From 7f52df0948e372bc580555da2912608be1aa492b Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Mon, 30 Mar 2026 10:24:29 -0700
Subject: [PATCH 1/9] Add 2-pass release build for Dynamic Dispatch table

When building for arm64 Apple platforms with the linker enabled, run
gen_snapshot twice: first in ELF mode to produce a temporary snapshot
for analyze_snapshot to compute the DD table manifest, caller links,
and slot mapping, then in assembly mode with --dd_slot_mapping to
produce the final snapshot with indirect calls wired up.

The DD table files (App.dd.link, App.dd_callers.link) are copied into
the shorebird supplement directory alongside the existing link files
so they can be bundled with releases and used during patch builds.
---
 .../flutter_tools/lib/src/base/build.dart     | 155 +++++++++++++++++-
 .../lib/src/build_system/targets/common.dart  |   3 +
 2 files changed, 157 insertions(+), 1 deletion(-)

diff --git a/packages/flutter_tools/lib/src/base/build.dart b/packages/flutter_tools/lib/src/base/build.dart
index 008b93da357d2..35b7ca5211cb8 100644
--- a/packages/flutter_tools/lib/src/base/build.dart
+++ b/packages/flutter_tools/lib/src/base/build.dart
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:io' as io;
+
 import 'package:process/process.dart';
 
 import '../artifacts.dart';
@@ -95,6 +97,7 @@ class AOTSnapshotter {
   }) : _logger = logger,
        _fileSystem = fileSystem,
        _xcode = xcode,
+       _processManager = processManager,
        _genSnapshot = GenSnapshot(
          artifacts: artifacts,
          processManager: processManager,
@@ -104,8 +107,14 @@ class AOTSnapshotter {
   final Logger _logger;
   final FileSystem _fileSystem;
   final Xcode _xcode;
+  final ProcessManager _processManager;
   final GenSnapshot _genSnapshot;
 
+  /// The maximum cascade byte threshold for the DD table cascade limiter.
+  /// Functions whose transitive caller tree exceeds this many compiled code
+  /// bytes are routed through the indirect dispatch table.
+  static const int _ddMaxBytes = 10000;
+
   /// Builds an architecture-specific ahead-of-time compiled snapshot of the specified script.
   Future<int> build({
     required TargetPlatform platform,
@@ -230,9 +239,44 @@ class AOTSnapshotter {
     genSnapshotArgs.add(mainPath);
 
     final snapshotType = SnapshotType(platform, buildMode);
+
+    // Dynamic Dispatch (DD) table: for arm64 Apple platforms with the linker
+    // enabled, we do a 2-pass build. Pass 1 produces a temp ELF for
+    // analyze_snapshot to compute the DD table and slot mapping. Pass 2
+    // produces the final assembly snapshot with indirect calls wired up.
+    final bool usesDDTable = usesLinker && darwinArch == DarwinArch.arm64;
+    String? ddSlotMappingPath;
+
+    if (usesDDTable) {
+      final ddResult = await _computeDDTable(
+        snapshotType: snapshotType,
+        darwinArch: darwinArch!,
+        mainPath: mainPath,
+        outputDir: outputDir,
+        genSnapshotArgs: genSnapshotArgs,
+      );
+      if (ddResult != 0) {
+        return ddResult;
+      }
+      final slotMappingFile = _fileSystem.file(
+        _fileSystem.path.join(outputDir.parent.path, 'App.dd_slots.link'),
+      );
+      if (slotMappingFile.existsSync()) {
+        ddSlotMappingPath = slotMappingFile.path;
+      }
+    }
+
+    // Insert DD slot mapping arg before mainPath (the last arg).
+    final finalGenSnapshotArgs = <String>[
+      ...genSnapshotArgs.take(genSnapshotArgs.length - 1),
+      if (ddSlotMappingPath != null)
+        '--dd_slot_mapping=$ddSlotMappingPath',
+      genSnapshotArgs.last, // mainPath
+    ];
+
     final int genSnapshotExitCode = await _genSnapshot.run(
       snapshotType: snapshotType,
-      additionalArgs: genSnapshotArgs,
+      additionalArgs: finalGenSnapshotArgs,
       darwinArch: darwinArch,
     );
     if (genSnapshotExitCode != 0) {
@@ -258,6 +302,115 @@ class AOTSnapshotter {
     }
   }
 
