[native assets] Support PATHEXT invocations with appended snapshot

This CL introduces an `IsolateData::asset_base_path` which contains
the fully resolved base path used for assets which are loaded with a
relative path. (Resolving both PATHEXT and symlinks.)

The asset base path is now only resolved once, instead of on every
relative asset load.

The asset base path is now eagerly resolved.
To prevent existing error messages for files not existing changing in
`dartdev` and `Isolate.spawnUri`, files not existing errors are
ignored.
To prevent `tests/standalone/io/named_pipe_script_test.dart` from
failing, failing to canonicalize a file path is treated as no asset
base path rather than reporting a failure.

TEST=pkg/dartdev/test/native_assets/*.dart

Bug: #60946
Change-Id: I79a9144d220dfb3e54311725d41f8f91c88db3a1
Cq-Include-Trybots: luci.dart.try:pkg-linux-debug-try,pkg-linux-release-arm64-try,pkg-linux-release-try,pkg-mac-release-try,pkg-mac-release-arm64-try,pkg-win-release-arm64-try,pkg-win-release-try,vm-aot-dyn-linux-debug-x64-try,vm-aot-android-release-arm64c-try,vm-aot-linux-debug-x64-try,vm-aot-mac-debug-arm64-try,vm-aot-win-debug-arm64-try,vm-aot-optimization-level-linux-release-x64-try,vm-aot-obfuscate-linux-release-x64-try,vm-msan-linux-release-x64-try,vm-asan-linux-release-x64-try,vm-linux-release-x64-try,vm-linux-debug-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/435421
Commit-Queue: Daco Harkes <[email protected]>
Reviewed-by: Martin Kustermann <[email protected]>

Author: dcharkes

pkg/dartdev/test/native_assets/build_test.dart

@@ -66,35 +66,15 @@ void main([List<String> args = const []]) async {
           final link = Link.fromUri(
               tempUri.resolve(OS.current.executableFileName('my_link')));
           await link.create(absoluteExeUri.toFilePath());
-          if (OS.current == OS.windows) {
-            for (final exeUri in [
-              removeDotExe(link.uri),
-              removeDotExe(absoluteExeUri),
-              removeDotExe(relativeExeUri),
-            ]) {
-              final result = await runProcess(
-                executable: exeUri,
-                arguments: [],
-                workingDirectory: dartAppUri,
-                logger: logger,
-              );
-              // TODO(https://dartbug.com/60946): Support PATHEXT.
-              expect(result.exitCode, isNot(0));
-              expect(
-                result.stderr,
-                stringContainsInOrder(
-                  [
-                    'Failed to canonicalize the script uri',
-                    'The system cannot find the file specified.',
-                  ],
-                ),
-              );
-            }
-          }
           for (final exeUri in [
             absoluteExeUri,
             relativeExeUri,
             link.uri,
+            if (OS.current == OS.windows) ...[
+              removeDotExe(absoluteExeUri),
+              removeDotExe(relativeExeUri),
+              removeDotExe(link.uri),
+            ]
           ]) {
             final result = await runProcess(
               executable: exeUri,

runtime/bin/analyze_snapshot.cc

@@ -213,7 +213,7 @@ int RunAnalyzer(int argc, char** argv) {
   }
 
   auto isolate_group_data = std::unique_ptr<IsolateGroupData>(
-      new IsolateGroupData(nullptr, nullptr, nullptr, false));
+      new IsolateGroupData(nullptr, nullptr, nullptr, nullptr, false));
 
   Dart_IsolateFlags isolate_flags;
   Dart_IsolateFlagsInitialize(&isolate_flags);

runtime/bin/gen_snapshot.cc

@@ -746,7 +746,7 @@ static int CreateIsolateAndSnapshot(const CommandLineOptions& inputs) {
   }
 
   auto isolate_group_data = std::unique_ptr<IsolateGroupData>(
-      new IsolateGroupData(nullptr, nullptr, nullptr, false));
+      new IsolateGroupData(nullptr, nullptr, nullptr, nullptr, false));
   Dart_Isolate isolate;
   char* error = nullptr;
 

runtime/bin/isolate_data.cc

@@ -10,10 +10,14 @@ namespace dart {
 namespace bin {
 
 IsolateGroupData::IsolateGroupData(const char* url,
+                                   const char* asset_resolution_base,
                                    const char* packages_file,
                                    AppSnapshot* app_snapshot,
                                    bool isolate_run_app_snapshot)
     : script_url((url != nullptr) ? Utils::StrDup(url) : nullptr),
+      asset_resolution_base((asset_resolution_base != nullptr)
+                                ? Utils::StrDup(asset_resolution_base)
+                                : nullptr),
       app_snapshot_(app_snapshot),
       resolved_packages_config_(nullptr),
       kernel_buffer_(nullptr),
@@ -29,6 +33,7 @@ IsolateGroupData::~IsolateGroupData() {
     delete loading_units_[i];
   }
   free(script_url);
+  free(asset_resolution_base);
   script_url = nullptr;
   free(packages_file_);
   packages_file_ = nullptr;

