Allow pnacl-freeze/thaw to redirect to stdin/stdout.

tools/pnacl-thaw/pnacl-thaw.cpp

Index: tools/pnacl-thaw/pnacl-thaw.cpp
diff --git a/tools/pnacl-thaw/pnacl-thaw.cpp b/tools/pnacl-thaw/pnacl-thaw.cpp
index b28c357165779af6ec11dd6e5e19cb225e8b7f31..6d23f69fde71c0f575eaf56e019c645d53367ef8 100644
--- a/tools/pnacl-thaw/pnacl-thaw.cpp
+++ b/tools/pnacl-thaw/pnacl-thaw.cpp
@@ -33,12 +33,19 @@ OutputFilename("o", cl::desc("Specify thawed pexe filename"),
 	       cl::value_desc("filename"));
 
 static cl::opt<std::string>
-InputFilename(cl::Positional, cl::desc("<frozen file>"), cl::Required);
+InputFilename(cl::Positional, cl::desc("<frozen file>"), cl::init("-"));
 
 static void WriteOutputFile(const Module *M) {
 
-  std::string ThawedFilename =
-    (OutputFilename.size() == 0 ? (InputFilename + ".thawed") : OutputFilename);
+  std::string ThawedFilename(OutputFilename);
+  if (OutputFilename.size() == 0) {
+    std::string input_filename;
+    if (InputFilename == "-")
+      input_filename = "<stdin>";
+    else
+      input_filename = InputFilename;
+    ThawedFilename = input_filename + ".thawed";
+  }
 
   std::string ErrorInfo;
   OwningPtr<tool_output_file> Out
@@ -72,7 +79,11 @@ int main(int argc, char **argv) {
   // Use the bitcode streaming interface
   DataStreamer *streamer = getDataFileStreamer(InputFilename, &ErrorMessage);
   if (streamer) {
-    std::string DisplayFilename = InputFilename;
+    std::string DisplayFilename;
+    if (InputFilename == "-")
+      DisplayFilename = "<stdin>";
+    else
+      DisplayFilename = InputFilename;
     M.reset(getNaClStreamedBitcodeModule(DisplayFilename, streamer, Context,
                                          &ErrorMessage));
     if(M.get() != 0 && M->MaterializeAllPermanently(&ErrorMessage)) {