runtime: skip trailing wrappers in runtime_expandFinalInlineFrame

The existing runtime_expandFinalInlineFrame implementation doesn't skip trailing wrappers, but
gentraceback does skip wrapper functions.
This change makes runtime_expandFinalInlineFrame handling wrapper functions consistent to gentraceback.

Fixes #58288

Change-Id: I1b0e2c10b0a89bcb1e787b98d27730cb40a34406
Reviewed-on: https://go-review.googlesource.com/c/go/+/465097
Reviewed-by: Michael Pratt <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Auto-Submit: Michael Pratt <[email protected]>
Run-TryBot: Michael Pratt <[email protected]>
Reviewed-by: David Chase <[email protected]>

Author: korniltsev

src/runtime/pprof/pprof_test.go

@@ -333,6 +333,23 @@ func inlinedCalleeDump(pcs []uintptr) {
 	dumpCallers(pcs)
 }
 
+type inlineWrapperInterface interface {
+	dump(stack []uintptr)
+}
+
+type inlineWrapper struct {
+}
+
+func (h inlineWrapper) dump(pcs []uintptr) {
+	dumpCallers(pcs)
+}
+
+func inlinedWrapperCallerDump(pcs []uintptr) {
+	var h inlineWrapperInterface
+	h = &inlineWrapper{}
+	h.dump(pcs)
+}
+
 func TestCPUProfileRecursion(t *testing.T) {
 	matches := matchAndAvoidStacks(stackContains, []string{"runtime/pprof.inlinedCallee", "runtime/pprof.recursionCallee", "runtime/pprof.recursionCaller"}, avoidFunctions())
 	p := testCPUProfile(t, matches, func(dur time.Duration) {
@@ -2054,6 +2071,8 @@ func TestTryAdd(t *testing.T) {
 	for i := range pcs {
 		inlinedCallerStack[i] = uint64(pcs[i])
 	}
+	wrapperPCs := make([]uintptr, 1)
+	inlinedWrapperCallerDump(wrapperPCs)
 
 	if _, found := findInlinedCall(recursionChainBottom, 4<<10); !found {
 		t.Skip("Can't determine whether anything was inlined into recursionChainBottom.")
@@ -2226,6 +2245,17 @@ func TestTryAdd(t *testing.T) {
 			{Value: []int64{70, 70 * period}, Location: []*profile.Location{{ID: 1}}},
 			{Value: []int64{80, 80 * period}, Location: []*profile.Location{{ID: 2}, {ID: 1}}},
 		},
+	}, {
+		name: "expand_wrapper_function",
+		input: []uint64{
+			3, 0, 500, // hz = 500. Must match the period.
+			4, 0, 50, uint64(wrapperPCs[0]),
+		},
+		count:    2,
+		wantLocs: [][]string{{"runtime/pprof.inlineWrapper.dump"}},
+		wantSamples: []*profile.Sample{
+			{Value: []int64{50, 50 * period}, Location: []*profile.Location{{ID: 1}}},
+		},
 	}}
 
 	for _, tc := range testCases {

src/runtime/symtab.go

@@ -230,7 +230,11 @@ func runtime_expandFinalInlineFrame(stk []uintptr) []uintptr {
 	}
 
 	// N.B. we want to keep the last parentPC which is not inline.
-	stk = append(stk, pc)
+	if f.funcID == funcID_wrapper && elideWrapperCalling(lastFuncID) {
+		// Ignore wrapper functions (except when they trigger panics).
+	} else {
+		stk = append(stk, pc)
+	}
 
 	return stk
 }