/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying

   file LICENSE.rst or https://cmake.org/licensing for details.  */

#include "cmBinUtilsLinuxELFLinker.h"

#include <queue>

#include <unordered_set>

#include <utility>

#include <cm/memory>

#include <cm/string_view>

#include <cmsys/RegularExpression.hxx>

#include "cmBinUtilsLinuxELFObjdumpGetRuntimeDependenciesTool.h"

#include "cmELF.h"

#include "cmLDConfigLDConfigTool.h"

#include "cmMakefile.h"

#include "cmMessageType.h"

#include "cmRuntimeDependencyArchive.h"

#include "cmStringAlgorithms.h"

#include "cmSystemTools.h"

static std::string ReplaceOrigin(std::string const& rpath,

                                 std::string const& origin)

{

  static cmsys::RegularExpression const originRegex(

    "(\\$ORIGIN)([^a-zA-Z0-9_]|$)");

  static cmsys::RegularExpression const originCurlyRegex("\\${ORIGIN}");

  cmsys::RegularExpressionMatch match;

  if (originRegex.find(rpath.c_str(), match)) {

    cm::string_view pathv(rpath);

    auto begin = pathv.substr(0, match.start(1));

    auto end = pathv.substr(match.end(1));

    return cmStrCat(begin, origin, end);

  }

  if (originCurlyRegex.find(rpath.c_str(), match)) {

    cm::string_view pathv(rpath);

    auto begin = pathv.substr(0, match.start());

    auto end = pathv.substr(match.end());

    return cmStrCat(begin, origin, end);

  }

  return rpath;

}

cmBinUtilsLinuxELFLinker::cmBinUtilsLinuxELFLinker(

  cmRuntimeDependencyArchive* archive)

  : cmBinUtilsLinker(archive)

{

}

bool cmBinUtilsLinuxELFLinker::Prepare()

{

  std::string tool = this->Archive->GetGetRuntimeDependenciesTool();

  if (tool.empty()) {

    tool = "objdump";

  }

  if (tool == "objdump") {

    this->Tool =

      cm::make_unique<cmBinUtilsLinuxELFObjdumpGetRuntimeDependenciesTool>(

        this->Archive);

  } else {

    this->SetError(cmStrCat(

      "Invalid value for CMAKE_GET_RUNTIME_DEPENDENCIES_TOOL: ", tool));

    return false;

  }

  std::string ldConfigTool =

    this->Archive->GetMakefile()->GetSafeDefinition("CMAKE_LDCONFIG_TOOL");

  if (ldConfigTool.empty()) {

    ldConfigTool = "ldconfig";

  }

  if (ldConfigTool == "ldconfig") {

    this->LDConfigTool =

      cm::make_unique<cmLDConfigLDConfigTool>(this->Archive);

    if (!this->LDConfigTool->GetLDConfigPaths(this->LDConfigPaths)) {

      return false;

    }

  } else {

    this->SetError(

      cmStrCat("Invalid value for CMAKE_LDCONFIG_TOOL: ", ldConfigTool));

    return false;

  }

  return true;

}

bool cmBinUtilsLinuxELFLinker::ScanDependencies(std::string const& file,

                                                cm::TargetType /* unused */)

{

  cmELF elf(file.c_str());

  if (!elf) {

    return false;

  }

  if (elf.GetMachine() != 0) {

    if (this->Machine != 0) {

      if (elf.GetMachine() != this->Machine) {

        this->SetError("All files must have the same architecture.");

        return false;

      }

    } else {

      this->Machine = elf.GetMachine();

    }

  }

  return this->ScanDependencies(file);

}

bool cmBinUtilsLinuxELFLinker::ScanDependencies(std::string const& mainFile)

{

  std::unordered_set<std::string> resolvedDependencies;

  std::queue<std::pair<std::string, std::vector<std::string>>> queueToResolve;

  queueToResolve.push(std::make_pair(mainFile, std::vector<std::string>{}));

  while (!queueToResolve.empty()) {

    std::string file = std::move(queueToResolve.front().first);

    std::vector<std::string> parentRpaths =

      std::move(queueToResolve.front().second);

    queueToResolve.pop();

    std::string origin = cmSystemTools::GetFilenamePath(file);

    std::vector<std::string> needed;

    std::vector<std::string> rpaths;

    std::vector<std::string> runpaths;

    if (!this->Tool->GetFileInfo(file, needed, rpaths, runpaths)) {

      return false;

    }

    for (auto& runpath : runpaths) {

      runpath = ReplaceOrigin(runpath, origin);

    }

    for (auto& rpath : rpaths) {

      rpath = ReplaceOrigin(rpath, origin);

    }

    std::vector<std::string> searchPaths;

    if (!runpaths.empty()) {

      searchPaths = runpaths;

    } else {

      searchPaths = rpaths;

      searchPaths.insert(searchPaths.end(), parentRpaths.begin(),

                         parentRpaths.end());

    }

    searchPaths.insert(searchPaths.end(), this->LDConfigPaths.begin(),

                       this->LDConfigPaths.end());

    for (auto const& dep : needed) {

      if (resolvedDependencies.count(dep) != 0 ||

          this->Archive->IsPreExcluded(dep)) {

        continue;

      }

      std::string path;

      bool resolved = false;

      if (dep.find('/') != std::string::npos) {

        this->SetError("Paths to dependencies are not supported");

        return false;

      }

      if (!this->ResolveDependency(dep, searchPaths, path, resolved)) {

        return false;

      }

      if (resolved) {

        resolvedDependencies.emplace(dep);

        if (!this->Archive->IsPostExcluded(path)) {

          bool unique;

          this->Archive->AddResolvedPath(dep, path, unique);

          if (unique) {

            std::vector<std::string> combinedParentRpaths = parentRpaths;

            combinedParentRpaths.insert(combinedParentRpaths.end(),

                                        rpaths.begin(), rpaths.end());

            queueToResolve.push(std::make_pair(path, combinedParentRpaths));

          }

        }

      } else {

        this->Archive->AddUnresolvedPath(dep);

      }

    }

  }

  return true;

}

namespace {

bool FileHasArchitecture(char const* filename, std::uint16_t machine)

{

  cmELF elf(filename);

  if (!elf) {

    return false;

  }

  return machine == 0 || machine == elf.GetMachine();

}

}

bool cmBinUtilsLinuxELFLinker::ResolveDependency(

  std::string const& name, std::vector<std::string> const& searchPaths,

  std::string& path, bool& resolved)

{

  for (auto const& searchPath : searchPaths) {

    path = cmStrCat(searchPath, '/', name);

    if (cmSystemTools::PathExists(path) &&

        FileHasArchitecture(path.c_str(), this->Machine)) {

      this->NormalizePath(path);

      resolved = true;

      return true;

    }

  }

  for (auto const& searchPath : this->Archive->GetSearchDirectories()) {

    path = cmStrCat(searchPath, '/', name);

    if (cmSystemTools::PathExists(path) &&

        FileHasArchitecture(path.c_str(), this->Machine)) {

      this->Archive->GetMakefile()->IssueMessage(

        MessageType::WARNING,

        cmStrCat("Dependency ", name, " found in search directory:\n  ",

                 searchPath,

                 "\nSee file(GET_RUNTIME_DEPENDENCIES) documentation for more "

                 "information."));

      resolved = true;

      return true;

    }

  }

  resolved = false;

  return true;

}