Manifest parsing with syntax

BuildSupport/SwiftSyntax/CMakeLists.txt

@@ -1,46 +1,16 @@
 include(FetchContent)
 
-# Ensure that the SwiftSyntax symbols we use are disjoint from elsewhere in
-# the compiler toolchain.
-set(SWIFT_MODULE_ABI_NAME_PREFIX "_PM")
-
-# Use separate target names so the underlying libraries have a prefix separate
-# from the rest of the toolchain.
-set(SWIFTSYNTAX_TARGET_NAMESPACE "_PM")
-
-# Handle installation on our own.
-set(SWIFT_SYNTAX_INSTALL_TARGETS NO)
-if(DEFINED SWIFTPM_PATH_TO_SWIFT_SYNTAX_SOURCE)
-  file(TO_CMAKE_PATH "${SWIFTPM_PATH_TO_SWIFT_SYNTAX_SOURCE}" swift_syntax_path)
-  FetchContent_Declare(SwiftSyntax
-    SOURCE_DIR "${swift_syntax_path}")
-else()
-  FetchContent_Declare(SwiftSyntax
-    GIT_REPOSITORY https://github.com/swiftlang/swift-syntax
-    GIT_TAG main)
+find_package(SwiftSyntax CONFIG GLOBAL)
+if(NOT SwiftSyntax_FOUND)
+  set(SWIFT_SYNTAX_INSTALL_TARGETS YES)
+  if(DEFINED SWIFTPM_PATH_TO_SWIFT_SYNTAX_SOURCE)
+    file(TO_CMAKE_PATH "${SWIFTPM_PATH_TO_SWIFT_SYNTAX_SOURCE}" swift_syntax_path)
+    FetchContent_Declare(SwiftSyntax
+      SOURCE_DIR "${swift_syntax_path}")
+  else()
+    FetchContent_Declare(SwiftSyntax
+      GIT_REPOSITORY https://github.com/swiftlang/swift-syntax
+      GIT_TAG main)
+  endif()
+  FetchContent_MakeAvailable(SwiftSyntax)
 endif()
-FetchContent_MakeAvailable(SwiftSyntax)
-
-# FIXME: Use FetchContent_Declare's EXCLUDE_FROM_ALL after CMake 3.28
-FetchContent_GetProperties(SwiftSyntax BINARY_DIR binary_dir)
-set_property(DIRECTORY "${binary_dir}" PROPERTY EXCLUDE_FROM_ALL TRUE)
-
-# Install SwiftPM versions of the swift-syntax libraries we use.
-set(SWIFTPM_SWIFT_SYNTAX_MODULES
-  _PMSwiftBasicFormat
-  _PMSwiftDiagnostics
-  _PMSwiftIDEUtils
-  _PMSwiftParser
-  _PMSwiftParserDiagnostics
-  _PMSwiftRefactor
-  _PMSwiftSyntax
-  _PMSwiftSyntaxBuilder
-)
-
-set(SWIFT_HOST_LIBRARIES_SUBDIRECTORY "swift/host")
-foreach(target ${SWIFTPM_SWIFT_SYNTAX_MODULES})
-    install(TARGETS ${target}
-      LIBRARY DESTINATION lib/${SWIFT_HOST_LIBRARIES_SUBDIRECTORY}
-      RUNTIME DESTINATION bin
-    )
-endforeach()

Package.swift

@@ -348,7 +348,16 @@ let package = Package(
                 "Basics",
                 "PackageModel",
                 "SourceControl",
-            ],
+            ] + swiftSyntaxDependencies(
+                [
+                    "SwiftDiagnostics",
+                    "SwiftIfConfig",
+                    "SwiftOperators",
+                    "SwiftParser",
+                    "SwiftParserDiagnostics",
+                    "SwiftSyntax",
+                ]
+            ),
             exclude: ["CMakeLists.txt", "README.md"],
             swiftSettings: commonExperimentalFeatures
         ),

Sources/Commands/CMakeLists.txt

@@ -62,7 +62,7 @@ add_library(Commands
   Utilities/XCTEvents.swift)
 target_link_libraries(Commands PUBLIC
   SwiftCollections::OrderedCollections
-  SwiftSyntax::_PMSwiftRefactor
+  SwiftSyntax::SwiftRefactor
   SwiftSystem::SystemPackage
   ArgumentParser
   Basics

Sources/CoreCommands/Options.swift

@@ -71,6 +71,9 @@ public struct GlobalOptions: ParsableArguments {
 
     @OptionGroup(title: "Trait Options")
     public var traits: TraitOptions
+
+    @OptionGroup(title: "Manifest Options")
+    public var manifest: ManifestOptions
 }
 
 public struct LocationOptions: ParsableArguments {
@@ -877,6 +880,36 @@ public struct SBOMOptions: ParsableArguments {
     }
 }
 
