lib/CompilerDriver/Action.cpp

//===--- Action.cpp - The LLVM Compiler Driver ------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open
// Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  Action class - implementation and auxiliary functions.
//
//===----------------------------------------------------------------------===//

#include "llvm/CompilerDriver/Action.h"

#include "llvm/Support/CommandLine.h"
#include "llvm/System/Program.h"

#include <iostream>
#include <stdexcept>

using namespace llvm;
using namespace llvmc;

extern cl::opt<bool> DryRun;
extern cl::opt<bool> VerboseMode;

namespace {
  int ExecuteProgram(const std::string& name,
                     const StrVector& args) {
    sys::Path prog = sys::Program::FindProgramByName(name);

    if (prog.isEmpty())
      throw std::runtime_error("Can't find program '" + name + "'");
    if (!prog.canExecute())
      throw std::runtime_error("Program '" + name + "' is not executable.");

    // Build the command line vector and the redirects array.
    const sys::Path* redirects[3] = {0,0,0};
    sys::Path stdout_redirect;

    std::vector<const char*> argv;
    argv.reserve((args.size()+2));
    argv.push_back(name.c_str());

    for (StrVector::const_iterator B = args.begin(), E = args.end();
         B!=E; ++B) {
      if (*B == ">") {
        ++B;
        stdout_redirect.set(*B);
        redirects[1] = &stdout_redirect;
      }
      else {
        argv.push_back((*B).c_str());
      }
    }
    argv.push_back(0);  // null terminate list.

    // Invoke the program.
    return sys::Program::ExecuteAndWait(prog, &argv[0], 0, &redirects[0]);
  }

  void print_string (const std::string& str) {
    std::cerr << str << ' ';
  }
}

int llvmc::Action::Execute() const {
  if (DryRun || VerboseMode) {
    std::cerr << Command_ << " ";
    std::for_each(Args_.begin(), Args_.end(), print_string);
    std::cerr << '\n';
  }
  if (DryRun)
    return 0;
  else
    return ExecuteProgram(Command_, Args_);
}