cache DriverSupport capabilities across targets (#7057)

motivation: DriverSupport capabilities require shelling, which was
called for every target, while it can be cached across them

changes: make DriverSupport a static util

Author: tomerd

Sources/Build/BuildDescription/ProductBuildDescription.swift

@@ -16,12 +16,6 @@ import PackageModel
 import OrderedCollections
 import SPMBuildCore
 
-#if USE_IMPL_ONLY_IMPORTS
-@_implementationOnly import DriverSupport
-#else
-import DriverSupport
-#endif
-
 import struct TSCBasic.SortedArray
 
 /// The build description for a product.

Sources/Build/BuildDescription/SwiftTargetBuildDescription.swift

@@ -55,8 +55,6 @@ public final class SwiftTargetBuildDescription {
     /// These are the resource files derived from plugins.
     private var pluginDerivedResources: [Resource]
 
-    private let driverSupport = DriverSupport()
-
     /// Path to the bundle generated for this module (if any).
     var bundlePath: AbsolutePath? {
         if let bundleName = target.underlyingTarget.potentialBundleName, needsResourceBundle {
@@ -255,6 +253,7 @@ public final class SwiftTargetBuildDescription {
         guard target.underlyingTarget is SwiftTarget else {
             throw InternalError("underlying target type mismatch \(target)")
         }
+
         self.package = package
         self.target = target
         self.toolsVersion = toolsVersion
@@ -267,13 +266,14 @@ public final class SwiftTargetBuildDescription {
         } else {
             self.testTargetRole = nil
         }
-        self.fileSystem = fileSystem
+
         self.tempsPath = buildParameters.buildPath.appending(component: target.c99name + ".build")
         self.derivedSources = Sources(paths: [], root: self.tempsPath.appending("DerivedSources"))
         self.buildToolPluginInvocationResults = buildToolPluginInvocationResults
         self.prebuildCommandResults = prebuildCommandResults
         self.requiredMacroProducts = requiredMacroProducts
         self.shouldGenerateTestObservation = shouldGenerateTestObservation
+        self.fileSystem = fileSystem
         self.observabilityScope = observabilityScope
 
         (self.pluginDerivedSources, self.pluginDerivedResources) = SharedTargetBuildDescription.computePluginGeneratedFiles(
@@ -411,7 +411,7 @@ public final class SwiftTargetBuildDescription {
     private func packageNameArgumentIfSupported(with pkg: ResolvedPackage, packageAccess: Bool) -> [String] {
         let flag = "-package-name"
         if pkg.manifest.usePackageNameFlag,
-           driverSupport.checkToolchainDriverFlags(flags: [flag], toolchain:  self.buildParameters.toolchain, fileSystem: self.fileSystem) {
+           DriverSupport.checkToolchainDriverFlags(flags: [flag], toolchain:  self.buildParameters.toolchain, fileSystem: self.fileSystem) {
             if packageAccess {
                 let pkgID = pkg.identity.description.spm_mangledToC99ExtendedIdentifier()
                 return [flag, pkgID]
@@ -439,7 +439,7 @@ public final class SwiftTargetBuildDescription {
         #endif
 
         // If we're using an OSS toolchain, add the required arguments bringing in the plugin server from the default toolchain if available.
-        if self.buildParameters.toolchain.isSwiftDevelopmentToolchain, driverSupport.checkSupportedFrontendFlags(flags: ["-external-plugin-path"], toolchain: self.buildParameters.toolchain, fileSystem: self.fileSystem), let pluginServer = try self.buildParameters.toolchain.swiftPluginServerPath {
+        if self.buildParameters.toolchain.isSwiftDevelopmentToolchain, DriverSupport.checkSupportedFrontendFlags(flags: ["-external-plugin-path"], toolchain: self.buildParameters.toolchain, fileSystem: self.fileSystem), let pluginServer = try self.buildParameters.toolchain.swiftPluginServerPath {
             let toolchainUsrPath = pluginServer.parentDirectory.parentDirectory
             let pluginPathComponents = ["lib", "swift", "host", "plugins"]
 

Sources/Build/BuildManifest/LLBuildManifestBuilder.swift

@@ -17,10 +17,8 @@ import PackageModel
 import SPMBuildCore
 
 #if USE_IMPL_ONLY_IMPORTS
-@_implementationOnly import DriverSupport
 @_implementationOnly import SwiftDriver
 #else
-import DriverSupport
 import SwiftDriver
 #endif
 

Sources/Build/BuildOperation.swift

@@ -101,8 +101,6 @@ public final class BuildOperation: PackageStructureDelegate, SPMBuildCore.BuildS
     /// Alternative path to search for pkg-config `.pc` files.
     private let pkgConfigDirectories: [AbsolutePath]
 
