//===--- llvmc.cpp - The LLVM Compiler Driver -------------------*- C++ -*-===//
// 
//                     The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
// 
//===----------------------------------------------------------------------===//
//
//  This tool provides a single point of access to the LLVM compilation tools.
//  It has many options. To discover the options supported please refer to the
//  tools' manual page (docs/CommandGuide/html/llvmc.html) or run the tool with
//  the --help option.
// 
//===------------------------------------------------------------------------===

#include "CompilerDriver.h"
#include "ConfigData.h"
#include "llvm/System/Signals.h"
#include "Support/CommandLine.h"
#include <iostream>

using namespace llvm;

namespace {
//===------------------------------------------------------------------------===
//===          PHASE OPTIONS
//===------------------------------------------------------------------------===
static cl::opt<CompilerDriver::Phases> FinalPhase(
  cl::desc("Choose final phase of compilation:"), 
  cl::init(CompilerDriver::LINKING),
  cl::values(
    clEnumValN(CompilerDriver::PREPROCESSING,"E",
      "Stop compilation after pre-processing phase"),
    clEnumValN(CompilerDriver::TRANSLATION, "t",
      "Stop compilation after translation phase"),
    clEnumValN(CompilerDriver::OPTIMIZATION,"c",
      "Stop compilation after optimization phase"),
    clEnumValN(CompilerDriver::ASSEMBLY,"S",
      "Stop compilation after assembly phase"),
    clEnumValEnd
  )
);

//===------------------------------------------------------------------------===
//===          OPTIMIZATION OPTIONS
//===------------------------------------------------------------------------===
static cl::opt<CompilerDriver::OptimizationLevels> OptLevel(
  cl::desc("Choose level of optimization to apply:"),
  cl::init(CompilerDriver::OPT_FAST_COMPILE),
  cl::values(
    clEnumValN(CompilerDriver::OPT_FAST_COMPILE,"O0",
      "An alias for the -O1 option."),
    clEnumValN(CompilerDriver::OPT_FAST_COMPILE,"O1",
      "Optimize for compilation speed, not execution speed."),
    clEnumValN(CompilerDriver::OPT_SIMPLE,"O2",
      "Perform simple translation time optimizations"),
    clEnumValN(CompilerDriver::OPT_AGGRESSIVE,"O3",
      "Perform aggressive translation time optimizations"),
    clEnumValN(CompilerDriver::OPT_LINK_TIME,"O4",
      "Perform link time optimizations"),
    clEnumValN(CompilerDriver::OPT_AGGRESSIVE_LINK_TIME,"O5",
      "Perform aggressive link time optimizations"),
    clEnumValEnd
  )
);

//===------------------------------------------------------------------------===
//===          TOOL OPTIONS
//===------------------------------------------------------------------------===

static cl::opt<std::string> PPToolOpts("Tpp", cl::ZeroOrMore,
  cl::desc("Pass specific options to the pre-processor"), 
  cl::value_desc("option"));

static cl::opt<std::string> AsmToolOpts("Tasm", cl::ZeroOrMore,
  cl::desc("Pass specific options to the assembler"),
  cl::value_desc("option"));

static cl::opt<std::string> OptToolOpts("Topt", cl::ZeroOrMore,
  cl::desc("Pass specific options to the optimizer"),
  cl::value_desc("option"));

static cl::opt<std::string> LinkToolOpts("Tlink", cl::ZeroOrMore,
  cl::desc("Pass specific options to the linker"),
  cl::value_desc("option"));

//===------------------------------------------------------------------------===
//===          INPUT OPTIONS
//===------------------------------------------------------------------------===

static cl::list<std::string> LibPaths("L", cl::Prefix,
  cl::desc("Specify a library search path"), cl::value_desc("directory"));
                                                                                                                                            
static cl::list<std::string> Libraries("l", cl::Prefix,
  cl::desc("Specify libraries to link to"), cl::value_desc("library prefix"));


//===------------------------------------------------------------------------===
//===          OUTPUT OPTIONS
//===------------------------------------------------------------------------===

static cl::opt<std::string> OutputFilename("o", 
  cl::desc("Override output filename"), cl::value_desc("filename"));

static cl::opt<std::string> OutputMachine("m", cl::Prefix,
  cl::desc("Specify a target machine"), cl::value_desc("machine"));
                                                                                                                                            
static cl::opt<bool> Native("native", cl::init(false),
  cl::desc("Generative native object and executables instead of bytecode"));

//===------------------------------------------------------------------------===
//===          INFORMATION OPTIONS
//===------------------------------------------------------------------------===

static cl::opt<bool> DryRun("dry-run", cl::Optional, cl::init(false),
  cl::desc("Do everything but perform the compilation actions"));

static cl::alias DryRunAlias("y", cl::Optional,
  cl::desc("Alias for -dry-run"), cl::aliasopt(DryRun));

static cl::opt<bool> Verbose("verbose", cl::Optional, cl::init(false),
  cl::desc("Print out each action taken"));

static cl::alias VerboseAlias("v", cl::Optional, 
  cl::desc("Alias for -verbose"), cl::aliasopt(Verbose));

static cl::opt<bool> Debug("debug", cl::Optional, cl::init(false), 
  cl::Hidden, cl::desc("Print out debugging information"));

static cl::alias DebugAlias("d", cl::Optional,
  cl::desc("Alias for -debug"), cl::aliasopt(Debug));

static cl::opt<bool> TimeActions("time-actions", cl::Optional, cl::init(false),
  cl::desc("Print execution time for each action taken"));

