WIP - UBSan support

Author: rahul-malik

Fixtures/CFamilyTargets/CUBSan/Package.swift

@@ -0,0 +1,10 @@
+// swift-tools-version:4.2
+import PackageDescription
+
+let package = Package(
+    name: "CUBSan",
+    targets: [
+        .target(name: "CUBSan", path: "Sources"),
+        .testTarget(name: "CUBSanTests", dependencies: ["CUBSan"]),
+    ]
+)

Fixtures/CFamilyTargets/CUBSan/Sources/HelloWorldExample.m

@@ -0,0 +1,9 @@
+#import <Foundation/Foundation.h>
+#import "HelloWorldExample.h"
+
+@implementation HelloWorld
+- (NSString *)hello:(NSString *)name {
+  __builtin_unreachable();
+  return @"";
+}
+@end

Fixtures/CFamilyTargets/CUBSan/Sources/include/HelloWorldExample.h

@@ -0,0 +1,7 @@
+#import <Foundation/Foundation.h>
+
+@interface HelloWorld : NSObject
+
+- (NSString *)hello:(NSString *)name;
+
+@end

Fixtures/CFamilyTargets/CUBSan/Tests/CUBSanTests/HelloWorldTest.m

@@ -0,0 +1,36 @@
+#import <XCTest/XCTest.h>
+
+# import "HelloWorldExample.h"
+
+@interface HelloWorldTest : XCTestCase
+
+@end
+
+@implementation HelloWorldTest
+
+- (HelloWorld *)helloWorld {
+  return [[HelloWorld alloc] init];
+}
+
+- (void)testNoName {
+  NSString *input = nil;
+  NSString *expected = @"Hello, World!";
+  NSString *result = [[self helloWorld] hello:input];
+  XCTAssertEqualObjects(expected, result);
+}
+
+- (void)testSampleName {
+  NSString *input = @"Alice";
+  NSString *expected = @"Hello, Alice!";
+  NSString *result = [[self helloWorld] hello:input];
+  XCTAssertEqualObjects(expected, result);
+}
+  
+- (void)testOtherSampleName {
+  NSString *input = @"Bob";
+  NSString *expected = @"Hello, Bob!";
+  NSString *result = [[self helloWorld] hello:input];
+  XCTAssertEqualObjects(expected, result);
+}
+
+@end

Sources/Build/BuildPlan.swift

@@ -462,7 +462,7 @@ public final class ProductBuildDescription {
     public func linkArguments() -> [String] {
         var args = [buildParameters.toolchain.swiftCompiler.asString]
         args += buildParameters.toolchain.extraSwiftCFlags
-        args += buildParameters.sanitizers.linkSwiftFlags()
+        args += buildParameters.sanitizers.linkFlags()
         args += additionalFlags
 
         if buildParameters.configuration == .debug {

Sources/Build/Sanitizers.swift

@@ -15,14 +15,20 @@ import Utility
 public enum Sanitizer: String {
     case address
     case thread
+    case undefined
 
     /// 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 "undefined"
         }
     }
+
+    public var flagName: String {
+        return "-fsanitize=\(self.rawValue)"
+    }
 }
 
 /// A set of enabled runtime sanitizers.
@@ -39,17 +45,18 @@ public struct EnabledSanitizers {
 
     /// Sanitization flags for the C family compiler (C/C++).
     public func compileCFlags() -> [String] {
-        return sanitizers.map({ "-fsanitize=\($0.rawValue)" })
+        return sanitizers.map{ $0.flagName }
     }
 
     /// Sanitization flags for the Swift compiler.
     public func compileSwiftFlags() -> [String] {
-        return sanitizers.map({ "-sanitize=\($0.rawValue)" })
+        // UBSan is only available for C family languages
+        return sanitizers.filter{ $0 != .undefined }.map{ $0.flagName }
     }
 
-    /// Sanitization flags for the Swift linker and compiler are the same so far.
-    public func linkSwiftFlags() -> [String] {
-        return compileSwiftFlags()
+    /// Sanitization flags for the linker
+    public func linkFlags() -> [String] {
+        return sanitizers.map{ $0.flagName }
     }
 
     public var isEmpty: Bool {
@@ -61,5 +68,6 @@ 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"),
     ])
 }