Add llvm-rs-as tool.

This tool takes an .ll file as input and generates bitcode from it.
The -bitcode-version flags allows to specify the version of the
bitcode that should be emitted.

Change-Id: I08b4f1fd0d7b218613e217249e648c9ca4393e38

1 files changed, 151 insertions, 0 deletions

diff --git a/llvm-rs-as.cpp b/llvm-rs-as.cpp
new file mode 100644
index 0000000..979c28a
--- /dev/null
+++ b/llvm-rs-as.cpp
@@ -0,0 +1,151 @@
+//===--- llvm-as.cpp - The low-level LLVM assembler -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This utility may be invoked in the following manner:
+//   llvm-as --help         - Output information about command line switches
+//   llvm-as [options]      - Read LLVM asm from stdin, write bitcode to stdout
+//   llvm-as [options] x.ll - Read LLVM asm from the x.ll file, write bitcode
+//                            to the x.bc file.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Assembly/Parser.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/SystemUtils.h"
+#include "llvm/Support/ToolOutputFile.h"
+
+#include "BitWriter_3_2/ReaderWriter_3_2.h"
+#include "BitWriter_2_9/ReaderWriter_2_9.h"
+#include "BitWriter_2_9_func/ReaderWriter_2_9_func.h"
+
+#include <memory>
+using namespace llvm;
+
+static cl::opt<std::string>
+InputFilename(cl::Positional, cl::desc("<input .llvm file>"), cl::init("-"));
+
+static cl::opt<std::string>
+OutputFilename("o", cl::desc("Override output filename"),
+               cl::value_desc("filename"));
+
+static cl::opt<bool>
+Force("f", cl::desc("Enable binary output on terminals"));
+
+static cl::opt<bool>
+DisableOutput("disable-output", cl::desc("Disable output"), cl::init(false));
+
+static cl::opt<bool>
+DumpAsm("d", cl::desc("Print assembly as parsed"), cl::Hidden);
+
+static cl::opt<bool>
+DisableVerify("disable-verify", cl::Hidden,
+              cl::desc("Do not run verifier on input LLVM (dangerous!)"));
+
+enum BCVersion {
+  BC29, BC29Func, BC32, BCHEAD
+};
+
+cl::opt<BCVersion> BitcodeVersion("bitcode-version",
+  cl::desc("Set the bitcode version to be written:"),
+  cl::values(
+    clEnumValN(BC29, "BC29", "Version 2.9"),
+     clEnumVal(BC29Func,     "Version 2.9 func"),
+     clEnumVal(BC32,         "Version 3.2"),
+     clEnumVal(BCHEAD,       "Most current version"),
+    clEnumValEnd), cl::init(BC32));
+
+static void WriteOutputFile(const Module *M) {
+  // Infer the output filename if needed.
+  if (OutputFilename.empty()) {
+    if (InputFilename == "-") {
+      OutputFilename = "-";
+    } else {
+      std::string IFN = InputFilename;
+      int Len = IFN.length();
+      if (IFN[Len-3] == '.' && IFN[Len-2] == 'l' && IFN[Len-1] == 'l') {
+        // Source ends in .ll
+        OutputFilename = std::string(IFN.begin(), IFN.end()-3);
+      } else {
+        OutputFilename = IFN;   // Append a .bc to it
+      }
+      OutputFilename += ".bc";
+    }
+  }
+
+  std::string ErrorInfo;
+  OwningPtr<tool_output_file> Out
+  (new tool_output_file(OutputFilename.c_str(), ErrorInfo,
+                        raw_fd_ostream::F_Binary));
+  if (!ErrorInfo.empty()) {
+    errs() << ErrorInfo << '\n';
+    exit(1);
+  }
+
+  if (Force || !CheckBitcodeOutputToConsole(Out->os(), true)) {
+    switch(BitcodeVersion) {
+      case BC29:
+        llvm_2_9::WriteBitcodeToFile(M, Out->os());
+        break;
+      case BC29Func:
+        llvm_2_9_func::WriteBitcodeToFile(M, Out->os());
+        break;
+      case BC32:
+        llvm_3_2::WriteBitcodeToFile(M, Out->os());
+        break;
+      case BCHEAD:
+        llvm::WriteBitcodeToFile(M, Out->os());
+        break;
+    }
+  }
+
+  // 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 .ll -> .bc assembler\n");
+
+  // Parse the file now...
+  SMDiagnostic Err;
+  OwningPtr<Module> M(ParseAssemblyFile(InputFilename, Err, Context));
+  if (M.get() == 0) {
+    Err.print(argv[0], errs());
+    return 1;
+  }
+
+  if (!DisableVerify) {
+    std::string Err;
+    if (verifyModule(*M.get(), ReturnStatusAction, &Err)) {
+      errs() << argv[0]
+             << ": assembly parsed, but does not verify as correct!\n";
+      errs() << Err;
+      return 1;
+    }
+  }
+
+  if (DumpAsm) errs() << "Here's the assembly:\n" << *M.get();
+
+  if (!DisableOutput)
+    WriteOutputFile(M.get());
+
+  return 0;
+}