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

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

#include "cmDyndepCollation.h"

#include <algorithm>

#include <map>

#include <ostream>

#include <set>

#include <utility>

#include <vector>

#include <cm/memory>

#include <cm/string_view>

#include <cmext/string_view>

#include <cm3p/json/value.h>

#include "cmBuildDatabase.h"

#include "cmCxxModuleMetadata.h"

#include "cmExportBuildFileGenerator.h"

#include "cmExportSet.h"

#include "cmFileSet.h"

#include "cmGenExContext.h"

#include "cmGeneratedFileStream.h"

#include "cmGeneratorExpression.h" // IWYU pragma: keep

#include "cmGeneratorTarget.h"

#include "cmGlobalGenerator.h"

#include "cmInstallCxxModuleBmiGenerator.h"

#include "cmInstallExportGenerator.h"

#include "cmInstallFileSetGenerator.h"

#include "cmInstallGenerator.h"

#include "cmListFileCache.h"

#include "cmMakefile.h"

#include "cmMessageType.h"

#include "cmOutputConverter.h"

#include "cmScanDepFormat.h"

#include "cmSourceFile.h"

#include "cmStringAlgorithms.h"

#include "cmSystemTools.h"

#include "cmTarget.h"

#include "cmTargetExport.h"

namespace {

struct TdiSourceInfo

{

  Json::Value Sources;

  Json::Value CxxModules;

};

TdiSourceInfo CollationInformationSources(cmGeneratorTarget const* gt,

                                          std::string const& config,

                                          cmDyndepGeneratorCallbacks const& cb)

{

  cm::GenEx::Context const context(gt->LocalGenerator, config);

  TdiSourceInfo info;

  cmTarget const* tgt = gt->Target;

  auto all_file_sets = tgt->GetAllFileSetNames();

  Json::Value& tdi_sources = info.Sources = Json::objectValue;

  Json::Value& tdi_cxx_module_info = info.CxxModules = Json::objectValue;

  enum class CompileType

  {

    ObjectAndBmi,

    BmiOnly,

  };

  std::map<std::string, std::pair<cmSourceFile const*, CompileType>> sf_map;

  {

    auto fill_sf_map = [gt, tgt, &sf_map](cmSourceFile const* sf,

                                          CompileType type) {

      auto full_path = sf->GetFullPath();

      if (full_path.empty()) {

        gt->Makefile->IssueMessage(

          MessageType::INTERNAL_ERROR,

          cmStrCat("Target \"", tgt->GetName(),

                   "\" has a full path-less source file."));

        return;

      }

      sf_map[full_path] = std::make_pair(sf, type);

    };

    std::vector<cmSourceFile const*> objectSources;

    gt->GetObjectSources(objectSources, config);

    for (auto const* sf : objectSources) {

      fill_sf_map(sf, CompileType::ObjectAndBmi);

    }

    std::vector<cmSourceFile const*> cxxModuleSources;

    gt->GetCxxModuleSources(cxxModuleSources, config);

    for (auto const* sf : cxxModuleSources) {

      fill_sf_map(sf, CompileType::BmiOnly);

    }

  }

  for (auto const& file_set_name : all_file_sets) {

    auto const* file_set = tgt->GetFileSet(file_set_name);

    if (!file_set) {

      gt->Makefile->IssueMessage(MessageType::INTERNAL_ERROR,

                                 cmStrCat("Target \"", tgt->GetName(),

                                          "\" is tracked to have file set \"",

                                          file_set_name,

                                          "\", but it was not found."));

      continue;

    }

    auto fs_type = file_set->GetType();

    // We only care about C++ module sources here.

    if (fs_type != "CXX_MODULES"_s) {

      continue;

    }

    auto fileEntries = file_set->CompileFileEntries();

    auto directoryEntries = file_set->CompileDirectoryEntries();

    auto directories =

      file_set->EvaluateDirectoryEntries(directoryEntries, context, gt);

    std::map<std::string, std::vector<std::string>> files_per_dirs;

    for (auto const& entry : fileEntries) {

      file_set->EvaluateFileEntry(directories, files_per_dirs, entry, context,

                                  gt);