+  /// Computes the Dynamic Dispatch (DD) table for the release snapshot.
+  ///
+  /// Runs gen_snapshot in ELF mode to produce a temporary snapshot, then uses
+  /// analyze_snapshot to compute the DD table manifest, caller links, and slot
+  /// mapping. The DD files are written next to the other link files in
+  /// [outputDir]'s parent.
+  ///
+  /// Returns 0 on success, non-zero on failure.
+  Future<int> _computeDDTable({
+    required SnapshotType snapshotType,
+    required DarwinArch darwinArch,
+    required String mainPath,
+    required Directory outputDir,
+    required List<String> genSnapshotArgs,
+  }) async {
+    _logger.printTrace('Computing DD table for release snapshot...');
+
+    final String linkDir = outputDir.parent.path;
+    final String tempElfPath = _fileSystem.path.join(outputDir.path, '_dd_analysis.elf');
+    final String ddTablePath = _fileSystem.path.join(linkDir, 'App.dd.link');
+    final String ddCallerLinksPath = _fileSystem.path.join(linkDir, 'App.dd_callers.link');
+    final String ddSlotMappingPath = _fileSystem.path.join(linkDir, 'App.dd_slots.link');
+
+    // Build a temporary ELF snapshot (no DD) for analyze_snapshot.
+    // Strip out assembly/link-dump args — we only need a bare ELF.
+    final elfArgs = <String>[
+      '--deterministic',
+      '--snapshot_kind=app-aot-elf',
+      '--elf=$tempElfPath',
+      mainPath,
+    ];
+    final int elfExitCode = await _genSnapshot.run(
+      snapshotType: snapshotType,
+      additionalArgs: elfArgs,
+      darwinArch: darwinArch,
+    );
+    if (elfExitCode != 0) {
+      _logger.printError('DD analysis: gen_snapshot (ELF pass) failed with exit code $elfExitCode');
+      return elfExitCode;
+    }
+
+    // Derive analyze_snapshot path from gen_snapshot path.
+    final genSnapshotArtifact = darwinArch == DarwinArch.arm64
+        ? Artifact.genSnapshotArm64
+        : Artifact.genSnapshotX64;
+    final genSnapshotPath = _genSnapshot.getSnapshotterPath(snapshotType, genSnapshotArtifact);
+    final analyzeSnapshotPath = _fileSystem.path.join(
+      _fileSystem.path.dirname(genSnapshotPath),
+      _fileSystem.path.basename(genSnapshotPath).replaceFirst('gen_snapshot', 'analyze_snapshot'),
+    );
+
+    if (!_fileSystem.file(analyzeSnapshotPath).existsSync()) {
+      _logger.printTrace('analyze_snapshot not found at $analyzeSnapshotPath, skipping DD table.');
+      _cleanupFile(tempElfPath);
+      return 0;
+    }
+
+    // Step 1: Compute DD table + caller links.
+    final int computeTableResult = await _runProcess(analyzeSnapshotPath, <String>[
+      '--compute_dd_table=$ddTablePath',
+      '--dd_caller_links=$ddCallerLinksPath',
+      '--dd_max_bytes=$_ddMaxBytes',
+      tempElfPath,
+    ]);
+    if (computeTableResult != 0) {
+      _logger.printError('DD analysis: compute_dd_table failed with exit code $computeTableResult');
+      _cleanupFile(tempElfPath);
+      return computeTableResult;
+    }
+
+    // Step 2: Compute DD slot mapping.
+    final int computeMappingResult = await _runProcess(analyzeSnapshotPath, <String>[
+      '--compute_dd_slot_mapping=$ddSlotMappingPath',
+      '--dd_table_data=$ddTablePath',
+      '--dd_caller_links=$ddCallerLinksPath',
+      tempElfPath,
+    ]);
+    if (computeMappingResult != 0) {
+      _logger.printError('DD analysis: compute_dd_slot_mapping failed with exit code $computeMappingResult');
+      _cleanupFile(tempElfPath);
+      return computeMappingResult;
+    }
+
+    _logger.printTrace('DD table computed successfully.');
+    _cleanupFile(tempElfPath);
+    return 0;
+  }
+
+  /// Runs a process and returns the exit code.
+  Future<int> _runProcess(String executable, List<String> args) async {
+    _logger.printTrace('Running: $executable ${args.join(' ')}');
+    final io.ProcessResult result = await _processManager.run(
+      <String>[executable, ...args],
+    );
+    if (result.exitCode != 0) {
+      _logger.printTrace('stdout: ${result.stdout}');
+      _logger.printTrace('stderr: ${result.stderr}');
+    }
+    return result.exitCode;
+  }
+
+  /// Deletes a file if it exists.
+  void _cleanupFile(String path) {
+    final file = _fileSystem.file(path);
+    if (file.existsSync()) {
+      file.deleteSync();
+    }
+  }
+
   /// Builds an iOS or macOS framework at [outputPath]/App.framework from the assembly
   /// source at [assemblyPath].
   Future<int> _buildFramework({
diff --git a/packages/flutter_tools/lib/src/build_system/targets/common.dart b/packages/flutter_tools/lib/src/build_system/targets/common.dart
index e67e646bebf1b..9a9768e37de42 100644
--- a/packages/flutter_tools/lib/src/build_system/targets/common.dart
+++ b/packages/flutter_tools/lib/src/build_system/targets/common.dart
@@ -537,5 +537,8 @@ abstract final class LinkSupplement {
     maybeCopy('App.dispatch_table.json');
     maybeCopy('App.ft.link');
     maybeCopy('App.field_table.json');
+    // DD table files (generated by analyze_snapshot during 2-pass release build).
+    maybeCopy('App.dd.link');
+    maybeCopy('App.dd_callers.link');
   }
 }

From 2d4910805f6c8cc80a5ae0076624ea961d2f11f0 Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Tue, 31 Mar 2026 15:43:08 -0700
Subject: [PATCH 2/9] Add DD analysis gen_snapshot command to test expectations

The 2-pass DD table build runs gen_snapshot in ELF mode before the
main assembly pass. Update tests to expect this additional command.
---
 .../test/general.shard/base/build_test.dart   | 30 +++++++++++++++++++
 .../build_system/targets/common_test.dart     | 10 +++++++
 .../build_system/targets/macos_test.dart      | 10 +++++++
 3 files changed, 50 insertions(+)

