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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>
70 lines
2.2 KiB
Go
70 lines
2.2 KiB
Go
// errorcheck -0 -m -l
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// Copyright 2019 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 for unsafe.Pointer rules.
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package escape
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import (
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"reflect"
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"unsafe"
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)
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// (1) Conversion of a *T1 to Pointer to *T2.
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func convert(p *float64) *uint64 { // ERROR "leaking param: p to result ~r0 level=0$"
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return (*uint64)(unsafe.Pointer(p))
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}
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// (3) Conversion of a Pointer to a uintptr and back, with arithmetic.
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func arithAdd() unsafe.Pointer {
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var x [2]byte // ERROR "moved to heap: x"
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return unsafe.Pointer(uintptr(unsafe.Pointer(&x[0])) + 1)
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}
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func arithSub() unsafe.Pointer {
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var x [2]byte // ERROR "moved to heap: x"
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return unsafe.Pointer(uintptr(unsafe.Pointer(&x[1])) - 1)
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}
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func arithMask() unsafe.Pointer {
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var x [2]byte // ERROR "moved to heap: x"
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return unsafe.Pointer(uintptr(unsafe.Pointer(&x[1])) &^ 1)
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}
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// (5) Conversion of the result of reflect.Value.Pointer or
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// reflect.Value.UnsafeAddr from uintptr to Pointer.
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// BAD: should be "leaking param: p to result ~r0 level=0$"
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func valuePointer(p *int) unsafe.Pointer { // ERROR "leaking param: p$"
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return unsafe.Pointer(reflect.ValueOf(p).Pointer())
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}
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// BAD: should be "leaking param: p to result ~r0 level=0$"
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func valueUnsafeAddr(p *int) unsafe.Pointer { // ERROR "leaking param: p$"
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return unsafe.Pointer(reflect.ValueOf(p).Elem().UnsafeAddr())
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}
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// (6) Conversion of a reflect.SliceHeader or reflect.StringHeader
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// Data field to or from Pointer.
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func fromSliceData(s []int) unsafe.Pointer { // ERROR "leaking param: s to result ~r0 level=0$"
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return unsafe.Pointer((*reflect.SliceHeader)(unsafe.Pointer(&s)).Data)
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}
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func fromStringData(s string) unsafe.Pointer { // ERROR "leaking param: s to result ~r0 level=0$"
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return unsafe.Pointer((*reflect.StringHeader)(unsafe.Pointer(&s)).Data)
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}
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func toSliceData(s *[]int, p unsafe.Pointer) { // ERROR "s does not escape" "leaking param: p$"
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(*reflect.SliceHeader)(unsafe.Pointer(s)).Data = uintptr(p)
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}
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func toStringData(s *string, p unsafe.Pointer) { // ERROR "s does not escape" "leaking param: p$"
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(*reflect.SliceHeader)(unsafe.Pointer(s)).Data = uintptr(p)
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}
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