    }

    Json::Value fs_dest = Json::nullValue;

    for (auto const& ig : gt->Makefile->GetInstallGenerators()) {

      if (auto const* fsg =

            dynamic_cast<cmInstallFileSetGenerator const*>(ig.get())) {

        if (fsg->GetTarget() == gt && fsg->GetFileSet() == file_set) {

          fs_dest = fsg->GetDestination(config);

          continue;

        }

      }

    }

    // Detect duplicate sources.

    std::set<std::string> visited_sources;

    for (auto const& files_per_dir : files_per_dirs) {

      for (auto const& file : files_per_dir.second) {

        auto const full_file = cmSystemTools::CollapseFullPath(file);

        auto lookup = sf_map.find(full_file);

        if (lookup == sf_map.end()) {

          if (visited_sources.count(full_file)) {

            // Duplicate source; raise an author warning.

            gt->Makefile->IssueMessage(

              MessageType::AUTHOR_WARNING,

              cmStrCat(

                "Target \"", tgt->GetName(), "\" has source file\n  ", file,

                "\nin a \"FILE_SET TYPE CXX_MODULES\" multiple times."));

            continue;

          }

          gt->Makefile->IssueMessage(

            MessageType::FATAL_ERROR,

            cmStrCat("Target \"", tgt->GetName(), "\" has source file\n  ",

                     file,

                     "\nin a \"FILE_SET TYPE CXX_MODULES\" but it is not "

                     "scheduled for compilation."));

          continue;

        }

        visited_sources.insert(full_file);

        auto const* sf = lookup->second.first;

        CompileType const ct = lookup->second.second;

        sf_map.erase(lookup);

        if (!sf) {

          gt->Makefile->IssueMessage(

            MessageType::INTERNAL_ERROR,

            cmStrCat("Target \"", tgt->GetName(), "\" has source file \"",

                     file, "\" which has not been tracked properly."));

          continue;

        }

        auto obj_path = ct == CompileType::ObjectAndBmi

          ? cb.ObjectFilePath(sf, config)

          : cb.BmiFilePath(sf, config);

        Json::Value& tdi_module_info = tdi_cxx_module_info[obj_path] =

          Json::objectValue;

        Json::Value& tdi_include_dirs =

          tdi_module_info["include-directories"] = Json::arrayValue;

        for (auto const& i : gt->GetIncludeDirectories(config, "CXX")) {

          tdi_include_dirs.append(i.Value);

        }

        Json::Value& tdi_defs = tdi_module_info["definitions"] =

          Json::arrayValue;

        for (auto const& i : gt->GetCompileDefinitions(config, "CXX")) {

          tdi_defs.append(i.Value);

        }

        Json::Value& tdi_opts = tdi_module_info["compile-options"] =

          Json::arrayValue;

        for (auto const& i : gt->GetCompileOptions(config, "CXX")) {

          tdi_opts.append(i.Value);

        }

        Json::Value& tdi_feats = tdi_module_info["compile-features"] =

          Json::arrayValue;

        for (auto const& i : gt->GetCompileFeatures(config)) {

          tdi_feats.append(i.Value);

        }

        tdi_module_info["source"] = full_file;

        tdi_module_info["bmi-only"] = ct == CompileType::BmiOnly;

        tdi_module_info["relative-directory"] = files_per_dir.first;

        tdi_module_info["name"] = file_set->GetName();

        tdi_module_info["type"] = file_set->GetType();

        tdi_module_info["visibility"] =

          std::string(cmFileSetVisibilityToName(file_set->GetVisibility()));

        tdi_module_info["destination"] = fs_dest;

      }

    }

  }

  for (auto const& sf_entry : sf_map) {

    CompileType const ct = sf_entry.second.second;

    if (ct == CompileType::BmiOnly) {

      continue;

    }

    auto const* sf = sf_entry.second.first;

    if (!gt->NeedDyndepForSource(sf->GetLanguage(), config, sf)) {

      continue;

    }

    auto full_file = cmSystemTools::CollapseFullPath(sf->GetFullPath());

    auto obj_path = cb.ObjectFilePath(sf, config);

    Json::Value& tdi_source_info = tdi_sources[obj_path] = Json::objectValue;

    tdi_source_info["source"] = full_file;

    tdi_source_info["language"] = sf->GetLanguage();

