Add support for the Scudo sanitizer.

Fixtures/Miscellaneous/DoubleFree/Package.swift

@@ -0,0 +1,18 @@
+// swift-tools-version:5.1
+
+import PackageDescription
+
+let package = Package(
+    name: "double-free",
+    targets: [
+        .target(
+            name: "lib",
+            dependencies: []),
+        .target(
+            name: "exec",
+            dependencies: ["lib"]),
+        .testTarget(
+            name: "libTests",
+            dependencies: ["lib"]),
+    ]
+)

Fixtures/Miscellaneous/DoubleFree/README.md

@@ -0,0 +1,3 @@
+# double-free
+
+A description of this package.

Fixtures/Miscellaneous/DoubleFree/Sources/exec/main.swift

@@ -0,0 +1,3 @@
+import lib
+
+executeDoubleFree()

Fixtures/Miscellaneous/DoubleFree/Sources/lib/lib.swift

@@ -0,0 +1,9 @@
+public func executeDoubleFree() {
+    let size = 512
+
+    let buffer = UnsafeMutableRawBufferPointer.allocate(byteCount: size, alignment: 1)
+    buffer[0] = 0
+    buffer.deallocate()
+    buffer.deallocate()
+    print(buffer[0])
+}

Fixtures/Miscellaneous/DoubleFree/Tests/LinuxMain.swift

@@ -0,0 +1,8 @@
+import XCTest
+
+import libTests
+
+var tests = [XCTestCaseEntry]()
+tests += libTests.__allTests()
+
+XCTMain(tests)

Fixtures/Miscellaneous/DoubleFree/Tests/libTests/XCTestManifests.swift

@@ -0,0 +1,15 @@
+import XCTest
+
+extension libTests {
+    static let __allTests = [
+        ("testDoubleFree", testDoubleFree),
+    ]
+}
+
+#if !os(macOS)
+public func __allTests() -> [XCTestCaseEntry] {
+    return [
+        testCase(libTests.__allTests),
+    ]
+}
+#endif

Fixtures/Miscellaneous/DoubleFree/Tests/libTests/libTests.swift

@@ -0,0 +1,8 @@
+import XCTest
+import lib
+
+final class libTests: XCTestCase {
+    func testDoubleFree() {
+        executeDoubleFree()
+    }
+}

Sources/SPMBuildCore/Sanitizers.swift

@@ -16,13 +16,15 @@ public enum Sanitizer: String, Encodable {
     case address
     case thread
     case undefined
+    case scudo
 
     /// Return an established short name for a sanitizer, e.g. "asan".
     public var shortName: String {
         switch self {
             case .address: return "asan"
             case .thread: return "tsan"
             case .undefined: return "ubsan"
+            case .scudo: return "scudo"
         }
     }
 }
@@ -72,6 +74,7 @@ extension Sanitizer: StringEnumArgument {
     public static let completion: ShellCompletion = .values([
         (address.rawValue, "enable Address sanitizer"),
         (thread.rawValue, "enable Thread sanitizer"),
-        (undefined.rawValue, "enable Undefined Behavior sanitizer")
+        (undefined.rawValue, "enable Undefined Behavior sanitizer"),
+        (scudo.rawValue, "enable Scudo hardened allocator")
     ])
 }

Tests/CommandsTests/RunToolTests.swift

@@ -128,4 +128,27 @@ final class RunToolTests: XCTestCase {
         }
       #endif
     }
+
+    func testSanitizeScudo() throws {
+        // Scudo is only supported on Linux.
+      #if os(Linux)
+        fixture(name: "Miscellaneous/DoubleFree") { path in
+            // Ensure that we don't abort() when we find the race. This avoids
+            // generating the crash report on macOS.
+            let cmdline = {
+                try SwiftPMProduct.SwiftRun.execute(
+                    ["--sanitize=scudo"], packagePath: path)
+            }
+            XCTAssertThrows(try cmdline()) { (error: SwiftPMProductError) in
+                switch error {
+                case .executionFailure(_, _, let error):
+                    XCTAssertMatch(error, .contains("invalid chunk state"))
+                    return true
+                default:
+                    return false
+                }
+            }
+        }
+      #endif
+    }
 }

Tests/CommandsTests/TestToolTests.swift

@@ -80,4 +80,25 @@ final class TestToolTests: XCTestCase {
         }
         #endif
     }
+
+    func testSanitizeScudo() throws {
+        // This test only runs on Linux because Scudo only runs on Linux
+      #if os(Linux)
+        fixture(name: "Miscellaneous/DoubleFree") { path in
+            let cmdline = {
+                try SwiftPMProduct.SwiftTest.execute(
+                    ["--sanitize=scudo"], packagePath: path)
+            }
+            XCTAssertThrows(try cmdline()) { (error: SwiftPMProductError) in
+                switch error {
+                case .executionFailure(_, _, let error):
+                    XCTAssertMatch(error, .contains("invalid chunk state"))
+                    return true
+                default:
+                    return false
+                }
+            }
+        }
+      #endif
+    }
 }