runtime/bin/isolate_data.h

@@ -36,13 +36,21 @@ class Loader;
 class IsolateGroupData {
  public:
   IsolateGroupData(const char* url,
+                   const char* asset_resolution_base,
                    const char* packages_file,
                    AppSnapshot* app_snapshot,
                    bool isolate_run_app_snapshot);
   ~IsolateGroupData();
 
   char* script_url;
 
+  // Base path for resolving assets with a relative path.
+  //
+  // This must be an absolute path pointing to a real file (not a symlink).
+  //
+  // May be nullptr.
+  char* asset_resolution_base;
+
   const std::shared_ptr<uint8_t>& kernel_buffer() const {
     return kernel_buffer_;
   }

runtime/bin/main_impl.cc

@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <cerrno>
 #include <memory>
 #include <utility>
 
@@ -35,6 +36,7 @@
 #include "include/dart_api.h"
 #include "include/dart_embedder_api.h"
 #include "include/dart_tools_api.h"
+#include "platform/assert.h"
 #include "platform/globals.h"
 #include "platform/syslog.h"
 #include "platform/utils.h"
@@ -257,8 +259,8 @@ static bool OnIsolateInitialize(void** child_callback_data, char** error) {
 static void* NativeAssetsDlopenRelative(const char* path, char** error) {
   auto isolate_group_data =
       reinterpret_cast<IsolateGroupData*>(Dart_CurrentIsolateGroupData());
-  const char* script_uri = isolate_group_data->script_url;
-  return NativeAssets::DlopenRelative(path, script_uri, error);
+  return NativeAssets::DlopenRelative(
+      path, isolate_group_data->asset_resolution_base, error);
 }
 
 static Dart_Isolate IsolateSetupHelper(Dart_Isolate isolate,
@@ -474,7 +476,8 @@ static Dart_Isolate CreateAndSetupKernelIsolate(const char* script_uri,
         &ignore_vm_snapshot_data, &ignore_vm_snapshot_instructions,
         &isolate_snapshot_data, &isolate_snapshot_instructions);
     isolate_group_data = new IsolateGroupData(
-        uri, packages_config, app_snapshot, isolate_run_app_snapshot);
+        uri, /*asset_resolution_base=*/nullptr, packages_config, app_snapshot,
+        isolate_run_app_snapshot);
     isolate_data = new IsolateData(isolate_group_data);
     isolate = Dart_CreateIsolateGroup(
         DART_KERNEL_ISOLATE_NAME, DART_KERNEL_ISOLATE_NAME,
@@ -492,8 +495,9 @@ static Dart_Isolate CreateAndSetupKernelIsolate(const char* script_uri,
     intptr_t kernel_service_buffer_size = 0;
     dfe.LoadKernelService(&kernel_service_buffer, &kernel_service_buffer_size);
     ASSERT(kernel_service_buffer != nullptr);
-    isolate_group_data = new IsolateGroupData(uri, packages_config, nullptr,
-                                              isolate_run_app_snapshot);
+    isolate_group_data = new IsolateGroupData(
+        uri, /*asset_resolution_base=*/nullptr, packages_config, nullptr,
+        isolate_run_app_snapshot);
     isolate_group_data->SetKernelBufferUnowned(
         const_cast<uint8_t*>(kernel_service_buffer),
         kernel_service_buffer_size);
@@ -529,7 +533,8 @@ static Dart_Isolate CreateAndSetupServiceIsolate(const char* script_uri,
   ASSERT(script_uri != nullptr);
   Dart_Isolate isolate = nullptr;
   auto isolate_group_data =
-      new IsolateGroupData(script_uri, packages_config, nullptr, false);
+      new IsolateGroupData(script_uri, /*asset_resolution_base=*/nullptr,
+                           packages_config, nullptr, false);
   ASSERT(flags != nullptr);
 
