From cb05a0aa6a05cbef05587f02473dbd7f6740b933 Mon Sep 17 00:00:00 2001 From: Matthew Dempsky Date: Tue, 5 Jan 2021 09:37:28 -0800 Subject: [PATCH] [dev.regabi] cmd/compile: remove toolstash scaffolding Now that CaptureVars is gone, we can remove the extra code in escape analysis that only served to appease toolstash -cmp. Change-Id: I8c811834f3d966e76702e2d362e3de414c94bea6 Reviewed-on: https://go-review.googlesource.com/c/go/+/281544 Run-TryBot: Matthew Dempsky TryBot-Result: Go Bot Trust: Matthew Dempsky Reviewed-by: Cuong Manh Le --- src/cmd/compile/internal/escape/escape.go | 69 ++----------------- .../compile/internal/logopt/logopt_test.go | 1 - test/chancap.go | 1 - test/fixedbugs/issue4085b.go | 1 - 4 files changed, 4 insertions(+), 68 deletions(-) diff --git a/src/cmd/compile/internal/escape/escape.go b/src/cmd/compile/internal/escape/escape.go index 2222f98003..5df82d8cdc 100644 --- a/src/cmd/compile/internal/escape/escape.go +++ b/src/cmd/compile/internal/escape/escape.go @@ -116,12 +116,6 @@ type escape struct { // label with a corresponding backwards "goto" (i.e., // unstructured loop). loopDepth int - - // loopSlop tracks how far off typecheck's "decldepth" variable - // would be from loopDepth at the same point during type checking. - // It's only needed to match CaptureVars's pessimism until it can be - // removed entirely. - loopSlop int } // An location represents an abstract location that stores a Go @@ -131,7 +125,6 @@ type location struct { curfn *ir.Func // enclosing function edges []edge // incoming edges loopDepth int // loopDepth at declaration - loopSlop int // loopSlop at declaration // derefs and walkgen are used during walkOne to track the // minimal dereferences from the walk root. @@ -233,14 +226,10 @@ func Batch(fns []*ir.Func, recursive bool) { // can decide whether closures should capture their free variables // by value or reference. for _, closure := range b.closures { - b.flowClosure(closure.k, closure.clo, false) + b.flowClosure(closure.k, closure.clo) } b.closures = nil - for _, orphan := range findOrphans(fns) { - b.flowClosure(b.blankLoc.asHole(), orphan, true) - } - for _, loc := range b.allLocs { if why := HeapAllocReason(loc.n); why != "" { b.flow(b.heapHole().addr(loc.n, why), loc) @@ -251,46 +240,6 @@ func Batch(fns []*ir.Func, recursive bool) { b.finish(fns) } -// findOrphans finds orphaned closure expressions that were originally -// contained within a function in fns, but were lost due to earlier -// optimizations. -// TODO(mdempsky): Remove after CaptureVars is gone. -func findOrphans(fns []*ir.Func) []*ir.ClosureExpr { - have := make(map[*ir.Func]bool) - for _, fn := range fns { - have[fn] = true - } - - parent := func(fn *ir.Func) *ir.Func { - if len(fn.ClosureVars) == 0 { - return nil - } - cv := fn.ClosureVars[0] - if cv.Defn == nil { - return nil // method value wrapper - } - return cv.Outer.Curfn - } - - outermost := func(fn *ir.Func) *ir.Func { - for { - outer := parent(fn) - if outer == nil { - return fn - } - fn = outer - } - } - - var orphans []*ir.ClosureExpr - for _, fn := range typecheck.Target.Decls { - if fn, ok := fn.