[release/5.0-preview4] Revert processing bundles in framework (#35679)v5.0.0-preview.4.20251.6

This commit reverts:
Revert "Single-File: Process bundles in the framework (#34274)"
This reverts commit 78b303df8fbb242985d049a277d0d199cafd51b5.

Revert "Single-File Bundler: Add a FileSize test (#35149)"
This reverts commit 779588a509b81d909ac5d496c172949ec1f1ddcc.

*Customer Scenario*

Publishing apps as a self-contained single-file doesn't work as expected.

* Publish needs to generate hostpolicy and hostfxr separate from the single file bundle
* Cross-platform publishing is incorrect

*Problem*

Since Static-apphost is not yet ready, processing bundle content in hostpolicy means that  hostpolicy and hostfxr DLLs need to be separate from the bundle. This causes self-contained single-file apps to not be a "single file" temporarily. 

The change also requires supporting changes from the SDK, to publish hostfxr and hostpolicy as separate files, and to invoke HostModel library with arguments that facilitate cross-platform publishing.

*Solution*

To solve these, problem, this change reverts:

Revert "Single-File: Process bundles in the framework (#34274)" commit 78b303df8fbb242985d049a277d0d199cafd51b5.

and a dependent test-only change:

Revert "Single-File Bundler: Add a FileSize test (#35149)" commit 779588a509b81d909ac5d496c172949ec1f1ddcc.

*Risk*

Medium
The change is contained to only host components: apphost, hostpolicy, and hostfxr.
However, the change is big, and needs testing in runtime and SDK repos.

*Testing*

Manually tested the SDK by inserting apphost, hostfxr, hostpolicy, and hostmodel library from this build into the `dotnet/packs` preview-4 SDK from https://github.com/dotnet/sdk/pull/11518 build.

Verified that:
* Singlefile apps can be published and run OK for  { Windows, Linux, Osx } x {netcoreapp3.0, netcoreapp3.1, netcoreapp5.0} 
* Cross-targeting builds of single-file apps build and run OK (ex: built on Windos, run on Mac).

1 files changed, 58 insertions, 83 deletions

diff --git a/src/installer/corehost/corehost.cpp b/src/installer/corehost/corehost.cpp
index 55b8ed62982..bb6b4ce60e5 100644
--- a/src/installer/corehost/corehost.cpp
+++ b/src/installer/corehost/corehost.cpp
@@ -11,7 +11,8 @@
 #include "utils.h"
 
 #if defined(FEATURE_APPHOST)
-#include "bundle_marker.h"
+#include "cli/apphost/bundle/marker.h"
+#include "cli/apphost/bundle/runner.h"
 
 #if defined(_WIN32)
 #include "cli/apphost/apphost.windows.h"
@@ -83,14 +84,6 @@ bool is_exe_enabled_for_execution(pal::string_t* app_dll)
 #define CURHOST_EXE
 #endif
 
-void need_newer_framework_error()
-{
-    pal::string_t url = get_download_url();
-    trace::error(_X("  _ To run this application, you need to install a newer version of .NET Core."));
-    trace::error(_X(""));
-    trace::error(_X("  - %s&apphost_version=%s"), url.c_str(), _STRINGIFY(COMMON_HOST_PKG_VER));
-}
-
 #if defined(CURHOST_EXE)
 
 int exe_start(const int argc, const pal::char_t* argv[])
@@ -104,8 +97,8 @@ int exe_start(const int argc, const pal::char_t* argv[])
 
     pal::string_t app_path;
     pal::string_t app_root;
-    bool requires_hostfxr_startupinfo_interface = false;
-
+    bool requires_v2_hostfxr_interface = false;
+    
 #if defined(FEATURE_APPHOST)
     pal::string_t embedded_app_name;
     if (!is_exe_enabled_for_execution(&embedded_app_name))
@@ -122,17 +115,29 @@ int exe_start(const int argc, const pal::char_t* argv[])
     auto pos_path_char = embedded_app_name.find(DIR_SEPARATOR);
     if (pos_path_char != pal::string_t::npos)
     {
-        requires_hostfxr_startupinfo_interface = true;
+        requires_v2_hostfxr_interface = true;
     }
 
