//===- CompilerDriver.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 file implements the bulk of the LLVM Compiler Driver (llvmc).
//
//===------------------------------------------------------------------------===

#include "CompilerDriver.h"
#include "ConfigLexer.h"
#include "llvm/Module.h"
#include "llvm/Bytecode/Reader.h"
#include "Support/FileUtilities.h"
#include "Support/SetVector.h"
#include "Support/StringExtras.h"
#include <iostream>

using namespace llvm;

namespace {

  void WriteAction(CompilerDriver::Action* action ) {
    std::cerr << action->program.c_str();
    std::vector<std::string>::iterator I = action->args.begin();
    while (I != action->args.end()) {
      std::cerr << " " + *I;
      ++I;
    }
    std::cerr << "\n";
  }

  void DumpAction(CompilerDriver::Action* action) {
    std::cerr << "command = " << action->program.c_str();
    std::vector<std::string>::iterator I = action->args.begin();
    while (I != action->args.end()) {
      std::cerr << " " + *I;
      ++I;
    }
    std::cerr << "\n";
    std::cerr << "flags = " << action->flags << "\n";
  }

  void DumpConfigData(CompilerDriver::ConfigData* cd, const std::string& type ){
    std::cerr << "Configuration Data For '" << cd->langName << "' (" << type 
      << ")\n";
    std::cerr << "PreProcessor: ";
    DumpAction(&cd->PreProcessor);
    std::cerr << "Translator: ";
    DumpAction(&cd->Translator);
    std::cerr << "Optimizer: ";
    DumpAction(&cd->Optimizer);
    std::cerr << "Assembler: ";
    DumpAction(&cd->Assembler);
    std::cerr << "Linker: ";
    DumpAction(&cd->Linker);
  }

  /// This specifies the passes to run for OPT_FAST_COMPILE (-O1)
  /// which should reduce the volume of code and make compilation
  /// faster. This is also safe on any llvm module. 
  static const char* DefaultFastCompileOptimizations[] = {
    "-simplifycfg", "-mem2reg", "-instcombine"
  };

  class CompilerDriverImpl : public CompilerDriver {
    /// @name Constructors
    /// @{
    public:
      CompilerDriverImpl(ConfigDataProvider& confDatProv )
        : cdp(&confDatProv)
        , finalPhase(LINKING)
        , optLevel(OPT_FAST_COMPILE) 
        , Flags(0)
        , machine()
        , LibraryPaths()
        , TempDir()
        , AdditionalArgs()
      {
        TempDir = sys::Path::GetTemporaryDirectory();
        sys::RemoveDirectoryOnSignal(TempDir);
        AdditionalArgs.reserve(NUM_PHASES);
        StringVector emptyVec;
        for (unsigned i = 0; i < NUM_PHASES; ++i)
          AdditionalArgs.push_back(emptyVec);
      }

      virtual ~CompilerDriverImpl() {
        cleanup();
        cdp = 0;
        LibraryPaths.clear();
        AdditionalArgs.clear();
      }

    /// @}
    /// @name Methods
    /// @{
    public:
      virtual void setFinalPhase( Phases phase ) { 
        finalPhase = phase; 
      }

      virtual void setOptimization( OptimizationLevels level ) { 
        optLevel = level; 
      }

      virtual void setDriverFlags( unsigned flags ) {
        Flags = flags & DRIVER_FLAGS_MASK; 
      }

      virtual void setOutputMachine( const std::string& machineName ) {
        machine = machineName;
      }

      virtual void setPhaseArgs(Phases phase, const StringVector& opts) {
        assert(phase <= LINKING && phase >= PREPROCESSING);
        AdditionalArgs[phase] = opts;
      }

      virtual void setLibraryPaths(const StringVector& paths) {
        StringVector::const_iterator I = paths.begin();
        StringVector::const_iterator E = paths.end();
        while (I != E) {
          sys::Path tmp;
          tmp.set_directory(*I);
          LibraryPaths.push_back(tmp);
          ++I;
        }
      }

      virtual void addLibraryPath( const sys::Path& libPath ) {
        LibraryPaths.push_back(libPath);
      }

