diff options
| -rw-r--r-- | src/cmd/compile/internal/gc/esc.go | 9 | ||||
| -rw-r--r-- | test/fixedbugs/issue19743.go | 31 |
2 files changed, 39 insertions, 1 deletions
diff --git a/src/cmd/compile/internal/gc/esc.go b/src/cmd/compile/internal/gc/esc.go index 4f37ff0e34..f4a70c4ac6 100644 --- a/src/cmd/compile/internal/gc/esc.go +++ b/src/cmd/compile/internal/gc/esc.go @@ -477,6 +477,10 @@ func escAnalyze(all []*Node, recursive bool) { for _, n := range all { if n.Op == ODCLFUNC { n.Esc = EscFuncPlanned + if Debug['m'] > 3 { + Dump("escAnalyze", n) + } + } } @@ -1675,7 +1679,10 @@ func (e *EscState) escflows(dst, src *Node, why *EscStep) { } // Don't bother building a graph for scalars. - if src.Type != nil && !haspointers(src.Type) { + if src.Type != nil && !haspointers(src.Type) && !isReflectHeaderDataField(src) { + if Debug['m'] > 3 { + fmt.Printf("%v::NOT flows:: %S <- %S\n", linestr(lineno), dst, src) + } return } diff --git a/test/fixedbugs/issue19743.go b/test/fixedbugs/issue19743.go new file mode 100644 index 0000000000..e57b19c8d0 --- /dev/null +++ b/test/fixedbugs/issue19743.go @@ -0,0 +1,31 @@ +// errorcheck -0 -m -l + +// Copyright 2017 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. + +package foo + +// Escape analysis needs to treat the uintptr-typed reflect.*Header fields as pointers. + +import ( + "reflect" + "unsafe" +) + +type immutableBytes []byte + +// Bug was failure to leak param b. +func toString(b immutableBytes) string { // ERROR "leaking param: b$" + var s string + if len(b) == 0 { + return s + } + + strHeader := (*reflect.StringHeader)(unsafe.Pointer(&s)) // ERROR "toString &s does not escape$" + strHeader.Data = (*reflect.SliceHeader)(unsafe.Pointer(&b)).Data // ERROR "toString &b does not escape$" + + l := len(b) + strHeader.Len = l + return s +} |