Revert "runtime: make stack traces of endless recursion print only to…

…p and bottom 50" This reverts commit 3a81338. Reason for revert: Some edge cases not properly covered due to changes within runtime traceback generation since 2017, that need to be examined. This change landed very late in the Go1.16 cycle. Change-Id: I8cf6f46ea0ef6161d878e79943e6c7cdac94bccf Reviewed-on: https://go-review.googlesource.com/c/go/+/268577 Trust: Emmanuel Odeke <[email protected]> Run-TryBot: Emmanuel Odeke <[email protected]> TryBot-Result: Go Bot <[email protected]> Reviewed-by: Keith Randall <[email protected]>
open-fork · Nov 9, 2020 · d495712 · d495712
1 parent 8badef4
commit d495712
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Showing 3 changed files with 47 additions and 265 deletions.
diff --git a/src/runtime/crash_test.go b/src/runtime/crash_test.go
@@ -240,132 +240,6 @@ func TestStackOverflow(t *testing.T) {
 	}
 }
 
-func TestStackOverflowTopAndBottomTraces(t *testing.T) {
-	output := runTestProg(t, "testprog", "StackOverflowTopAndBottomTraces")
-
-	// 1. First things first, we expect to traverse from
-	//    runtime: goroutine stack exceeds 10000-byte limit
-	// and down to the very end until we see:
-	//    runtime.goexit()
-	mustHaves := []string{
-		// Top half expectations
-		"\\s*runtime: goroutine stack exceeds 10000-byte limit\n",
-		"\\s*fatal error: stack overflow\n",
-		"\\s*runtime stack:\n",
-		"\\s*runtime.throw[^\n]+\n\t.+:\\d+ [^\n]+",
-		"\\s+runtime\\.newstack[^\n]+\n\t.+:\\d+ [^\n]+",
-		"\\s+runtime.morestack[^\n]+\n\t.+:\\d+ [^\n]+",
-		"\\s+goroutine 1 \\[running\\]:",
-
-		// Bottom half expectations
-		"\\s*main.main\\(\\)\n",
-		"\\s*runtime.main\\(\\)\n",
-		"\\s*runtime.goexit\\(\\)\n",
-	}
-
-	for _, pat := range mustHaves {
-		reg := regexp.MustCompile(pat)
-		match := reg.FindAllString(output, -1)
-		if len(match) == 0 {
-			t.Errorf("Failed to find pattern %q", pat)
-		}
-	}
-
-	// 2. Split top and bottom halves by the "... ({n} stack frames omitted)" message
-	regHalving := regexp.MustCompile("\\.{3} \\(\\d+ stack frames omitted\\)")
-	halverMatches := regHalving.FindAllString(output, -1)
-	if len(halverMatches) != 1 {
-		t.Fatal("Failed to find the `stack frames omitted` pattern")
-	}
-	str := string(output)
-	halver := halverMatches[0]
-	midIndex := strings.Index(str, halver)
-	topHalf, bottomHalf := str[:midIndex], str[midIndex+len(halver):]
-	// 2.1. Sanity check, len(topHalf) >= halver || len(bottomHalf) >= halver
-	if len(topHalf) < len(halver) || len(bottomHalf) < len(halver) {
-		t.Fatalf("Sanity check len(topHalf) = %d len(bottomHalf) = %d; both must be >= len(halver) %d",
-			len(topHalf), len(bottomHalf), len(halver))
-	}
-
-	// 3. In each of the halves, we should have an equal number
-	// of stacktraces before and after the "omitted frames" message.
-	regStackTraces := regexp.MustCompile("\n[^\n]+\n\t.+:\\d+ .+ fp=0x.+ sp=0x.+ pc=0x.+")
-	topHalfStackTraces := regStackTraces.FindAllString(topHalf, -1)
-	bottomHalfStackTraces := regStackTraces.FindAllString(bottomHalf, -1)
-	nTopHalf, nBottomHalf := len(topHalfStackTraces), len(bottomHalfStackTraces)
-	if nTopHalf == 0 || nBottomHalf == 0 {
-		t.Fatal("Both lengths of stack-halves should be non-zero")
