// RUN: cir-opt %s -cir-flatten-cfg -o %t.cir
// RUN: FileCheck --input-file=%t.cir %s

// Regression test: catch handler whose cleanup scope body contains a
// nested try.  After inner flattening, the normal and catch paths
// merge at a multi-predecessor block before reaching end_catch and
// the handler's yield.  The end_catch assertion must handle
// multi-predecessor blocks when walking backward from the yield.

!s32i = !cir.int<s, 32>
!u8i = !cir.int<u, 8>
!void = !cir.void

cir.func private @may_throw()
cir.func private @inner_may_throw()

cir.func @test_catch_with_nested_try() {
  cir.scope {
    cir.try {
      cir.call @may_throw() : () -> ()
      cir.yield
    } catch all (%eh_token : !cir.eh_token) {
      %catch_token, %exn_ptr = cir.begin_catch %eh_token : !cir.eh_token -> (!cir.catch_token, !cir.ptr<!cir.void>)
      cir.cleanup.scope {
        cir.try {
          cir.call @inner_may_throw() : () -> ()
          cir.yield
        } catch all (%inner_eh : !cir.eh_token) {
          %inner_ct, %inner_ep = cir.begin_catch %inner_eh : !cir.eh_token -> (!cir.catch_token, !cir.ptr<!cir.void>)
          cir.cleanup.scope {
            cir.yield
          } cleanup all {
            cir.end_catch %inner_ct : !cir.catch_token
            cir.yield
          }
          cir.yield
        }
        cir.yield
      } cleanup all {
        cir.end_catch %catch_token : !cir.catch_token
        cir.yield
      }
      cir.yield
    }
  }
  cir.return
}

// Verify that flattening succeeds and produces the expected structure:
// outer try_call, dispatch to catch handler, inner try_call inside
// the catch handler, end_catch for both inner and outer catches,
// and branches to the continue block.

// CHECK-LABEL: cir.func @test_catch_with_nested_try()
// CHECK:         cir.try_call @may_throw()
// CHECK:       ^{{bb[0-9]+}}(%{{.*}}: !cir.eh_token):
// CHECK:         cir.begin_catch
// CHECK:         cir.try_call @inner_may_throw()
// CHECK:         cir.begin_catch
// CHECK:         cir.end_catch
// CHECK:         cir.end_catch
// CHECK:         cir.return