diff --git a/packages/flutter_tools/test/general.shard/base/build_test.dart b/packages/flutter_tools/test/general.shard/base/build_test.dart
index 90cc0c26ac1db..90a926f70ec4e 100644
--- a/packages/flutter_tools/test/general.shard/base/build_test.dart
+++ b/packages/flutter_tools/test/general.shard/base/build_test.dart
@@ -210,6 +210,16 @@ void main() {
         mode: BuildMode.profile,
       );
       processManager.addCommands(<FakeCommand>[
+        // DD analysis: gen_snapshot ELF pass for DD table computation.
+        FakeCommand(
+          command: <String>[
+            genSnapshotPath,
+            '--deterministic',
+            '--snapshot_kind=app-aot-elf',
+            '--elf=${fileSystem.path.join(outputPath, '_dd_analysis.elf')}',
+            'main.dill',
+          ],
+        ),
         FakeCommand(
           command: <String>[
             genSnapshotPath,
@@ -286,6 +296,16 @@ void main() {
         mode: BuildMode.profile,
       );
       processManager.addCommands(<FakeCommand>[
+        // DD analysis: gen_snapshot ELF pass for DD table computation.
+        FakeCommand(
+          command: <String>[
+            genSnapshotPath,
+            '--deterministic',
+            '--snapshot_kind=app-aot-elf',
+            '--elf=${fileSystem.path.join(outputPath, '_dd_analysis.elf')}',
+            'main.dill',
+          ],
+        ),
         FakeCommand(
           command: <String>[
             genSnapshotPath,
@@ -358,6 +378,16 @@ void main() {
         mode: BuildMode.release,
       );
       processManager.addCommands(<FakeCommand>[
+        // DD analysis: gen_snapshot ELF pass for DD table computation.
+        FakeCommand(
+          command: <String>[
+            genSnapshotPath,
+            '--deterministic',
+            '--snapshot_kind=app-aot-elf',
+            '--elf=${fileSystem.path.join(outputPath, '_dd_analysis.elf')}',
+            'main.dill',
+          ],
+        ),
         FakeCommand(
           command: <String>[
             genSnapshotPath,
diff --git a/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart b/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart
index c0dda6b07591e..34ecc13e58479 100644
--- a/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart
+++ b/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart
@@ -809,6 +809,16 @@ void main() {
       iosEnvironment.defines[kSdkRoot] = 'path/to/iPhoneOS.sdk';
       final String build = iosEnvironment.buildDir.path;
       processManager.addCommands(<FakeCommand>[
+        // DD analysis: gen_snapshot ELF pass for DD table computation.
+        FakeCommand(
+          command: <String>[
+            'Artifact.genSnapshotArm64.TargetPlatform.ios.profile',
+            '--deterministic',
+            kElfAot,
+            '--elf=$build/arm64/_dd_analysis.elf',
+            '$build/app.dill',
+          ],
+        ),
         FakeCommand(
           command: <String>[
             // This path is not known by the cache due to the iOS gen_snapshot split.
diff --git a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
index d57c76c444c7f..e697c87ae6a30 100644
--- a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
+++ b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
@@ -946,6 +946,16 @@ flavors:
 
       final build = environment.buildDir.path;
       processManager.addCommands(<FakeCommand>[
+        // DD analysis: gen_snapshot ELF pass for DD table computation (arm64 only).
+        FakeCommand(
+          command: <String>[
+            'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
+            '--deterministic',
+            '--snapshot_kind=app-aot-elf',
+            '--elf=${environment.buildDir.childFile('arm64/_dd_analysis.elf').path}',
+            environment.buildDir.childFile('app.dill').path,
+          ],
+        ),
         FakeCommand(
           command: <String>[
             'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',

From 27e03b7b6a32b23b7835fa1c001bb8e90ba4214e Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Tue, 31 Mar 2026 16:00:29 -0700
Subject: [PATCH 3/9] Fix macOS universal binary test command order for
 concurrent DD build

The arm64 DD analysis pass delays the arm64 assembly, so x86_64
(which skips DD) completes its build first when both run concurrently
via Future.wait.
---
 .../build_system/targets/macos_test.dart      | 53 ++++++++++---------
 1 file changed, 29 insertions(+), 24 deletions(-)

diff --git a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
index e697c87ae6a30..fc88c6fa61748 100644
--- a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
+++ b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
@@ -947,6 +947,9 @@ flavors:
       final build = environment.buildDir.path;
       processManager.addCommands(<FakeCommand>[
         // DD analysis: gen_snapshot ELF pass for DD table computation (arm64 only).
+        // arm64 and x86_64 builds run concurrently via Future.wait. arm64 starts
+        // the DD ELF pass first, then x86_64 (which skips DD) starts its assembly
+        // pass before arm64's DD ELF completes and proceeds to its assembly pass.
         FakeCommand(
           command: <String>[
             'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
@@ -958,34 +961,36 @@ flavors:
         ),
         FakeCommand(
           command: <String>[
-            'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
+            'Artifact.genSnapshotX64.TargetPlatform.darwin.release',
             '--deterministic',
             ...linkInfoArgsFor(build),
             '--snapshot_kind=app-aot-assembly',
-            '--assembly=${environment.buildDir.childFile('arm64/snapshot_assembly.S').path}',
+            '--assembly=${environment.buildDir.childFile('x86_64/snapshot_assembly.S').path}',
             environment.buildDir.childFile('app.dill').path,
           ],
         ),
         FakeCommand(
           command: <String>[
-            'Artifact.genSnapshotX64.TargetPlatform.darwin.release',
+            'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
             '--deterministic',
             ...linkInfoArgsFor(build),
             '--snapshot_kind=app-aot-assembly',
-            '--assembly=${environment.buildDir.childFile('x86_64/snapshot_assembly.S').path}',
+            '--assembly=${environment.buildDir.childFile('arm64/snapshot_assembly.S').path}',
             environment.buildDir.childFile('app.dill').path,
           ],
         ),
+        // x86_64 framework build completes before arm64 because arm64's DD
+        // analysis pass delays it.
         FakeCommand(
           command: <String>[
             'xcrun',
             'cc',
             '-arch',
-            'arm64',
+            'x86_64',
             '-c',
-            environment.buildDir.childFile('arm64/snapshot_assembly.S').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.S').path,
             '-o',
-            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -993,11 +998,11 @@ flavors:
             'xcrun',
             'cc',
             '-arch',
-            'x86_64',
+            'arm64',
             '-c',
-            environment.buildDir.childFile('x86_64/snapshot_assembly.S').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.S').path,
             '-o',
-            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1005,7 +1010,7 @@ flavors:
             'xcrun',
             'clang',
             '-arch',
-            'arm64',
+            'x86_64',
             '-dynamiclib',
             '-Xlinker',
             '-rpath',
@@ -1019,8 +1024,8 @@ flavors:
             '-install_name',
             '@rpath/App.framework/App',
             '-o',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
-            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1028,7 +1033,7 @@ flavors:
             'xcrun',
             'clang',
             '-arch',
-            'x86_64',
+            'arm64',
             '-dynamiclib',
             '-Xlinker',
             '-rpath',
@@ -1042,8 +1047,8 @@ flavors:
             '-install_name',
             '@rpath/App.framework/App',
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
-            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1051,8 +1056,8 @@ flavors:
             'xcrun',
             'dsymutil',
             '-o',
-            environment.buildDir.childFile('arm64/App.framework.dSYM').path,
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework.dSYM').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1060,8 +1065,8 @@ flavors:
             'xcrun',
             'dsymutil',
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework.dSYM').path,
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework.dSYM').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1069,9 +1074,9 @@ flavors:
             'xcrun',
             'strip',
             '-x',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
             '-o',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1079,9 +1084,9 @@ flavors:
             'xcrun',
             'strip',
             '-x',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
           ],
         ),
         FakeCommand(

