArg(OPT_l))
+    return true;
+  if (Args.hasArg(OPT_version))
+    return true;
+
   if (!Args.hasArg(OPT_INPUT) && !Args.hasArg(OPT_l))
     fatal("no input files");
 
diff --git a/MinGW/Options.td b/MinGW/Options.td
index b6e6b09c7..eff46a972 100644
--- a/MinGW/Options.td
+++ b/MinGW/Options.td
@@ -48,7 +48,9 @@ def strip_debug: F<"strip-debug">,
     HelpText<"Omit all debug information, but keep symbol information">;
 def whole_archive: F<"whole-archive">,
     HelpText<"Include all object files for following archives">;
+def v: Flag<["-"], "v">, HelpText<"Display the version number">;
 def verbose: F<"verbose">, HelpText<"Verbose mode">;
+def version: F<"version">, HelpText<"Display the version number and exit">;
 def require_defined: S<"require-defined">,
     HelpText<"Force symbol to be added to symbol table as an undefined one">;
 def require_defined_eq: J<"require-defined=">, Alias<require_defined>;
@@ -90,5 +92,3 @@ def: J<"plugin-opt=">;
 def: J<"sysroot">;
 def: F<"start-group">;
 def: F<"tsaware">;
-def: Flag<["-"], "v">;
-def: F<"version">;