Source file test/inline.go

     1  // errorcheck -0 -m -d=inlfuncswithclosures=1
     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  // Test, using compiler diagnostic flags, that inlining is working.
     8  // Compiles but does not run.
     9  
    10  package foo
    11  
    12  import (
    13  	"runtime"
    14  	"unsafe"
    15  )
    16  
    17  func add2(p *byte, n uintptr) *byte { // ERROR "can inline add2" "leaking param: p to result"
    18  	return (*byte)(add1(unsafe.Pointer(p), n)) // ERROR "inlining call to add1"
    19  }
    20  
    21  func add1(p unsafe.Pointer, x uintptr) unsafe.Pointer { // ERROR "can inline add1" "leaking param: p to result"
    22  	return unsafe.Pointer(uintptr(p) + x)
    23  }
    24  
    25  func f(x *byte) *byte { // ERROR "can inline f" "leaking param: x to result"
    26  	return add2(x, 1) // ERROR "inlining call to add2" "inlining call to add1"
    27  }
    28  
    29  //go:noinline
    30  func g(x int) int {
    31  	return x + 1
    32  }
    33  
    34  func h(x int) int { // ERROR "can inline h"
    35  	return x + 2
    36  }
    37  
    38  func i(x int) int { // ERROR "can inline i"
    39  	const y = 2
    40  	return x + y
    41  }
    42  
    43  func j(x int) int { // ERROR "can inline j"
    44  	switch {
    45  	case x > 0:
    46  		return x + 2
    47  	default:
    48  		return x + 1
    49  	}
    50  }
    51  
    52  func _() int { // ERROR "can inline _"
    53  	tmp1 := h
    54  	tmp2 := tmp1
    55  	return tmp2(0) // ERROR "inlining call to h"
    56  }
    57  
    58  var somethingWrong error
    59  
    60  // local closures can be inlined
    61  func l(x, y int) (int, int, error) { // ERROR "can inline l"
    62  	e := func(err error) (int, int, error) { // ERROR "can inline l.func1" "func literal does not escape" "leaking param: err to result"
    63  		return 0, 0, err
    64  	}
    65  	if x == y {
    66  		e(somethingWrong) // ERROR "inlining call to l.func1"
    67  	} else {
    68  		f := e
    69  		f(nil) // ERROR "inlining call to l.func1"
    70  	}
    71  	return y, x, nil
    72  }
    73  
    74  // any re-assignment prevents closure inlining
    75  func m() int {
    76  	foo := func() int { return 1 } // ERROR "can inline m.func1" "func literal does not escape"
    77  	x := foo()
    78  	foo = func() int { return 2 } // ERROR "can inline m.func2" "func literal does not escape"
    79  	return x + foo()
    80  }
    81  
    82  // address taking prevents closure inlining
    83  func n() int {
    84  	foo := func() int { return 1 } // ERROR "can inline n.func1" "func literal does not escape"
    85  	bar := &foo
    86  	x := (*bar)() + foo()
    87  	return x
    88  }
    89  
    90  // make sure assignment inside closure is detected
    91  func o() int {
    92  	foo := func() int { return 1 } // ERROR "can inline o.func1" "func literal does not escape"
    93  	func(x int) {                  // ERROR "can inline o.func2"
    94  		if x > 10 {
    95  			foo = func() int { return 2 } // ERROR "func literal does not escape" "can inline o.func2"
    96  		}
    97  	}(11) // ERROR "inlining call to o.func2"
    98  	return foo()
    99  }
   100  
   101  func p() int { // ERROR "can inline p"
   102  	return func() int { return 42 }() // ERROR "can inline p.func1" "inlining call to p.func1"
   103  }
   104  
   105  func q(x int) int { // ERROR "can inline q"
   106  	foo := func() int { return x * 2 } // ERROR "can inline q.func1" "func literal does not escape"
   107  	return foo()                       // ERROR "inlining call to q.func1"
   108  }
   109  
   110  func r(z int) int {
   111  	foo := func(x int) int { // ERROR "can inline r.func1" "func literal does not escape"
   112  		return x + z
   113  	}
   114  	bar := func(x int) int { // ERROR "func literal does not escape" "can inline r.func2"
   115  		return x + func(y int) int { // ERROR "can inline r.func2.1" "can inline r.func3"
   116  			return 2*y + x*z
   117  		}(x) // ERROR "inlining call to r.func2.1"
   118  	}
   119  	return foo(42) + bar(42) // ERROR "inlining call to r.func1" "inlining call to r.func2" "inlining call to r.func3"
   120  }
   121  
   122  func s0(x int) int { // ERROR "can inline s0"
   123  	foo := func() { // ERROR "can inline s0.func1" "func literal does not escape"
   124  		x = x + 1
   125  	}
   126  	foo() // ERROR "inlining call to s0.func1"
   127  	return x
   128  }
   129  
   130  func s1(x int) int { // ERROR "can inline s1"
   131  	foo := func() int { // ERROR "can inline s1.func1" "func literal does not escape"
   132  		return x
   133  	}
   134  	x = x + 1
   135  	return foo() // ERROR "inlining call to s1.func1"
   136  }
   137  
   138  // can't currently inline functions with a break statement
   139  func switchBreak(x, y int) int {
   140  	var n int
   141  	switch x {
   142  	case 0:
   143  		n = 1
   144  	Done:
   145  		switch y {
   146  		case 0:
   147  			n += 10
   148  			break Done
   149  		}
   150  		n = 2
   151  	}
   152  	return n
   153  }
   154  
   155  func switchType(x interface{}) int { // ERROR "can inline switchType" "x does not escape"
   156  	switch x.(type) {
   157  	case int:
   158  		return x.(int)
   159  	default:
   160  		return 0
   161  	}
   162  }
   163  
   164  type T struct{}
   165  
   166  func (T) meth(int, int) {} // ERROR "can inline T.meth"
   167  
   168  func k() (T, int, int) { return T{}, 0, 0 } // ERROR "can inline k"
   169  
   170  func _() { // ERROR "can inline _"
   171  	T.meth(k()) // ERROR "inlining call to k" "inlining call to T.meth"
   172  }
   173  
   174  func small1() { // ERROR "can inline small1"
   175  	runtime.GC()
   176  }
   177  func small2() int { // ERROR "can inline small2"
   178  	return runtime.GOMAXPROCS(0)
   179  }
   180  func small3(t T) { // ERROR "can inline small3"
   181  	t.meth2(3, 5)
   182  }
   183  func small4(t T) { // not inlineable - has 2 calls.
