Add capability to query '-print-target-info' in-process using libSwiftScan API

Author: artemcm

Sources/CSwiftScan/include/swiftscan_header.h

@@ -207,6 +207,10 @@ typedef struct {
   void
   (*swiftscan_scan_invocation_dispose)(swiftscan_scan_invocation_t);
 
+  //=== Target Info Functions-------- ---------------------------------------===//
+  swiftscan_string_ref_t
+  (*swiftscan_compiler_target_info_query)(swiftscan_scan_invocation_t);
+
   //=== Functionality Query Functions ---------------------------------------===//
   swiftscan_string_set_t *
   (*swiftscan_compiler_supported_arguments_query)(void);

Sources/SwiftDriver/ExplicitModuleBuilds/ModuleDependencyScanning.swift

@@ -236,7 +236,7 @@ public extension Driver {
     return fallbackToFrontend
   }
 
-  private func sanitizeCommandForLibScanInvocation(_ command: inout [String]) {
+  func sanitizeCommandForLibScanInvocation(_ command: inout [String]) {
     // Remove the tool executable to only leave the arguments. When passing the
     // command line into libSwiftScan, the library is itself the tool and only
     // needs to parse the remaining arguments.
@@ -485,7 +485,7 @@ public extension Driver {
                                                                   contents)
   }
 
-  fileprivate func itemizedJobCommand(of job: Job, useResponseFiles: ResponseFileHandling,
+  func itemizedJobCommand(of job: Job, useResponseFiles: ResponseFileHandling,
                                       using resolver: ArgsResolver) throws -> [String] {
     let (args, _) = try resolver.resolveArgumentList(for: job,
                                                      useResponseFiles: useResponseFiles)

Sources/SwiftDriver/Jobs/PrintTargetInfoJob.swift

@@ -10,6 +10,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+import protocol TSCBasic.FileSystem
+import class Foundation.JSONDecoder
+
 /// Swift versions are major.minor.
 struct SwiftVersion {
   var major: Int
@@ -173,3 +176,65 @@ extension Toolchain {
     )
   }
 }
+
+extension Driver {
+  static func queryTargetInfoInProcess(of toolchain: Toolchain,
+                                       fileSystem: FileSystem,
+                                       invocationCommand: [String]) throws -> FrontendTargetInfo? {
+    let optionalSwiftScanLibPath = try toolchain.lookupSwiftScanLib()
+    if let swiftScanLibPath = optionalSwiftScanLibPath,
+       fileSystem.exists(swiftScanLibPath) {
+      let libSwiftScanInstance = try SwiftScan(dylib: swiftScanLibPath)
+      if libSwiftScanInstance.canQueryTargetInfo() {
+        let targetInfoData = try libSwiftScanInstance.queryTargetInfoJSON(invocationCommand: invocationCommand)
+        return try JSONDecoder().decode(FrontendTargetInfo.self, from: targetInfoData)
+      }
+    }
+    return nil
+  }
+
+  func computeTargetInfo(target: Triple?,
+                         targetVariant: Triple?,
+                         sdkPath: VirtualPath? = nil,
+                         resourceDirPath: VirtualPath? = nil,
+                         runtimeCompatibilityVersion: String? = nil,
+                         requiresInPlaceExecution: Bool = false,
+                         useStaticResourceDir: Bool = false,
+                         swiftCompilerPrefixArgs: [String],
+                         executor: DriverExecutor) throws -> FrontendTargetInfo {
+    let frontendTargetInfoJob =
+      try toolchain.printTargetInfoJob(target: target, targetVariant: targetVariant,
+                                       sdkPath: sdkPath, resourceDirPath: resourceDirPath,
+                                       runtimeCompatibilityVersion: runtimeCompatibilityVersion,
+                                       requiresInPlaceExecution: requiresInPlaceExecution,
+                                       useStaticResourceDir: useStaticResourceDir,
+                                       swiftCompilerPrefixArgs: swiftCompilerPrefixArgs)
+    var command = try itemizedJobCommand(of: frontendTargetInfoJob,
+                                         useResponseFiles: .disabled,
+                                         using: executor.resolver)
+    sanitizeCommandForLibScanInvocation(&command)
+    if let targetInfo =
+        try Self.queryTargetInfoInProcess(of: toolchain, fileSystem: fileSystem,
+                                          invocationCommand: command) {
+      return targetInfo
+    }
+
+    // Fallback: Invoke `swift-frontend -print-target-info` and decode the output
+    return try executor.execute(
+      job: frontendTargetInfoJob,
+      capturingJSONOutputAs: FrontendTargetInfo.self,
+      forceResponseFiles: false,
+      recordedInputModificationDates: [:])
+  }
+
+  /// This method exists for testing purposes only
+  @_spi(Testing) public func verifyBeingAbleToQueryTargetInfoInProcess(invocationCommand: [String]) throws -> Bool {
+    guard let targetInfo = try Self.queryTargetInfoInProcess(of: toolchain,
+                                                             fileSystem: fileSystem,
+                                                             invocationCommand: invocationCommand) else {
+      return false
+    }
+    print("libSwiftScan Compiler: \(targetInfo.compilerVersion)")
+    return true
+  }
+}