  }

  return info;

}

Json::Value CollationInformationDatabaseInfo(cmGeneratorTarget const* gt,

                                             std::string const& config)

{

  Json::Value db_info;

  auto db_path = gt->BuildDatabasePath("CXX", config);

  if (!db_path.empty()) {

    db_info["template-path"] = cmStrCat(db_path, ".in");

    db_info["output"] = db_path;

  }

  return db_info;

}

Json::Value CollationInformationBmiInstallation(cmGeneratorTarget const* gt,

                                                std::string const& config)

{

  cmInstallCxxModuleBmiGenerator const* bmi_gen = nullptr;

  for (auto const& ig : gt->Makefile->GetInstallGenerators()) {

    if (auto const* bmig =

          dynamic_cast<cmInstallCxxModuleBmiGenerator const*>(ig.get())) {

      if (bmig->GetTarget() == gt) {

        bmi_gen = bmig;

        continue;

      }

    }

  }

  if (bmi_gen) {

    Json::Value tdi_bmi_info = Json::objectValue;

    tdi_bmi_info["permissions"] = bmi_gen->GetFilePermissions();

    tdi_bmi_info["destination"] = bmi_gen->GetDestination(config);

    char const* msg_level = "";

    switch (bmi_gen->GetMessageLevel()) {

      case cmInstallGenerator::MessageDefault:

        break;

      case cmInstallGenerator::MessageAlways:

        msg_level = "MESSAGE_ALWAYS";

        break;

      case cmInstallGenerator::MessageLazy:

        msg_level = "MESSAGE_LAZY";

        break;

      case cmInstallGenerator::MessageNever:

        msg_level = "MESSAGE_NEVER";

        break;

    }

    tdi_bmi_info["message-level"] = msg_level;

    tdi_bmi_info["script-location"] = bmi_gen->GetScriptLocation(config);

    return tdi_bmi_info;

  }

  return Json::nullValue;

}

Json::Value CollationInformationExports(cmGeneratorTarget const* gt)

{

  Json::Value tdi_exports = Json::arrayValue;

  std::string export_name = gt->GetExportName();

  std::string fs_export_name = gt->GetFilesystemExportName();

  auto const& all_install_exports = gt->GetGlobalGenerator()->GetExportSets();

  for (auto const& exp : all_install_exports) {

    // Ignore exports sets which are not for this target.

    auto const& targets = exp.second.GetTargetExports();

    auto tgt_export =

      std::find_if(targets.begin(), targets.end(),

                   [gt](std::unique_ptr<cmTargetExport> const& te) {

                     return te->Target == gt;

                   });

    if (tgt_export == targets.end()) {

      continue;

    }

    auto const* installs = exp.second.GetInstallations();

    for (auto const* install : *installs) {

      Json::Value tdi_export_info = Json::objectValue;

      auto const& ns = install->GetNamespace();

      auto const& dest = install->GetDestination();

      auto const& cxxm_dir = install->GetCxxModuleDirectory();

      auto const& export_prefix = install->GetTempDir();

      tdi_export_info["namespace"] = ns;

      tdi_export_info["export-name"] = export_name;

      tdi_export_info["filesystem-export-name"] = fs_export_name;

      tdi_export_info["destination"] = dest;

      tdi_export_info["cxx-module-info-dir"] = cxxm_dir;

      tdi_export_info["export-prefix"] = export_prefix;

      tdi_export_info["install"] = true;

      tdi_exports.append(tdi_export_info);

    }

  }

  auto const& all_build_exports =

    gt->GetGlobalGenerator()->GetBuildExportSets();

  for (auto const& exp_entry : all_build_exports) {

    auto const* exp = exp_entry.second;

    std::vector<cmExportBuildFileGenerator::TargetExport> targets;

    exp->GetTargets(targets);

    // Ignore exports sets which are not for this target.

    auto const& name = gt->GetName();

    bool has_current_target =

      std::any_of(targets.begin(), targets.end(),

                  [name](cmExportBuildFileGenerator::TargetExport const& te) {

                    return te.Name == name;

                  });

    if (!has_current_target) {

      continue;

