Pin SwiftSyntax to a tagged version (realm#4674)

Specifically this tag:
https://github.com/apple/swift-syntax/releases/tag/0.50800.0-SNAPSHOT-2022-12-29-a

This should make SwiftPM happier about the stability of the pinned
version.

Also switch the CI job to run on macOS to avoid adding Linux-only deps
to the `Package.resolved` file (e.g. CryptoSwift).

.github/workflows/update_swift_syntax.yml

@@ -8,28 +8,22 @@ on:
 
 jobs:
   update_swift_syntax:
-    runs-on: ubuntu-latest
+    runs-on: macos-12
     steps:
     - name: Checkout source
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
     - name: Update SwiftSyntax
       id: update-swift-syntax
       run: ./tools/update-swift-syntax.sh
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-    - name: Check for changes
-      id: state
-      run: |
-        if ! git diff-index --quiet HEAD --; then
-          echo "dirty=true" >> $GITHUB_OUTPUT
-        fi
     - name: Create PR
-      if: steps.state.outputs.dirty == 'true'
+      if: steps.update-swift-syntax.outputs.needs_update == 'true'
       uses: peter-evans/create-pull-request@923ad837f191474af6b1721408744feb989a4c27
       with:
         title: Update SwiftSyntax
         body: |
-          Diff: https://github.com/apple/swift-syntax/compare/${{ steps.update-swift-syntax.outputs.old_commit }}...${{ steps.update-swift-syntax.outputs.new_commit }}
+          Diff: https://github.com/apple/swift-syntax/compare/${{ steps.update-swift-syntax.outputs.old_tag }}...${{ steps.update-swift-syntax.outputs.new_tag }}
         commit-message: Update SwiftSyntax
         delete-branch: true
         branch: update-swift-syntax

Package.resolved

@@ -32,7 +32,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-syntax.git",
       "state" : {
-        "revision" : "60e2097fa967e3bd0a2c3f08b1c672865c1f1d60"
+        "revision" : "edd2d0cdb988ac45e2515e0dd0624e4a6de54a94",
+        "version" : "0.50800.0-SNAPSHOT-2022-12-29-a"
       }
     },
     {

Package.swift

@@ -30,7 +30,7 @@ let package = Package(
     ],
     dependencies: [
         .package(url: "https://github.com/apple/swift-argument-parser.git", .upToNextMinor(from: "1.2.0")),
-        .package(url: "https://github.com/apple/swift-syntax.git", revision: "60e2097fa967e3bd0a2c3f08b1c672865c1f1d60"),
+        .package(url: "https://github.com/apple/swift-syntax.git", exact: "0.50800.0-SNAPSHOT-2022-12-29-a"),
         .package(url: "https://github.com/jpsim/SourceKitten.git", .upToNextMinor(from: "0.33.1")),
         .package(url: "https://github.com/jpsim/Yams.git", from: "5.0.1"),
         .package(url: "https://github.com/scottrhoyt/SwiftyTextTable.git", from: "0.9.0"),

bazel/repos.bzl

@@ -19,10 +19,10 @@ def swiftlint_repos():
 
     http_archive(
         name = "com_github_apple_swift_syntax",
-        sha256 = "18f910a68c06e7a11f813b781704bff2ef6ebd676ccc7506dc479fc95811a64f", # SwiftSyntax sha256
+        sha256 = "2024415299a487fcb3b2d7500d2e7c149b4bc4f3b94408edd601457ee27f6b11", # SwiftSyntax sha256
         build_file = "@SwiftLint//bazel:SwiftSyntax.BUILD",
-        strip_prefix = "swift-syntax-60e2097fa967e3bd0a2c3f08b1c672865c1f1d60",
-        url = "https://github.com/apple/swift-syntax/archive/60e2097fa967e3bd0a2c3f08b1c672865c1f1d60.tar.gz",
+        strip_prefix = "swift-syntax-0.50800.0-SNAPSHOT-2022-12-29-a",
+        url = "https://github.com/apple/swift-syntax/archive/refs/tags/0.50800.0-SNAPSHOT-2022-12-29-a.tar.gz",
     )
 
     http_archive(

tools/update-swift-syntax.sh

@@ -2,22 +2,23 @@
 
 set -euo pipefail
 
-readonly old_commit="$(grep "apple/swift-syntax" Package.swift | sed -nr 's/.*revision: \"([a-f0-9]{40})\"\),$/\1/p')"
+readonly old_tag="$(sed -n 's/.* exact: "\(.*\)".*/\1/p' Package.swift)"
 if [ $# -eq 0 ]; then
-  readonly new_commit="$(curl -s -H "Authorization: token $GITHUB_TOKEN" -H "Accept: application/vnd.github.VERSION.sha" "https://api.github.com/repos/apple/swift-syntax/commits/main")"
+  readonly new_tag="$(curl -s -H "Authorization: token $GITHUB_TOKEN" -H "Accept: application/vnd.github+json" "https://api.github.com/repos/apple/swift-syntax/releases?per_page=1" | sed -n 's/.*tag_name":"\([^"]*\)".*/\1/p')"
 else
-  readonly new_commit="$1"
+  readonly new_tag="$1"
 fi
 
-if [[ "$old_commit" == "$new_commit" ]]; then
-  echo "SwiftSyntax is already up to date"
+if [[ "$old_tag" == "$new_tag" ]]; then
+  echo "SwiftSyntax is already up to date at $new_tag"
   exit 0
 fi
 
-echo "Updating SwiftSyntax from $old_commit to $new_commit"
+echo "Updating SwiftSyntax from $old_tag to $new_tag"
 if [[ "${GITHUB_ACTIONS-}" == "true" ]]; then
-  echo "old_commit=$old_commit" >> $GITHUB_OUTPUT
-  echo "new_commit=$new_commit" >> $GITHUB_OUTPUT
+  echo "needs_update=true" >> $GITHUB_OUTPUT
+  echo "old_tag=$old_tag" >> $GITHUB_OUTPUT
+  echo "new_tag=$new_tag" >> $GITHUB_OUTPUT
 fi
 
 # $1 — string to match
@@ -31,11 +32,12 @@ function replace() {
   fi
 }
 
-replace "$old_commit" "$new_commit" Package.swift
-replace "$old_commit" "$new_commit" Package.resolved
-replace "$old_commit" "$new_commit" bazel/repos.bzl
+replace "$old_tag" "$new_tag" Package.swift
+swift package update
 
-readonly url="https://github.com/apple/swift-syntax/archive/$new_commit.tar.gz"
+replace "$old_tag" "$new_tag" bazel/repos.bzl
+
+readonly url="https://github.com/apple/swift-syntax/archive/refs/tags/$new_tag.tar.gz"
 output="$(mktemp -d)/download"
 if ! curl -s --location --fail --output "$output" "$url"; then
   echo "error: failed to download $url" >&2