Add SwiftBuild coverage support

Ensure the SwiftBuild build systam has feature parity with the Native
build system as it relates to coverage.

Fixes: #9077
Fixes: #9197
Issue: rdar://159461439

Author: bkhouri

Fixtures/Coverage/Simple/.gitignore

@@ -0,0 +1,8 @@
+.DS_Store
+/.build
+/Packages
+xcuserdata/
+DerivedData/
+.swiftpm/configuration/registries.json
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
+.netrc

Fixtures/Coverage/Simple/Package.swift

@@ -0,0 +1,26 @@
+// swift-tools-version: 6.2
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "Simple",
+    products: [
+        // Products define the executables and libraries a package produces, making them visible to other packages.
+        .library(
+            name: "Simple",
+            targets: ["Simple"]
+        ),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package, defining a module or a test suite.
+        // Targets can depend on other targets in this package and products from dependencies.
+        .target(
+            name: "Simple"
+        ),
+        .testTarget(
+            name: "SimpleTests",
+            dependencies: ["Simple"]
+        ),
+    ]
+)

Fixtures/Coverage/Simple/Sources/Simple/Simple.swift

@@ -0,0 +1,10 @@
+// The Swift Programming Language
+// https://docs.swift.org/swift-book
+
+public func greet(name: String = "world") -> String {
+    return "Hello, \(name)!"
+}
+
+public func libA() -> String {
+    return "libA"
+}

Fixtures/Coverage/Simple/Tests/SimpleTests/SimpleTests.swift

@@ -0,0 +1,24 @@
+import Testing
+import XCTest
+@testable import Simple
+
+@Test(
+    arguments: [
+        "Bob",
+        "Alice",
+        "",
+    ]
+)
+ func testGreet(
+    name: String
+ ) async throws {
+    let actual = greet(name: name)
+
+    #expect(actual == "Hello, \(name)!")
+}
+
+final class SimpleTests: XCTestCase {
+    func testExample() throws {
+        XCTAssertEqual(libA(), "libA", "Actual is not as expected")
+    }
+}

Sources/Basics/FileSystem/AbsolutePath.swift

@@ -53,14 +53,19 @@ public struct AbsolutePath: Hashable, Sendable {
     /// The input string will be normalized if needed, as described in the
     /// documentation for AbsolutePath.
     public init(validating pathString: String) throws {
-        self.underlying = try .init(validating: pathString)
+        self.underlying = try .init(
+            validating: pathString.trimmingCharacters(in: .whitespacesAndNewlines),
+        )
     }
 
     /// Initializes an AbsolutePath from a string that may be either absolute
     /// or relative; if relative, `basePath` is used as the anchor; if absolute,
     /// it is used as is, and in this case `basePath` is ignored.
     public init(validating pathString: String, relativeTo basePath: AbsolutePath) throws {
-        self.underlying = try .init(validating: pathString, relativeTo: basePath.underlying)
+        self.underlying = try .init(
+            validating: pathString.trimmingCharacters(in: .whitespacesAndNewlines),
+            relativeTo: basePath.underlying,
+        )
     }
 
     /// Initializes the AbsolutePath by concatenating a relative path to an

Sources/Basics/FileSystem/RelativePath.swift

@@ -9,7 +9,7 @@
 // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 //===----------------------------------------------------------------------===//
-
+import Foundation
 import struct TSCBasic.RelativePath
 
 // public for transition
@@ -40,7 +40,9 @@ public struct RelativePath: Hashable, Sendable {
 
     /// Convenience initializer that verifies that the path is relative.
     public init(validating pathString: String) throws {
-        self.underlying = try .init(validating: pathString)
+        self.underlying = try .init(
+            validating: pathString.trimmingCharacters(in: .whitespacesAndNewlines),
+        )
     }
 