    }

    Json::Value tdi_export_info = Json::objectValue;

    auto const& ns = exp->GetNamespace();

    auto const& main_fn = exp->GetMainExportFileName();

    auto const& cxxm_dir = exp->GetCxxModuleDirectory();

    auto dest = cmsys::SystemTools::GetParentDirectory(main_fn);

    auto const& export_prefix =

      cmSystemTools::GetFilenamePath(exp->GetMainExportFileName());

    tdi_export_info["namespace"] = ns;

    tdi_export_info["export-name"] = export_name;

    tdi_export_info["filesystem-export-name"] = fs_export_name;

    tdi_export_info["destination"] = dest;

    tdi_export_info["cxx-module-info-dir"] = cxxm_dir;

    tdi_export_info["export-prefix"] = export_prefix;

    tdi_export_info["install"] = false;

    tdi_exports.append(tdi_export_info);

  }

  return tdi_exports;

}

}

void cmDyndepCollation::AddCollationInformation(

  Json::Value& tdi, cmGeneratorTarget const* gt, std::string const& config,

  cmDyndepGeneratorCallbacks const& cb)

{

  auto sourcesInfo = CollationInformationSources(gt, config, cb);

  tdi["sources"] = sourcesInfo.Sources;

  tdi["cxx-modules"] = sourcesInfo.CxxModules;

  tdi["database-info"] = CollationInformationDatabaseInfo(gt, config);

  tdi["bmi-installation"] = CollationInformationBmiInstallation(gt, config);

  tdi["exports"] = CollationInformationExports(gt);

  tdi["config"] = config;

}

struct SourceInfo

{

  std::string SourcePath;

  std::string Language;

};

struct CxxModuleFileSet

{

  std::string Name;

  bool BmiOnly = false;

  std::string RelativeDirectory;

  std::string SourcePath;

  std::string Type;

  cmFileSetVisibility Visibility = cmFileSetVisibility::Private;

  cm::optional<std::string> Destination;

  std::vector<std::string> IncludeDirectories;

  std::vector<std::string> Definitions;

  std::vector<std::string> CompileOptions;

  std::vector<std::string> CompileFeatures;

};

struct CxxModuleDatabaseInfo

{

  std::string TemplatePath;

  std::string Output;

};

struct CxxModuleBmiInstall

{

  std::string Component;

  std::string Destination;

  bool ExcludeFromAll;

  bool Optional;

  std::string Permissions;

  std::string MessageLevel;

  std::string ScriptLocation;

};

struct CxxModuleExport

{

  std::string Name;

  std::string FilesystemName;

  std::string Destination;

  std::string Prefix;

  std::string CxxModuleInfoDir;

  std::string Namespace;

  bool Install;

};

struct CxxModuleExportOutputHelper

{

  CxxModuleExport const* Export;

  std::unique_ptr<cmGeneratedFileStream> File;

  cmCxxModuleMetadata Manifest;

};

struct cmCxxModuleExportInfo

{

  std::map<std::string, SourceInfo> ObjectToSource;

  std::map<std::string, CxxModuleFileSet> ObjectToFileSet;

  cm::optional<CxxModuleDatabaseInfo> DatabaseInfo;

  cm::optional<CxxModuleBmiInstall> BmiInstallation;

  std::vector<CxxModuleExport> Exports;

  std::string Config;

};

void cmCxxModuleExportInfoDeleter::operator()(cmCxxModuleExportInfo* ei) const

{

  delete ei;

}

std::unique_ptr<cmCxxModuleExportInfo, cmCxxModuleExportInfoDeleter>

cmDyndepCollation::ParseExportInfo(Json::Value const& tdi)

{

  auto export_info =

    std::unique_ptr<cmCxxModuleExportInfo, cmCxxModuleExportInfoDeleter>(

      new cmCxxModuleExportInfo);

  export_info->Config = tdi["config"].asString();

  if (export_info->Config.empty()) {

    export_info->Config = "noconfig";