From 71e58c6ca174cebb243ee7cfc1b3bd37f929ed87 Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Tue, 31 Mar 2026 17:23:33 -0700
Subject: [PATCH 4/9] Skip DD table computation when analyze_snapshot is absent

Move the analyze_snapshot existence check before the gen_snapshot ELF
pass so the entire DD computation is a no-op on standard Flutter SDKs
that don't ship analyze_snapshot. This fixes iOS smoke test failures
where gen_snapshot was being invoked unnecessarily in ELF mode.

Also reverts test changes that are no longer needed since DD commands
won't appear when analyze_snapshot doesn't exist in the test filesystem.
---
 .../flutter_tools/lib/src/base/build.dart     | 34 ++++++-----
 .../test/general.shard/base/build_test.dart   | 30 ---------
 .../build_system/targets/common_test.dart     | 10 ---
 .../build_system/targets/macos_test.dart      | 61 +++++++------------
 4 files changed, 41 insertions(+), 94 deletions(-)

diff --git a/packages/flutter_tools/lib/src/base/build.dart b/packages/flutter_tools/lib/src/base/build.dart
index 35b7ca5211cb8..3b66f37027836 100644
--- a/packages/flutter_tools/lib/src/base/build.dart
+++ b/packages/flutter_tools/lib/src/base/build.dart
@@ -319,6 +319,24 @@ class AOTSnapshotter {
   }) async {
     _logger.printTrace('Computing DD table for release snapshot...');
 
+    // Derive analyze_snapshot path from gen_snapshot path.
+    // Check for it early so we can skip the entire DD computation (including
+    // the gen_snapshot ELF pass) when using a standard Flutter SDK that doesn't
+    // ship analyze_snapshot.
+    final genSnapshotArtifact = darwinArch == DarwinArch.arm64
+        ? Artifact.genSnapshotArm64
+        : Artifact.genSnapshotX64;
+    final genSnapshotPath = _genSnapshot.getSnapshotterPath(snapshotType, genSnapshotArtifact);
+    final analyzeSnapshotPath = _fileSystem.path.join(
+      _fileSystem.path.dirname(genSnapshotPath),
+      _fileSystem.path.basename(genSnapshotPath).replaceFirst('gen_snapshot', 'analyze_snapshot'),
+    );
+
+    if (!_fileSystem.file(analyzeSnapshotPath).existsSync()) {
+      _logger.printTrace('analyze_snapshot not found at $analyzeSnapshotPath, skipping DD table.');
+      return 0;
+    }
+
     final String linkDir = outputDir.parent.path;
     final String tempElfPath = _fileSystem.path.join(outputDir.path, '_dd_analysis.elf');
     final String ddTablePath = _fileSystem.path.join(linkDir, 'App.dd.link');
@@ -343,22 +361,6 @@ class AOTSnapshotter {
       return elfExitCode;
     }
 
-    // Derive analyze_snapshot path from gen_snapshot path.
-    final genSnapshotArtifact = darwinArch == DarwinArch.arm64
-        ? Artifact.genSnapshotArm64
-        : Artifact.genSnapshotX64;
-    final genSnapshotPath = _genSnapshot.getSnapshotterPath(snapshotType, genSnapshotArtifact);
-    final analyzeSnapshotPath = _fileSystem.path.join(
-      _fileSystem.path.dirname(genSnapshotPath),
-      _fileSystem.path.basename(genSnapshotPath).replaceFirst('gen_snapshot', 'analyze_snapshot'),
-    );
-
-    if (!_fileSystem.file(analyzeSnapshotPath).existsSync()) {
-      _logger.printTrace('analyze_snapshot not found at $analyzeSnapshotPath, skipping DD table.');
-      _cleanupFile(tempElfPath);
-      return 0;
-    }
-
     // Step 1: Compute DD table + caller links.
     final int computeTableResult = await _runProcess(analyzeSnapshotPath, <String>[
       '--compute_dd_table=$ddTablePath',
diff --git a/packages/flutter_tools/test/general.shard/base/build_test.dart b/packages/flutter_tools/test/general.shard/base/build_test.dart
index 90a926f70ec4e..90cc0c26ac1db 100644
--- a/packages/flutter_tools/test/general.shard/base/build_test.dart
+++ b/packages/flutter_tools/test/general.shard/base/build_test.dart
@@ -210,16 +210,6 @@ void main() {
         mode: BuildMode.profile,
       );
       processManager.addCommands(<FakeCommand>[
-        // DD analysis: gen_snapshot ELF pass for DD table computation.
-        FakeCommand(
-          command: <String>[
-            genSnapshotPath,
-            '--deterministic',
-            '--snapshot_kind=app-aot-elf',
-            '--elf=${fileSystem.path.join(outputPath, '_dd_analysis.elf')}',
-            'main.dill',
-          ],
-        ),
         FakeCommand(
           command: <String>[
             genSnapshotPath,
@@ -296,16 +286,6 @@ void main() {
         mode: BuildMode.profile,
       );
       processManager.addCommands(<FakeCommand>[
-        // DD analysis: gen_snapshot ELF pass for DD table computation.
-        FakeCommand(
-          command: <String>[
-            genSnapshotPath,
-            '--deterministic',
-            '--snapshot_kind=app-aot-elf',
-            '--elf=${fileSystem.path.join(outputPath, '_dd_analysis.elf')}',
-            'main.dill',
-          ],
-        ),
         FakeCommand(
           command: <String>[
             genSnapshotPath,
@@ -378,16 +358,6 @@ void main() {
         mode: BuildMode.release,
       );
       processManager.addCommands(<FakeCommand>[
-        // DD analysis: gen_snapshot ELF pass for DD table computation.
-        FakeCommand(
-          command: <String>[
-            genSnapshotPath,
-            '--deterministic',
-            '--snapshot_kind=app-aot-elf',
-            '--elf=${fileSystem.path.join(outputPath, '_dd_analysis.elf')}',
-            'main.dill',
-          ],
-        ),
         FakeCommand(
           command: <String>[
             genSnapshotPath,
diff --git a/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart b/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart
index 34ecc13e58479..c0dda6b07591e 100644
--- a/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart
+++ b/packages/flutter_tools/test/general.shard/build_system/targets/common_test.dart
@@ -809,16 +809,6 @@ void main() {
       iosEnvironment.defines[kSdkRoot] = 'path/to/iPhoneOS.sdk';
       final String build = iosEnvironment.buildDir.path;
       processManager.addCommands(<FakeCommand>[
-        // DD analysis: gen_snapshot ELF pass for DD table computation.
-        FakeCommand(
-          command: <String>[
-            'Artifact.genSnapshotArm64.TargetPlatform.ios.profile',
-            '--deterministic',
-            kElfAot,
-            '--elf=$build/arm64/_dd_analysis.elf',
-            '$build/app.dill',
-          ],
-        ),
         FakeCommand(
           command: <String>[
             // This path is not known by the cache due to the iOS gen_snapshot split.
diff --git a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
index fc88c6fa61748..d57c76c444c7f 100644
--- a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
+++ b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
@@ -946,51 +946,36 @@ flavors:
 