-	}
-	// The bottom half will always have the 50 non-runtime frames along with these 3 frames:
-	// * main.main()
-	// * "runtime.main"
-	// * "runtime.goexit"
-	// hence we need to decrement 3 counted lines.
-	if nTopHalf != nBottomHalf-3 {
-		t.Errorf("len(topHalfStackTraces)=%d len(bottomHalfStackTraces)-3=%d yet must be equal\n", nTopHalf, nBottomHalf-3)
-	}
-
-	// 4. Next, prune out the:
-	// func...
-	//    line...
-	// pairs in both of the halves.
-	prunes := []struct {
-		src     *string
-		matches []string
-	}{
-		{src: &topHalf, matches: topHalfStackTraces},
-		{src: &bottomHalf, matches: bottomHalfStackTraces},
-	}
-
-	for _, prune := range prunes {
-		str := *prune.src
-		for _, match := range prune.matches {
-			index := strings.Index(str, match)
-			str = str[:index] + str[index+len(match):]
-		}
-		*prune.src = str
-	}
-
-	// 5. Now match and prune out the remaining patterns in the top and bottom halves.
-	// We aren't touching the bottom stack since its patterns are already matched
-	// by the:
-	//    func...
-	//	 line...
-	// pairs
-	topPartPrunables := []string{
-		"^\\s*runtime: goroutine stack exceeds 10000-byte limit\n",
-		"\\s*fatal error: stack overflow\n",
-		"\\s*runtime stack:\n",
-		"\\s*runtime.throw[^\n]+\n\t.+:\\d+ [^\n]+",
-		"\\s+runtime\\.newstack[^\n]+\n\t.+:\\d+ [^\n]+",
-		"\\s+runtime.morestack[^\n]+\n\t.+:\\d+ [^\n]+",
-		"\\s+goroutine 1 \\[running\\]:",
-	}
-
-	for _, pat := range topPartPrunables {
-		reg := regexp.MustCompile(pat)
-		matches := reg.FindAllString(topHalf, -1)
-		if len(matches) == 0 {
-			t.Errorf("top stack traces do not contain pattern: %q", reg)
-		} else if len(matches) != 1 {
-			t.Errorf("inconsistent state got %d matches want only 1", len(matches))
-		} else {
-			match := matches[0]
-			idx := strings.Index(topHalf, match)
-			topHalf = topHalf[:idx] + topHalf[idx+len(match):]
-		}
-	}
-
-	// 6. At the end we should only be left with
-	// newlines in both the top and bottom halves.
-	topHalf = strings.TrimSpace(topHalf)
-	bottomHalf = strings.TrimSpace(bottomHalf)
-	if topHalf != "" && bottomHalf != "" {
-		t.Fatalf("len(topHalf)=%d len(bottomHalf)=%d\ntopHalf=\n%s\n\nbottomHalf=\n%s",
-			len(topHalf), len(bottomHalf), topHalf, bottomHalf)
-	}
-}
-
 func TestThreadExhaustion(t *testing.T) {
 	output := runTestProg(t, "testprog", "ThreadExhaustion")
 	want := "runtime: program exceeds 10-thread limit\nfatal error: thread exhaustion"

diff --git a/src/runtime/testdata/testprog/deadlock.go b/src/runtime/testdata/testprog/deadlock.go
@@ -20,7 +20,6 @@ func init() {
 	register("LockedDeadlock2", LockedDeadlock2)
 	register("GoexitDeadlock", GoexitDeadlock)
 	register("StackOverflow", StackOverflow)
-	register("StackOverflowTopAndBottomTraces", StackOverflowTopAndBottomTraces)
 	register("ThreadExhaustion", ThreadExhaustion)
 	register("RecursivePanic", RecursivePanic)
 	register("RecursivePanic2", RecursivePanic2)
@@ -86,18 +85,6 @@ func StackOverflow() {
 	f()
 }
 
-func StackOverflowTopAndBottomTraces() {
-	var fi, gi func()
-	fi = func() {
-		gi()
-	}
-	gi = func() {
-		fi()
-	}
-	debug.SetMaxStack(10000)
-	fi()
-}
-
 func ThreadExhaustion() {
 	debug.SetMaxThreads(10)
 	c := make(chan int)