    /// @}
    /// @name Functions
    /// @{
    private:
      bool isSet(DriverFlags flag) {
        return 0 != ((flag & DRIVER_FLAGS_MASK) & Flags);
      }

      void cleanup() {
        if (!isSet(KEEP_TEMPS_FLAG)) {
          if (TempDir.is_directory() && TempDir.writable())
            TempDir.destroy_directory(/*remove_contents=*/true);
        } else {
          std::cout << "Temporary files are in " << TempDir.get() << "\n";
        }
      }

      sys::Path MakeTempFile(const std::string& basename, const std::string& suffix ) {
        sys::Path result(TempDir);
        if (!result.append_file(basename))
          throw basename + ": can't use this file name";
        if (!result.append_suffix(suffix))
          throw suffix + ": can't use this file suffix";
        return result;
      }

      Action* GetAction(ConfigData* cd, 
                        const sys::Path& input, 
                        const sys::Path& output,
                        Phases phase)
      {
        Action* pat = 0; ///< The pattern/template for the action
        Action* action = new Action; ///< The actual action to execute

        // Get the action pattern
        switch (phase) {
          case PREPROCESSING: pat = &cd->PreProcessor; break;
          case TRANSLATION:   pat = &cd->Translator; break;
          case OPTIMIZATION:  pat = &cd->Optimizer; break;
          case ASSEMBLY:      pat = &cd->Assembler; break;
          case LINKING:       pat = &cd->Linker; break;
          default:
            assert(!"Invalid driver phase!");
            break;
        }
        assert(pat != 0 && "Invalid command pattern");

        // Copy over some pattern things that don't need to change
        action->program = pat->program;
        action->flags = pat->flags;

        // Do the substitutions from the pattern to the actual
        StringVector::iterator PI = pat->args.begin();
        StringVector::iterator PE = pat->args.end();
        while (PI != PE) {
          if ((*PI)[0] == '%') {
            if (*PI == "%in%") {
              action->args.push_back(input.get());
            } else if (*PI == "%out%") {
              action->args.push_back(output.get());
            } else if (*PI == "%time%") {
              if (isSet(TIME_PASSES_FLAG))
                action->args.push_back("-time-passes");
            } else if (*PI == "%stats%") {
              if (isSet(SHOW_STATS_FLAG))
                action->args.push_back("-stats");
            } else if (*PI == "%force%") {
              if (isSet(FORCE_FLAG))
                action->args.push_back("-f");
            } else if (*PI == "%verbose%") {
              if (isSet(VERBOSE_FLAG))
                action->args.push_back("-v");
            } else if (*PI == "%target%") {
              // FIXME: Ignore for now
            } else if (*PI == "%opt%") {
              if (!isSet(EMIT_RAW_FLAG)) {
                if (cd->opts.size() > static_cast<unsigned>(optLevel) && 
                    !cd->opts[optLevel].empty())
                  action->args.insert(action->args.end(), cd->opts[optLevel].begin(),
                      cd->opts[optLevel].end());
                else
                  throw std::string("Optimization options for level ") + 
                        utostr(unsigned(optLevel)) + " were not specified";
              }
            } else if (*PI == "%args%") {
              if (AdditionalArgs.size() > unsigned(phase))
                if (!AdditionalArgs[phase].empty()) {
                  // Get specific options for each kind of action type
                  StringVector& addargs = AdditionalArgs[phase];
                  // Add specific options for each kind of action type
                  action->args.insert(action->args.end(), addargs.begin(), addargs.end());
                }
            } else {
              throw "Invalid substitution name" + *PI;
            }
          } else {
            // Its not a substitution, just put it in the action
            action->args.push_back(*PI);
          }
          PI++;
        }