       final build = environment.buildDir.path;
       processManager.addCommands(<FakeCommand>[
-        // DD analysis: gen_snapshot ELF pass for DD table computation (arm64 only).
-        // arm64 and x86_64 builds run concurrently via Future.wait. arm64 starts
-        // the DD ELF pass first, then x86_64 (which skips DD) starts its assembly
-        // pass before arm64's DD ELF completes and proceeds to its assembly pass.
         FakeCommand(
           command: <String>[
             'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
             '--deterministic',
-            '--snapshot_kind=app-aot-elf',
-            '--elf=${environment.buildDir.childFile('arm64/_dd_analysis.elf').path}',
-            environment.buildDir.childFile('app.dill').path,
-          ],
-        ),
-        FakeCommand(
-          command: <String>[
-            'Artifact.genSnapshotX64.TargetPlatform.darwin.release',
-            '--deterministic',
             ...linkInfoArgsFor(build),
             '--snapshot_kind=app-aot-assembly',
-            '--assembly=${environment.buildDir.childFile('x86_64/snapshot_assembly.S').path}',
+            '--assembly=${environment.buildDir.childFile('arm64/snapshot_assembly.S').path}',
             environment.buildDir.childFile('app.dill').path,
           ],
         ),
         FakeCommand(
           command: <String>[
-            'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
+            'Artifact.genSnapshotX64.TargetPlatform.darwin.release',
             '--deterministic',
             ...linkInfoArgsFor(build),
             '--snapshot_kind=app-aot-assembly',
-            '--assembly=${environment.buildDir.childFile('arm64/snapshot_assembly.S').path}',
+            '--assembly=${environment.buildDir.childFile('x86_64/snapshot_assembly.S').path}',
             environment.buildDir.childFile('app.dill').path,
           ],
         ),
-        // x86_64 framework build completes before arm64 because arm64's DD
-        // analysis pass delays it.
         FakeCommand(
           command: <String>[
             'xcrun',
             'cc',
             '-arch',
-            'x86_64',
+            'arm64',
             '-c',
-            environment.buildDir.childFile('x86_64/snapshot_assembly.S').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.S').path,
             '-o',
-            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -998,11 +983,11 @@ flavors:
             'xcrun',
             'cc',
             '-arch',
-            'arm64',
+            'x86_64',
             '-c',
-            environment.buildDir.childFile('arm64/snapshot_assembly.S').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.S').path,
             '-o',
-            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1010,7 +995,7 @@ flavors:
             'xcrun',
             'clang',
             '-arch',
-            'x86_64',
+            'arm64',
             '-dynamiclib',
             '-Xlinker',
             '-rpath',
@@ -1024,8 +1009,8 @@ flavors:
             '-install_name',
             '@rpath/App.framework/App',
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
-            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1033,7 +1018,7 @@ flavors:
             'xcrun',
             'clang',
             '-arch',
-            'arm64',
+            'x86_64',
             '-dynamiclib',
             '-Xlinker',
             '-rpath',
@@ -1047,8 +1032,8 @@ flavors:
             '-install_name',
             '@rpath/App.framework/App',
             '-o',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
-            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1056,8 +1041,8 @@ flavors:
             'xcrun',
             'dsymutil',
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework.dSYM').path,
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework.dSYM').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1065,8 +1050,8 @@ flavors:
             'xcrun',
             'dsymutil',
             '-o',
-            environment.buildDir.childFile('arm64/App.framework.dSYM').path,
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework.dSYM').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1074,9 +1059,9 @@ flavors:
             'xcrun',
             'strip',
             '-x',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1084,9 +1069,9 @@ flavors:
             'xcrun',
             'strip',
             '-x',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
             '-o',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
           ],
         ),
         FakeCommand(

From c1cfbf9acc11ac08b2bb0e20e9e18bf27fba51ac Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Tue, 31 Mar 2026 17:35:33 -0700
Subject: [PATCH 5/9] Fix macOS universal binary test command order for DD
 table async

