Swift Build linker fixes for linux tests

Author: owenv

Sources/SwiftBuildSupport/PackagePIFBuilder+Helpers.swift

@@ -897,7 +897,7 @@ extension ProjectModel.BuildSettings {
                 // Appending implies the setting is resilient to having ["$(inherited)"]
                 self.platformSpecificSettings[platform]![setting]!.append(contentsOf: values)
 
-            case .SWIFT_VERSION:
+            case .SWIFT_VERSION, .DYLIB_INSTALL_NAME_BASE:
                 self.platformSpecificSettings[platform]![setting] = values // We are not resilient to $(inherited).
 
             case .ARCHS, .IPHONEOS_DEPLOYMENT_TARGET, .SPECIALIZATION_SDK_OPTIONS:
@@ -919,6 +919,9 @@ extension ProjectModel.BuildSettings {
             case .SWIFT_VERSION:
                 self[.SWIFT_VERSION] = values.only.unwrap(orAssert: "Invalid values for 'SWIFT_VERSION': \(values)")
 
+            case .DYLIB_INSTALL_NAME_BASE:
+                self[.DYLIB_INSTALL_NAME_BASE] = values.only.unwrap(orAssert: "Invalid values for 'DYLIB_INSTALL_NAME_BASE': \(values)")
+
             case .ARCHS, .IPHONEOS_DEPLOYMENT_TARGET, .SPECIALIZATION_SDK_OPTIONS:
                 fatalError("Unexpected BuildSettings.Declaration: \(setting)")
             }
@@ -947,7 +950,7 @@ extension ProjectModel.BuildSettings.MultipleValueSetting {
             self = .SPECIALIZATION_SDK_OPTIONS
         case .SWIFT_ACTIVE_COMPILATION_CONDITIONS:
             self = .SWIFT_ACTIVE_COMPILATION_CONDITIONS
-        case .ARCHS, .IPHONEOS_DEPLOYMENT_TARGET, .SWIFT_VERSION:
+        case .ARCHS, .IPHONEOS_DEPLOYMENT_TARGET, .SWIFT_VERSION, .DYLIB_INSTALL_NAME_BASE:
             return nil
         }
     }

Sources/SwiftBuildSupport/PackagePIFBuilder.swift

@@ -364,6 +364,7 @@ public final class PackagePIFBuilder {
             case .framework: .framework
             case .executable: .executable
             case .unitTest: .unitTest
+            case .swiftpmTestRunner: .unitTestRunner
             case .bundle: .bundle
             case .packageProduct: .packageProduct
             case .hostBuildTool: fatalError("Unexpected hostBuildTool type")
@@ -499,7 +500,15 @@ public final class PackagePIFBuilder {
         settings[.WATCHOS_DEPLOYMENT_TARGET] = builder.deploymentTargets[.watchOS] ?? nil
         settings[.DRIVERKIT_DEPLOYMENT_TARGET] = builder.deploymentTargets[.driverKit] ?? nil
         settings[.XROS_DEPLOYMENT_TARGET] = builder.deploymentTargets[.visionOS] ?? nil
-        settings[.DYLIB_INSTALL_NAME_BASE] = "@rpath"
+
+        for machoPlatform in [ProjectModel.BuildSettings.Platform.macOS, .macCatalyst, .iOS, .watchOS, .tvOS, .xrOS, .driverKit] {
+            settings.platformSpecificSettings[machoPlatform]![.DYLIB_INSTALL_NAME_BASE]! = ["@rpath"]
+        }
+        for elfPlatform in [ProjectModel.BuildSettings.Platform.linux, .android] {
+            // FIXME: Treating $ORIGIN as part of the soname is not really the right thing to do here
+            settings.platformSpecificSettings[elfPlatform]![.DYLIB_INSTALL_NAME_BASE]! = ["$ORIGIN"]
+        }
+
         settings[.USE_HEADERMAP] = "NO"
         settings[.OTHER_SWIFT_FLAGS].lazilyInitializeAndMutate(initialValue: ["$(inherited)"]) { $0.append("-DXcode") }
 

Sources/SwiftBuildSupport/PackagePIFProjectBuilder+Products.swift

@@ -1036,13 +1036,10 @@ extension PackagePIFProjectBuilder {
         settings[.PRODUCT_BUNDLE_IDENTIFIER] = "\(self.package.identity).\(name)"
             .spm_mangledToBundleIdentifier()
         settings[.EXECUTABLE_NAME] = name
-        settings[.LD_RUNPATH_SEARCH_PATHS] = [
-            "@loader_path/Frameworks",
-            "@loader_path/../Frameworks",
-            "$(inherited)"
-        ]
         settings[.SKIP_INSTALL] = "NO"
         settings[.SWIFT_VERSION] = "5.0"
+        // This should eventually be set universally for all package targets/products.
+        settings[.LINKER_DRIVER] = "swiftc"
 
         let deploymentTargets = unitTestProduct.deploymentTargets
         settings[.MACOSX_DEPLOYMENT_TARGET] = deploymentTargets?[.macOS] ?? nil