Upload debug symbols in engine v2 fuchsia build. (#47626)

This is the last missing piece to migrate fuchsia to engine v2 and will allow us to remove more of the old recipe versions.

Bug: flutter/flutter#135189

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

ci/builders/linux_fuchsia.json

@@ -72,7 +72,21 @@
                     "flutter/shell/platform/fuchsia:fuchsia",
                     "fuchsia_tests"
                 ]
-            }
+            },
+            "tests": [
+                {
+                    "name": "Upload to Symbol Server for arch: arm64",
+                    "language": "python3",
+                    "script": "flutter/tools/fuchsia/upload_to_symbol_server.py",
+                    "parameters": [
+                        "--symbol-dir",
+                        "out/fuchsia_debug_arm64/.build-id",
+                        "--engine-version",
+                        "${REVISION}",
+                        "--upload"
+                    ]
+                }
+            ]
         },
         {
             "drone_dimensions": [
@@ -143,7 +157,21 @@
                     "flutter/shell/platform/fuchsia:fuchsia",
                     "fuchsia_tests"
                 ]
-            }
+            },
+            "tests": [
+                {
+                    "name": "Upload to Symbol Server for arch: x64",
+                    "language": "python3",
+                    "script": "flutter/tools/fuchsia/upload_to_symbol_server.py",
+                    "parameters": [
+                        "--symbol-dir",
+                        "out/fuchsia_debug_x64/.build-id",
+                        "--engine-version",
+                        "${REVISION}",
+                        "--upload"
+                    ]
+                }
+            ]
         }
     ],
     "generators": {
@@ -164,7 +192,7 @@
                 "parameters": [
                     "--engine-version",
                     "${REVISION}",
-		    "--upload",
+                    "--upload",
                     "--target-arch",
                     "arm64",
                     "--out-dir",
@@ -182,7 +210,7 @@
                 "parameters": [
                     "--engine-version",
                     "${REVISION}",
-		    "--upload",
+                    "--upload",
                     "--target-arch",
                     "x64",
                     "--out-dir",

tools/fuchsia/upload_to_symbol_server.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python3
+#
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Uploads debug symbols to the symbols server."""
+
+import argparse
+import os
+import subprocess
+import sys
+import tempfile
+
+## Path to the engine root checkout. This is used to calculate absolute
+## paths if relative ones are passed to the script.
+BUILD_ROOT_DIR = os.path.abspath(
+    os.path.join(os.path.realpath(__file__), '..', '..', '..', '..')
+)
+FUCHSIA_ARTIFACTS_DEBUG_NAMESPACE = 'debug'
+FUCHSIA_ARTIFACTS_BUCKET_NAME = 'fuchsia-artifacts-release'
+
+
+def remote_filename(exec_path):
+  # An example of exec_path is:
+  # out/fuchsia_debug_x64/flutter-fuchsia-x64/d4/917f5976.debug
+  # In the above example "d4917f5976" is the elf BuildID for the
+  # executable. First 2 characters are used as the directory name
+  # and the rest of the string is the name of the unstripped executable.
+  parts = exec_path.split('/')
+  # We want d4917f5976.debug as the result.
+  return ''.join(parts[-2:])
+
+
+def process_symbols(should_upload, symbol_dir):
+  full_path = os.path.join(BUILD_ROOT_DIR, symbol_dir)
+
+  files = []
+  for (dirpath, dirnames, filenames) in os.walk(full_path):
+    files.extend([os.path.join(dirpath, f) for f in filenames])
+
+  # Remove dbg_files
+  files = [f for f in files if 'dbg_success' not in f]
+
+  for file in files:
+    remote_path = 'gs://%s/%s' % (
+        FUCHSIA_ARTIFACTS_BUCKET_NAME, remote_filename(file)
+    )
+    if should_upload:
+      command = 'gsutil cp %s %s' % (full_path, remote_path)
+      subprocess.check_call(command)
+    else:
+      print(remote_path)
+
+
+def main():
+  parser = argparse.ArgumentParser()
+
+  parser.add_argument(
+      '--symbol-dir',
+      required=True,
+      help='Directory that contain the debug symbols.'
+  )
+  parser.add_argument(
+      '--engine-version',
+      required=True,
+      help='Specifies the flutter engine SHA.'
+  )
+  parser.add_argument(
+      '--upload',
+      default=False,
+      action='store_true',
+      help='If set, uploads symbols to the server.'
+  )
+
+  args = parser.parse_args()
+
+  should_upload = args.upload
+  engine_version = args.engine_version
+  if not engine_version:
+    engine_version = 'HEAD'
+    should_upload = False
+
+  process_symbols(should_upload, args.symbol_dir)
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())