 #if defined(DART_PRECOMPILED_RUNTIME)
@@ -642,9 +647,9 @@ static Dart_Isolate CreateAndSetupDartDevIsolate(const char* script_uri,
     app_snapshot->SetBuffers(
         &ignore_vm_snapshot_data, &ignore_vm_snapshot_instructions,
         &isolate_snapshot_data, &isolate_snapshot_instructions);
-    isolate_group_data =
-        new IsolateGroupData(DART_DEV_ISOLATE_NAME, packages_config,
-                             app_snapshot, isolate_run_app_snapshot);
+    isolate_group_data = new IsolateGroupData(
+        DART_DEV_ISOLATE_NAME, /*asset_resolution_base=*/nullptr,
+        packages_config, app_snapshot, isolate_run_app_snapshot);
     isolate_data = new IsolateData(isolate_group_data);
     isolate = Dart_CreateIsolateGroup(
         DART_DEV_ISOLATE_NAME, DART_DEV_ISOLATE_NAME, isolate_snapshot_data,
@@ -664,8 +669,8 @@ static Dart_Isolate CreateAndSetupDartDevIsolate(const char* script_uri,
       delete app_snapshot;
     }
     isolate_group_data =
-        new IsolateGroupData(DART_DEV_ISOLATE_NAME, packages_config, nullptr,
-                             isolate_run_app_snapshot);
+        new IsolateGroupData(DART_DEV_ISOLATE_NAME, nullptr, packages_config,
+                             nullptr, isolate_run_app_snapshot);
     uint8_t* application_kernel_buffer = nullptr;
     intptr_t application_kernel_buffer_size = 0;
     dfe.ReadScript(dartdev_path.get(), nullptr, &application_kernel_buffer,
@@ -698,6 +703,7 @@ static Dart_Isolate CreateAndSetupDartDevIsolate(const char* script_uri,
 static Dart_Isolate CreateIsolateGroupAndSetupHelper(
     bool is_main_isolate,
     const char* script_uri,
+    const char* asset_resolution_base,
     const char* name,
     const char* packages_config,
     Dart_IsolateFlags* flags,
@@ -778,8 +784,9 @@ static Dart_Isolate CreateIsolateGroupAndSetupHelper(
   PathSanitizer packages_config_sanitizer(packages_config);
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
 
-  auto isolate_group_data = new IsolateGroupData(
-      script_uri, packages_config, app_snapshot, isolate_run_app_snapshot);
+  auto isolate_group_data =
+      new IsolateGroupData(script_uri, asset_resolution_base, packages_config,
+                           app_snapshot, isolate_run_app_snapshot);
   if (kernel_buffer != nullptr) {
     isolate_group_data->SetKernelBufferNewlyOwned(kernel_buffer,
                                                   kernel_buffer_size);
@@ -845,6 +852,74 @@ static Dart_Isolate CreateIsolateGroupAndSetupHelper(
 
 #undef CHECK_RESULT
 
+static CStringUniquePtr ResolveSymlinks(const char* path, char** error) {
+  auto file_type = File::GetType(nullptr, path, /*follow_links=*/true);
+  switch (file_type) {
+    case File::kIsLink:
+      UNREACHABLE();
+    case File::kIsSock:
+    case File::kIsPipe:
+      // Don't use pipes or sockets as base paths for assets resolution.
+      return CStringUniquePtr();
+    case File::kDoesNotExist:
+      // Don't try to resolve symlinks if the file doesn't exist.
+      // `dartdev` and `Isolate.spawnUri` will already issue an error.
+      return CStringUniquePtr();
+    case File::kIsFile:
+    case File::kIsDirectory:
+      break;
+  }
+
+  const size_t kPathBufSize = PATH_MAX + 1;
+  char canon_path[kPathBufSize];
+  auto result = File::GetCanonicalPath(nullptr, path, canon_path, kPathBufSize);
+  if (result == nullptr) {
+    OSError os_error;
+    *error = Utils::SCreate(
+        "Failed to canonicalize path '%s'. OS error: '%s' (%i).\n", path,
+        os_error.message(), os_error.code());
+    return CStringUniquePtr();
+  }
+  return CStringUniquePtr(Utils::StrDup(canon_path));
+}
+
+// Get a file path from the script uri if it is a file uri and resolve symlinks.
+static CStringUniquePtr FindAssetResolutionBase(const char* script_uri,
+                                                char** error) {
+  static const char* data_schema = "data:";
+  static const int data_schema_length = 5;
+  static const char* package_scheme = "package:";
+  static const int package_scheme_length = 8;
+  static const char* https_scheme = "https://";
+  static const int https_scheme_length = 8;
+  static const char* http_scheme = "http://";
+  static const int http_scheme_length = 7;
+  static const char* file_schema = "file://";
+  static const int file_schema_length = 7;
+
+  if ((strlen(script_uri) > data_schema_length &&
+       strncmp(script_uri, data_schema, data_schema_length) == 0) ||
+      (strlen(script_uri) > data_schema_length &&
+       strncmp(script_uri, package_scheme, package_scheme_length) == 0) ||
+      (strlen(script_uri) > package_scheme_length &&
+       strncmp(script_uri, https_scheme, https_scheme_length) == 0) ||
+      (strlen(script_uri) > http_scheme_length &&
+       strncmp(script_uri, http_scheme, http_scheme_length) == 0)) {
+    // No base path for assets.
+    return CStringUniquePtr();
+  }
+
+  if (strlen(script_uri) > file_schema_length &&
+      strncmp(script_uri, file_schema, file_schema_length) == 0) {
+    // Isolate.spawnUri sets a `source` including the file schema,
+    // e.g. Isolate.spawnUri may make the embedder pass a file:// uri.
+    return ResolveSymlinks(File::UriToPath(script_uri).get(), error);
+  }
+
+  // It's possible to spawn uri without a scheme, assume file path.
+  return ResolveSymlinks(script_uri, error);
+}
+
 static Dart_Isolate CreateIsolateGroupAndSetup(const char* script_uri,
                                                const char* main,
                                                const char* package_root,
@@ -895,9 +970,13 @@ static Dart_Isolate CreateIsolateGroupAndSetup(const char* script_uri,
   }
 
