[vcpkg-x-set-installed] Implement --dry-run (#12132)

* [vcpkg-x-set-installed] Implement --dry-run

* [vcpkg] Address code review comments

Co-authored-by: Robert Schumacher <roschuma@microsoft.com>

toolsrc/src/vcpkg/commands.setinstalled.cpp

@@ -13,11 +13,17 @@
 
 namespace vcpkg::Commands::SetInstalled
 {
+    static constexpr StringLiteral OPTION_DRY_RUN = "--dry-run";
+
+    static constexpr CommandSwitch INSTALL_SWITCHES[] = {
+        {OPTION_DRY_RUN, "Do not actually build or install"},
+    };
+
     const CommandStructure COMMAND_STRUCTURE = {
         create_example_string(R"(x-set-installed <package>...)"),
-        1,
+        0,
         SIZE_MAX,
-        {},
+        {INSTALL_SWITCHES},
         nullptr,
     };
 
@@ -39,6 +45,8 @@ namespace vcpkg::Commands::SetInstalled
         auto binaryprovider =
             create_binary_provider_from_configs(paths, args.binarysources).value_or_exit(VCPKG_LINE_INFO);
 
+        const bool dry_run = Util::Sets::contains(options.switches, OPTION_DRY_RUN);
+
         const Build::BuildPackageOptions install_plan_options = {
             Build::UseHeadVersion::NO,
             Build::AllowDownloads::YES,
@@ -76,6 +84,7 @@ namespace vcpkg::Commands::SetInstalled
         // currently (or once) installed specifications
         auto status_db = database_load_check(paths);
         std::vector<PackageSpec> specs_to_remove;
+        std::set<PackageSpec> specs_installed;
         for (auto&& status_pgh : status_db)
         {
             if (!status_pgh->is_installed()) continue;
@@ -86,25 +95,33 @@ namespace vcpkg::Commands::SetInstalled
             {
                 specs_to_remove.push_back(status_pgh->package.spec);
             }
-        }
+            else
-
-        auto remove_plan = Dependencies::create_remove_plan(specs_to_remove, status_db);
-
-        for (const auto& action : remove_plan)
             {
-            Remove::perform_remove_plan_action(paths, action, Remove::Purge::NO, &status_db);
+                specs_installed.emplace(status_pgh->package.spec);
+            }
         }
 
-        auto real_action_plan = Dependencies::create_feature_install_plan(provider, *cmake_vars, specs, status_db);
+        action_plan.remove_actions = Dependencies::create_remove_plan(specs_to_remove, status_db);
 
-        for (auto& action : real_action_plan.install_actions)
+        for (const auto& action : action_plan.remove_actions)
         {
-            action.build_options = install_plan_options;
+            // This should not technically be needed, however ensuring that all specs to be removed are not included in
+            // `specs_installed` acts as a sanity check
+            specs_installed.erase(action.spec);
         }
 
-        Dependencies::print_plan(real_action_plan, true);
+        Util::erase_remove_if(action_plan.install_actions, [&](const Dependencies::InstallPlanAction& ipa) {
+            return Util::Sets::contains(specs_installed, ipa.spec);
+        });
 
-        const auto summary = Install::perform(real_action_plan,
+        Dependencies::print_plan(action_plan, true, paths.ports);
+
+        if (dry_run)
+        {
+            Checks::exit_success(VCPKG_LINE_INFO);
+        }
+
+        const auto summary = Install::perform(action_plan,
                                               Install::KeepGoing::NO,
                                               paths,
                                               status_db,

toolsrc/src/vcpkg/dependencies.cpp

@@ -948,7 +948,14 @@ namespace vcpkg::Dependencies
 
     void print_plan(const ActionPlan& action_plan, const bool is_recursive, const fs::path& default_ports_dir)
     {
-        std::vector<const RemovePlanAction*> remove_plans;
+        if (action_plan.remove_actions.empty() && action_plan.already_installed.empty() &&
+            action_plan.install_actions.empty())
+        {
+            System::print2("All requested packages are currently installed.\n");
+            return;
+        }
+
+        std::set<PackageSpec> remove_specs;
         std::vector<const InstallPlanAction*> rebuilt_plans;
         std::vector<const InstallPlanAction*> only_install_plans;
         std::vector<const InstallPlanAction*> new_plans;
@@ -962,16 +969,16 @@ namespace vcpkg::Dependencies
 
         for (auto&& remove_action : action_plan.remove_actions)
         {
-            remove_plans.emplace_back(&remove_action);
+            remove_specs.emplace(remove_action.spec);
         }
         for (auto&& install_action : action_plan.install_actions)
         {
             // remove plans are guaranteed to come before install plans, so we know the plan will be contained
             // if at all.
-            auto it = Util::find_if(remove_plans,
+            auto it = remove_specs.find(install_action.spec);
-                                    [&](const RemovePlanAction* plan) { return plan->spec == install_action.spec; });
+            if (it != remove_specs.end())
-            if (it != remove_plans.end())
             {
+                remove_specs.erase(it);
                 rebuilt_plans.push_back(&install_action);
             }
             else
@@ -988,7 +995,6 @@ namespace vcpkg::Dependencies
         }
         already_installed_plans = Util::fmap(action_plan.already_installed, [](auto&& action) { return &action; });
 
-        std::sort(remove_plans.begin(), remove_plans.end(), &RemovePlanAction::compare_by_name);
         std::sort(rebuilt_plans.begin(), rebuilt_plans.end(), &InstallPlanAction::compare_by_name);
         std::sort(only_install_plans.begin(), only_install_plans.end(), &InstallPlanAction::compare_by_name);
         std::sort(new_plans.begin(), new_plans.end(), &InstallPlanAction::compare_by_name);
@@ -1019,6 +1025,16 @@ namespace vcpkg::Dependencies
                            '\n');
         }
 
+        if (!remove_specs.empty())
+        {
+            std::string msg = "The following packages will be removed:\n";
+            for (auto spec : remove_specs)
+            {
+                Strings::append(msg, to_output_string(RequestType::USER_REQUESTED, spec.to_string()), '\n');
+            }
+            System::print2(msg);
+        }
+
         if (!rebuilt_plans.empty())
         {
             System::print2("The following packages will be rebuilt:\n", actions_to_output_string(rebuilt_plans), '\n');
@@ -1039,8 +1055,8 @@ namespace vcpkg::Dependencies
 
         if (has_non_user_requested_packages)
             System::print2("Additional packages (*) will be modified to complete this operation.\n");
-
+        bool have_removals = !remove_specs.empty() || !rebuilt_plans.empty();
-        if (!remove_plans.empty() && !is_recursive)
+        if (have_removals && !is_recursive)
         {
             System::print2(System::Color::warning,
                            "If you are sure you want to rebuild the above packages, run the command with the "