go/test/escape_calls.go
Matthew Dempsky abefcac10a cmd/compile: skip escape analysis diagnostics for OADDR
For most nodes (e.g., OPTRLIT, OMAKESLICE, OCONVIFACE), escape
analysis prints "escapes to heap" or "does not escape" to indicate
whether that node's allocation can be heap or stack allocated.

These messages are also emitted for OADDR, even though OADDR does not
actually allocate anything itself. Moreover, it's redundant because
escape analysis already prints "moved to heap" diagnostics when an
OADDR node like "&x" causes x to require heap allocation.

Because OADDR nodes don't allocate memory, my escape analysis rewrite
doesn't naturally emit the "escapes to heap" / "does not escape"
diagnostics for them. It's also non-trivial to replicate the exact
semantics esc.go uses for OADDR.

Since there are so many of these messages, I'm disabling them in this
CL by themselves. I modified esc.go to suppress the Warnl calls
without any other behavior changes, and then used a shell script to
automatically remove any ERROR messages mentioned by run.go in
"missing error" or "no match for" lines.

Fixes #16300.
Updates #23109.

Change-Id: I3993e2743c3ff83ccd0893f4e73b366ff8871a57
Reviewed-on: https://go-review.googlesource.com/c/go/+/170319
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
2019-04-02 16:34:03 +00:00

54 lines
1.2 KiB
Go

// 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 function parameters.
// In this test almost everything is BAD except the simplest cases
// where input directly flows to output.
package foo
func f(buf []byte) []byte { // ERROR "leaking param: buf to result ~r1 level=0$"
return buf
}
func g(*byte) string
func h(e int) {
var x [32]byte // ERROR "moved to heap: x$"
g(&f(x[:])[0])
}
type Node struct {
s string
left, right *Node
}
func walk(np **Node) int { // ERROR "leaking param content: np"
n := *np
w := len(n.s)
if n == nil {
return 0
}
wl := walk(&n.left)
wr := walk(&n.right)
if wl < wr {
n.left, n.right = n.right, n.left
wl, wr = wr, wl
}
*np = n
return w + wl + wr
}
// Test for bug where func var f used prototype's escape analysis results.
func prototype(xyz []string) {} // ERROR "prototype xyz does not escape"
func bar() {
var got [][]string
f := prototype
f = func(ss []string) { got = append(got, ss) } // ERROR "leaking param: ss" "func literal does not escape"
s := "string"
f([]string{s}) // ERROR "\[\]string literal escapes to heap"
}