   bool is_main_isolate = false;
-  return CreateIsolateGroupAndSetupHelper(is_main_isolate, script_uri, main,
-                                          package_config, flags, callback_data,
-                                          error, &exit_code);
+  auto asset_resolution_base = FindAssetResolutionBase(script_uri, error);
+  if (*error != nullptr) {
+    return nullptr;
+  }
+  return CreateIsolateGroupAndSetupHelper(
+      is_main_isolate, script_uri, asset_resolution_base.get(), main,
+      package_config, flags, callback_data, error, &exit_code);
 }
 
 static void OnIsolateShutdown(void* isolate_group_data, void* isolate_data) {
@@ -985,6 +1064,7 @@ static void CompileAndSaveKernel(const char* script_name,
 }
 
 void RunMainIsolate(const char* script_name,
+                    const char* asset_resolution_base,
                     const char* package_config_override,
                     CommandLineOptions* dart_options) {
   if (script_name != nullptr) {
@@ -1021,7 +1101,7 @@ void RunMainIsolate(const char* script_name,
   flags.snapshot_is_dontneed_safe = dontneed_safe;
 
   Dart_Isolate isolate = CreateIsolateGroupAndSetupHelper(
-      /* is_main_isolate */ true, script_name, "main",
+      /* is_main_isolate */ true, script_name, asset_resolution_base, "main",
       Options::packages_file() == nullptr ? package_config_override
                                           : Options::packages_file(),
       &flags, nullptr /* callback_data */, &error, &exit_code);
@@ -1129,6 +1209,7 @@ void main(int argc, char** argv) {
 #endif
 
   char* script_name = nullptr;
+  CStringUniquePtr asset_resolution_base = CStringUniquePtr();
   // Allows the dartdev process to point to the desired package_config.
   char* package_config_override = nullptr;
   const int EXTRA_VM_ARGUMENTS = 10;
@@ -1215,6 +1296,15 @@ void main(int argc, char** argv) {
     if (app_snapshot != nullptr) {
       script_name = argv[0];
 
+      char* error = nullptr;
+      asset_resolution_base = ResolveSymlinks(executable_path, &error);
+      if (error != nullptr) {
+        Syslog::PrintErr("%s", error);
+        free(error);
+        delete app_snapshot;
+        Platform::Exit(kErrorExitCode);
+      }
+
       // Store the executable name.
       Platform::SetExecutableName(argv[0]);
 
@@ -1429,11 +1519,21 @@ void main(int argc, char** argv) {
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)
 
   if (should_run_user_program) {
+    if (asset_resolution_base.get() == nullptr) {
+      asset_resolution_base = ResolveSymlinks(script_name, &error);
+      if (error != nullptr) {
+        Syslog::PrintErr("%s", error);
+        free(error);
+        delete app_snapshot;
+        Platform::Exit(kErrorExitCode);
+      }
+    }
     if (Options::gen_snapshot_kind() == kKernel) {
       CompileAndSaveKernel(script_name, package_config_override, &dart_options);
     } else {
       // Run the main isolate until we aren't told to restart.
-      RunMainIsolate(script_name, package_config_override, &dart_options);
+      RunMainIsolate(script_name, asset_resolution_base.get(),
+                     package_config_override, &dart_options);
     }
   }
 
@@ -1453,6 +1553,7 @@ void main(int argc, char** argv) {
   if (ran_dart_dev && script_name != nullptr) {
     free(script_name);
   }
+  asset_resolution_base.reset();
 
   // Free copied argument strings if converted.
   if (argv_converted) {