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Source file test/inline.go

Documentation: test

  // errorcheck -0 -m
  
  // Copyright 2015 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  // Test, using compiler diagnostic flags, that inlining is working.
  // Compiles but does not run.
  
  package foo
  
  import (
  	"errors"
  	"unsafe"
  )
  
  func add2(p *byte, n uintptr) *byte { // ERROR "can inline add2" "leaking param: p to result"
  	return (*byte)(add1(unsafe.Pointer(p), n)) // ERROR "inlining call to add1"
  }
  
  func add1(p unsafe.Pointer, x uintptr) unsafe.Pointer { // ERROR "can inline add1" "leaking param: p to result"
  	return unsafe.Pointer(uintptr(p) + x)
  }
  
  func f(x *byte) *byte { // ERROR "can inline f" "leaking param: x to result"
  	return add2(x, 1) // ERROR "inlining call to add2" "inlining call to add1"
  }
  
  //go:noinline
  func g(x int) int {
  	return x + 1
  }
  
  func h(x int) int { // ERROR "can inline h"
  	return x + 2
  }
  
  func i(x int) int { // ERROR "can inline i"
  	const y = 2
  	return x + y
  }
  
  func j(x int) int { // ERROR "can inline j"
  	switch {
  	case x > 0:
  		return x + 2
  	default:
  		return x + 1
  	}
  }
  
  var somethingWrong error = errors.New("something went wrong")
  
  // local closures can be inlined
  func l(x, y int) (int, int, error) {
  	e := func(err error) (int, int, error) { // ERROR "can inline l.func1" "func literal does not escape" "leaking param: err to result"
  		return 0, 0, err
  	}
  	if x == y {
  		e(somethingWrong) // ERROR "inlining call to l.func1"
  	}
  	return y, x, nil
  }
  
  // any re-assignment prevents closure inlining
  func m() int {
  	foo := func() int { return 1 } // ERROR "can inline m.func1" "func literal does not escape"
  	x := foo()
  	foo = func() int { return 2 } // ERROR "can inline m.func2" "func literal does not escape"
  	return x + foo()
  }
  
  // address taking prevents closure inlining
  func n() int {
  	foo := func() int { return 1 } // ERROR "can inline n.func1" "func literal does not escape"
  	bar := &foo                    // ERROR "&foo does not escape"
  	x := (*bar)() + foo()
  	return x
  }
  
  // make sure assignment inside closure is detected
  func o() int {
  	foo := func() int { return 1 } // ERROR "can inline o.func1" "func literal does not escape"
  	func(x int) {                  // ERROR "func literal does not escape"
  		if x > 10 {
  			foo = func() int { return 2 } // ERROR "can inline o.func2" "func literal escapes"
  		}
  	}(11)
  	return foo()
  }
  
  func p() int {
  	return func() int { return 42 }() // ERROR "can inline p.func1" "inlining call to p.func1"
  }
  
  func q(x int) int {
  	foo := func() int { return x * 2 } // ERROR "can inline q.func1" "q func literal does not escape"
  	return foo()                       // ERROR "inlining call to q.func1"
  }
  
  func r(z int) int {
  	foo := func(x int) int { // ERROR "can inline r.func1" "r func literal does not escape"
  		return x + z
  	}
  	bar := func(x int) int { // ERROR "r func literal does not escape"
  		return x + func(y int) int { // ERROR "can inline r.func2.1"
  			return 2*y + x*z
  		}(x) // ERROR "inlining call to r.func2.1"
  	}
  	return foo(42) + bar(42) // ERROR "inlining call to r.func1"
  }
  
  func s0(x int) int {
  	foo := func() { // ERROR "can inline s0.func1" "s0 func literal does not escape"
  		x = x + 1
  	}
  	foo() // ERROR "inlining call to s0.func1" "&x does not escape"
  	return x
  }
  
  func s1(x int) int {
  	foo := func() int { // ERROR "can inline s1.func1" "s1 func literal does not escape"
  		return x
  	}
  	x = x + 1
  	return foo() // ERROR "inlining call to s1.func1" "&x does not escape"
  }
  
  // can't currently inline functions with a break statement
  func switchBreak(x, y int) int {
  	var n int
  	switch x {
  	case 0:
  		n = 1
  	Done:
  		switch y {
  		case 0:
  			n += 10
  			break Done
  		}
  		n = 2
  	}
  	return n
  }
  
  // can't currently inline functions with a type switch
  func switchType(x interface{}) int { // ERROR "switchType x does not escape"
  	switch x.(type) {
  	case int:
  		return x.(int)
  	default:
  		return 0
  	}
  }
  
  type T struct{}
  
  func (T) meth(int, int) {} // ERROR "can inline T.meth"
  
  func k() (T, int, int) { return T{}, 0, 0 } // ERROR "can inline k"
  
  func _() { // ERROR "can inline _"
  	T.meth(k()) // ERROR "inlining call to k" "inlining call to T.meth"
  }
  

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