The arm64 build's async _computeDDTable() check (even a no-op when
analyze_snapshot is absent) introduces an await that lets x86_64
reach gen_snapshot first in Future.wait. Reorder test expectations
to match the actual interleaving: x86_64 before arm64 at each step.
---
 .../build_system/targets/macos_test.dart      | 55 +++++++++++--------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
index d57c76c444c7f..9216b5a1e5af7 100644
--- a/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
+++ b/packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart
@@ -945,37 +945,44 @@ flavors:
           .createSync(recursive: true);
 
       final build = environment.buildDir.path;
+      // Because arm64 goes through an async _computeDDTable() check (even
+      // though it returns immediately when analyze_snapshot is absent), x86_64
+      // reaches gen_snapshot first when both run concurrently via Future.wait.
+      // After that first yield, the two builds interleave at each await point.
       processManager.addCommands(<FakeCommand>[
+        // x86_64 gen_snapshot runs first (arm64 is still in _computeDDTable).
         FakeCommand(
           command: <String>[
-            'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
+            'Artifact.genSnapshotX64.TargetPlatform.darwin.release',
             '--deterministic',
             ...linkInfoArgsFor(build),
             '--snapshot_kind=app-aot-assembly',
-            '--assembly=${environment.buildDir.childFile('arm64/snapshot_assembly.S').path}',
+            '--assembly=${environment.buildDir.childFile('x86_64/snapshot_assembly.S').path}',
             environment.buildDir.childFile('app.dill').path,
           ],
         ),
+        // arm64 gen_snapshot runs next.
         FakeCommand(
           command: <String>[
-            'Artifact.genSnapshotX64.TargetPlatform.darwin.release',
+            'Artifact.genSnapshotArm64.TargetPlatform.darwin.release',
             '--deterministic',
             ...linkInfoArgsFor(build),
             '--snapshot_kind=app-aot-assembly',
-            '--assembly=${environment.buildDir.childFile('x86_64/snapshot_assembly.S').path}',
+            '--assembly=${environment.buildDir.childFile('arm64/snapshot_assembly.S').path}',
             environment.buildDir.childFile('app.dill').path,
           ],
         ),
+        // From here on the two builds interleave: x86_64 then arm64 at each step.
         FakeCommand(
           command: <String>[
             'xcrun',
             'cc',
             '-arch',
-            'arm64',
+            'x86_64',
             '-c',
-            environment.buildDir.childFile('arm64/snapshot_assembly.S').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.S').path,
             '-o',
-            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -983,11 +990,11 @@ flavors:
             'xcrun',
             'cc',
             '-arch',
-            'x86_64',
+            'arm64',
             '-c',
-            environment.buildDir.childFile('x86_64/snapshot_assembly.S').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.S').path,
             '-o',
-            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -995,7 +1002,7 @@ flavors:
             'xcrun',
             'clang',
             '-arch',
-            'arm64',
+            'x86_64',
             '-dynamiclib',
             '-Xlinker',
             '-rpath',
@@ -1009,8 +1016,8 @@ flavors:
             '-install_name',
             '@rpath/App.framework/App',
             '-o',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
-            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1018,7 +1025,7 @@ flavors:
             'xcrun',
             'clang',
             '-arch',
-            'x86_64',
+            'arm64',
             '-dynamiclib',
             '-Xlinker',
             '-rpath',
@@ -1032,8 +1039,8 @@ flavors:
             '-install_name',
             '@rpath/App.framework/App',
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
-            environment.buildDir.childFile('x86_64/snapshot_assembly.o').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/snapshot_assembly.o').path,
           ],
         ),
         FakeCommand(
@@ -1041,8 +1048,8 @@ flavors:
             'xcrun',
             'dsymutil',
             '-o',
-            environment.buildDir.childFile('arm64/App.framework.dSYM').path,
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework.dSYM').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1050,8 +1057,8 @@ flavors:
             'xcrun',
             'dsymutil',
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework.dSYM').path,
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework.dSYM').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1059,9 +1066,9 @@ flavors:
             'xcrun',
             'strip',
             '-x',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
             '-o',
-            environment.buildDir.childFile('arm64/App.framework/App').path,
+            environment.buildDir.childFile('x86_64/App.framework/App').path,
           ],
         ),
         FakeCommand(
@@ -1069,9 +1076,9 @@ flavors:
             'xcrun',
             'strip',
             '-x',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
             '-o',
-            environment.buildDir.childFile('x86_64/App.framework/App').path,
+            environment.buildDir.childFile('arm64/App.framework/App').path,
           ],
         ),
         FakeCommand(

From b74213d458d492ce53a7ad74e48149719259933f Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Wed, 1 Apr 2026 05:55:48 -0700
Subject: [PATCH 6/9] fix: pass DD function identity file in base build
 pipeline

The DD slot mapping now uses kernel_offset-based function matching
(instead of function names). The base build must export an identity
side file during gen_snapshot pass 1 and pass it to
analyze_snapshot --compute_dd_slot_mapping.

Without this, the DDSlotMapping has empty kernel_offset_to_slot and
FinalizeIndirectStaticCallTable can't assign any DD slots, resulting
in an empty DD table in the base snapshot.
---
 packages/flutter_tools/lib/src/base/build.dart | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/packages/flutter_tools/lib/src/base/build.dart b/packages/flutter_tools/lib/src/base/build.dart
index 3b66f37027836..7f699abe25ce0 100644
--- a/packages/flutter_tools/lib/src/base/build.dart
+++ b/packages/flutter_tools/lib/src/base/build.dart
@@ -342,13 +342,17 @@ class AOTSnapshotter {
     final String ddTablePath = _fileSystem.path.join(linkDir, 'App.dd.link');
     final String ddCallerLinksPath = _fileSystem.path.join(linkDir, 'App.dd_callers.link');
     final String ddSlotMappingPath = _fileSystem.path.join(linkDir, 'App.dd_slots.link');
+    final String ddIdentityPath = _fileSystem.path.join(linkDir, 'App.dd_identity.link');
 
