//===- RustWrapper.cpp - Rust wrapper for core functions --------*- C++ -*-===
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===
//
// This file defines alternate interfaces to core functions that are more
// readily callable by Rust's FFI.
//
//===----------------------------------------------------------------------===

#include "llvm/LLVMContext.h"
#include "llvm/Linker.h"
#include "llvm/PassManager.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Assembly/Parser.h"
#include "llvm/Assembly/PrintModulePass.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/Host.h"
#include "llvm-c/Core.h"
#include "llvm-c/BitReader.h"
#include "llvm-c/Object.h"
#include <cstdlib>

using namespace llvm;

static const char *LLVMRustError;

extern "C" LLVMMemoryBufferRef
LLVMRustCreateMemoryBufferWithContentsOfFile(const char *Path) {
  LLVMMemoryBufferRef MemBuf = NULL;
  LLVMCreateMemoryBufferWithContentsOfFile(Path, &MemBuf,
    const_cast<char **>(&LLVMRustError));
  return MemBuf;
}

extern "C" const char *LLVMRustGetLastError(void) {
  return LLVMRustError;
}

extern "C" void LLVMAddBasicAliasAnalysisPass(LLVMPassManagerRef PM);

extern "C" void LLVMRustAddPrintModulePass(LLVMPassManagerRef PMR,
                                           LLVMModuleRef M,
                                           const char* path) {
  PassManager *PM = unwrap<PassManager>(PMR);
  std::string ErrorInfo;
  raw_fd_ostream OS(path, ErrorInfo, raw_fd_ostream::F_Binary);
  formatted_raw_ostream FOS(OS);
  PM->add(createPrintModulePass(&FOS));
  PM->run(*unwrap(M));
}

extern "C" bool LLVMLinkModules(LLVMModuleRef Dest, LLVMModuleRef Src) {
  static std::string err;

  // For some strange reason, unwrap() doesn't work here. "No matching
  // function" error.
  Module *DM = reinterpret_cast<Module *>(Dest);
  Module *SM = reinterpret_cast<Module *>(Src);
  if (Linker::LinkModules(DM, SM, Linker::DestroySource, &err)) {
    LLVMRustError = err.c_str();
    return false;
  }
  return true;
}

extern "C" void
LLVMRustWriteOutputFile(LLVMPassManagerRef PMR,
                        LLVMModuleRef M,
                        const char *triple,
                        const char *path,
                        TargetMachine::CodeGenFileType FileType,
                        CodeGenOpt::Level OptLevel,
			bool EnableSegmentedStacks) {

  InitializeAllTargets();
  InitializeAllTargetMCs();
  InitializeAllAsmPrinters();
  InitializeAllAsmParsers();

  TargetOptions Options;
  Options.NoFramePointerElim = true;
  Options.EnableSegmentedStacks = EnableSegmentedStacks;

  std::string Err;
  const Target *TheTarget = TargetRegistry::lookupTarget(triple, Err);
  std::string FeaturesStr;
  std::string Trip(triple);
  std::string CPUStr = llvm::sys::getHostCPUName();
  TargetMachine *Target =
    TheTarget->createTargetMachine(Trip, CPUStr, FeaturesStr,
				   Options, Reloc::PIC_,
				   CodeModel::Default, OptLevel);
  bool NoVerify = false;
  PassManager *PM = unwrap<PassManager>(PMR);
  std::string ErrorInfo;
  raw_fd_ostream OS(path, ErrorInfo,
                    raw_fd_ostream::F_Binary);
  formatted_raw_ostream FOS(OS);

  bool foo = Target->addPassesToEmitFile(*PM, FOS, FileType, NoVerify);
  assert(!foo);
  (void)foo;
  PM->run(*unwrap(M));
  delete Target;
}

extern "C" LLVMModuleRef LLVMRustParseAssemblyFile(const char *Filename) {

  SMDiagnostic d;
  Module *m = ParseAssemblyFile(Filename, d, getGlobalContext());
  if (m) {
    return wrap(m);
  } else {
    LLVMRustError = d.getMessage().c_str();
    return NULL;
  }
}

extern "C" LLVMModuleRef LLVMRustParseBitcode(LLVMMemoryBufferRef MemBuf) {
  LLVMModuleRef M;
  return LLVMParseBitcode(MemBuf, &M, const_cast<char **>(&LLVMRustError))
         ? NULL : M;
}

extern "C" LLVMValueRef LLVMRustConstSmallInt(LLVMTypeRef IntTy, unsigned N,
                                              LLVMBool SignExtend) {
  return LLVMConstInt(IntTy, (unsigned long long)N, SignExtend);
}

extern "C" LLVMValueRef LLVMRustConstInt(LLVMTypeRef IntTy, 
					 unsigned N_hi,
					 unsigned N_lo,
					 LLVMBool SignExtend) {
  unsigned long long N = N_hi;
  N <<= 32;
  N |= N_lo;
  return LLVMConstInt(IntTy, N, SignExtend);
}

extern bool llvm::TimePassesIsEnabled;
extern "C" void LLVMRustEnableTimePasses() {
  TimePassesIsEnabled = true;
}

extern "C" void LLVMRustPrintPassTimings() {
  raw_fd_ostream OS (2, false); // stderr.
  TimerGroup::printAll(OS);
}

extern "C" LLVMValueRef LLVMGetOrInsertFunction(LLVMModuleRef M,
                                                const char* Name,
                                                LLVMTypeRef FunctionTy) {
  return wrap(unwrap(M)->getOrInsertFunction(Name,
                                             unwrap<FunctionType>(FunctionTy)));
}

extern "C" LLVMTypeRef LLVMMetadataTypeInContext(LLVMContextRef C) {
  return wrap(Type::getMetadataTy(*unwrap(C)));
}
extern "C" LLVMTypeRef LLVMMetadataType(void) {
  return LLVMMetadataTypeInContext(LLVMGetGlobalContext());
}