        // Finally, we're done
        return action;
      }

      bool DoAction(Action*action) {
        assert(action != 0 && "Invalid Action!");
        if (isSet(VERBOSE_FLAG))
          WriteAction(action);
        if (!isSet(DRY_RUN_FLAG)) {
          action->program = sys::Program::FindProgramByName(action->program.get());
          if (action->program.is_empty())
            throw "Can't find program '" + action->program.get() + "'";

          // Invoke the program
          return 0 == action->program.ExecuteAndWait(action->args);
        }
        return true;
      }

      /// This method tries various variants of a linkage item's file
      /// name to see if it can find an appropriate file to link with
      /// in the directory specified.
      llvm::sys::Path GetPathForLinkageItem(const std::string& link_item,
                                            const sys::Path& dir) {
        sys::Path fullpath(dir);
        fullpath.append_file(link_item);
        fullpath.append_suffix("bc");
        if (fullpath.readable()) 
          return fullpath;
        fullpath.elide_suffix();
        fullpath.append_suffix("o");
        if (fullpath.readable()) 
          return fullpath;
        fullpath = dir;
        fullpath.append_file(std::string("lib") + link_item);
        fullpath.append_suffix("a");
        if (fullpath.readable())
          return fullpath;
        fullpath.elide_suffix();
        fullpath.append_suffix("so");
        if (fullpath.readable())
          return fullpath;

        // Didn't find one.
        fullpath.clear();
        return fullpath;
      }

      /// This method processes a linkage item. The item could be a
      /// Bytecode file needing translation to native code and that is
      /// dependent on other bytecode libraries, or a native code
      /// library that should just be linked into the program.
      bool ProcessLinkageItem(const llvm::sys::Path& link_item,
                              SetVector<sys::Path>& set,
                              std::string& err) {
        // First, see if the unadorned file name is not readable. If so,
        // we must track down the file in the lib search path.
        sys::Path fullpath;
        if (!link_item.readable()) {
          // First, look for the library using the -L arguments specified
          // on the command line.
          PathVector::iterator PI = LibraryPaths.begin();
          PathVector::iterator PE = LibraryPaths.end();
          while (PI != PE && fullpath.is_empty()) {
            fullpath = GetPathForLinkageItem(link_item.get(),*PI);
            ++PI;
          }

          // If we didn't find the file in any of the library search paths
          // so we have to bail. No where else to look.
          if (fullpath.is_empty()) {
            err = std::string("Can't find linkage item '") + link_item.get() + "'";
            return false;
          }
        } else {
          fullpath = link_item;
        }

        // If we got here fullpath is the path to the file, and its readable.
        set.insert(fullpath);

        // If its an LLVM bytecode file ...
        if (CheckMagic(fullpath.get(), "llvm")) {
          // Process the dependent libraries recursively
          Module::LibraryListType modlibs;
          if (GetBytecodeDependentLibraries(fullpath.get(),modlibs)) {
            // Traverse the dependent libraries list
            Module::lib_iterator LI = modlibs.begin();
            Module::lib_iterator LE = modlibs.end();
            while ( LI != LE ) {
              if (!ProcessLinkageItem(sys::Path(*LI),set,err)) {
                if (err.empty()) {
                  err = std::string("Library '") + *LI + 
                        "' is not valid for linking but is required by file '" +
                        fullpath.get() + "'";
                } else {
                  err += " which is required by file '" + fullpath.get() + "'";
                }
                return false;
              }
              ++LI;
            }
          } else if (err.empty()) {
            err = std::string("The dependent libraries could not be extracted from '")
                              + fullpath.get();
            return false;
          }
        }
        return true;
      }

