test/SILGen/witnesses_canonical.swift

// RUN: %target-swift-emit-silgen %s | %FileCheck %s

// rdar://problem/20714534 -- we need to canonicalize an associated type's
// protocols when emitting witness method table for a conformance.

protocol _ST {}

protocol ST : _ST {}

protocol _CDT : ST {}

struct _S<T : _CDT> : CT {
  internal init(a: T, b: Int) {}
}

extension _CDT {
  subscript(b: Int) -> _S<Self> {
    return _S(a: self, b: b)
  }
}

protocol CT : ST, _CDT {
  associatedtype _SS : ST, _CDT

  subscript(_bounds: Int) -> _SS { get }
}

// CHECK: sil_witness_table hidden <T where T : _CDT> _S<T>: CT module witnesses_canonical {
// associated_type_protocol (_SS: _CDT): _S<_S<T>>: specialize <T = _S<T>> (<T where T : _CDT> _S<T>: _CDT module witnesses_canonical)

// rdar://problem/21599502 -- make sure we get requirements on
// associated types from protocols we inherit.
protocol P1 { }
protocol P2 { }

protocol Q1 {
  associatedtype Assoc : P1
}

protocol Q2 {
  associatedtype Assoc : P2
}

protocol Q3 : Q1, Q2 {
  associatedtype Assoc
}

struct XP : P1, P2 { }

struct XQ3 : Q3 {
  typealias Assoc = XP
}

// CHECK: sil_witness_table hidden XQ3: Q3 module witnesses_canonical {
// CHECK:  associated_type_protocol (Assoc: P1): XP: P1 module witnesses_canonical
// CHECK:  associated_type_protocol (Assoc: P2): XP: P2 module witnesses_canonical
// CHECK:  associated_type Assoc: XP
// CHECK: }