  }

  Json::Value const& tdi_exports = tdi["exports"];

  if (tdi_exports.isArray()) {

    for (auto const& tdi_export : tdi_exports) {

      CxxModuleExport exp;

      exp.Install = tdi_export["install"].asBool();

      exp.Name = tdi_export["export-name"].asString();

      exp.FilesystemName = tdi_export["filesystem-export-name"].asString();

      exp.Destination = tdi_export["destination"].asString();

      exp.Prefix = tdi_export["export-prefix"].asString();

      exp.CxxModuleInfoDir = tdi_export["cxx-module-info-dir"].asString();

      exp.Namespace = tdi_export["namespace"].asString();

      export_info->Exports.push_back(exp);

    }

  }

  auto const& database_info = tdi["database-info"];

  if (database_info.isObject()) {

    CxxModuleDatabaseInfo db_info;

    db_info.TemplatePath = database_info["template-path"].asString();

    db_info.Output = database_info["output"].asString();

    export_info->DatabaseInfo = db_info;

  }

  auto const& bmi_installation = tdi["bmi-installation"];

  if (bmi_installation.isObject()) {

    CxxModuleBmiInstall bmi_install;

    bmi_install.Component = bmi_installation["component"].asString();

    bmi_install.Destination = bmi_installation["destination"].asString();

    bmi_install.ExcludeFromAll = bmi_installation["exclude-from-all"].asBool();

    bmi_install.Optional = bmi_installation["optional"].asBool();

    bmi_install.Permissions = bmi_installation["permissions"].asString();

    bmi_install.MessageLevel = bmi_installation["message-level"].asString();

    bmi_install.ScriptLocation =

      bmi_installation["script-location"].asString();

    export_info->BmiInstallation = bmi_install;

  }

  Json::Value const& tdi_cxx_modules = tdi["cxx-modules"];

  if (tdi_cxx_modules.isObject()) {

    for (auto i = tdi_cxx_modules.begin(); i != tdi_cxx_modules.end(); ++i) {

      CxxModuleFileSet& fsi = export_info->ObjectToFileSet[i.key().asString()];

      auto const& tdi_cxx_module_info = *i;

      fsi.Name = tdi_cxx_module_info["name"].asString();

      fsi.BmiOnly = tdi_cxx_module_info["bmi-only"].asBool();

      fsi.RelativeDirectory =

        tdi_cxx_module_info["relative-directory"].asString();

      if (!fsi.RelativeDirectory.empty() &&

          fsi.RelativeDirectory.back() != '/') {

        fsi.RelativeDirectory = cmStrCat(fsi.RelativeDirectory, '/');

      }

      fsi.SourcePath = tdi_cxx_module_info["source"].asString();

      fsi.Type = tdi_cxx_module_info["type"].asString();

      fsi.Visibility = cmFileSetVisibilityFromName(

        tdi_cxx_module_info["visibility"].asString(), nullptr);

      auto const& tdi_fs_dest = tdi_cxx_module_info["destination"];

      if (tdi_fs_dest.isString()) {

        fsi.Destination = tdi_fs_dest.asString();

      }

      for (auto const& j : tdi_cxx_module_info["include-directories"]) {

        fsi.IncludeDirectories.push_back(j.asString());

      }

      for (auto const& j : tdi_cxx_module_info["definitions"]) {

        fsi.Definitions.push_back(j.asString());

      }

      for (auto const& j : tdi_cxx_module_info["compile-options"]) {

        fsi.CompileOptions.push_back(j.asString());

      }

      for (auto const& j : tdi_cxx_module_info["compile-features"]) {

        fsi.CompileFeatures.push_back(j.asString());

      }

    }

  }

  Json::Value const& tdi_sources = tdi["sources"];

  if (tdi_sources.isObject()) {

    for (auto i = tdi_sources.begin(); i != tdi_sources.end(); ++i) {

      SourceInfo& si = export_info->ObjectToSource[i.key().asString()];

      auto const& tdi_source = *i;

      si.SourcePath = tdi_source["source"].asString();

      si.Language = tdi_source["language"].asString();

    }

  }

  return export_info;

}

bool cmDyndepCollation::WriteDyndepMetadata(

  std::string const& lang, std::vector<cmScanDepInfo> const& objects,

  cmCxxModuleExportInfo const& export_info,

  cmDyndepMetadataCallbacks const& cb)

{

  // Only C++ supports any of the file-set or BMI installation considered

  // below.

  if (lang != "CXX"_s) {

    return true;

