Add type checker performance tests.

Add type checker performance tests under
validation-test/Sema/type_checker_perf.

Under ./fast/ we have tests that compile reasonably quickly now but at
one point did not.

Under ./slow/ we have tests that are still very slow to compile.

Some tests use %scale-test and others
-solver-expression-time-threshold to determine if they are scaling
well or compiling fast enough.

I've got several more tests gathered that have not yet been set up to
run in our test system. Those are forthcoming!

Further contributions welcome.

Thanks go to @xedin who helped collect most of the test cases.

Author: rudkx

validation-test/Sema/type_checker_perf/fast/rdar17077404.swift

@@ -0,0 +1,23 @@
+// RUN: %target-typecheck-verify-swift -solver-expression-time-threshold=1
+// REQUIRES: tools-release,no_asserts
+
+func memoize<A: Hashable, R>(
+  f: @escaping ((A) -> R, A) -> R
+) -> ((A) -> R) {
+  var memo = Dictionary<A,R>()
+
+  var recur: ((A) -> R)!
+  recur = { (a: A) -> R in
+    if let r = memo[a] { return r }
+    let r = f(recur, a)
+    memo[a] = r
+    return r
+  }
+
+  return recur
+}
+
+let fibonacci = memoize {
+  (fibonacci, n) in
+  n < 2 ? n as Int : fibonacci(n - 1) + fibonacci(n - 2)
+}

validation-test/Sema/type_checker_perf/fast/rdar19029974.swift

@@ -0,0 +1,19 @@
+// RUN: %target-typecheck-verify-swift -solver-expression-time-threshold=1
+// REQUIRES: tools-release,no_asserts
+
+infix operator <*> : AdditionPrecedence
+func <*><A, B>(lhs: ((A) -> B)?, rhs: A?) -> B? {
+  if let lhs1 = lhs, let rhs1 = rhs {
+    return lhs1(rhs1)
+  }
+  return nil
+}
+
+func cons<T, U>(lhs: T) -> (U) -> (T, U) {
+   return { rhs in (lhs, rhs) }
+}
+
+var str: String? = "x"
+if let f = cons <*> str <*> (cons <*> str <*> (cons <*> str <*> (cons <*> str <*> (cons <*> str <*> (cons <*> str <*> (cons <*> str <*> str)))))) {
+   print("\(f)")
+}

validation-test/Sema/type_checker_perf/slow/rdar17024694.swift

@@ -0,0 +1,8 @@
+// RUN: %target-typecheck-verify-swift -solver-expression-time-threshold=1
+// REQUIRES: tools-release,no_asserts
+
+2...100.reversed().filter({ $0 % 11 == 0 }).map {
+  // expected-error@-1 {{expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions}}
+  "\($0) bottles of beer on the wall, \($0) bottles of beer;\n"
+  + "  take eleven down, pass 'em around, \($0-11) bottles of beer on the wall!"
+}

validation-test/Sema/type_checker_perf/slow/rdar17170728.swift

@@ -0,0 +1,11 @@
+// RUN: %target-typecheck-verify-swift -solver-expression-time-threshold=1
+// REQUIRES: tools-release,no_asserts
+
+let i: Int? = 1
+let j: Int?
+let k: Int? = 2
+
+let _ = [i, j, k].reduce(0 as Int?) {
+  // expected-error@-1 {{expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions}}
+  $0 != nil && $1 != nil ? $0! + $1! : ($0 != nil ? $0! : ($1 != nil ? $1! : nil))
+}

validation-test/Sema/type_checker_perf/slow/rdar18360240.swift.gyb

@@ -0,0 +1,10 @@
+// RUN: not %scale-test --begin 1 --end 3 --step 1 --select incrementScopeCounter %s
+// REQUIRES: OS=macosx
+// REQUIRES: asserts
+
+let empty: [Int] = []
+let _ = empty +
+%for i in range(0, N):
+    empty +
+%end
+    empty

validation-test/Sema/type_checker_perf/slow/rdar18699199.swift.gyb

@@ -0,0 +1,17 @@
+// RUN: not %scale-test --begin 1 --end 3 --step 1 --select incrementScopeCounter %s
+// REQUIRES: OS=macosx
+// REQUIRES: asserts
+public enum E
+{
+    case First,
+%for i in range(0, N):
+    C${i},
+%end
+    End
+
+    static let toRawValues = [
+%for i in range(0, N):
+    C${i}: String("hi"),
+%end
+    ]
+}

validation-test/Sema/type_checker_perf/slow/rdar18724501.swift

@@ -0,0 +1,12 @@
+// RUN: not %scale-test --begin 1 --end 3 --step 1 --select incrementScopeCounter %s
+// REQUIRES: OS=macosx
+// REQUIRES: asserts
+
+typealias X = (Range<Int>, [Range<Int>])
+
+let samples: ContiguousArray<X> = [
+  (0..<1, [ 1..<1, 2..<3 ]),
+%for i in range(0, N):
+  (0..<1, [ 1..<1, 2..<3 ]),
+%end
+]

validation-test/Sema/type_checker_perf/slow/rdar18800950.swift

@@ -0,0 +1,11 @@
+// RUN: %target-typecheck-verify-swift -solver-expression-time-threshold=1
+// REQUIRES: tools-release,no_asserts
+
+// Mixed Float and Double arithmetic
+func rdar18800950(v: Float) -> Double {
+  let c1: Float = 1.0
+  let c2 = 2.0
+  let r = v / c1
+  let _ = (c2 * 2 * (3 * (1 - c1 / v) - 4) * r + 5) * (c2 * 2 * (3 * (1 - c1 / v) - 4) * r + 5)
+  // expected-error@-1 {{expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions}}
+}

validation-test/Sema/type_checker_perf/slow/rdar19181998.swift.gyb

@@ -0,0 +1,14 @@
+// RUN: not %scale-test --begin 1 --end 4 --step 1 --select incrementScopeCounter %s
+// REQUIRES: OS=macosx
+// REQUIRES: asserts
+
+public func test(_ fn: @escaping () -> Void) {}
+
+test {
+  let _: Set<Set<Int>> = Set([
+      Set([1]),
+%for i in range(0, N):
+      Set([1]),
+%end
+    ])
+}

validation-test/Sema/type_checker_perf/slow/rdar19368383.swift

@@ -0,0 +1,16 @@
+// RUN: %target-typecheck-verify-swift -solver-expression-time-threshold=1
+// REQUIRES: tools-release,no_asserts
+
+// Missing force of optional result of dictionary lookup.
+func rdar19368383(d: [String : String]) -> [String] {
+  var r = [String]()
+  r += [ // expected-error {{expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions}}
+    "1" + d["2"] + "3",
+    "1" + d["2"] + "3",
+    "1" + d["2"] + "3",
+    "1" + d["2"] + "3",
+    "1" + d["2"] + "3",
+    "1" + d["2"] + "3",
+  ]
+  return r
+}