text: //===---- IRReader.cpp - Reader for LLVM IR files -------------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm/IRReader/IRReader.h"
  // #include "llvm-c/Core.h"
  // #include "llvm-c/IRReader.h"
  #include "llvm/AsmParser/Parser.h"
  #include "llvm/Bitcode/ReaderWriter.h"
  #include "llvm/IR/LLVMContext.h"
  #include "llvm/IR/Module.h"
  #include "llvm/Support/MemoryBuffer.h"
  #include "llvm/Support/SourceMgr.h"
  #include "llvm/Support/Timer.h"
  #include "llvm/Support/raw_ostream.h"
  #include <system_error>
  
  using namespace llvm;
  
  namespace llvm {
    extern bool TimePassesIsEnabled;
  }
  
  static const char *const TimeIRParsingGroupName = "LLVM IR Parsing";
  static const char *const TimeIRParsingName = "Parse IR";
  
  static std::unique_ptr<Module>
  getLazyIRModule(std::unique_ptr<MemoryBuffer> Buffer, SMDiagnostic &Err,
                  LLVMContext &Context) {
    if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
                  (const unsigned char *)Buffer->getBufferEnd())) {
      ErrorOr<std::unique_ptr<Module>> ModuleOrErr =
          getLazyBitcodeModule(std::move(Buffer), Context);
      if (std::error_code EC = ModuleOrErr.getError()) {
        Err = SMDiagnostic(Buffer->getBufferIdentifier(), SourceMgr::DK_Error,
                           EC.message());
        return nullptr;
      }
      return std::move(ModuleOrErr.get());
    }
  
    return parseAssembly(Buffer->getMemBufferRef(), Err, Context);
  }
  
  std::unique_ptr<Module> llvm::getLazyIRFileModule(StringRef Filename,
                                                    SMDiagnostic &Err,
                                                    LLVMContext &Context) {
    ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
        MemoryBuffer::getFileOrSTDIN(Filename);
    if (std::error_code EC = FileOrErr.getError()) {
      Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
                         "Could not open input file: " + EC.message());
      return nullptr;
    }
  
    return getLazyIRModule(std::move(FileOrErr.get()), Err, Context);
  }
  
  std::unique_ptr<Module> llvm::parseIR(MemoryBufferRef Buffer, SMDiagnostic &Err,
                                        LLVMContext &Context) {
    NamedRegionTimer T(TimeIRParsingName, TimeIRParsingGroupName,
                       TimePassesIsEnabled);
    if (isBitcode((const unsigned char *)Buffer.getBufferStart(),
                  (const unsigned char *)Buffer.getBufferEnd())) {
      ErrorOr<std::unique_ptr<Module>> ModuleOrErr =
          parseBitcodeFile(Buffer, Context);
      if (std::error_code EC = ModuleOrErr.getError()) {
        Err = SMDiagnostic(Buffer.getBufferIdentifier(), SourceMgr::DK_Error,
                           EC.message());
        return nullptr;
      }
      return std::move(ModuleOrErr.get());
    }
  
    return parseAssembly(Buffer, Err, Context);
  }
  
  std::unique_ptr<Module> llvm::parseIRFile(StringRef Filename, SMDiagnostic &Err,
                                            LLVMContext &Context) {
    ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
        MemoryBuffer::getFileOrSTDIN(Filename);
    if (std::error_code EC = FileOrErr.getError()) {
      Err = SMDiagnostic(Filename, SourceMgr::DK_Error,
                         "Could not open input file: " + EC.message());
      return nullptr;
    }
  
    return parseIR(FileOrErr.get()->getMemBufferRef(), Err, Context);
  }
  
  #if 0 // HLSL Change Starts
  
  //===----------------------------------------------------------------------===//
  // C API.
  //===----------------------------------------------------------------------===//
  
  LLVMBool LLVMParseIRInContext(LLVMContextRef ContextRef,
                                LLVMMemoryBufferRef MemBuf, LLVMModuleRef *OutM,
                                char **OutMessage) {
    SMDiagnostic Diag;
  
    std::unique_ptr<MemoryBuffer> MB(unwrap(MemBuf));
    *OutM =
        wrap(parseIR(MB->getMemBufferRef(), Diag, *unwrap(ContextRef)).release());
  
    if(!*OutM) {
      if (OutMessage) {
        std::string buf;
        raw_string_ostream os(buf);
  
        Diag.print(nullptr, os, false);
        os.flush();
  
        *OutMessage = _strdup(buf.c_str());
      }
      return 1;
    }
  
    return 0;
  }
  
  #endif // HLSL Change Ends
  