+public struct ManifestOptions: ParsableArguments {
+    public init() {}
+
+    @Option(
+        name: .customLong("experimental-manifest-processing-mode"),
+        help: "Specifies how manifest files are processed"
+    )
+    public var manifestProcessingMode: ManifestProcessingMode = .onlyExecuted
+
+    @Flag(
+        name: .customLong("experimental-show-manifest-parser-limitations"),
+        help: "Show any manifest parser limitations uncovered in the manifest file"
+    )
+    public var showManifestParserLimitations: Bool = false
+
+    public enum ManifestProcessingMode: String, ExpressibleByArgument {
+        case onlyParsed = "only-parsed"
+        case onlyExecuted = "only-executed"
+        case crosscheck = "crosscheck"
+        case parsedWithFallback = "parsed-with-fallback"
+
+        public static var allValueDescriptions: [String: String] {
+            ["only-parsed" : "Use the built-in manifest parser",
+             "only-executed" : "Build and execute the manifest",
+             "parsed-with-fallback": "Use the built-in manifest parser. If it encounters limitations, fall back to building and executing the manifest.",
+             "crosscheck" : "Use both the built-in manifest parser and also execute the manifest, cross-checking the results"]
+        }
+    }
+}
+
 // MARK: - Extensions
 
 extension BuildConfiguration {

Sources/CoreCommands/SwiftCommandState.swift

@@ -848,7 +848,7 @@ public final class SwiftCommandState {
         return rootManifests.values.map { $0.toolsVersion }.min()
     }
 
-    func getManifestLoader() throws -> ManifestLoader {
+    func getManifestLoader() throws -> any ManifestLoaderProtocol {
         try self._manifestLoader.get()
     }
 
@@ -1113,7 +1113,16 @@ public final class SwiftCommandState {
         )
     })
 
-    private lazy var _manifestLoader: Result<ManifestLoader, Swift.Error> = Result(catching: {
+    private func createParsingManifestLoader() throws -> ParsingManifestLoader {
+        return try ParsingManifestLoader(
+            toolchain: self.getHostToolchain(),
+            pruneDependencies: self.options.resolver.pruneDependencies,
+            extraManifestFlags: self.options.build.manifestFlags,
+            environment: nil
+        )
+    }
+
+    private func createExecutingManifestLoader() throws -> ManifestLoader {
         let cachePath: AbsolutePath? = switch (
             self.options.caching.shouldDisableManifestCaching,
             self.options.caching.manifestCachingMode
@@ -1143,6 +1152,21 @@ public final class SwiftCommandState {
             importRestrictions: .none,
             pruneDependencies: self.options.resolver.pruneDependencies
         )
+    }
+
+    private lazy var _manifestLoader: Result<any ManifestLoaderProtocol, Swift.Error> = Result(
+        catching: {
+            switch self.options.manifest.manifestProcessingMode {
+            case .onlyParsed: try createParsingManifestLoader()
+            case .onlyExecuted: try createExecutingManifestLoader()
+            case .crosscheck, .parsedWithFallback:
+                ChainedParsingManifestLoader(
+                    parsingLoader: try createParsingManifestLoader(),
+                    executingLoader: try createExecutingManifestLoader(),
+                    showLimitations: self.options.manifest.showManifestParserLimitations,
+                    crosscheck: self.options.manifest.manifestProcessingMode == .crosscheck
+                )
+        }
     })
 
     /// An enum indicating the execution status of run commands.

Sources/PackageLoading/CMakeLists.txt

@@ -21,12 +21,28 @@ add_library(PackageLoading
   RegistryReleaseMetadataSerialization.swift
   Target+PkgConfig.swift
   TargetSourcesBuilder.swift
-  ToolsVersionParser.swift)
+  ToolsVersionParser.swift
+
+  ManifestParsing/BuildConfiguration+HostToolchain.swift
+  ManifestParsing/ChainedParsingManifestLoader.swift
+  ManifestParsing/ManifestParseLimitation.swift
+  ManifestParsing/ManifestParserError.swift
+  ManifestParsing/ParsingManifestLoader.swift
+)
+
 target_link_libraries(PackageLoading PUBLIC
   TSCBasic
   Basics
   PackageModel
-  TSCUtility)
+  TSCUtility
+
+  SwiftSyntax::SwiftDiagnostics
+  SwiftSyntax::SwiftIfConfig
+  SwiftSyntax::SwiftOperators
+  SwiftSyntax::SwiftParser
+  SwiftSyntax::SwiftParserDiagnostics
+  SwiftSyntax::SwiftSyntax
+)
 target_link_libraries(PackageLoading PUBLIC
   $<$<NOT:$<PLATFORM_ID:Darwin>>:Foundation>)
 target_link_libraries(PackageLoading PRIVATE

Sources/PackageLoading/ManifestParsing/BuildConfiguration+HostToolchain.swift

@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 2014-2026 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import Basics
+import SwiftIfConfig
+import TSCUtility
+import Foundation
+
+extension StaticBuildConfiguration {
+    public static func getHostConfiguration(
+        usingSwiftCompiler swiftCompiler: AbsolutePath,
+        extraManifestFlags: [String],
+    ) throws -> StaticBuildConfiguration {
+        // Call the compiler to get the static build configuration JSON.
+        let compilerOutput: String
+        do {
+            let args = [swiftCompiler.pathString, "-frontend", "-print-static-build-config"] + extraManifestFlags
+            let result = try AsyncProcess.popen(arguments: args)
+            compilerOutput = try result.utf8Output()
+        } catch {
+            throw InternalError("Failed to get target info (\(error.interpolationDescription))")
+        }
+
+        // Parse the compiler's JSON output.
+        guard let outputData = compilerOutput.data(using: .utf8) else {
+            throw InternalError("Failed to get data from compiler output for static build configuration: \(compilerOutput)")
+        }
+
+        let decoder = JSONDecoder()
+        return try decoder.decode(StaticBuildConfiguration.self, from: outputData)
+    }
+}