From b9704872d11ae224ca96a1bd2fab0da10ce806d7 Mon Sep 17 00:00:00 2001 From: Matthew Dempsky Date: Wed, 4 Sep 2019 15:16:25 -0700 Subject: [PATCH] cmd/compile: better integrate parameter tagging with escape.go This CL moves parameter tagging to before escape analysis is complete, so we still have access to EscLocation. This will be useful once EscLocation starts tracking higher-fidelity escape details. Notably, this CL stops using n.Esc to record parameter escape analysis details. Now escape analysis only ever sets n.Esc to EscNone or EscHeap. (It still defaults to EscUnknown, and is set to EscNever in some places though.) Passes toolstash-check. Updates #33981. Change-Id: I50a91ea1e38c442092de6cd14e20b211f8f818c9 Reviewed-on: https://go-review.googlesource.com/c/go/+/193178 Run-TryBot: Matthew Dempsky TryBot-Result: Gobot Gobot Reviewed-by: Cherry Zhang --- src/cmd/compile/internal/gc/esc.go | 44 ++++++++++++++++-------- src/cmd/compile/internal/gc/escape.go | 49 ++++++++++----------------- test/uintptrescapes2.go | 2 +- 3 files changed, 49 insertions(+), 46 deletions(-) diff --git a/src/cmd/compile/internal/gc/esc.go b/src/cmd/compile/internal/gc/esc.go index 2ade014e795..c350d7c1bc0 100644 --- a/src/cmd/compile/internal/gc/esc.go +++ b/src/cmd/compile/internal/gc/esc.go @@ -405,19 +405,7 @@ const unsafeUintptrTag = "unsafe-uintptr" // marked go:uintptrescapes. const uintptrEscapesTag = "uintptr-escapes" -func esctag(fn *Node) { - fn.Esc = EscFuncTagged - - narg := 0 - for _, fs := range types.RecvsParams { - for _, f := range fs(fn.Type).Fields().Slice() { - narg++ - f.Note = escparamtag(fn, narg, f) - } - } -} - -func escparamtag(fn *Node, narg int, f *types.Field) string { +func (e *Escape) paramTag(fn *Node, narg int, f *types.Field) string { name := func() string { if f.Sym != nil { return f.Sym.Name @@ -446,8 +434,15 @@ func escparamtag(fn *Node, narg int, f *types.Field) string { // External functions are assumed unsafe, unless // //go:noescape is given before the declaration. if fn.Noescape() { + if Debug['m'] != 0 && f.Sym != nil { + Warnl(fn.Pos, "%S %v does not escape", funcSym(fn), name()) + } return mktag(EscNone) } + + if Debug['m'] != 0 && f.Sym != nil { + Warnl(fn.Pos, "leaking param: %v", name()) + } return mktag(EscHeap) } @@ -477,5 +472,26 @@ func escparamtag(fn *Node, narg int, f *types.Field) string { } n := asNode(f.Nname) - return mktag(int(n.Esc)) + loc := e.oldLoc(n) + esc := finalizeEsc(loc.paramEsc) + + if Debug['m'] != 0 && !loc.escapes { + if esc == EscNone { + Warnl(n.Pos, "%S %S does not escape", funcSym(fn), n) + } else if esc == EscHeap { + Warnl(n.Pos, "leaking param: %S", n) + } else { + if esc&EscContentEscapes != 0 { + Warnl(n.Pos, "leaking param content: %S", n) + } + for i := 0; i < numEscReturns; i++ { + if x := getEscReturn(esc, i); x >= 0 { + res := n.Name.Curfn.Type.Results().Field(i).Sym + Warnl(n.Pos, "leaking param: %S to result %v level=%d", n, res, x) + } + } + } + } + + return mktag(int(esc)) } diff --git a/src/cmd/compile/internal/gc/escape.go b/src/cmd/compile/internal/gc/escape.go index c428fb35a07..ff958beef3e 100644 --- a/src/cmd/compile/internal/gc/escape.go +++ b/src/cmd/compile/internal/gc/escape.go @@ -147,12 +147,7 @@ func escapeFuncs(fns []*Node, recursive bool) { e.curfn = nil e.walkAll() - e.finish() - - // Record parameter tags for package export data. - for _, fn := range fns { - esctag(fn) - } + e.finish(fns) } func (e *Escape) initFunc(fn *Node) { @@ -1258,7 +1253,20 @@ func (l *EscLocation) leakTo(sink *EscLocation, derefs int) { } } -func (e *Escape) finish() { +func (e *Escape) finish(fns []*Node) { + // Record parameter tags for package export data. + for _, fn := range fns { + fn.Esc = EscFuncTagged + + narg := 0 + for _, fs := range types.RecvsParams { + for _, f := range fs(fn.Type).Fields().Slice() { + narg++ + f.Note = e.paramTag(fn, narg, f) + } + } + } + for _, loc := range e.allLocs { n := loc.n if n == nil { @@ -1279,27 +1287,10 @@ func (e *Escape) finish() { } n.Esc = EscHeap addrescapes(n) - } else if loc.isName(PPARAM) { - n.Esc = finalizeEsc(loc.paramEsc) - - if Debug['m'] != 0 && types.Haspointers(n.Type) { - if n.Esc == EscNone { - Warnl(n.Pos, "%S %S does not escape", funcSym(loc.curfn), n) - } else if n.Esc == EscHeap { - Warnl(n.Pos, "leaking param: %S", n) - } else { - if n.Esc&EscContentEscapes != 0 { - Warnl(n.Pos, "leaking param content: %S", n) - } - for i := 0; i < numEscReturns; i++ { - if x := getEscReturn(n.Esc, i); x >= 0 { - res := n.Name.Curfn.Type.Results().Field(i).Sym - Warnl(n.Pos, "leaking param: %S to result %v level=%d", n, res, x) - } - } - } - } } else { + if Debug['m'] != 0 && n.Op != ONAME && n.Op != OTYPESW && n.Op != ORANGE && n.Op != ODEFER { + Warnl(n.Pos, "%S %S does not escape", funcSym(loc.curfn), n) + } n.Esc = EscNone if loc.transient { switch n.Op { @@ -1307,10 +1298,6 @@ func (e *Escape) finish() { n.SetNoescape(true) } } - - if Debug['m'] != 0 && n.Op != ONAME && n.Op != OTYPESW && n.Op != ORANGE && n.Op != ODEFER { - Warnl(n.Pos, "%S %S does not escape", funcSym(loc.curfn), n) - } } } } diff --git a/test/uintptrescapes2.go b/test/uintptrescapes2.go index b8117b857bf..866efd94d84 100644 --- a/test/uintptrescapes2.go +++ b/test/uintptrescapes2.go @@ -18,7 +18,7 @@ func F1(a uintptr) {} // ERROR "escaping uintptr" //go:uintptrescapes //go:noinline -func F2(a ...uintptr) {} // ERROR "escaping ...uintptr" "a does not escape" +func F2(a ...uintptr) {} // ERROR "escaping ...uintptr" //go:uintptrescapes //go:noinline