cmd/compile: only inline method wrapper if method don't contain closures

CL 327871 changes methodWrapper to always perform inlining after global
escape analysis. However, inlining the method may reveal closures, which
require walking all function bodies to decide whether to capture free
variables by value or by ref.

To fix it, just not doing inline if the method contains any closures.

Fixes #53702

Change-Id: I4b0255b86257cc6fe7e5fafbc545cc5cff9113e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/426334
Reviewed-by: Matthew Dempsky <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Run-TryBot: Cuong Manh Le <[email protected]>
Reviewed-by: Heschi Kreinick <[email protected]>

src/cmd/compile/internal/reflectdata/reflect.go

@@ -1904,14 +1904,14 @@ func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSy
 	// the TOC to the appropriate value for that module. But if it returns
 	// directly to the wrapper's caller, nothing will reset it to the correct
 	// value for that function.
+	var call *ir.CallExpr
 	if !base.Flag.Cfg.Instrumenting && rcvr.IsPtr() && methodrcvr.IsPtr() && method.Embedded != 0 && !types.IsInterfaceMethod(method.Type) && !(base.Ctxt.Arch.Name == "ppc64le" && base.Ctxt.Flag_dynlink) && !generic {
-		call := ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)
+		call = ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)
 		call.Args = ir.ParamNames(fn.Type())
 		call.IsDDD = fn.Type().IsVariadic()
 		fn.Body.Append(ir.NewTailCallStmt(base.Pos, call))
 	} else {
 		fn.SetWrapper(true) // ignore frame for panic+recover matching
-		var call *ir.CallExpr
 
 		if generic && dot.X != nthis {
 			// If there is embedding involved, then we should do the
@@ -1996,7 +1996,22 @@ func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSy
 	typecheck.Stmts(fn.Body)
 
 	if AfterGlobalEscapeAnalysis {
-		inline.InlineCalls(fn)
+		// Inlining the method may reveal closures, which require walking all function bodies
+		// to decide whether to capture free variables by value or by ref. So we only do inline
+		// if the method do not contain any closures, otherwise, the escape analysis may make
+		// dead variables resurrected, and causing liveness analysis confused, see issue #53702.
+		var canInline bool
+		switch x := call.X.(type) {
+		case *ir.Name:
+			canInline = len(x.Func.Closures) == 0
+		case *ir.SelectorExpr:
+			if x.Op() == ir.OMETHEXPR {
+				canInline = x.FuncName().Func != nil && len(x.FuncName().Func.Closures) == 0
+			}
+		}
+		if canInline {
+			inline.InlineCalls(fn)
+		}
 		escape.Batch([]*ir.Func{fn}, false)
 	}
 

test/run.go

@@ -535,10 +535,6 @@ func (ctxt *context) match(name string) bool {
 
 func init() {
 	checkShouldTest()
-	// TODO(cuonglm): remove once we fix non-unified frontend or when it gone.
-	if optimizationOff() {
-		delete(go118Failures, "fixedbugs/issue53702.go")
-	}
 }
 
 // goGcflags returns the -gcflags argument to use with go build / go run.
@@ -1986,7 +1982,6 @@ var types2Failures32Bit = setOf(
 )
 
 var go118Failures = setOf(
-	"fixedbugs/issue53702.go",  // 1.18 compiler failed with "Value live at entry" error
 	"fixedbugs/issue54343.go",  // 1.18 compiler assigns receiver parameter to global variable
 	"typeparam/nested.go",      // 1.18 compiler doesn't support function-local types with generics
 	"typeparam/issue51521.go",  // 1.18 compiler produces bad panic message and link error