-    private let driverSupport = DriverSupport()
-
     public init(
         buildParameters: BuildParameters,
         cacheBuildManifest: Bool,
@@ -186,7 +184,7 @@ public final class BuildOperation: PackageStructureDelegate, SPMBuildCore.BuildS
             return
         }
         // Ensure the compiler supports the import-scan operation
-        guard driverSupport.checkSupportedFrontendFlags(flags: ["import-prescan"], toolchain: self.buildParameters.toolchain, fileSystem: localFileSystem) else {
+        guard DriverSupport.checkSupportedFrontendFlags(flags: ["import-prescan"], toolchain: self.buildParameters.toolchain, fileSystem: localFileSystem) else {
             return
         }
 

Sources/Build/BuildPlan/BuildPlan.swift

@@ -374,7 +374,12 @@ public class BuildPlan: SPMBuildCore.BuildPlan {
 
         // Plan the derived test targets, if necessary.
         if buildParameters.testingParameters.testProductStyle.requiresAdditionalDerivedTestTargets {
-            let derivedTestTargets = try Self.makeDerivedTestTargets(buildParameters, graph, self.fileSystem, self.observabilityScope)
+            let derivedTestTargets = try Self.makeDerivedTestTargets(
+                buildParameters,
+                graph,
+                self.fileSystem,
+                self.observabilityScope
+            )
             for item in derivedTestTargets {
                 var derivedTestTargets = [item.entryPointTargetBuildDescription.target]
 

Sources/Commands/Utilities/SymbolGraphExtract.swift

@@ -36,7 +36,6 @@ public struct SymbolGraphExtract {
     var includeSPISymbols = false
     var emitExtensionBlockSymbols = false
     var outputFormat = OutputFormat.json(pretty: false)
-    private let driverSupport = DriverSupport()
 
     /// Access control levels.
     public enum AccessLevel: String, RawRepresentable, CaseIterable, ExpressibleByArgument {
@@ -82,7 +81,7 @@ public struct SymbolGraphExtract {
         }
 
         let extensionBlockSymbolsFlag = emitExtensionBlockSymbols ? "-emit-extension-block-symbols" : "-omit-extension-block-symbols"
-        if driverSupport.checkSupportedFrontendFlags(flags: [extensionBlockSymbolsFlag.trimmingCharacters(in: ["-"])], toolchain: buildParameters.toolchain, fileSystem: fileSystem) {
+        if DriverSupport.checkSupportedFrontendFlags(flags: [extensionBlockSymbolsFlag.trimmingCharacters(in: ["-"])], toolchain: buildParameters.toolchain, fileSystem: fileSystem) {
             commandLine += [extensionBlockSymbolsFlag]
         } else {
             observabilityScope.emit(warning: "dropped \(extensionBlockSymbolsFlag) flag because it is not supported by this compiler version")

Sources/CoreCommands/SwiftTool.swift

@@ -253,8 +253,6 @@ public final class SwiftTool {
 
     fileprivate var buildSystemProvider: BuildSystemProvider?
 
-    private let driverSupport = DriverSupport()
-
     /// Create an instance of this tool.
     ///
     /// - parameter options: The command line options to be passed to this tool.
@@ -707,7 +705,7 @@ public final class SwiftTool {
                 omitFramePointers: options.build.omitFramePointers
             ),
             driverParameters: .init(
-                canRenameEntrypointFunctionName: driverSupport.checkSupportedFrontendFlags(
+                canRenameEntrypointFunctionName: DriverSupport.checkSupportedFrontendFlags(
                     flags: ["entry-point-function-name"],
                     toolchain: toolchain,
                     fileSystem: self.fileSystem
@@ -859,11 +857,11 @@ public final class SwiftTool {
 
             var extraManifestFlags = self.options.build.manifestFlags
             // Disable the implicit concurrency import if the compiler in use supports it to avoid warnings if we are building against an older SDK that does not contain a Concurrency module.
-            if driverSupport.checkSupportedFrontendFlags(flags: ["disable-implicit-concurrency-module-import"], toolchain: try self.buildParameters().toolchain, fileSystem: self.fileSystem) {
+            if DriverSupport.checkSupportedFrontendFlags(flags: ["disable-implicit-concurrency-module-import"], toolchain: try self.buildParameters().toolchain, fileSystem: self.fileSystem) {
                 extraManifestFlags += ["-Xfrontend", "-disable-implicit-concurrency-module-import"]
             }
             // Disable the implicit string processing import if the compiler in use supports it to avoid warnings if we are building against an older SDK that does not contain a StringProcessing module.
-            if driverSupport.checkSupportedFrontendFlags(flags: ["disable-implicit-string-processing-module-import"], toolchain: try self.buildParameters().toolchain, fileSystem: self.fileSystem) {
+            if DriverSupport.checkSupportedFrontendFlags(flags: ["disable-implicit-string-processing-module-import"], toolchain: try self.buildParameters().toolchain, fileSystem: self.fileSystem) {
                 extraManifestFlags += ["-Xfrontend", "-disable-implicit-string-processing-module-import"]
             }
 

Sources/DriverSupport/DriverSupportUtils.swift

@@ -17,12 +17,11 @@ import class TSCBasic.Process
 import enum TSCBasic.ProcessEnv
 import struct TSCBasic.ProcessResult
 