-    app_path.assign(get_directory(host_path));
-    append_path(&app_path, embedded_app_name.c_str());
+    if (bundle::marker_t::is_bundle())
+    {
+        bundle::runner_t bundle_runner(host_path);
+        StatusCode bundle_status = bundle_runner.extract();
+
+        if (bundle_status != StatusCode::Success)
+        {
+            trace::error(_X("A fatal error was encountered. Could not extract contents of the bundle"));
+            return bundle_status;
+        }
 
-    if (bundle_marker_t::is_bundle())
+        app_path.assign(bundle_runner.extraction_dir());
+    }
+    else
     {
-        trace::info(_X("Detected Single-File app bundle"));
+        app_path.assign(get_directory(host_path));
     }
-    else if (!pal::realpath(&app_path))
+
+    append_path(&app_path, embedded_app_name.c_str());
+    if (!pal::realpath(&app_path))
     {
         trace::error(_X("The application to execute does not exist: '%s'."), app_path.c_str());
         return StatusCode::LibHostAppRootFindFailure;
@@ -195,88 +200,58 @@ int exe_start(const int argc, const pal::char_t* argv[])
 
     // Obtain the entrypoints.
     int rc;
-#if defined(FEATURE_APPHOST)
-    if (bundle_marker_t::is_bundle())
-    {
-        hostfxr_main_bundle_startupinfo_fn hostfxr_main_bundle_startupinfo = reinterpret_cast<hostfxr_main_bundle_startupinfo_fn>(pal::get_symbol(fxr, "hostfxr_main_bundle_startupinfo"));
-        if (hostfxr_main_bundle_startupinfo != nullptr)
-        {
-            const pal::char_t* host_path_cstr = host_path.c_str();
-            const pal::char_t* dotnet_root_cstr = dotnet_root.empty() ? nullptr : dotnet_root.c_str();
-            const pal::char_t* app_path_cstr = app_path.empty() ? nullptr : app_path.c_str();
-            int64_t bundle_header_offset = bundle_marker_t::header_offset();
-
-            trace::info(_X("Invoking fx resolver [%s] hostfxr_main_bundle_startupinfo"), fxr_path.c_str());
-            trace::info(_X("Host path: [%s]"), host_path.c_str());
-            trace::info(_X("Dotnet path: [%s]"), dotnet_root.c_str());
-            trace::info(_X("App path: [%s]"), app_path.c_str());
-            trace::info(_X("Bundle Header Offset: [%lx]"), bundle_header_offset);
-
-            hostfxr_set_error_writer_fn set_error_writer_fn = reinterpret_cast<hostfxr_set_error_writer_fn>(pal::get_symbol(fxr, "hostfxr_set_error_writer"));
-            propagate_error_writer_t propagate_error_writer_to_hostfxr(set_error_writer_fn);
-            rc = hostfxr_main_bundle_startupinfo(argc, argv, host_path_cstr, dotnet_root_cstr, app_path_cstr, bundle_header_offset);
-        }
-        else
-        {
-            // The host components will be statically linked with the app-host: https://github.com/dotnet/runtime/issues/32823
-            // Once this work is completed, an outdated hostfxr can only be found for framework-related apps.
-            trace::error(_X("The required library %s does not support single-file apps."), fxr_path.c_str());			
-            need_newer_framework_error();
-            rc = StatusCode::FrameworkMissingFailure;
-        }
-    }
-    else
-#endif // defined(FEATURE_APPHOST)
+    hostfxr_main_startupinfo_fn main_fn_v2 = reinterpret_cast<hostfxr_main_startupinfo_fn>(pal::get_symbol(fxr, "hostfxr_main_startupinfo"));
+    if (main_fn_v2 != nullptr)
     {
-        hostfxr_main_startupinfo_fn hostfxr_main_startupinfo = reinterpret_cast<hostfxr_main_startupinfo_fn>(pal::get_symbol(fxr, "hostfxr_main_startupinfo"));
-        if (hostfxr_main_startupinfo != nullptr)
-        {
-            const pal::char_t* host_path_cstr = host_path.c_str();
-            const pal::char_t* dotnet_root_cstr = dotnet_root.empty() ? nullptr : dotnet_root.c_str();
-            const pal::char_t* app_path_cstr = app_path.empty() ? nullptr : app_path.c_str();
+        const pal::char_t* host_path_cstr = host_path.c_str();
+        const pal::char_t* dotnet_root_cstr = dotnet_root.empty() ? nullptr : dotnet_root.c_str();
+        const pal::char_t* app_path_cstr = app_path.empty() ? nullptr : app_path.c_str();
 
