Copy Bitwriter to generate PNaClBitwriter.

tools/pnacl-freeze/pnacl-freeze.cpp

+//===-- pnacl-freeze.cpp - The low-level PNaCl bitcode freezer     --------===//
+//
+//===----------------------------------------------------------------------===//
+//
+// This utility may be invoked in the following manner:
+//  llvm-compress [Options] x.bc - read x.bc and generate compressed y.bcc
+//
+//  Options:
+//      --help   - Output information about command line switches
+//

[Karl, 2013/04/24 18:25:59]

Cleaned up comments describing command.

+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/Assembly/AssemblyAnnotationWriter.h"
+#include "llvm/Bitcode/PNaCl/PNaClReaderWriter.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/DebugInfo.h"
+#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"), cl::value_desc("filename"));
+
+static cl::opt<std::string>
+InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::Required);
+
+static void WriteOutputFile(const Module *M) {
+
+  std::string FrozenFilename =
+    (OutputFilename.size() == 0 ? (InputFilename + ".frozen") : OutputFilename);
+
+  std::string ErrorInfo;
+  OwningPtr<tool_output_file> Out
+  (new tool_output_file(FrozenFilename.c_str(), ErrorInfo,
+                        raw_fd_ostream::F_Binary));
+  if (!ErrorInfo.empty()) {
+    errs() << ErrorInfo << '\n';
+    exit(1);
+  }
+
+  PNaClWriteBitcodeToFile(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, "llvm .bc -> .bc compressor\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));
+    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;
+}