-public class DriverSupport {
-    private var flagsMap = ThreadSafeBox<[String: Set<String>]>()
-    public init() {}
+public enum DriverSupport {
+    private static var flagsMap = ThreadSafeBox<[String: Set<String>]>()
 
     // This checks _frontend_ supported flags, which are not necessarily supported in the driver.
-    public func checkSupportedFrontendFlags(
+    public static func checkSupportedFrontendFlags(
         flags: Set<String>,
         toolchain: PackageModel.Toolchain,
         fileSystem: FileSystem
@@ -55,7 +54,7 @@ public class DriverSupport {
     // This checks if given flags are supported in the built-in toolchain driver. Currently
     // there's no good way to get the supported flags from it, so run `swiftc -h` directly
     // to get the flags and cache the result.
-    public func checkToolchainDriverFlags(
+    public static func checkToolchainDriverFlags(
         flags: Set<String>,
         toolchain: PackageModel.Toolchain,
         fileSystem: FileSystem

Sources/SPMTestSupport/misc.swift

@@ -20,6 +20,7 @@ import PackageGraph
 import PackageLoading
 import PackageModel
 import SourceControl
+import struct SPMBuildCore.BuildParameters
 import TSCTestSupport
 import Workspace
 import func XCTest.XCTFail

Tests/BuildTests/BuildPlanTests.swift

@@ -12,6 +12,7 @@
 
 @testable import Basics
 @testable import Build
+import DriverSupport
 import PackageLoading
 @testable import PackageGraph
 @testable import PackageModel
@@ -21,20 +22,13 @@ import SwiftDriver
 import Workspace
 import XCTest
 
-#if USE_IMPL_ONLY_IMPORTS
-@_implementationOnly import DriverSupport
-#else
-import DriverSupport
-#endif
-
 import struct TSCBasic.ByteString
 import class TSCBasic.InMemoryFileSystem
 
 import enum TSCUtility.Diagnostics
 
 final class BuildPlanTests: XCTestCase {
     let inputsDir = AbsolutePath(#file).parentDirectory.appending(components: "Inputs")
-    private let driverSupport = DriverSupport()
 
     /// The j argument.
     private var j: String {
@@ -533,7 +527,7 @@ final class BuildPlanTests: XCTestCase {
     }
 
     func testPackageNameFlag() throws {
-        let isFlagSupportedInDriver = try driverSupport.checkToolchainDriverFlags(flags: ["package-name"], toolchain: UserToolchain.default, fileSystem: localFileSystem)
+        let isFlagSupportedInDriver = try DriverSupport.checkToolchainDriverFlags(flags: ["package-name"], toolchain: UserToolchain.default, fileSystem: localFileSystem)
         try fixture(name: "Miscellaneous/PackageNameFlag") { fixturePath in
             let (stdout, _) = try executeSwiftBuild(fixturePath.appending("appPkg"), extraArgs: ["-v"])
             XCTAssertMatch(stdout, .contains("-module-name Foo"))
@@ -555,7 +549,7 @@ final class BuildPlanTests: XCTestCase {
     }
 
     func testTargetsWithPackageAccess() throws {
-        let isFlagSupportedInDriver = try driverSupport.checkToolchainDriverFlags(flags: ["package-name"], toolchain: UserToolchain.default, fileSystem: localFileSystem)
+        let isFlagSupportedInDriver = try DriverSupport.checkToolchainDriverFlags(flags: ["package-name"], toolchain: UserToolchain.default, fileSystem: localFileSystem)
         try fixture(name: "Miscellaneous/TargetPackageAccess") { fixturePath in
             let (stdout, _) = try executeSwiftBuild(fixturePath.appending("libPkg"), extraArgs: ["-v"])
             if isFlagSupportedInDriver {

Tests/CommandsTests/APIDiffTests.swift

@@ -13,24 +13,17 @@
 import Basics
 import Build
 import Commands
+import DriverSupport
 import Foundation
 import PackageModel
 import SourceControl
 import SPMTestSupport
 import Workspace
 import XCTest
 
-#if USE_IMPL_ONLY_IMPORTS
-@_implementationOnly import DriverSupport
-#else
-import DriverSupport
-#endif
-
 import enum TSCBasic.ProcessEnv
 
 final class APIDiffTests: CommandsTestCase {
-    private let driverSupport = DriverSupport()
-
     @discardableResult
     private func execute(
         _ args: [String],
@@ -61,7 +54,7 @@ final class APIDiffTests: CommandsTestCase {
       // not all of which can be tested for easily. Fortunately, we can test for the
       // `-disable-fail-on-error` option, and any version which supports this flag
       // will meet the other requirements.
-      guard driverSupport.checkSupportedFrontendFlags(flags: ["disable-fail-on-error"], toolchain: try UserToolchain.default, fileSystem: localFileSystem) else {
+      guard DriverSupport.checkSupportedFrontendFlags(flags: ["disable-fail-on-error"], toolchain: try UserToolchain.default, fileSystem: localFileSystem) else {
         throw XCTSkip("swift-api-digester is too old")
       }
     }