-            trace::info(_X("Invoking fx resolver [%s] hostfxr_main_startupinfo"), fxr_path.c_str());
-            trace::info(_X("Host path: [%s]"), host_path.c_str());
-            trace::info(_X("Dotnet path: [%s]"), dotnet_root.c_str());
-            trace::info(_X("App path: [%s]"), app_path.c_str());
+        trace::info(_X("Invoking fx resolver [%s] v2"), fxr_path.c_str());
+        trace::info(_X("Host path: [%s]"), host_path.c_str());
+        trace::info(_X("Dotnet path: [%s]"), dotnet_root.c_str());
+        trace::info(_X("App path: [%s]"), app_path.c_str());
 
-            hostfxr_set_error_writer_fn set_error_writer_fn = reinterpret_cast<hostfxr_set_error_writer_fn>(pal::get_symbol(fxr, "hostfxr_set_error_writer"));
+        hostfxr_set_error_writer_fn set_error_writer_fn = reinterpret_cast<hostfxr_set_error_writer_fn>(pal::get_symbol(fxr, "hostfxr_set_error_writer"));
+        {
             propagate_error_writer_t propagate_error_writer_to_hostfxr(set_error_writer_fn);
 
-            rc = hostfxr_main_startupinfo(argc, argv, host_path_cstr, dotnet_root_cstr, app_path_cstr);
+            rc = main_fn_v2(argc, argv, host_path_cstr, dotnet_root_cstr, app_path_cstr);
 
-            // This check exists to provide an error message for UI apps when running 3.0 apps on 2.0 only hostfxr, which doesn't support error writer redirection. 
             if (trace::get_error_writer() != nullptr && rc == static_cast<int>(StatusCode::FrameworkMissingFailure) && !set_error_writer_fn)
             {
-                need_newer_framework_error();
+                pal::string_t url = get_download_url();
+                trace::error(_X("  _ To run this application, you need to install a newer version of .NET."));
+                trace::error(_X(""));
+                trace::error(_X("  - %s"), url.c_str());
             }
         }
+    }
+    else
+    {
+        if (requires_v2_hostfxr_interface)
+        {
+            trace::error(_X("The required library %s does not support relative app dll paths."), fxr_path.c_str());
+            rc = StatusCode::CoreHostEntryPointFailure;
+        }
         else
         {
-            if (requires_hostfxr_startupinfo_interface)
+            trace::info(_X("Invoking fx resolver [%s] v1"), fxr_path.c_str());
+
+            // Previous corehost trace messages must be printed before calling trace::setup in hostfxr
+            trace::flush();
+
+            // For compat, use the v1 interface. This requires additional file I\O to re-parse parameters and
+            // for apphost, does not support DOTNET_ROOT or dll with different name for exe.
+            hostfxr_main_fn main_fn_v1 = reinterpret_cast<hostfxr_main_fn>(pal::get_symbol(fxr, "hostfxr_main"));
+            if (main_fn_v1 != nullptr)
             {
-                trace::error(_X("The required library %s does not support relative app dll paths."), fxr_path.c_str());
-                rc = StatusCode::CoreHostEntryPointFailure;
+                rc = main_fn_v1(argc, argv);
             }
             else
             {
-                trace::info(_X("Invoking fx resolver [%s] v1"), fxr_path.c_str());
-
-                // Previous corehost trace messages must be printed before calling trace::setup in hostfxr
-                trace::flush();
-
-                // For compat, use the v1 interface. This requires additional file I\O to re-parse parameters and
-                // for apphost, does not support DOTNET_ROOT or dll with different name for exe.
-                hostfxr_main_fn main_fn_v1 = reinterpret_cast<hostfxr_main_fn>(pal::get_symbol(fxr, "hostfxr_main"));
-                if (main_fn_v1 != nullptr)
-                {
-                    rc = main_fn_v1(argc, argv);
-                }
-                else
-                {
-                    trace::error(_X("The required library %s does not contain the expected entry point."), fxr_path.c_str());
-                    rc = StatusCode::CoreHostEntryPointFailure;
-                }
+                trace::error(_X("The required library %s does not contain the expected entry point."), fxr_path.c_str());
+                rc = StatusCode::CoreHostEntryPointFailure;
             }
         }
     }