| // RUN: %target-swift-emit-silgen %s -verify |
| // REQUIRES: asserts |
| |
| // TF-881: User-defined Swift derivative functions cannot capture local values. |
| // Captured local values become extra SIL function arguments, breaking the |
| // expected derivative function type logic. |
| // |
| // In the short term, we should diagnose these cases to prevent crashes. |
| // In the long term, we should investigate supporting these cases. |
| |
| do { |
| let capturedValue: Int = 3 |
| |
| func original(_ x: Float) -> Float { x } |
| |
| // expected-error @+1 {{attribute '@derivative' can only be used in a non-local scope}} |
| @derivative(of: original) |
| func vjp(_ x: Float) -> (value: Float, pullback: (Float) -> Float) { |
| // Reference a local variable. |
| // This causes the top-level SIL function @vjp to have extra arguments. |
| _ = capturedValue |
| return (x, { $0 }) |
| } |
| } |
| |
| // Original crasher: |
| // SIL verification failed: apply doesn't have right number of arguments for function: site.getNumArguments() == substConv.getNumSILArguments() |
| // Verifying instruction: |
| // %0 = argument of bb0 : $Float // user: %2 |
| // // function_ref vjp #1 (_:) in |
| // %1 = function_ref @$s4main3vjpL_ySf5value_S2fc8pullbacktSfF : $@convention(thin) (Float, Int) -> (Float, @owned @callee_guaranteed (Float) -> Float) // user: %2 |
| // -> %2 = apply %1(%0) : $@convention(thin) (Float, Int) -> (Float, @owned @callee_guaranteed (Float) -> Float) // user: %3 |
| // return %2 : $(Float, @callee_guaranteed (Float) -> Float) // id: %3 |
| // In function: |
| // // AD__$s4main8originalL_yS2fF__vjp_src_0_wrt_0 |
| // sil hidden [always_inline] [ossa] @AD__$s4main8originalL_yS2fF__vjp_src_0_wrt_0 : $@convention(thin) (Float) -> (Float, @owned @callee_guaranteed (Float) -> Float) { |
| // // %0 // user: %2 |
| // bb0(%0 : $Float): |
| // // function_ref vjp #1 (_:) in |
| // %1 = function_ref @$s4main3vjpL_ySf5value_S2fc8pullbacktSfF : $@convention(thin) (Float, Int) -> (Float, @owned @callee_guaranteed (Float) -> Float) // user: %2 |
| // %2 = apply %1(%0) : $@convention(thin) (Float, Int) -> (Float, @owned @callee_guaranteed (Float) -> Float) // user: %3 |
| // return %2 : $(Float, @callee_guaranteed (Float) -> Float) // id: %3 |
| // } // end sil function 'AD__$s4main8originalL_yS2fF__vjp_src_0_wrt_0' |