     /// Directory component.  For a relative path without any path separators,

Sources/Commands/SwiftTestCommand.swift

@@ -14,6 +14,7 @@ import ArgumentParser
 
 @_spi(SwiftPMInternal)
 import Basics
+import struct Basics.Triple
 
 import _Concurrency
 
@@ -597,7 +598,11 @@ public struct SwiftTestCommand: AsyncSwiftCommand {
         for product in testProducts {
             // Export the codecov data as JSON.
             let jsonPath = productsBuildParameters.codeCovAsJSONPath(packageName: rootManifest.displayName)
-            try await exportCodeCovAsJSON(to: jsonPath, testBinary: product.binaryPath, swiftCommandState: swiftCommandState)
+            try await exportCodeCovAsJSON(
+                to: jsonPath,
+                testBinary: product.binaryPath,
+                swiftCommandState: swiftCommandState,
+            )
         }
     }
 
@@ -619,7 +624,6 @@ public struct SwiftTestCommand: AsyncSwiftCommand {
             }
         }
         args += ["-o", productsBuildParameters.codeCovDataFile.pathString]
-
         try await AsyncProcess.checkNonZeroExit(arguments: args)
     }
 
@@ -632,11 +636,18 @@ public struct SwiftTestCommand: AsyncSwiftCommand {
         // Export using the llvm-cov tool.
         let llvmCov = try swiftCommandState.getTargetToolchain().getLLVMCov()
         let (productsBuildParameters, _) = try swiftCommandState.buildParametersForTest(options: self.options)
+        let archArgs: [String] = if let arch = productsBuildParameters.triple.llvmCovArchArgument {
+        // let archArgs: [String] = if let arch = productsBuildParameters.triple.arch {
+            ["--arch", "\(arch)"]
+        } else {
+            []
+        }
         let args = [
             llvmCov.pathString,
             "export",
             "-instr-profile=\(productsBuildParameters.codeCovDataFile)",
-            testBinary.pathString
+        ] + archArgs + [
+            testBinary.pathString,
         ]
         let result = try await AsyncProcess.popen(arguments: args)
 
@@ -709,6 +720,21 @@ extension SwiftTestCommand {
     }
 }
 
+fileprivate extension Triple {
+    var llvmCovArchArgument: String? {
+        guard let arch = self.arch else {
+            return nil
+        }
+        switch arch {
+        case .aarch64:
+            // macOS uses arm64, Linux might use aarch64
+            return ProcessInfo.hostOperatingSystem == .macOS ? "arm64" : "aarch64"
+        default:
+            return "\(arch)"
+        }
+    }
+}
+
 extension SwiftTestCommand {
     struct Last: SwiftCommand {
         @OptionGroup(visibility: .hidden)

Sources/SwiftBuildSupport/SwiftBuildSystem.swift

@@ -1077,8 +1077,8 @@ public final class SwiftBuildSystem: SPMBuildCore.BuildSystem {
 
     private static func constructTestingSettingsOverrides(from parameters: BuildParameters.Testing) -> [String: String] {
         var settings: [String: String] = [:]
-        // TODO: enableCodeCoverage
-        // explicitlyEnabledTestability
+
+        settings["CLANG_COVERAGE_MAPPING"] = parameters.enableCodeCoverage ? "YES" : "NO"
 
         switch parameters.explicitlyEnabledTestability {
         case true:

Sources/_InternalTestSupport/SwiftTesting+TraitsBug.swift

@@ -54,6 +54,13 @@ extension Trait where Self == Testing.Bug {
         )
     }
 
+    public static var IssueWindowsPathTestsFailures: Self {
+        .issue(
+            "https://github.com/swiftlang/swift-package-manager/issues/8511",
+            relationship: .defect,
+        )
+    }
+
     public static var IssueWindowsCannotSaveAttachment: Self {
         // error: unable to write file 'C:\Users\ContainerAdministrator\AppData\Local\Temp\CFamilyTargets_CDynamicLookup.hNxGHC\CFamilyTargets_CDynamicLookup\.build\x86_64-unknown-windows-msvc\Intermediates.noindex\CDynamicLookup.build\Release-windows\CDynamicLookup.build\Objects-normal\x86_64\CDynamicLookup.LinkFileList': No such file or directory (2)
         .issue(