  }

  bool result = true;

  // Prepare the export information blocks.

  std::string const config_upper =

    cmSystemTools::UpperCase(export_info.Config);

  std::vector<CxxModuleExportOutputHelper> exports;

  for (auto const& exp : export_info.Exports) {

    CxxModuleExportOutputHelper exp_helper;

    std::string const export_dir =

      cmStrCat(exp.Prefix, '/', exp.CxxModuleInfoDir, '/');

    std::string const property_file_path =

      cmStrCat(export_dir, "target-"_s, exp.FilesystemName, '-',

               export_info.Config, ".cmake"_s);

    exp_helper.Manifest.MetadataFilePath =

      cmStrCat(exp.Destination, '/', exp.CxxModuleInfoDir, "/target-"_s,

               exp.FilesystemName, '-', export_info.Config, ".modules.json"_s);

    exp_helper.File =

      cm::make_unique<cmGeneratedFileStream>(property_file_path);

    // Set up the preamble.

    *exp_helper.File << "set_property(TARGET \"" << exp.Namespace << exp.Name

                     << "\"\n"

                        "  PROPERTY IMPORTED_CXX_MODULES_"

                     << config_upper << '\n';

    exp_helper.Export = &exp;

    exports.emplace_back(std::move(exp_helper));

  }

  std::unique_ptr<cmBuildDatabase> module_database;

  cmBuildDatabase::LookupTable build_database_lookup;

  if (export_info.DatabaseInfo) {

    module_database =

      cmBuildDatabase::Load(export_info.DatabaseInfo->TemplatePath);

    if (module_database) {

      build_database_lookup = module_database->GenerateLookupTable();

    } else {

      cmSystemTools::Error(

        cmStrCat("Failed to read the template build database ",

                 export_info.DatabaseInfo->TemplatePath));

      result = false;

    }

  }

  std::unique_ptr<cmGeneratedFileStream> bmi_install_script;

  if (export_info.BmiInstallation) {

    bmi_install_script = cm::make_unique<cmGeneratedFileStream>(

      export_info.BmiInstallation->ScriptLocation);

  }

  auto cmEscape = [](cm::string_view str) {

    return cmOutputConverter::EscapeForCMake(

      str, cmOutputConverter::WrapQuotes::NoWrap);

  };

  auto install_destination =

    [&cmEscape](std::string const& dest) -> std::pair<bool, std::string> {

    if (cmSystemTools::FileIsFullPath(dest)) {

      return std::make_pair(true, cmEscape(dest));

    }

    return std::make_pair(false,

                          cmStrCat("${_IMPORT_PREFIX}/", cmEscape(dest)));

  };

  // public/private requirement tracking.

  std::set<std::string> private_modules;

  std::map<std::string, std::set<std::string>> public_source_requires;

  for (cmScanDepInfo const& object : objects) {

    // Convert to forward slashes.

    auto output_path = object.PrimaryOutput;

#ifdef _WIN32

    cmSystemTools::ConvertToUnixSlashes(output_path);

#endif

    auto source_info_itr = export_info.ObjectToSource.find(output_path);

    // Update the module compilation database `requires` field if needed.

    if (source_info_itr != export_info.ObjectToSource.end()) {

      auto const& sourcePath = source_info_itr->second.SourcePath;

      auto bdb_entry = build_database_lookup.find(sourcePath);

      if (bdb_entry != build_database_lookup.end()) {

        bdb_entry->second->Requires.clear();

        for (auto const& req : object.Requires) {

          bdb_entry->second->Requires.push_back(req.LogicalName);

        }

      } else if (export_info.DatabaseInfo) {

        cmSystemTools::Error(

          cmStrCat("Failed to find module database entry for ", sourcePath));

        result = false;

      }

    }

    // Find the fileset for this object.

    auto fileset_info_itr = export_info.ObjectToFileSet.find(output_path);

    bool const has_provides = !object.Provides.empty();

    if (fileset_info_itr == export_info.ObjectToFileSet.end()) {

      // If it provides anything, it should have type `CXX_MODULES`

      // and be present.

      if (has_provides) {

        // Take the first module provided to provide context.

        auto const& provides = object.Provides[0];

        cmSystemTools::Error(

          cmStrCat("Output ", object.PrimaryOutput, " provides the `",

                   provides.LogicalName,

                   "` module but it is not found in a `FILE_SET` of type "

                   "`CXX_MODULES`"));

        result = false;

      }

      // This object file does not provide anything, so nothing more needs to

      // be done.

      continue;

    }

    auto const& file_set = fileset_info_itr->second;

    // Update the module compilation database `provides` field if needed.