(*ir.Func); ok && have[outermost(fn)] && !have[fn] { - orphans = append(orphans, fn.OClosure) - } - } - return orphans -} - func (b *batch) with(fn *ir.Func) *escape { return &escape{ batch: b, @@ -348,15 +297,11 @@ func (b *batch) walkFunc(fn *ir.Func) { } } -func (b *batch) flowClosure(k hole, clo *ir.ClosureExpr, orphan bool) { +func (b *batch) flowClosure(k hole, clo *ir.ClosureExpr) { for _, cv := range clo.Func.ClosureVars { n := cv.Canonical() - if n.Opt == nil && orphan { - continue // n.Curfn must have been an orphan too - } - loc := b.oldLoc(cv) - if !loc.captured && !orphan { + if !loc.captured { base.FatalfAt(cv.Pos(), "closure variable never captured: %v", cv) } @@ -454,9 +399,6 @@ func (e *escape) stmt(n ir.Node) { if base.Flag.LowerM > 2 { fmt.Printf("%v:%v non-looping label\n", base.FmtPos(base.Pos), n) } - if s := n.Label.Name; !strings.HasPrefix(s, ".") && !strings.Contains(s, "ยท") { - e.loopSlop++ - } case looping: if base.Flag.LowerM > 2 { fmt.Printf("%v: %v looping label\n", base.FmtPos(base.Pos), n) @@ -597,7 +539,6 @@ func (e *escape) stmts(l ir.Nodes) { func (e *escape) block(l ir.Nodes) { old := e.loopDepth e.stmts(l) - e.loopSlop += e.loopDepth - old e.loopDepth = old } @@ -821,7 +762,7 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) { // Ignore reassignments to the variable in straightline code // preceding the first capture by a closure. - if loc.loopDepth+loc.loopSlop == e.loopDepth+e.loopSlop { + if loc.loopDepth == e.loopDepth { loc.reassigned = false } } @@ -1286,7 +1227,6 @@ func (e *escape) dcl(n *ir.Name) hole { } loc := e.oldLoc(n) loc.loopDepth = e.loopDepth - loc.loopSlop = e.loopSlop return loc.asHole() } @@ -1323,7 +1263,6 @@ func (e *escape) newLoc(n ir.Node, transient bool) *location { n: n, curfn: e.curfn, loopDepth: e.loopDepth, - loopSlop: e.loopSlop, transient: transient, } e.allLocs = append(e.allLocs, loc) diff --git a/src/cmd/compile/internal/logopt/logopt_test.go b/src/cmd/compile/internal/logopt/logopt_test.go index 1d1e21b060..71976174b0 100644 --- a/src/cmd/compile/internal/logopt/logopt_test.go +++ b/src/cmd/compile/internal/logopt/logopt_test.go @@ -154,7 +154,6 @@ func s15a8(x *[15]int64) [15]int64 { // On not-amd64, test the host architecture and os arches := []string{runtime.GOARCH} goos0 := runtime.GOOS - goos0 = "" + goos0 // TODO(mdempsky): Remove once CaptureVars is gone. if runtime.GOARCH == "amd64" { // Test many things with "linux" (wasm will get "js") arches = []string{"arm", "arm64", "386", "amd64", "mips", "mips64", "ppc64le", "riscv64", "s390x", "wasm"} goos0 = "linux" diff --git a/test/chancap.go b/test/chancap.go index 3a4f67638a..8dce9247cd 100644 --- a/test/chancap.go +++ b/test/chancap.go @@ -41,7 +41,6 @@ func main() { n := -1 shouldPanic("makechan: size out of range", func() { _ = make(T, n) }) shouldPanic("makechan: size out of range", func() { _ = make(T, int64(n)) }) - n = 0 + n // TODO(mdempsky): Remove once CaptureVars is gone. if ptrSize == 8 { // Test mem > maxAlloc var n2 int64 = 1 << 59 diff --git a/test/fixedbugs/issue4085b.go b/test/fixedbugs/issue4085b.go index b69e10c6cc..cf27512da0 100644 --- a/test/fixedbugs/issue4085b.go +++ b/test/fixedbugs/issue4085b.go @@ -22,7 +22,6 @@ func main() { testMakeInAppend(n) var t *byte - n = 0 + n // TODO(mdempsky): Remove once CaptureVars is gone. if unsafe.Sizeof(t) == 8 { // Test mem > maxAlloc var n2 int64 = 1 << 59