     // Build a temporary ELF snapshot (no DD) for analyze_snapshot.
     // Strip out assembly/link-dump args — we only need a bare ELF.
+    // Export DD function identity (InstructionsTable index → kernel_offset)
+    // so the slot mapping can use kernel_offset-based function matching.
     final elfArgs = <String>[
       '--deterministic',
       '--snapshot_kind=app-aot-elf',
       '--elf=$tempElfPath',
+      '--print_dd_function_identity_to=$ddIdentityPath',
       mainPath,
     ];
     final int elfExitCode = await _genSnapshot.run(
@@ -371,24 +375,29 @@ class AOTSnapshotter {
     if (computeTableResult != 0) {
       _logger.printError('DD analysis: compute_dd_table failed with exit code $computeTableResult');
       _cleanupFile(tempElfPath);
+      _cleanupFile(ddIdentityPath);
       return computeTableResult;
     }
 
-    // Step 2: Compute DD slot mapping.
+    // Step 2: Compute DD slot mapping using identity file for
+    // kernel_offset-based function matching.
     final int computeMappingResult = await _runProcess(analyzeSnapshotPath, <String>[
       '--compute_dd_slot_mapping=$ddSlotMappingPath',
       '--dd_table_data=$ddTablePath',
       '--dd_caller_links=$ddCallerLinksPath',
+      '--dd_function_identity=$ddIdentityPath',
       tempElfPath,
     ]);
     if (computeMappingResult != 0) {
       _logger.printError('DD analysis: compute_dd_slot_mapping failed with exit code $computeMappingResult');
       _cleanupFile(tempElfPath);
+      _cleanupFile(ddIdentityPath);
       return computeMappingResult;
     }
 
     _logger.printTrace('DD table computed successfully.');
     _cleanupFile(tempElfPath);
+    _cleanupFile(ddIdentityPath);
     return 0;
   }
 

From fa050e0a0b3e8902ec853fedbc9aa38cccfd8e34 Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Thu, 2 Apr 2026 16:47:02 -0700
Subject: [PATCH 7/9] feat: make DD table max bytes configurable via
 environment variable

Read SHOREBIRD_DD_MAX_BYTES from the environment to allow overriding
the cascade limiter threshold. Defaults to 10000 if not set.

An environment variable is used (rather than a command-line flag) so
that older Flutter builds without DD table support silently ignore it.
---
 packages/flutter_tools/lib/src/base/build.dart | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/packages/flutter_tools/lib/src/base/build.dart b/packages/flutter_tools/lib/src/base/build.dart
index 7f699abe25ce0..a2277acbd95ee 100644
--- a/packages/flutter_tools/lib/src/base/build.dart
+++ b/packages/flutter_tools/lib/src/base/build.dart
@@ -110,10 +110,19 @@ class AOTSnapshotter {
   final ProcessManager _processManager;
   final GenSnapshot _genSnapshot;
 
-  /// The maximum cascade byte threshold for the DD table cascade limiter.
+  /// The default cascade byte threshold for the DD table cascade limiter.
+  static const int _ddMaxBytesDefault = 10000;
+
+  /// The cascade byte threshold for the DD table cascade limiter.
   /// Functions whose transitive caller tree exceeds this many compiled code
   /// bytes are routed through the indirect dispatch table.
-  static const int _ddMaxBytes = 10000;
+  ///
+  /// Overridable via the SHOREBIRD_DD_MAX_BYTES environment variable. An
+  /// environment variable is used (rather than a command-line flag) so that
+  /// older Flutter builds without DD table support silently ignore it.
+  static int get _ddMaxBytes =>
+      int.tryParse(io.Platform.environment['SHOREBIRD_DD_MAX_BYTES'] ?? '') ??
+      _ddMaxBytesDefault;
 
   /// Builds an architecture-specific ahead-of-time compiled snapshot of the specified script.
   Future<int> build({

From 4259c50eeec66731e04caf095df2bff3c38f0a05 Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Thu, 2 Apr 2026 22:31:47 -0700
Subject: [PATCH 8/9] chore: bump dart_sdk_revision to cascade-limiter

Updates dart_sdk_revision to include SIMARM64 simulator fixes
(DoRedirectedCall, ClobberVolatileRegisters, Execute reason param)
needed for ios_debug engine builds.
---
 DEPS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/DEPS b/DEPS
index 0a222ea156b76..19af2c91f4174 100644
--- a/DEPS
+++ b/DEPS
@@ -16,7 +16,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   'llvm_git': 'https://llvm.googlesource.com',
   'skia_revision': 'a183ded9ad67d998a5b0fe4cd86d3ef5402ffb45',
-  "dart_sdk_revision": "667fc4ab87165889877a529f72c17bdb3b36738d",
+  "dart_sdk_revision": "c7c0514cb1cf73a921eff762195f5210740aafef",
   "dart_sdk_git": "git@github.com:shorebirdtech/dart-sdk.git",
   "updater_git": "https://github.com/shorebirdtech/updater.git",
   "updater_rev": "dc2cd0a86a89e53cd5c0f87efe4ccea93fae9eae",

From 5572ff22855e405c4c4e5477706670e63c72ab5f Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <brandon@shorebird.dev>
Date: Thu, 2 Apr 2026 22:32:00 -0700
Subject: [PATCH 9/9] fix: copy Rust updater library to build output dir for
 Ninja tracking
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The GN action for building the Rust updater via cargo declared only a
stamp file as output. The library path referenced by libs[] was in the
source tree, so Ninja couldn't map it to any build rule — causing
"missing and no known rule to make it" for targets where the pre-built
library didn't already exist (e.g. host_debug on macOS).