//===------------------------------------------------------------------------===
//===          ADVANCED OPTIONS
//===------------------------------------------------------------------------===

static cl::opt<std::string> ConfigDir("config-dir", cl::Optional,
  cl::desc("Specify a configuration directory to override defaults"),
  cl::value_desc("directory"));

static cl::opt<bool> EmitRawCode("emit-raw-code", cl::Hidden,
  cl::desc("Emit raw, unoptimized code"));

//===------------------------------------------------------------------------===
//===          POSITIONAL OPTIONS
//===------------------------------------------------------------------------===

static cl::list<std::string> Files(cl::Positional, cl::OneOrMore,
  cl::desc("[Sources/objects/libraries]"));

static cl::list<std::string> Languages("x", cl::ZeroOrMore,
  cl::desc("Specify the source language for subsequent files"),
  cl::value_desc("language"));

//===------------------------------------------------------------------------===
//===          GetFileType - determine type of a file
//===------------------------------------------------------------------------===
const std::string GetFileType(const std::string& fname, unsigned pos ) {
  static std::vector<std::string>::iterator langIt = Languages.begin();
  static std::string CurrLang = "";

  // If a -x LANG option has been specified ..
  if ( langIt != Languages.end() )
    // If the -x LANG option came before the current file on command line
    if ( Languages.getPosition( langIt - Languages.begin() ) < pos ) {
      // use that language
      CurrLang = *langIt++;
      return CurrLang;
    }

  // If there's a current language in effect
  if (!CurrLang.empty())
    return CurrLang; // use that language

  // otherwise just determine lang from the filename's suffix
  return fname.substr( fname.rfind('.',fname.size()) + 1 );
}

} // end anonymous namespace


/// @brief The main program for llvmc
int main(int argc, char **argv) {
  // Make sure we print stack trace if we get bad signals
  PrintStackTraceOnErrorSignal();

  // Parse the command line options
  cl::ParseCommandLineOptions(argc, argv, 
    " LLVM Compilation Driver (llvmc)\n\n"
    "  This program provides easy invocation of the LLVM tool set\n"
    "  and source language compiler tools.\n"
  );

  // Deal with unimplemented options.
  if (Native)
    std::cerr << argv[0] << ": Not implemented yet: -native";
  if (EmitRawCode)
    std::cerr << argv[0] << ": Not implemented yet: -emit-raw-code";

  // Default the output file, only if we're going to try to link
  if (OutputFilename.empty() && OptLevel == CompilerDriver::LINKING)
    OutputFilename = "a.out";

  // Construct the ConfigDataProvider object
  LLVMC_ConfigDataProvider Provider;

  // Construct the CompilerDriver object
  CompilerDriver CD(Provider);

  // Configure the driver based on options
  CD.setVerbose(Verbose);
  CD.setDebug(Debug);
  CD.setDryRun(DryRun);
  CD.setFinalPhase(FinalPhase);
  CD.setOptimization(OptLevel);
  CD.setOutputMachine(OutputMachine);
  CD.setEmitNativeCode(Native);
  CD.setEmitRawCode(EmitRawCode);
  std::vector<std::string>::iterator pathIt = LibPaths.begin();
  while ( pathIt != LibPaths.end() ) {
      CD.addLibraryPath( *pathIt++ );
  }

  // Prepare the list of files to be compiled by the CompilerDriver.
  CompilerDriver::InputList InpList;
  std::vector<std::string>::iterator fileIt = Files.begin();
  std::vector<std::string>::iterator libIt  = Libraries.begin();
  unsigned libPos = 0, filePos = 0;
  while ( 1 ) {
    if ( libIt != Libraries.end() )
      libPos = Libraries.getPosition( libIt - Libraries.begin() );
    else
      libPos = 0;
    if ( fileIt != Files.end() )
      filePos = Files.getPosition( fileIt - Files.begin() );
    else
      filePos = 0;

    if ( filePos != 0 && (libPos == 0 || filePos < libPos) ) {
      // Add a source file
      InpList.push_back( std::make_pair(*fileIt, GetFileType(*fileIt,filePos)));
      ++fileIt;
    }
    else if ( libPos != 0 && (filePos == 0 || libPos < filePos) ) {
      // Add a library
      InpList.push_back( std::make_pair(*libIt++,""));
    }
    else
      break; // we're done with the list
  }

  // Tell the driver to do its thing
  int result = CD.execute(InpList,OutputFilename);
  if (result != 0) {
    std::cerr << argv[0] << ": Error executing actions. Terminated.\n";
    return result;
  }

  // All is good, return success
  return 0;
}