[toolsrc] Optionally allow vcpkg to clean after each build (#6522)

* [toolsrc] Optionally allow vcpkg to clean packages, buildtrees and downloads after each build
Adds switch --clean-after-build

* [toolsrc] Clarify that --clean-after-build deletes downloads

* [toolsrc] Revert changes to ci download caching behaviour

5 files changed, 22 insertions, 3 deletions

diff --git a/toolsrc/src/vcpkg/build.cpp b/toolsrc/src/vcpkg/build.cpp
index c5f145052..1f28e9f30 100644
--- a/toolsrc/src/vcpkg/build.cpp
+++ b/toolsrc/src/vcpkg/build.cpp
@@ -70,6 +70,7 @@ namespace vcpkg::Build::Command
             Build::AllowDownloads::YES,

             Build::CleanBuildtrees::NO,

             Build::CleanPackages::NO,

+            Build::CleanDownloads::NO,

             Build::DownloadTool::BUILT_IN,

             GlobalState::g_binary_caching ? Build::BinaryCaching::YES : Build::BinaryCaching::NO,

             Build::FailOnTombstone::NO,

diff --git a/toolsrc/src/vcpkg/commands.ci.cpp b/toolsrc/src/vcpkg/commands.ci.cpp
index 10cb7d9fe..4d31c4fbe 100644
--- a/toolsrc/src/vcpkg/commands.ci.cpp
+++ b/toolsrc/src/vcpkg/commands.ci.cpp
@@ -229,6 +229,7 @@ namespace vcpkg::Commands::CI
             Build::AllowDownloads::YES,
             Build::CleanBuildtrees::YES,
             Build::CleanPackages::YES,
+            Build::CleanDownloads::NO,
             Build::DownloadTool::BUILT_IN,
             GlobalState::g_binary_caching ? Build::BinaryCaching::YES : Build::BinaryCaching::NO,
             Build::FailOnTombstone::YES,
@@ -372,6 +373,7 @@ namespace vcpkg::Commands::CI
             Build::AllowDownloads::YES,
             Build::CleanBuildtrees::YES,
             Build::CleanPackages::YES,
+            Build::CleanDownloads::NO,
             Build::DownloadTool::BUILT_IN,
             GlobalState::g_binary_caching ? Build::BinaryCaching::YES : Build::BinaryCaching::NO,
             Build::FailOnTombstone::YES,
diff --git a/toolsrc/src/vcpkg/commands.upgrade.cpp b/toolsrc/src/vcpkg/commands.upgrade.cpp
index 29627db3d..29815ca94 100644
--- a/toolsrc/src/vcpkg/commands.upgrade.cpp
+++ b/toolsrc/src/vcpkg/commands.upgrade.cpp
@@ -155,6 +155,7 @@ namespace vcpkg::Commands::Upgrade
             Build::AllowDownloads::YES,
             Build::CleanBuildtrees::NO,
             Build::CleanPackages::NO,
+            Build::CleanDownloads::NO,
             Build::DownloadTool::BUILT_IN,
             GlobalState::g_binary_caching ? Build::BinaryCaching::YES : Build::BinaryCaching::NO,
             Build::FailOnTombstone::NO,
diff --git a/toolsrc/src/vcpkg/export.cpp b/toolsrc/src/vcpkg/export.cpp
index 870d2c49e..f6a95b61f 100644
--- a/toolsrc/src/vcpkg/export.cpp
+++ b/toolsrc/src/vcpkg/export.cpp
@@ -75,6 +75,7 @@ namespace vcpkg::Export
             Build::AllowDownloads::YES,
             Build::CleanBuildtrees::NO,
             Build::CleanPackages::NO,
+            Build::CleanDownloads::NO,
             Build::DownloadTool::BUILT_IN,
             Build::BinaryCaching::NO,
             Build::FailOnTombstone::NO,
diff --git a/toolsrc/src/vcpkg/install.cpp b/toolsrc/src/vcpkg/install.cpp
index 6e7ad274d..7fb304c17 100644
--- a/toolsrc/src/vcpkg/install.cpp
+++ b/toolsrc/src/vcpkg/install.cpp
@@ -367,6 +367,16 @@ namespace vcpkg::Install
                 fs.remove_all(package_dir, ec);
             }
 
+            if (action.build_options.clean_downloads == Build::CleanDownloads::YES)
+            {
+                auto& fs = paths.get_filesystem();
+                const fs::path download_dir = paths.downloads;
+                std::error_code ec;
+                for(auto& p: fs.get_files_non_recursive(download_dir))
+                    if (!fs.is_directory(p))
+                        fs.remove(p);
+            }
+
             return {code, std::move(bcf)};
         }
 
@@ -463,14 +473,16 @@ namespace vcpkg::Install
     static constexpr StringLiteral OPTION_KEEP_GOING = "--keep-going";
     static constexpr StringLiteral OPTION_XUNIT = "--x-xunit";
     static constexpr StringLiteral OPTION_USE_ARIA2 = "--x-use-aria2";
+    static constexpr StringLiteral OPTION_CLEAN_AFTER_BUILD = "--clean-after-build";
 
-    static constexpr std::array<CommandSwitch, 6> INSTALL_SWITCHES = {{
+    static constexpr std::array<CommandSwitch, 7> INSTALL_SWITCHES = {{
         {OPTION_DRY_RUN, "Do not actually build or install"},
         {OPTION_USE_HEAD_VERSION, "Install the libraries on the command line using the latest upstream sources"},
         {OPTION_NO_DOWNLOADS, "Do not download new sources"},
         {OPTION_RECURSE, "Allow removal of packages as part of installation"},
         {OPTION_KEEP_GOING, "Continue installing packages on failure"},
         {OPTION_USE_ARIA2, "Use aria2 to perform download tasks"},
+        {OPTION_CLEAN_AFTER_BUILD, "Clean buildtrees, packages and downloads after building each package"},
     }};
     static constexpr std::array<CommandSetting, 1> INSTALL_SETTINGS = {{
         {OPTION_XUNIT, "File to output results in XUnit format (Internal use)"},
@@ -623,6 +635,7 @@ namespace vcpkg::Install
         const bool no_downloads = Util::Sets::contains(options.switches, (OPTION_NO_DOWNLOADS));
         const bool is_recursive = Util::Sets::contains(options.switches, (OPTION_RECURSE));
         const bool use_aria2 = Util::Sets::contains(options.switches, (OPTION_USE_ARIA2));
+        const bool clean_after_build = Util::Sets::contains(options.switches, (OPTION_CLEAN_AFTER_BUILD));
         const KeepGoing keep_going = to_keep_going(Util::Sets::contains(options.switches, OPTION_KEEP_GOING));
 
         // create the plan
@@ -634,8 +647,9 @@ namespace vcpkg::Install
         const Build::BuildPackageOptions install_plan_options = {
             Util::Enum::to_enum<Build::UseHeadVersion>(use_head_version),
             Util::Enum::to_enum<Build::AllowDownloads>(!no_downloads),
-            Build::CleanBuildtrees::NO,
-            Build::CleanPackages::NO,
+            clean_after_build ? Build::CleanBuildtrees::YES : Build::CleanBuildtrees::NO,
+            clean_after_build ? Build::CleanPackages::YES : Build::CleanPackages::NO,
+            clean_after_build ? Build::CleanDownloads::YES : Build::CleanDownloads::NO,
             download_tool,
             GlobalState::g_binary_caching ? Build::BinaryCaching::YES : Build::BinaryCaching::NO,
             Build::FailOnTombstone::NO,