[test] add ABI validation for the internals of sort()

Author: glessard

validation-test/stdlib/Sort-ABI.swift

@@ -0,0 +1,76 @@
+// RUN: %target-run-stdlib-swift
+// REQUIRES: executable_test
+
+import StdlibUnittest
+
+var SortABITestSuite =  TestSuite("SortABI")
+
+SortABITestSuite.test("_merge-ABI") {
+  let result = withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+    buffer -> Bool in
+    _ = buffer.initialize(from: 0..<10)
+    return withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+      _merge(
+        low: buffer.baseAddress! + 5,
+        mid: buffer.baseAddress! + 8,
+        high: buffer.baseAddress! + 9,
+        buffer: $0.baseAddress!,
+        by: <
+      )
+    }
+  }
+  // The return value is legacy ABI. It was originally added as a
+  // workaround for a compiler bug (now fixed). See SR-14750 (rdar://45044610).
+  // `_merge` always returns `true`
+  expectEqual(result, true)
+}
+
+SortABITestSuite.test("_mergeRuns-ABI") {
+  let result = withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+    temp -> Bool in
+    _ = temp.initialize(from: 0..<10)
+    var buffer = temp
+    var runs = [5..<8, 8..<9]
+    return withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+      buffer._mergeRuns(&runs, at: 1, buffer: $0.baseAddress!, by: <)
+    }
+  }
+  // The return value is legacy ABI. It was originally added as a
+  // workaround for a compiler bug (now fixed). See SR-14750 (rdar://45044610).
+  // `_mergeRuns` always returns `true`
+  expectEqual(result, true)
+}
+
+SortABITestSuite.test("_mergeTopRuns-ABI") {
+  let result = withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+    temp -> Bool in
+    _ = temp.initialize(from: 0..<10)
+    var buffer = temp
+    var runs = [5..<8, 8..<9]
+    return withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+      buffer._mergeTopRuns(&runs, buffer: $0.baseAddress!, by: <)
+    }
+  }
+  // The return value is legacy ABI. It was originally added as a
+  // workaround for a compiler bug (now fixed). See SR-14750 (rdar://45044610).
+  // `_mergeTopRuns` always returns `true`
+  expectEqual(result, true)
+}
+
+SortABITestSuite.test("_finalizeRuns-ABI") {
+  let result = withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+    temp -> Bool in
+    _ = temp.initialize(from: 0..<10)
+    var buffer = temp
+    var runs = [5..<8, 8..<9]
+    return withUnsafeTemporaryAllocation(of: Int.self, capacity: 10) {
+      buffer._finalizeRuns(&runs, buffer: $0.baseAddress!, by: <)
+    }
+  }
+  // The return value is legacy ABI. It was originally added as a
+  // workaround for a compiler bug (now fixed). See SR-14750 (rdar://45044610).
+  // `_finalizeRuns` always returns `true`
+  expectEqual(result, true)
+}
+
+runAllTests()