go/test/live_syscall.go
David Chase 9c066bab64 cmd/compile: mark temps with new AutoTemp flag, and use it.
This is an extension of
https://go-review.googlesource.com/c/31662/
to mark all the temporaries, not just the ssa-generated ones.

Before-and-after ls -l `go tool -n compile` shows a 3%
reduction in size (or rather, a prior 3% inflation for
failing to filter temps out properly.)

Replaced name-dependent "is it a temp?" tests with calls to
*Node.IsAutoTmp(), which depends on AutoTemp.  Also replace
calls to istemp(n) with n.IsAutoTmp(), to reduce duplication
and clean up function name space.  Generated temporaries
now come with a "." prefix to avoid (apparently harmless)
clashes with legal Go variable names.

Fixes #17644.
Fixes #17240.

Change-Id: If1417f29c79a7275d7303ddf859b51472890fd43
Reviewed-on: https://go-review.googlesource.com/32255
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-10-31 19:38:50 +00:00

28 lines
665 B
Go

// errorcheck -0 -m -live
// +build !windows
// 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 and liveness inferred for syscall.Syscall-like functions.
package p
import (
"syscall"
"unsafe"
)
func f(uintptr) // ERROR "f assuming arg#1 is unsafe uintptr"
func g() {
var t int
f(uintptr(unsafe.Pointer(&t))) // ERROR "live at call to f: .?autotmp" "g &t does not escape"
}
func h() {
var v int
syscall.Syscall(0, 1, uintptr(unsafe.Pointer(&v)), 2) // ERROR "live at call to Syscall: .?autotmp" "h &v does not escape"
}