    /// @}
    /// @name Methods
    /// @{
    public:
      virtual int execute(const InputList& InpList, const sys::Path& Output ) {
        try {
          // Echo the configuration of options if we're running verbose
          if (isSet(DEBUG_FLAG)) {
            std::cerr << "Compiler Driver Options:\n";
            std::cerr << "DryRun = " << isSet(DRY_RUN_FLAG) << "\n";
            std::cerr << "Verbose = " << isSet(VERBOSE_FLAG) << " \n";
            std::cerr << "TimeActions = " << isSet(TIME_ACTIONS_FLAG) << "\n";
            std::cerr << "TimePasses = " << isSet(TIME_PASSES_FLAG) << "\n";
            std::cerr << "ShowStats = " << isSet(SHOW_STATS_FLAG) << "\n";
            std::cerr << "EmitRawCode = " << isSet(EMIT_RAW_FLAG) << "\n";
            std::cerr << "EmitNativeCode = " << isSet(EMIT_NATIVE_FLAG) << "\n";
            std::cerr << "ForceOutput = " << isSet(FORCE_FLAG) << "\n";
            std::cerr << "KeepTemps = " << isSet(KEEP_TEMPS_FLAG) << "\n";
            std::cerr << "OutputMachine = " << machine << "\n";
            InputList::const_iterator I = InpList.begin();
            while ( I != InpList.end() ) {
              std::cerr << "Input: " << I->first.get() << "(" << I->second << ")\n";
              ++I;
            }
            std::cerr << "Output: " << Output.get() << "\n";
          }

          // If there's no input, we're done.
          if (InpList.empty())
            throw std::string("Nothing to compile.");

          // If they are asking for linking and didn't provide an output
          // file then its an error (no way for us to "make up" a meaningful
          // file name based on the various linker input files).
          if (finalPhase == LINKING && Output.is_empty())
            throw std::string(
              "An output file name must be specified for linker output");

          // This vector holds all the resulting actions of the following loop.
          std::vector<Action*> actions;

          /// PRE-PROCESSING / TRANSLATION / OPTIMIZATION / ASSEMBLY phases
          // for each input item
          SetVector<sys::Path> LinkageItems;
          sys::Path OutFile(Output);
          InputList::const_iterator I = InpList.begin();
          while ( I != InpList.end() ) {
            // Get the suffix of the file name
            const std::string& ftype = I->second;

            // If its a library, bytecode file, or object file, save 
            // it for linking below and short circuit the 
            // pre-processing/translation/assembly phases
            if (ftype.empty() ||  ftype == "o" || ftype == "bc") {
              // We shouldn't get any of these types of files unless we're 
              // later going to link. Enforce this limit now.
              if (finalPhase != LINKING) {
                throw std::string(
                  "Pre-compiled objects found but linking not requested");
              }
              LinkageItems.insert(I->first);
              ++I; continue; // short circuit remainder of loop
            }

            // At this point, we know its something we need to translate
            // and/or optimize. See if we can get the configuration data
            // for this kind of file.
            ConfigData* cd = cdp->ProvideConfigData(I->second);
            if (cd == 0)
              throw std::string("Files of type '") + I->second + 
                    "' are not recognized."; 
            if (isSet(DEBUG_FLAG))
              DumpConfigData(cd,I->second);

            // Initialize the input file
            sys::Path InFile(I->first);

            // PRE-PROCESSING PHASE
            Action& action = cd->PreProcessor;

            // Get the preprocessing action, if needed, or error if appropriate
            if (!action.program.is_empty()) {
              if (action.isSet(REQUIRED_FLAG) || finalPhase == PREPROCESSING) {
                if (finalPhase == PREPROCESSING)
                  actions.push_back(GetAction(cd,InFile,OutFile,PREPROCESSING));
                else {
                  sys::Path TempFile(MakeTempFile(I->first.get(),"E"));
                  actions.push_back(GetAction(cd,InFile,TempFile,PREPROCESSING));
                  InFile = TempFile;
                }
              }
            } else if (finalPhase == PREPROCESSING) {
              throw cd->langName + " does not support pre-processing";
            } else if (action.isSet(REQUIRED_FLAG)) {
              throw std::string("Don't know how to pre-process ") + 
                    cd->langName + " files";
            }

            // Short-circuit remaining actions if all they want is pre-processing
            if (finalPhase == PREPROCESSING) { ++I; continue; };