Fix: the build_rust_updater.py script now copies the cargo-built
library from the source tree to target_gen_dir, which is declared as
an action output. This lets Ninja properly order the link step after
the cargo build.
---
 DEPS                                          |  2 +-
 .../flutter/shell/common/shorebird/BUILD.gn   | 17 ++++++++++++----
 .../common/shorebird/build_rust_updater.gni   |  7 ++++++-
 .../common/shorebird/build_rust_updater.py    | 20 ++++++++++++++++---
 4 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/DEPS b/DEPS
index 19af2c91f4174..3525ae20966fe 100644
--- a/DEPS
+++ b/DEPS
@@ -16,7 +16,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   'llvm_git': 'https://llvm.googlesource.com',
   'skia_revision': 'a183ded9ad67d998a5b0fe4cd86d3ef5402ffb45',
-  "dart_sdk_revision": "c7c0514cb1cf73a921eff762195f5210740aafef",
+  "dart_sdk_revision": "4452ab217de",
   "dart_sdk_git": "git@github.com:shorebirdtech/dart-sdk.git",
   "updater_git": "https://github.com/shorebirdtech/updater.git",
   "updater_rev": "dc2cd0a86a89e53cd5c0f87efe4ccea93fae9eae",
diff --git a/engine/src/flutter/shell/common/shorebird/BUILD.gn b/engine/src/flutter/shell/common/shorebird/BUILD.gn
index 66695791bd402..ca18086a67b31 100644
--- a/engine/src/flutter/shell/common/shorebird/BUILD.gn
+++ b/engine/src/flutter/shell/common/shorebird/BUILD.gn
@@ -17,21 +17,30 @@ source_set("snapshots_data_handle") {
 }
 
 if (shorebird_updater_supported) {
+  # The library is copied from cargo's source-tree output into the build
+  # output dir so GN/Ninja can track it as an action output and properly
+  # order the link step after the cargo build.
+  _updater_output_lib = "$target_gen_dir/$shorebird_updater_lib_name"
+
   action("build_rust_updater") {
     script = "//flutter/shell/common/shorebird/build_rust_updater.py"
 
-    # The stamp file is the declared output for Ninja dependency tracking.
     _stamp =
         "$target_gen_dir/rust_updater_${shorebird_updater_rust_target}.stamp"
-    outputs = [ _stamp ]
+    outputs = [
+      _stamp,
+      _updater_output_lib,
+    ]
 
     args = [
       "--rust-target",
       shorebird_updater_rust_target,
       "--manifest-dir",
       rebase_path("$shorebird_updater_dir", root_build_dir),
+      "--cargo-output-lib",
+      rebase_path("$shorebird_updater_cargo_lib", root_build_dir),
       "--output-lib",
-      rebase_path("$shorebird_updater_output_lib", root_build_dir),
+      rebase_path("$_updater_output_lib", root_build_dir),
       "--stamp",
       rebase_path(_stamp, root_build_dir),
     ]
@@ -73,7 +82,7 @@ source_set("updater") {
 
   if (shorebird_updater_supported) {
     deps += [ ":build_rust_updater" ]
-    libs = [ shorebird_updater_output_lib ]
+    libs = [ _updater_output_lib ]
 
     if (is_win) {
       libs += [ "userenv.lib" ]
diff --git a/engine/src/flutter/shell/common/shorebird/build_rust_updater.gni b/engine/src/flutter/shell/common/shorebird/build_rust_updater.gni
index 147395685e35d..ef53ab6bd1dd8 100644
--- a/engine/src/flutter/shell/common/shorebird/build_rust_updater.gni
+++ b/engine/src/flutter/shell/common/shorebird/build_rust_updater.gni
@@ -60,7 +60,12 @@ if (shorebird_updater_supported) {
     _updater_lib_name = "libupdater.a"
   }
 
-  shorebird_updater_output_lib = "$shorebird_updater_dir/target/$shorebird_updater_rust_target/release/$_updater_lib_name"
+  # Path where cargo produces the library (in the source tree).
+  shorebird_updater_cargo_lib = "$shorebird_updater_dir/target/$shorebird_updater_rust_target/release/$_updater_lib_name"
+
+  # The library filename, used by BUILD.gn to construct the output path
+  # in target_gen_dir (which is only available inside BUILD.gn targets).
+  shorebird_updater_lib_name = _updater_lib_name
 
   # Glob all .rs source files so the input list stays in sync automatically.
   shorebird_updater_rs_sources =
diff --git a/engine/src/flutter/shell/common/shorebird/build_rust_updater.py b/engine/src/flutter/shell/common/shorebird/build_rust_updater.py
index 7212e4ef21348..0effa29e118a6 100644
--- a/engine/src/flutter/shell/common/shorebird/build_rust_updater.py
+++ b/engine/src/flutter/shell/common/shorebird/build_rust_updater.py
@@ -19,7 +19,14 @@ def main():
   parser.add_argument(
       '--manifest-dir', required=True, help='Directory containing the workspace Cargo.toml'
   )
-  parser.add_argument('--output-lib', required=True, help='Expected output library path')
+  parser.add_argument(
+      '--cargo-output-lib',
+      required=True,
+      help='Path where cargo places the built library (in the source tree)'
+  )
+  parser.add_argument(
+      '--output-lib', required=True, help='Path to copy the library to (in the build output dir)'
+  )
   parser.add_argument('--stamp', required=True, help='Stamp file to write on success')
   parser.add_argument('--ndk-path', help='Path to the Android NDK (required for Android targets)')
   parser.add_argument(
@@ -45,6 +52,7 @@ def main():
   # Ninja runs the action). Resolve them to absolute paths so they work
   # regardless of cargo's working directory.
   manifest_path = os.path.abspath(os.path.join(args.manifest_dir, 'Cargo.toml'))
+  cargo_output_lib = os.path.abspath(args.cargo_output_lib)
   output_lib = os.path.abspath(args.output_lib)
 
   cmd = [
@@ -65,10 +73,16 @@ def main():
     print(f'ERROR: cargo build failed with exit code {result.returncode}', file=sys.stderr)
     return result.returncode
 
-  if not os.path.exists(output_lib):
-    print(f'ERROR: Expected output library not found: {output_lib}', file=sys.stderr)
+  if not os.path.exists(cargo_output_lib):
+    print(f'ERROR: Cargo output library not found: {cargo_output_lib}', file=sys.stderr)
     return 1
 
+  # Copy the library from the cargo output (source tree) to the build output
+  # dir so GN/Ninja can track it as an action output.
+  import shutil
+  os.makedirs(os.path.dirname(output_lib), exist_ok=True)
+  shutil.copy2(cargo_output_lib, output_lib)
+
   # Write stamp file to signal success to Ninja.
   with open(args.stamp, 'w') as f:
     f.write('')