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![Matthew Dempsky](/assets/img/avatar_default.png)
The compiler renames anonymous and blank result parameters to ~rN or ~bN, but the current semantics for computing N are rather annoying and difficult to reproduce cleanly. They also lead to difficult to read escape analysis results in tests. This CL changes N to always be calculated as the parameter's index within the function's result parameter tuple. E.g., if a function has a single result, it will now always be named "~r0". The normative change to this CL is fairly simple, but it requires updating a lot of test expectations. Change-Id: I58a3c94de00cb822cb94efe52d115531193c993c Reviewed-on: https://go-review.googlesource.com/c/go/+/323010 Trust: Matthew Dempsky <mdempsky@google.com> Trust: Dan Scales <danscales@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>
175 lines
3.8 KiB
Go
175 lines
3.8 KiB
Go
// errorcheck -0 -m -l
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// Copyright 2015 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Test escape analysis through ... parameters.
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package foo
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func FooN(vals ...*int) (s int) { // ERROR "vals does not escape"
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for _, v := range vals {
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s += *v
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}
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return s
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}
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// Append forces heap allocation and copies entries in vals to heap, therefore they escape to heap.
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func FooNx(x *int, vals ...*int) (s int) { // ERROR "leaking param: x" "leaking param content: vals"
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vals = append(vals, x)
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return FooN(vals...)
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}
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var sink []*int
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func FooNy(x *int, vals ...*int) (s int) { // ERROR "leaking param: x" "leaking param: vals"
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vals = append(vals, x)
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sink = vals
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return FooN(vals...)
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}
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func FooNz(vals ...*int) (s int) { // ERROR "leaking param: vals"
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sink = vals
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return FooN(vals...)
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}
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func TFooN() {
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for i := 0; i < 1000; i++ {
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var i, j int
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FooN(&i, &j) // ERROR "... argument does not escape"
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}
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}
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func TFooNx() {
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for i := 0; i < 1000; i++ {
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var i, j, k int // ERROR "moved to heap: i" "moved to heap: j" "moved to heap: k"
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FooNx(&k, &i, &j) // ERROR "... argument does not escape"
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}
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}
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func TFooNy() {
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for i := 0; i < 1000; i++ {
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var i, j, k int // ERROR "moved to heap: i" "moved to heap: j" "moved to heap: k"
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FooNy(&k, &i, &j) // ERROR "... argument escapes to heap"
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}
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}
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func TFooNz() {
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for i := 0; i < 1000; i++ {
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var i, j int // ERROR "moved to heap: i" "moved to heap: j"
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FooNz(&i, &j) // ERROR "... argument escapes to heap"
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}
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}
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var isink *int32
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func FooI(args ...interface{}) { // ERROR "leaking param content: args"
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for i := 0; i < len(args); i++ {
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switch x := args[i].(type) {
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case nil:
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println("is nil")
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case int32:
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println("is int32")
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case *int32:
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println("is *int32")
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isink = x
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case string:
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println("is string")
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}
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}
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}
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func TFooI() {
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a := int32(1) // ERROR "moved to heap: a"
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b := "cat"
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c := &a
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FooI(a, b, c) // ERROR "a escapes to heap" "b escapes to heap" "... argument does not escape"
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}
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func FooJ(args ...interface{}) *int32 { // ERROR "leaking param: args to result ~r0 level=1"
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for i := 0; i < len(args); i++ {
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switch x := args[i].(type) {
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case nil:
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println("is nil")
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case int32:
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println("is int32")
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case *int32:
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println("is *int32")
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return x
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case string:
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println("is string")
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}
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}
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return nil
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}
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func TFooJ1() {
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a := int32(1)
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b := "cat"
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c := &a
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FooJ(a, b, c) // ERROR "a does not escape" "b does not escape" "... argument does not escape"
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}
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func TFooJ2() {
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a := int32(1) // ERROR "moved to heap: a"
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b := "cat"
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c := &a
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isink = FooJ(a, b, c) // ERROR "a escapes to heap" "b escapes to heap" "... argument does not escape"
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}
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type fakeSlice struct {
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l int
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a *[4]interface{}
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}
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func FooK(args fakeSlice) *int32 { // ERROR "leaking param: args to result ~r0 level=1"
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for i := 0; i < args.l; i++ {
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switch x := (*args.a)[i].(type) {
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case nil:
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println("is nil")
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case int32:
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println("is int32")
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case *int32:
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println("is *int32")
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return x
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case string:
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println("is string")
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}
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}
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return nil
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}
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func TFooK2() {
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a := int32(1) // ERROR "moved to heap: a"
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b := "cat"
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c := &a
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fs := fakeSlice{3, &[4]interface{}{a, b, c, nil}} // ERROR "a escapes to heap" "b escapes to heap" "&\[4\]interface {}{...} does not escape"
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isink = FooK(fs)
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}
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func FooL(args []interface{}) *int32 { // ERROR "leaking param: args to result ~r0 level=1"
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for i := 0; i < len(args); i++ {
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switch x := args[i].(type) {
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case nil:
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println("is nil")
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case int32:
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println("is int32")
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case *int32:
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println("is *int32")
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return x
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case string:
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println("is string")
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}
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}
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return nil
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}
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func TFooL2() {
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a := int32(1) // ERROR "moved to heap: a"
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b := "cat"
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c := &a
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s := []interface{}{a, b, c} // ERROR "a escapes to heap" "b escapes to heap" "\[\]interface {}{...} does not escape"
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isink = FooL(s)
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}
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