   184  	t.meth2(runtime.GOMAXPROCS(0), 5)
   185  }
   186  func (T) meth2(int, int) { // not inlineable - has 2 calls.
   187  	runtime.GC()
   188  	runtime.GC()
   189  }
   190  
   191  // Issue #29737 - make sure we can do inlining for a chain of recursive functions
   192  func ee() { // ERROR "can inline ee"
   193  	ff(100) // ERROR "inlining call to ff" "inlining call to gg" "inlining call to hh"
   194  }
   195  
   196  func ff(x int) { // ERROR "can inline ff"
   197  	if x < 0 {
   198  		return
   199  	}
   200  	gg(x - 1)
   201  }
   202  func gg(x int) { // ERROR "can inline gg"
   203  	hh(x - 1)
   204  }
   205  func hh(x int) { // ERROR "can inline hh"
   206  	ff(x - 1) // ERROR "inlining call to ff"  // ERROR "inlining call to gg"
   207  }
   208  
   209  // Issue #14768 - make sure we can inline for loops.
   210  func for1(fn func() bool) { // ERROR "can inline for1" "fn does not escape"
   211  	for {
   212  		if fn() {
   213  			break
   214  		} else {
   215  			continue
   216  		}
   217  	}
   218  }
   219  
   220  // BAD: for2 should be inlineable too.
   221  func for2(fn func() bool) { // ERROR "fn does not escape"
   222  Loop:
   223  	for {
   224  		if fn() {
   225  			break Loop
   226  		} else {
   227  			continue Loop
   228  		}
   229  	}
   230  }
   231  
   232  // Issue #18493 - make sure we can do inlining of functions with a method value
   233  type T1 struct{}
   234  
   235  func (a T1) meth(val int) int { // ERROR "can inline T1.meth" "inlining call to T1.meth"
   236  	return val + 5
   237  }
   238  
   239  func getMeth(t1 T1) func(int) int { // ERROR "can inline getMeth"
   240  	return t1.meth // ERROR "t1.meth escapes to heap"
   241  }
   242  
   243  func ii() { // ERROR "can inline ii"
   244  	var t1 T1
   245  	f := getMeth(t1) // ERROR "inlining call to getMeth" "t1.meth does not escape"
   246  	_ = f(3)
   247  }
   248  
   249  // Issue #42194 - make sure that functions evaluated in
   250  // go and defer statements can be inlined.
   251  func gd1(int) {
   252  	defer gd1(gd2()) // ERROR "inlining call to gd2"
   253  	defer gd3()()    // ERROR "inlining call to gd3"
   254  	go gd1(gd2())    // ERROR "inlining call to gd2"
   255  	go gd3()()       // ERROR "inlining call to gd3"
   256  }
   257  
   258  func gd2() int { // ERROR "can inline gd2"
   259  	return 1
   260  }
   261  
   262  func gd3() func() { // ERROR "can inline gd3"
   263  	return ii
   264  }
   265  
   266  // Issue #42788 - ensure ODEREF OCONVNOP* OADDR is low cost.
   267  func EncodeQuad(d []uint32, x [6]float32) { // ERROR "can inline EncodeQuad" "d does not escape"
   268  	_ = d[:6]
   269  	d[0] = float32bits(x[0]) // ERROR "inlining call to float32bits"
   270  	d[1] = float32bits(x[1]) // ERROR "inlining call to float32bits"
   271  	d[2] = float32bits(x[2]) // ERROR "inlining call to float32bits"
   272  	d[3] = float32bits(x[3]) // ERROR "inlining call to float32bits"
   273  	d[4] = float32bits(x[4]) // ERROR "inlining call to float32bits"
   274  	d[5] = float32bits(x[5]) // ERROR "inlining call to float32bits"
   275  }
   276  
   277  // float32bits is a copy of math.Float32bits to ensure that
   278  // these tests pass with `-gcflags=-l`.
   279  func float32bits(f float32) uint32 { // ERROR "can inline float32bits"
   280  	return *(*uint32)(unsafe.Pointer(&f))
   281  }
   282  
   283  // Ensure OCONVNOP is zero cost.
   284  func Conv(v uint64) uint64 { // ERROR "can inline Conv"
   285  	return conv2(conv2(conv2(v))) // ERROR "inlining call to (conv1|conv2)"
   286  }
   287  func conv2(v uint64) uint64 { // ERROR "can inline conv2"
   288  	return conv1(conv1(conv1(conv1(v)))) // ERROR "inlining call to conv1"
   289  }
   290  func conv1(v uint64) uint64 { // ERROR "can inline conv1"
   291  	return uint64(uint64(uint64(uint64(uint64(uint64(uint64(uint64(uint64(uint64(uint64(v)))))))))))
   292  }
   293  

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