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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:18:25 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 13:18:25 +0000 |
commit | 109be507377fe7f6e8819ac94041d3fdcdf6fd2f (patch) | |
tree | 2806a689f8fab4a2ec9fc949830ef270a91d667d /test/escape_array.go | |
parent | Initial commit. (diff) | |
download | golang-1.19-109be507377fe7f6e8819ac94041d3fdcdf6fd2f.tar.xz golang-1.19-109be507377fe7f6e8819ac94041d3fdcdf6fd2f.zip |
Adding upstream version 1.19.8.upstream/1.19.8upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'test/escape_array.go')
-rw-r--r-- | test/escape_array.go | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/test/escape_array.go b/test/escape_array.go new file mode 100644 index 0000000..83062c9 --- /dev/null +++ b/test/escape_array.go @@ -0,0 +1,129 @@ +// errorcheck -0 -m -l + +// 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 escape analysis for arrays and some large things + +package foo + +var Ssink *string + +type U [2]*string + +func bar(a, b *string) U { // ERROR "leaking param: a to result ~r0 level=0$" "leaking param: b to result ~r0 level=0$" + return U{a, b} +} + +func foo(x U) U { // ERROR "leaking param: x to result ~r0 level=0$" + return U{x[1], x[0]} +} + +func bff(a, b *string) U { // ERROR "leaking param: a to result ~r0 level=0$" "leaking param: b to result ~r0 level=0$" + return foo(foo(bar(a, b))) +} + +func tbff1() *string { + a := "cat" + b := "dog" // ERROR "moved to heap: b$" + u := bff(&a, &b) + _ = u[0] + return &b +} + +// BAD: need fine-grained analysis to track u[0] and u[1] differently. +func tbff2() *string { + a := "cat" // ERROR "moved to heap: a$" + b := "dog" // ERROR "moved to heap: b$" + u := bff(&a, &b) + _ = u[0] + return u[1] +} + +func car(x U) *string { // ERROR "leaking param: x to result ~r0 level=0$" + return x[0] +} + +// BAD: need fine-grained analysis to track x[0] and x[1] differently. +func fun(x U, y *string) *string { // ERROR "leaking param: x to result ~r0 level=0$" "leaking param: y to result ~r0 level=0$" + x[0] = y + return x[1] +} + +func fup(x *U, y *string) *string { // ERROR "leaking param: x to result ~r0 level=1$" "leaking param: y$" + x[0] = y // leaking y to heap is intended + return x[1] +} + +func fum(x *U, y **string) *string { // ERROR "leaking param: x to result ~r0 level=1$" "leaking param content: y$" + x[0] = *y + return x[1] +} + +func fuo(x *U, y *U) *string { // ERROR "leaking param: x to result ~r0 level=1$" "leaking param content: y$" + x[0] = y[0] + return x[1] +} + +// These two tests verify that: +// small array literals are stack allocated; +// pointers stored in small array literals do not escape; +// large array literals are heap allocated; +// pointers stored in large array literals escape. +func hugeLeaks1(x **string, y **string) { // ERROR "leaking param content: x" "y does not escape" + a := [10]*string{*y} + _ = a + // 4 x 4,000,000 exceeds MaxStackVarSize, therefore it must be heap allocated if pointers are 4 bytes or larger. + b := [4000000]*string{*x} // ERROR "moved to heap: b" + _ = b +} + +func hugeLeaks2(x *string, y *string) { // ERROR "leaking param: x" "y does not escape" + a := [10]*string{y} + _ = a + // 4 x 4,000,000 exceeds MaxStackVarSize, therefore it must be heap allocated if pointers are 4 bytes or larger. + b := [4000000]*string{x} // ERROR "moved to heap: b" + _ = b +} + +// BAD: x need not leak. +func doesNew1(x *string, y *string) { // ERROR "leaking param: x" "leaking param: y" + a := new([10]*string) // ERROR "new\(\[10\]\*string\) does not escape" + a[0] = x + b := new([65537]*string) // ERROR "new\(\[65537\]\*string\) escapes to heap" + b[0] = y +} + +type a10 struct { + s *string + i [10]int32 +} + +type a65537 struct { + s *string + i [65537]int32 +} + +// BAD: x need not leak. +func doesNew2(x *string, y *string) { // ERROR "leaking param: x" "leaking param: y" + a := new(a10) // ERROR "new\(a10\) does not escape" + a.s = x + b := new(a65537) // ERROR "new\(a65537\) escapes to heap" + b.s = y +} + +// BAD: x need not leak. +func doesMakeSlice(x *string, y *string) { // ERROR "leaking param: x" "leaking param: y" + a := make([]*string, 10) // ERROR "make\(\[\]\*string, 10\) does not escape" + a[0] = x + b := make([]*string, 65537) // ERROR "make\(\[\]\*string, 65537\) escapes to heap" + b[0] = y +} + +func nonconstArray() { + n := 32 + s1 := make([]int, n) // ERROR "make\(\[\]int, n\) escapes to heap" + s2 := make([]int, 0, n) // ERROR "make\(\[\]int, 0, n\) escapes to heap" + _, _ = s1, s2 +} |