Copy LLVM bitcode reader to generate a PNaCl wire format reader.

tools/pnacl-thaw/pnacl-thaw.cpp

 /* Copyright 2013 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can
  * be found in the LICENSE file.
  */
 
-//===-- pnacl-freeze.cpp - The low-level NaCl bitcode freezer     --------===//
+//===-- pnacl-thaw.cpp - The low-level NaCl bitcode thawer ----------------===//
 //
 //===----------------------------------------------------------------------===//
 //
-// Generates NaCl pexe wire format.
+// Converts NaCl pexe wire format back to LLVM pexe.

[jvoung (off chromium), 2013/04/29 18:02:08]

nit: "pexe" seems like a NaCl thing, so perhaps just call it "LLVM bitcode"
instead of "LLVM pexe" as you do in the help message below.

[Karl, 2013/04/29 20:44:37]

Done.

 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/IR/LLVMContext.h"
-#include "llvm/Assembly/AssemblyAnnotationWriter.h"
+#include "llvm/IR/LLVMContext.h"

[jvoung (off chromium), 2013/04/29 18:02:08]

include the context header only once?

[Karl, 2013/04/29 20:44:37]

Done.

 // Note: We need the following to provide the API for calling the NaCl
-// Bitcode Writer to generate the frozen file.
+// Bitcode Reader to read the frozen file.
 #include "llvm/Bitcode/NaCl/NaClReaderWriter.h"
 // Note: We need the following to provide the API for calling the (LLVM)
-// Bitcode Reader to read in the corresonding pexe file to freeze.
+// Bitcode Writer to generate the corresponding LLVM bitcode file.
 #include "llvm/Bitcode/ReaderWriter.h"
-#include "llvm/DebugInfo.h"

[jvoung (off chromium), 2013/04/29 18:02:08]

can you apply similar cleanup to pnacl-freeze?

[Karl, 2013/04/29 20:44:37]

Done.

-#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/DataStream.h"
-#include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/ManagedStatic.h"
-#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/ToolOutputFile.h"
-#include "llvm/Support/system_error.h"
-
-// llvm/Bitcode/BitstreamWriter.h
 
 using namespace llvm;
 
-
 static cl::opt<std::string>
-OutputFilename("o", cl::desc("Specify output filename"),
+OutputFilename("o", cl::desc("Specify thawed pexe filename"),
                cl::value_desc("filename"));
 
 static cl::opt<std::string>
-InputFilename(cl::Positional, cl::desc("<pexe file>"), cl::Required);
+InputFilename(cl::Positional, cl::desc("<frozen file>"), cl::Required);
 
 static void WriteOutputFile(const Module *M) {
 
-  std::string FrozenFilename =
-    (OutputFilename.size() == 0 ? (InputFilename + ".frozen") : OutputFilename);
+  std::string ThawedFilename =
+    (OutputFilename.size() == 0 ? (InputFilename + ".thawed") : OutputFilename);
 
   std::string ErrorInfo;
   OwningPtr<tool_output_file> Out
-    (new tool_output_file(FrozenFilename.c_str(), ErrorInfo,
+    (new tool_output_file(ThawedFilename.c_str(), ErrorInfo,
                           raw_fd_ostream::F_Binary));
   if (!ErrorInfo.empty()) {
     errs() << ErrorInfo << '\n';
     exit(1);
   }
 
-  NaClWriteBitcodeToFile(M, Out->os());
+  WriteBitcodeToFile(M, Out->os());
 
   // Declare success.
   Out->keep();
 }
 
 int main(int argc, char **argv) {
   // Print a stack trace if we signal out.
   sys::PrintStackTraceOnErrorSignal();
   PrettyStackTraceProgram X(argc, argv);
 
   LLVMContext &Context = getGlobalContext();
   llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
 
-  cl::ParseCommandLineOptions(argc, argv, "Generates NaCl pexe wire format\n");
+  cl::ParseCommandLineOptions(
+      argc, argv, "Converts NaCl pexe wire format into LLVM bitcode format\n");
 
   std::string ErrorMessage;
   std::auto_ptr<Module> M;
 
   // Use the bitcode streaming interface
   DataStreamer *streamer = getDataFileStreamer(InputFilename, &ErrorMessage);
   if (streamer) {
     std::string DisplayFilename = InputFilename;
-    M.reset(getStreamedBitcodeModule(DisplayFilename, streamer, Context,
-                                     &ErrorMessage));
+    M.reset(getNaClStreamedBitcodeModule(DisplayFilename, streamer, Context,
+                                         &ErrorMessage));
     if(M.get() != 0 && M->MaterializeAllPermanently(&ErrorMessage)) {
       M.reset();
     }
   }
 
   if (M.get() == 0) {
     errs() << argv[0] << ": ";
     if (ErrorMessage.size())
       errs() << ErrorMessage << "\n";
     else
       errs() << "bitcode didn't read correctly.\n";
     return 1;
   }
 
   WriteOutputFile(M.get());
   return 0;
 }