ci: Check Package.swift differences on CI (#5854)

* Set default C language to compiler default

* Bump GCC C version to GNU11

* Use GNU17

* Remove GCC_C_LANGUAGE_STANDARD

* Restore xcconfig changes

* Update changelog

* Update tests to check building with both package files

* Only delete newer package files

* ci: Lint Package.swift differences on CI

* Update job name

* Rename job to `Check` instead of `Lint`

* Update trigger path in check-package-diff workflow to match package file naming convention

* Add error message if check fails

* Update message

* Remove change in Changelog

Author: itaybre

.github/workflows/check-package-diff.yml

@@ -0,0 +1,24 @@
+# We want to ensure that the Package.swift and Package@swift-5.9.swift are in sync.
+
+name: Check Package.swift Diff
+
+on:
+  push:
+    branches:
+      - main
+
+  pull_request:
+    paths:
+      - ".github/workflows/check-package-diff.yml"
+      - "Package*.swift"
+      - "Makefile"
+      - "Utils/expected_package_diff.patch"
+
+jobs:
+  check:
+    name: Check Package.swift Diff
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Check Package.swift Diff
+        run: make check-package-diff

.gitignore

@@ -104,3 +104,5 @@ Sentry-Dynamic-WithARM64e.xcframework*
 SentrySwiftUI.xcframework*
 Sentry-WithoutUIKitOrAppKit.xcframework*
 Sentry-WithoutUIKitOrAppKit-WithARM64e.xcframework*
+
+current_package_diff.patch

Makefile

@@ -183,3 +183,18 @@ xcode-ci:
 	xcodegen --spec Samples/watchOS-Swift/watchOS-Swift.yml
 	xcodegen --spec TestSamples/SwiftUITestSample/SwiftUITestSample.yml
 	xcodegen --spec TestSamples/SwiftUICrashTest/SwiftUICrashTest.yml
+
+.PHONY: check-package-diff update-package-diff
+# Diff will return an error if the files are different, so we need to ignore it with `|| true`.
+check-package-diff:
+	diff Package.swift Package@swift-5.9.swift > current_package_diff.patch || true
+	@if diff ./Utils/expected_package_diff.patch current_package_diff.patch > /dev/null 2>&1; then \
+		echo "--> Package diff check passed - no changes detected"; \
+	else \
+		echo "--> Package diff check failed - changes detected! Make sure to run \"make update-package-diff\" to update the expected diff."; \
+		exit 1; \
+	fi
+
+# Diff will return an error if the files are different, so we need to ignore it with `|| true`.
+update-package-diff:
+	diff Package.swift Package@swift-5.9.swift > ./Utils/expected_package_diff.patch || true

Utils/expected_package_diff.patch

@@ -0,0 +1,25 @@
+1,2c1,5
+< // swift-tools-version:5.3
+< #if canImport(Darwin)   
+---
+> // swift-tools-version:5.9
+> // This Package.swift for Swift 5.9 (and newer) fixes an issue on Xcode 26 when linking `SentrySwiftUI`.
+> // Don't remove this comment.
+> 
+> #if canImport(Darwin)
+15d17
+<     .library(name: "Sentry-Dynamic-WithARM64e", targets: ["Sentry-Dynamic-WithARM64e"]),
+39a42,44
+>         swiftSettings: [
+>             .interoperabilityMode(.Cxx, .when(platforms: [.visionOS]))
+>         ],
+53c58
+< if let env = env, String(cString: env, encoding: .utf8) == "1" {
+---
+> if let env = env, String(cString: env) == "1" {
+84a90
+>             publicHeadersPath: "",
+100c106
+<     platforms: [.iOS(.v11), .macOS(.v10_13), .tvOS(.v11), .watchOS(.v4)],
+---
+>     platforms: [.iOS(.v11), .macOS(.v10_13), .tvOS(.v11), .watchOS(.v4), .visionOS(.v1)],