            /// TRANSLATION PHASE
            action = cd->Translator;

            // Get the translation action, if needed, or error if appropriate
            if (!action.program.is_empty()) {
              if (action.isSet(REQUIRED_FLAG) || finalPhase == TRANSLATION) {
                if (finalPhase == TRANSLATION) 
                  actions.push_back(GetAction(cd,InFile,OutFile,TRANSLATION));
                else {
                  sys::Path TempFile(MakeTempFile(I->first.get(),"trans")); 
                  actions.push_back(GetAction(cd,InFile,TempFile,TRANSLATION));
                  InFile = TempFile;
                }

                // ll -> bc Helper
                if (action.isSet(OUTPUT_IS_ASM_FLAG)) {
                  /// The output of the translator is an LLVM Assembly program
                  /// We need to translate it to bytecode
                  Action* action = new Action();
                  action->program.set_file("llvm-as");
                  action->args.push_back(InFile.get());
                  action->args.push_back("-o");
                  InFile.append_suffix("bc");
                  action->args.push_back(InFile.get());
                  actions.push_back(action);
                }
              }
            } else if (finalPhase == TRANSLATION) {
              throw cd->langName + " does not support translation";
            } else if (action.isSet(REQUIRED_FLAG)) {
              throw std::string("Don't know how to translate ") + 
                    cd->langName + " files";
            }

            // Short-circuit remaining actions if all they want is translation
            if (finalPhase == TRANSLATION) { ++I; continue; }

            /// OPTIMIZATION PHASE
            action = cd->Optimizer;

            // Get the optimization action, if needed, or error if appropriate
            if (!isSet(EMIT_RAW_FLAG)) {
              if (!action.program.is_empty()) {
                if (action.isSet(REQUIRED_FLAG) || finalPhase == OPTIMIZATION) {
                  if (finalPhase == OPTIMIZATION)
                    actions.push_back(GetAction(cd,InFile,OutFile,OPTIMIZATION));
                  else {
                    sys::Path TempFile(MakeTempFile(I->first.get(),"opt"));
                    actions.push_back(GetAction(cd,InFile,TempFile,OPTIMIZATION));
                    InFile = TempFile;
                  }
                  // ll -> bc Helper
                  if (action.isSet(OUTPUT_IS_ASM_FLAG)) {
                    /// The output of the translator is an LLVM Assembly program
                    /// We need to translate it to bytecode
                    Action* action = new Action();
                    action->program.set_file("llvm-as");
                    action->args.push_back(InFile.get());
                    action->args.push_back("-f");
                    action->args.push_back("-o");
                    InFile.append_suffix("bc");
                    action->args.push_back(InFile.get());
                    actions.push_back(action);
                  }
                }
              } else if (finalPhase == OPTIMIZATION) {
                throw cd->langName + " does not support optimization";
              } else if (action.isSet(REQUIRED_FLAG)) {
                throw std::string("Don't know how to optimize ") + 
                    cd->langName + " files";
              }
            }

            // Short-circuit remaining actions if all they want is optimization
            if (finalPhase == OPTIMIZATION) { ++I; continue; }

            /// ASSEMBLY PHASE
            action = cd->Assembler;

            if (finalPhase == ASSEMBLY || isSet(EMIT_NATIVE_FLAG)) {
              if (isSet(EMIT_NATIVE_FLAG)) {
                if (action.program.is_empty()) {
                  throw std::string("Native Assembler not specified for ") +
                        cd->langName + " files";
                } else if (finalPhase == ASSEMBLY) {
                  actions.push_back(GetAction(cd,InFile,OutFile,ASSEMBLY));
                } else {
                  sys::Path TempFile(MakeTempFile(I->first.get(),"S"));
                  actions.push_back(GetAction(cd,InFile,TempFile,ASSEMBLY));
                  InFile = TempFile;
                }
              } else {
                // Just convert back to llvm assembly with llvm-dis
                Action* action = new Action();
                action->program.set_file("llvm-dis");
                action->args.push_back(InFile.get());
                action->args.push_back("-f");
                action->args.push_back("-o");
                action->args.push_back(OutFile.get());
                actions.push_back(action);
              }
            }