    {

      auto bdb_entry = build_database_lookup.find(file_set.SourcePath);

      if (bdb_entry != build_database_lookup.end()) {

        // Clear the provides mapping; we will re-initialize it here.

        if (!object.Provides.empty()) {

          bdb_entry->second->Provides.clear();

        }

        for (auto const& prov : object.Provides) {

          auto bmiName = cb.ModuleFile(prov.LogicalName);

          if (bmiName) {

            bdb_entry->second->Provides[prov.LogicalName] = *bmiName;

          } else {

            cmSystemTools::Error(

              cmStrCat("Failed to find BMI location for ", prov.LogicalName));

            result = false;

          }

        }

        for (auto const& req : object.Requires) {

          bdb_entry->second->Requires.push_back(req.LogicalName);

        }

      } else if (export_info.DatabaseInfo) {

        cmSystemTools::Error(cmStrCat(

          "Failed to find module database entry for ", file_set.SourcePath));

        result = false;

      }

    }

    // Verify the fileset type for the object.

    if (file_set.Type == "CXX_MODULES"_s) {

      if (!has_provides) {

        cmSystemTools::Error(

          cmStrCat("Output ", object.PrimaryOutput,

                   " is of type `CXX_MODULES` but does not provide a module "

                   "interface unit or partition"));

        result = false;

        continue;

      }

    } else if (file_set.Type == "CXX_MODULE_HEADERS"_s) {

      // TODO.

    } else {

      if (has_provides) {

        auto const& provides = object.Provides[0];

        cmSystemTools::Error(cmStrCat(

          "Source ", file_set.SourcePath, " provides the `",

          provides.LogicalName, "` C++ module but is of type `", file_set.Type,

          "` module but must be of type `CXX_MODULES`"));

        result = false;

      }

      // Not a C++ module; ignore.

      continue;

    }

    if (!cmFileSetVisibilityIsForInterface(file_set.Visibility)) {

      // Nothing needs to be conveyed about non-`PUBLIC` modules.

      for (auto const& p : object.Provides) {

        private_modules.insert(p.LogicalName);

      }

      continue;

    }

    // The module is public. Record what it directly requires.

    {

      auto& reqs = public_source_requires[file_set.SourcePath];

      for (auto const& r : object.Requires) {

        reqs.insert(r.LogicalName);

      }

    }

    // Write out properties and install rules for any exports.

    for (auto const& p : object.Provides) {

      bool bmi_dest_is_abs = false;

      std::string bmi_destination;

      if (export_info.BmiInstallation) {

        auto dest =

          install_destination(export_info.BmiInstallation->Destination);

        bmi_dest_is_abs = dest.first;

        bmi_destination = cmStrCat(dest.second, '/');

      }

      std::string install_bmi_path;

      std::string build_bmi_path;

      auto m = cb.ModuleFile(p.LogicalName);

      if (m) {

        install_bmi_path = cmStrCat(

          bmi_destination, cmEscape(cmSystemTools::GetFilenameNameView(*m)));

        build_bmi_path = cmEscape(*m);

      }

      for (auto& exp : exports) {

        std::string iface_source;

        cmCxxModuleMetadata::ModuleData mod;

        if (exp.Export->Install && file_set.Destination) {

          auto rel =

            cmStrCat('/', file_set.RelativeDirectory,

                     cmSystemTools::GetFilenameNameView(file_set.SourcePath));

          iface_source = cmStrCat(

            install_destination(*file_set.Destination).second, cmEscape(rel));

          mod.SourcePath = cmStrCat(*file_set.Destination, rel);

        } else {

          iface_source = cmEscape(file_set.SourcePath);

          mod.SourcePath = file_set.SourcePath;

        }

        std::string bmi_path;

        if (exp.Export->Install && export_info.BmiInstallation) {

          bmi_path = install_bmi_path;

