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Diffstat (limited to '')
-rw-r--r-- | test/fixedbugs/issue13799.go | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/test/fixedbugs/issue13799.go b/test/fixedbugs/issue13799.go new file mode 100644 index 0000000..fbdd4c3 --- /dev/null +++ b/test/fixedbugs/issue13799.go @@ -0,0 +1,190 @@ +// 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, using compiler diagnostic flags, that the escape analysis is working. +// Compiles but does not run. Inlining is disabled. +// Registerization is disabled too (-N), which should +// have no effect on escape analysis. + +package main + +import "fmt" + +func main() { + // Just run test over and over again. This main func is just for + // convenience; if test were the main func, we could also trigger + // the panic just by running the program over and over again + // (sometimes it takes 1 time, sometimes it takes ~4,000+). + for iter := 0; ; iter++ { + if iter%50 == 0 { + fmt.Println(iter) // ERROR "iter escapes to heap$" "... argument does not escape$" + } + test1(iter) + test2(iter) + test3(iter) + test4(iter) + test5(iter) + test6(iter) + } +} + +func test1(iter int) { + + const maxI = 500 + m := make(map[int][]int) // ERROR "make\(map\[int\]\[\]int\) escapes to heap$" + + // The panic seems to be triggered when m is modified inside a + // closure that is both recursively called and reassigned to in a + // loop. + + // Cause of bug -- escape of closure failed to escape (shared) data structures + // of map. Assign to fn declared outside of loop triggers escape of closure. + // Heap -> stack pointer eventually causes badness when stack reallocation + // occurs. + + var fn func() // ERROR "moved to heap: fn$" + for i := 0; i < maxI; i++ { // ERROR "moved to heap: i$" + // var fn func() // this makes it work, because fn stays off heap + j := 0 // ERROR "moved to heap: j$" + fn = func() { // ERROR "func literal escapes to heap$" + m[i] = append(m[i], 0) + if j < 25 { + j++ + fn() + } + } + fn() + } + + if len(m) != maxI { + panic(fmt.Sprintf("iter %d: maxI = %d, len(m) = %d", iter, maxI, len(m))) // ERROR "iter escapes to heap$" "len\(m\) escapes to heap$" "maxI escapes to heap$" "... argument does not escape$" + } +} + +func test2(iter int) { + + const maxI = 500 + m := make(map[int][]int) // ERROR "make\(map\[int\]\[\]int\) does not escape$" + + // var fn func() + for i := 0; i < maxI; i++ { + var fn func() // this makes it work, because fn stays off heap + j := 0 + fn = func() { // ERROR "func literal does not escape$" + m[i] = append(m[i], 0) + if j < 25 { + j++ + fn() + } + } + fn() + } + + if len(m) != maxI { + panic(fmt.Sprintf("iter %d: maxI = %d, len(m) = %d", iter, maxI, len(m))) // ERROR "iter escapes to heap$" "len\(m\) escapes to heap$" "maxI escapes to heap$" "... argument does not escape$" + } +} + +func test3(iter int) { + + const maxI = 500 + var x int // ERROR "moved to heap: x$" + m := &x + + var fn func() // ERROR "moved to heap: fn$" + for i := 0; i < maxI; i++ { + // var fn func() // this makes it work, because fn stays off heap + j := 0 // ERROR "moved to heap: j$" + fn = func() { // ERROR "func literal escapes to heap$" + if j < 100 { + j++ + fn() + } else { + *m = *m + 1 + } + } + fn() + } + + if *m != maxI { + panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "maxI escapes to heap$" "... argument does not escape$" + } +} + +func test4(iter int) { + + const maxI = 500 + var x int + m := &x + + // var fn func() + for i := 0; i < maxI; i++ { + var fn func() // this makes it work, because fn stays off heap + j := 0 + fn = func() { // ERROR "func literal does not escape$" + if j < 100 { + j++ + fn() + } else { + *m = *m + 1 + } + } + fn() + } + + if *m != maxI { + panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "maxI escapes to heap$" "... argument does not escape$" + } +} + +type str struct { + m *int +} + +func recur1(j int, s *str) { // ERROR "s does not escape" + if j < 100 { + j++ + recur1(j, s) + } else { + *s.m++ + } +} + +func test5(iter int) { + + const maxI = 500 + var x int // ERROR "moved to heap: x$" + m := &x + + var fn *str + for i := 0; i < maxI; i++ { + // var fn *str // this makes it work, because fn stays off heap + fn = &str{m} // ERROR "&str{...} escapes to heap" + recur1(0, fn) + } + + if *m != maxI { + panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "maxI escapes to heap$" "... argument does not escape$" + } +} + +func test6(iter int) { + + const maxI = 500 + var x int + m := &x + + // var fn *str + for i := 0; i < maxI; i++ { + var fn *str // this makes it work, because fn stays off heap + fn = &str{m} // ERROR "&str{...} does not escape" + recur1(0, fn) + } + + if *m != maxI { + panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "maxI escapes to heap$" "... argument does not escape$" + } +} |