Sources/SwiftDriver/SwiftScan/SwiftScan.swift

@@ -14,6 +14,8 @@
 
 import func Foundation.strdup
 import func Foundation.free
+import class Foundation.JSONDecoder
+import struct Foundation.Data
 
 import protocol TSCBasic.DiagnosticData
 import struct TSCBasic.AbsolutePath
@@ -80,7 +82,7 @@ internal extension swiftscan_diagnostic_severity_t {
 }
 
 /// Wrapper for libSwiftScan, taking care of initialization, shutdown, and dispatching dependency scanning queries.
-internal final class SwiftScan {
+@_spi(Testing) public final class SwiftScan {
   /// The path to the libSwiftScan dylib.
   let path: AbsolutePath
 
@@ -311,6 +313,25 @@ internal final class SwiftScan {
       throw DependencyScanningError.argumentQueryFailed
     }
   }
+
+  @_spi(Testing) public func canQueryTargetInfo() -> Bool {
+    return api.swiftscan_compiler_target_info_query != nil &&
+           api.swiftscan_string_set_dispose != nil
+  }
+
+  func queryTargetInfoJSON(invocationCommand: [String]) throws -> Data {
+    // Create and configure the scanner invocation
+    let invocation = api.swiftscan_scan_invocation_create()
+    defer { api.swiftscan_scan_invocation_dispose(invocation) }
+    withArrayOfCStrings(invocationCommand) { invocationStringArray in
+      api.swiftscan_scan_invocation_set_argv(invocation,
+                                             Int32(invocationCommand.count),
+                                             invocationStringArray)
+    }
+    let targetInfoString = try toSwiftString(api.swiftscan_compiler_target_info_query(invocation))
+    let targetInfoData = Data(targetInfoString.utf8)
+    return targetInfoData
+  }
 }
 
 // Used for testing purposes only
@@ -347,6 +368,10 @@ private extension swiftscan_functions_t {
     self.swiftscan_compiler_supported_features_query =
       try loadOptional("swiftscan_compiler_supported_features_query")
 
+    // Target Info query
+    self.swiftscan_compiler_target_info_query =
+      try loadOptional("swiftscan_compiler_target_info_query")
+
     // Dependency scanner serialization/deserialization features
     self.swiftscan_scanner_cache_serialize =
       try loadOptional("swiftscan_scanner_cache_serialize")

Tests/SwiftDriverTests/SwiftDriverTests.swift

@@ -4769,9 +4769,14 @@ final class SwiftDriverTests: XCTestCase {
   }
 
   func testPrintTargetInfo() throws {
+    print("Begin testPrintTargetInfo")
+
     do {
-      var driver = try Driver(args: ["swift", "-print-target-info", "-target", "arm64-apple-ios12.0", "-sdk", "bar", "-resource-dir", "baz"])
+      print("testPrintTargetInfo -> driver 1")
+      var driver = try Driver(args: ["swift", "-print-target-info", "-sdk", "bar", "-resource-dir", "baz"])
+      print("testPrintTargetInfo -> planBuild 1")
       let plannedJobs = try driver.planBuild()
+      print("testPrintTargetInfo -> done 1")
       XCTAssertTrue(plannedJobs.count == 1)
       let job = plannedJobs[0]
       XCTAssertEqual(job.kind, .printTargetInfo)
@@ -4781,6 +4786,24 @@ final class SwiftDriverTests: XCTestCase {
       XCTAssertTrue(job.commandLine.contains(.flag("-resource-dir")))
     }
 
+    do {
+      let targetInfoArgs = ["-print-target-info", "-sdk", "bar", "-resource-dir", "baz"]
+      print("testPrintTargetInfo -> driver 2")
+      let driver = try Driver(args: ["swift"] + targetInfoArgs)
+      print("testPrintTargetInfo -> getScanLibPath")
+      let swiftScanLibPath = try XCTUnwrap(driver.toolchain.lookupSwiftScanLib())
+      print("Attempting to use scanner library at: \(swiftScanLibPath.debugDescription)")
+      if localFileSystem.exists(swiftScanLibPath) {
+        print("Library Exists")
+        let libSwiftScanInstance = try SwiftScan(dylib: swiftScanLibPath)
+        if libSwiftScanInstance.canQueryTargetInfo() {
+          print("Library able to query target info")
+          XCTAssertTrue(try driver.verifyBeingAbleToQueryTargetInfoInProcess(invocationCommand: targetInfoArgs))
+          print("Verified")
+        }
+      }
+    }
+
     do {
       struct MockExecutor: DriverExecutor {
         let resolver: ArgsResolver