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go/test/escape_struct_param1.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

299 lines
9.7 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 *struct function parameters.
// Note companion strict_param2 checks struct function parameters with similar tests.
package notmain
var Ssink *string
type U struct {
_sp *string
_spp **string
}
type V struct {
_u U
_up *U
_upp **U
}
func (u *U) SP() *string { // ERROR "leaking param: u to result ~r0 level=1$"
return u._sp
}
func (u *U) SPP() **string { // ERROR "leaking param: u to result ~r0 level=1$"
return u._spp
}
func (u *U) SPPi() *string { // ERROR "leaking param: u to result ~r0 level=2$"
return *u._spp
}
func tSPPi() {
s := "cat" // ERROR "moved to heap: s$"
ps := &s
pps := &ps
pu := &U{ps, pps} // ERROR "tSPPi &U literal does not escape$"
Ssink = pu.SPPi()
}
func tiSPP() {
s := "cat" // ERROR "moved to heap: s$"
ps := &s
pps := &ps
pu := &U{ps, pps} // ERROR "tiSPP &U literal does not escape$"
Ssink = *pu.SPP()
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of ps
func tSP() {
s := "cat" // ERROR "moved to heap: s$"
ps := &s // ERROR "moved to heap: ps$"
pps := &ps
pu := &U{ps, pps} // ERROR "tSP &U literal does not escape$"
Ssink = pu.SP()
}
func (v *V) u() U { // ERROR "leaking param: v to result ~r0 level=1$"
return v._u
}
func (v *V) UP() *U { // ERROR "leaking param: v to result ~r0 level=1$"
return v._up
}
func (v *V) UPP() **U { // ERROR "leaking param: v to result ~r0 level=1$"
return v._upp
}
func (v *V) UPPia() *U { // ERROR "leaking param: v to result ~r0 level=2$"
return *v._upp
}
func (v *V) UPPib() *U { // ERROR "leaking param: v to result ~r0 level=2$"
return *v.UPP()
}
func (v *V) USPa() *string { // ERROR "leaking param: v to result ~r0 level=1$"
return v._u._sp
}
func (v *V) USPb() *string { // ERROR "leaking param: v to result ~r0 level=1$"
return v.u()._sp
}
func (v *V) USPPia() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return *v._u._spp
}
func (v *V) USPPib() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return v._u.SPPi()
}
func (v *V) UPiSPa() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return v._up._sp
}
func (v *V) UPiSPb() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return v._up.SP()
}
func (v *V) UPiSPc() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return v.UP()._sp
}
func (v *V) UPiSPd() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return v.UP().SP()
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
func tUPiSPa() {
s1 := "ant"
s2 := "bat" // ERROR "moved to heap: s2$"
s3 := "cat" // ERROR "moved to heap: s3$"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4 // ERROR "moved to heap: ps4$"
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPa &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPa &V literal does not escape$"
Ssink = v.UPiSPa() // Ssink = &s3 (only &s3 really escapes)
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
func tUPiSPb() {
s1 := "ant"
s2 := "bat" // ERROR "moved to heap: s2$"
s3 := "cat" // ERROR "moved to heap: s3$"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4 // ERROR "moved to heap: ps4$"
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPb &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPb &V literal does not escape$"
Ssink = v.UPiSPb() // Ssink = &s3 (only &s3 really escapes)
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
func tUPiSPc() {
s1 := "ant"
s2 := "bat" // ERROR "moved to heap: s2$"
s3 := "cat" // ERROR "moved to heap: s3$"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4 // ERROR "moved to heap: ps4$"
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPc &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPc &V literal does not escape$"
Ssink = v.UPiSPc() // Ssink = &s3 (only &s3 really escapes)
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
func tUPiSPd() {
s1 := "ant"
s2 := "bat" // ERROR "moved to heap: s2$"
s3 := "cat" // ERROR "moved to heap: s3$"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4 // ERROR "moved to heap: ps4$"
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPd &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "&U literal escapes to heap$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPd &V literal does not escape$"
Ssink = v.UPiSPd() // Ssink = &s3 (only &s3 really escapes)
}
func (v V) UPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return *v._up._spp
}
func (v V) UPiSPPib() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return v._up.SPPi()
}
func (v V) UPiSPPic() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return *v.UP()._spp
}
func (v V) UPiSPPid() *string { // ERROR "leaking param: v to result ~r0 level=2$"
return v.UP().SPPi()
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
func tUPiSPPia() {
s1 := "ant"
s2 := "bat"
s3 := "cat"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPPia &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "tUPiSPPia &U literal does not escape$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPPia &V literal does not escape$"
Ssink = v.UPiSPPia() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
func tUPiSPPib() {
s1 := "ant"
s2 := "bat"
s3 := "cat"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPPib &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "tUPiSPPib &U literal does not escape$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPPib &V literal does not escape$"
Ssink = v.UPiSPPib() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
func tUPiSPPic() {
s1 := "ant"
s2 := "bat"
s3 := "cat"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPPic &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "tUPiSPPic &U literal does not escape$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPPic &V literal does not escape$"
Ssink = v.UPiSPPic() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
}
// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
func tUPiSPPid() {
s1 := "ant"
s2 := "bat"
s3 := "cat"
s4 := "dog" // ERROR "moved to heap: s4$"
s5 := "emu" // ERROR "moved to heap: s5$"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4
ps6 := &s6 // ERROR "moved to heap: ps6$"
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPiSPPid &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "tUPiSPPid &U literal does not escape$"
v := &V{u1, u2, &u3} // ERROR "tUPiSPPid &V literal does not escape$"
Ssink = v.UPiSPPid() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
}
func (v *V) UPPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=4$"
return *(*v._upp)._spp
}
// This test isolates the one value that needs to escape, not because
// it distinguishes fields but because it knows that &s6 is the only
// value reachable by two indirects from v.
// The test depends on the level cap in the escape analysis tags
// being able to encode that fact.
func tUPPiSPPia() {
s1 := "ant"
s2 := "bat"
s3 := "cat"
s4 := "dog"
s5 := "emu"
s6 := "fox" // ERROR "moved to heap: s6$"
ps2 := &s2
ps4 := &s4
ps6 := &s6
u1 := U{&s1, &ps2}
u2 := &U{&s3, &ps4} // ERROR "tUPPiSPPia &U literal does not escape$"
u3 := &U{&s5, &ps6} // ERROR "tUPPiSPPia &U literal does not escape$"
v := &V{u1, u2, &u3} // ERROR "tUPPiSPPia &V literal does not escape$"
Ssink = v.UPPiSPPia() // Ssink = *&ps6 = &s6 (only &s6 really escapes)
}