issue13273.go

     1  // errorcheck
     2  
     3  // Copyright 2015 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // Check that we correctly construct (and report errors)
     8  // for unary expressions of the form <-x where we only
     9  // know after parsing x whether <-x is a receive operation
    10  // or a channel type.
    11  
    12  package n
    13  
    14  func f() {
    15  	// test case from issue 13273
    16  	<-chan int((chan int)(nil))
    17  
    18  	<-chan int(nil)
    19  	<-chan chan int(nil)
    20  	<-chan chan chan int(nil)
    21  	<-chan chan chan chan int(nil)
    22  	<-chan chan chan chan chan int(nil)
    23  
    24  	<-chan<-chan int(nil)
    25  	<-chan<-chan<-chan int(nil)
    26  	<-chan<-chan<-chan<-chan int(nil)
    27  	<-chan<-chan<-chan<-chan<-chan int(nil)
    28  
    29  	<-chan (<-chan int)(nil)
    30  	<-chan (<-chan (<-chan int))(nil)
    31  	<-chan (<-chan (<-chan (<-chan int)))(nil)
    32  	<-chan (<-chan (<-chan (<-chan (<-chan int))))(nil)
    33  
    34  	<-(<-chan int)(nil)
    35  	<-(<-chan chan int)(nil)
    36  	<-(<-chan chan chan int)(nil)
    37  	<-(<-chan chan chan chan int)(nil)
    38  	<-(<-chan chan chan chan chan int)(nil)
    39  
    40  	<-(<-chan<-chan int)(nil)
    41  	<-(<-chan<-chan<-chan int)(nil)
    42  	<-(<-chan<-chan<-chan<-chan int)(nil)
    43  	<-(<-chan<-chan<-chan<-chan<-chan int)(nil)
    44  
    45  	<-(<-chan (<-chan int))(nil)
    46  	<-(<-chan (<-chan (<-chan int)))(nil)
    47  	<-(<-chan (<-chan (<-chan (<-chan int))))(nil)
    48  	<-(<-chan (<-chan (<-chan (<-chan (<-chan int)))))(nil)
    49  
    50  	type _ <-<-chan int // ERROR "unexpected <-, expected chan|expected .*chan.*"
    51  	<-<-chan int // ERROR "unexpected <-, expected chan|expecting {" (new parser: same error as for type decl)
    52  
    53  	type _ <-chan<-int // ERROR "unexpected int, expected chan|expected .*chan.*|expected chan|expected .*;.* or .*}.* or newline"
    54  	<-chan<-int // ERROR "unexpected int, expected chan|expecting {" (new parser: same error as for type decl)
    55  }
    56
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