        } else if (!exp.Export->Install) {

          bmi_path = build_bmi_path;

        }

        if (iface_source.empty()) {

          // No destination for the C++ module source; ignore this property

          // value.

          continue;

        }

        mod.LogicalName = p.LogicalName;

        mod.IsInterface = p.IsInterface;

        // FIXME(#27565): Local arguments may refer to include directories or

        // other resources which live in unknown locations on the consuming

        // machine. There's no general-purpose way to solve this with module

        // manifests as currently specified. For now, forego serializing them

        // and rely on CPS to fill in the blanks.

        exp.Manifest.Modules.emplace_back(std::move(mod));

        *exp.File << "    \"" << cmEscape(p.LogicalName) << '='

                  << iface_source;

        if (!bmi_path.empty()) {

          *exp.File << ',' << bmi_path;

        }

        *exp.File << "\"\n";

      }

      if (bmi_install_script) {

        auto const& bmi_install = *export_info.BmiInstallation;

        *bmi_install_script << "if (CMAKE_INSTALL_COMPONENT STREQUAL \""

                            << cmEscape(bmi_install.Component) << '\"';

        if (!bmi_install.ExcludeFromAll) {

          *bmi_install_script << " OR NOT CMAKE_INSTALL_COMPONENT";

        }

        *bmi_install_script << ")\n";

        *bmi_install_script << "  file(INSTALL\n"

                               "    DESTINATION \"";

        if (!bmi_dest_is_abs) {

          *bmi_install_script << "${CMAKE_INSTALL_PREFIX}/";

        }

        *bmi_install_script << cmEscape(bmi_install.Destination)

                            << "\"\n"

                               "    TYPE FILE\n";

        if (bmi_install.Optional) {

          *bmi_install_script << "    OPTIONAL\n";

        }

        if (!bmi_install.MessageLevel.empty()) {

          *bmi_install_script << "    " << bmi_install.MessageLevel << "\n";

        }

        if (!bmi_install.Permissions.empty()) {

          *bmi_install_script << "    PERMISSIONS" << bmi_install.Permissions

                              << "\n";

        }

        *bmi_install_script << "    FILES \"" << *m << "\")\n";

        if (bmi_dest_is_abs) {

          *bmi_install_script

            << "  list(APPEND CMAKE_ABSOLUTE_DESTINATION_FILES\n"

               "    \""

            << cmEscape(cmSystemTools::GetFilenameNameView(*m))

            << "\")\n"

               "  if (CMAKE_WARN_ON_ABSOLUTE_INSTALL_DESTINATION)\n"

               "    message(WARNING\n"

               "      \"ABSOLUTE path INSTALL DESTINATION : "

               "${CMAKE_ABSOLUTE_DESTINATION_FILES}\")\n"

               "  endif ()\n"

               "  if (CMAKE_ERROR_ON_ABSOLUTE_INSTALL_DESTINATION)\n"

               "    message(FATAL_ERROR\n"

               "      \"ABSOLUTE path INSTALL DESTINATION forbidden (by "

               "caller): ${CMAKE_ABSOLUTE_DESTINATION_FILES}\")\n"

               "  endif ()\n";

        }

        *bmi_install_script << "endif ()\n";

      }

    }

  }

  for (auto const& exp : exports) {

    cmCxxModuleMetadata::SaveToFile(

      cmStrCat(exp.Export->Prefix, '/', exp.Export->CxxModuleInfoDir,

               "/target-"_s, exp.Export->FilesystemName, '-',

               export_info.Config, ".modules.json"_s),

      exp.Manifest);

    *exp.File << ")\n";

  }

  // Check that public sources only require public modules.

  for (auto const& pub_reqs : public_source_requires) {

    for (auto const& req : pub_reqs.second) {

      if (private_modules.count(req)) {

        cmSystemTools::Error(cmStrCat(

          "Public C++ module source `", pub_reqs.first, "` requires the `",

          req, "` C++ module which is provided by a private source"));

        result = false;

      }

    }

  }

  if (module_database) {

    if (module_database->HasPlaceholderNames()) {

      cmSystemTools::Error(

        "Module compilation database still contains placeholders");