            // Short-circuit remaining actions if all they want is assembly output
            if (finalPhase == ASSEMBLY) { ++I; continue; }
              
            // Register the OutFile as a link candidate
            LinkageItems.insert(InFile);

            // Go to next file to be processed
            ++I;
          }

          /// RUN THE COMPILATION ACTIONS
          std::vector<Action*>::iterator AI = actions.begin();
          std::vector<Action*>::iterator AE = actions.end();
          while (AI != AE) {
            if (!DoAction(*AI))
              throw "Action failed";
            AI++;
          }

          /// LINKING PHASE
          actions.clear();
          if (finalPhase == LINKING) {
            if (isSet(EMIT_NATIVE_FLAG)) {
              throw "llvmc doesn't know how to link native code yet";
            } else {
              // First, we need to examine the files to ensure that they all contain
              // bytecode files. Since the final output is bytecode, we can only
              // link bytecode.
              SetVector<sys::Path>::const_iterator I = LinkageItems.begin();
              SetVector<sys::Path>::const_iterator E = LinkageItems.end();
              std::string errmsg;

              while (I != E && ProcessLinkageItem(*I,LinkageItems,errmsg))
                ++I;

              if (!errmsg.empty())
                throw errmsg;

              // Insert the system libraries.
              LibraryPaths.push_back(sys::Path::GetSystemLibraryPath1());
              LibraryPaths.push_back(sys::Path::GetSystemLibraryPath2());

              // We're emitting bytecode so let's build an llvm-link Action
              Action* link = new Action();
              link->program.set_file("llvm-link");
              for (PathVector::const_iterator I=LinkageItems.begin(), 
                   E=LinkageItems.end(); I != E; ++I )
                link->args.push_back(I->get());
              if (isSet(VERBOSE_FLAG))
                link->args.push_back("-v");
              link->args.push_back("-f");
              link->args.push_back("-o");
              link->args.push_back(OutFile.get());
              if (isSet(TIME_PASSES_FLAG))
                link->args.push_back("-time-passes");
              if (isSet(SHOW_STATS_FLAG))
                link->args.push_back("-stats");
              actions.push_back(link);
            }
          }

          /// RUN THE LINKING ACTIONS
          AI = actions.begin();
          AE = actions.end();
          while (AI != AE) {
            if (!DoAction(*AI))
              throw std::string("Action failed");
            AI++;
          }
        } catch (std::string& msg) {
          cleanup();
          throw;
        } catch (...) {
          cleanup();
          throw std::string("Unspecified error");
        }
        cleanup();
        return 0;
      }

    /// @}
    /// @name Data
    /// @{
    private:
      ConfigDataProvider* cdp;      ///< Where we get configuration data from
      Phases finalPhase;            ///< The final phase of compilation
      OptimizationLevels optLevel;  ///< The optimization level to apply
      unsigned Flags;               ///< The driver flags
      std::string machine;          ///< Target machine name
      PathVector LibraryPaths;      ///< -L options
      sys::Path TempDir;            ///< Name of the temporary directory.
      StringTable AdditionalArgs;   ///< The -Txyz options

    /// @}
  };
}

CompilerDriver::~CompilerDriver() {
}

CompilerDriver*
CompilerDriver::Get(ConfigDataProvider& CDP) {
  return new CompilerDriverImpl(CDP);
}

CompilerDriver::ConfigData::ConfigData()
  : langName()
  , PreProcessor()
  , Translator()
  , Optimizer()
  , Assembler()
  , Linker()
{
  StringVector emptyVec;
  for (unsigned i = 0; i < NUM_PHASES; ++i)
    opts.push_back(emptyVec);
}

// vim: sw=2 smartindent smarttab tw=80 autoindent expandtab