internal/telemetry/cmd/stacks: cmd/compile reopen

Support re-opening issues for the compiler.

Fixes golang/go#71045.

Change-Id: I6e5dad81220c74923919b4c72f7bc1089af6c37d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/644018
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

Author: jba

gopls/internal/telemetry/cmd/stacks/stacks.go

@@ -626,13 +626,23 @@ func shouldReopen(issue *Issue, stacks map[string]map[Info]int64) bool {
 	if !ok {
 		return false
 	}
-	// TODO(jba?): handle other programs
-	if issueProgram != "gopls" {
-		return false
+
+	matchProgram := func(infoProg string) bool {
+		switch issueProgram {
+		case "gopls":
+			return path.Base(infoProg) == issueProgram
+		case "go":
+			// At present, we only care about compiler stacks.
+			// Issues should have milestones like "Go1.24".
+			return infoProg == "cmd/compile"
+		default:
+			return false
+		}
 	}
+
 	for _, stack := range issue.newStacks {
 		for info := range stacks[stack] {
-			if path.Base(info.Program) == issueProgram && semver.Compare(info.ProgramVersion, issueVersion) >= 0 {
+			if matchProgram(info.Program) && semver.Compare(semVer(info.ProgramVersion), issueVersion) >= 0 {
 				log.Printf("reopening issue #%d: purportedly fixed in %s@%s, but found a new stack from version %s",
 					issue.Number, issueProgram, issueVersion, info.ProgramVersion)
 				return true
@@ -647,19 +657,46 @@ func (i *Issue) isFixed() bool {
 	return i.State == "closed" && i.StateReason == "completed"
 }
 
-// parseMilestone parses a the title of a GitHub milestone that is in the format
-// PROGRAM/VERSION. For example, "gopls/v0.17.0".
+// parseMilestone parses a the title of a GitHub milestone.
+// If  it is in the format PROGRAM/VERSION (for example, "gopls/v0.17.0"),
+// then it returns PROGRAM and VERSION.
+// If it is in the format Go1.X, then it returns "go" as the program and
+// "v1.X" or "v1.X.0" as the version.
+// Otherwise, the last return value is false.
 func parseMilestone(m *Milestone) (program, version string, ok bool) {
 	if m == nil {
 		return "", "", false
 	}
+	if strings.HasPrefix(m.Title, "Go") {
+		v := semVer(m.Title)
+		if !semver.IsValid(v) {
+			return "", "", false
+		}
+		return "go", v, true
+	}
 	program, version, ok = morestrings.CutLast(m.Title, "/")
 	if !ok || program == "" || version == "" || version[0] != 'v' {
 		return "", "", false
 	}
 	return program, version, true
 }
 
+// semVer returns a semantic version for its argument, which may already be
+// a semantic version, or may be a Go version.
+//
+//	 v1.2.3 => v1.2.3
+//		go1.24 => v1.24
+//		Go1.23.5 => v1.23.5
+//	 goHome => vHome
+//
+// It returns "", false if the go version is in the wrong format.
+func semVer(v string) string {
+	if strings.HasPrefix(v, "go") || strings.HasPrefix(v, "Go") {
+		return "v" + v[2:]
+	}
+	return v
+}
+
 // stackID returns a 32-bit identifier for a stack
 // suitable for use in GitHub issue titles.
 func stackID(stack string) string {

gopls/internal/telemetry/cmd/stacks/stacks_test.go

@@ -269,7 +269,8 @@ func TestMarshalUpdateIssueFields(t *testing.T) {
 func TestShouldReopen(t *testing.T) {
 	const stack = "stack"
 	const gopls = "golang.org/x/tools/gopls"
-	const milestoneVersion = "v0.2.0"
+	goplsMilestone := &Milestone{Title: "gopls/v0.2.0"}
+	goMilestone := &Milestone{Title: "Go1.23"}
 
 	for _, tc := range []struct {
 		name  string
@@ -279,44 +280,61 @@ func TestShouldReopen(t *testing.T) {
 	}{
 		{
 			"issue open",
-			Issue{State: "open"},
+			Issue{State: "open", Milestone: goplsMilestone},
 			Info{Program: gopls, ProgramVersion: "v0.2.0"},
 			false,
 		},
 		{
 			"issue closed but not fixed",
-			Issue{State: "closed", StateReason: "not_planned"},
+			Issue{State: "closed", StateReason: "not_planned", Milestone: goplsMilestone},
 			Info{Program: gopls, ProgramVersion: "v0.2.0"},
 			false,
 		},
 		{
 			"different program",
-			Issue{State: "closed", StateReason: "completed"},
+			Issue{State: "closed", StateReason: "completed", Milestone: goplsMilestone},
 			Info{Program: "other", ProgramVersion: "v0.2.0"},
 			false,
 		},
 		{
 			"later version",
-			Issue{State: "closed", StateReason: "completed"},
+			Issue{State: "closed", StateReason: "completed", Milestone: goplsMilestone},
 			Info{Program: gopls, ProgramVersion: "v0.3.0"},
 			true,
 		},
 		{
 			"earlier version",
-			Issue{State: "closed", StateReason: "completed"},
+			Issue{State: "closed", StateReason: "completed", Milestone: goplsMilestone},
 			Info{Program: gopls, ProgramVersion: "v0.1.0"},
 			false,
 		},
 		{
 			"same version",
-			Issue{State: "closed", StateReason: "completed"},
+			Issue{State: "closed", StateReason: "completed", Milestone: goplsMilestone},
 			Info{Program: gopls, ProgramVersion: "v0.2.0"},
 			true,
 		},
+		{
+			"compiler later version",
+			Issue{State: "closed", StateReason: "completed", Milestone: goMilestone},
+			Info{Program: "cmd/compile", ProgramVersion: "go1.24"},
+			true,
+		},
+		{
+			"compiler earlier version",
+			Issue{State: "closed", StateReason: "completed", Milestone: goMilestone},
+			Info{Program: "cmd/compile", ProgramVersion: "go1.22"},
+			false,
+		},
+		{
+			"compiler same version",
+			Issue{State: "closed", StateReason: "completed", Milestone: goMilestone},
+			Info{Program: "cmd/compile", ProgramVersion: "go1.23"},
+			true,
+		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			tc.issue.Number = 1
-			tc.issue.Milestone = &Milestone{Title: "gopls/" + milestoneVersion}
 			tc.issue.newStacks = []string{stack}
 			got := shouldReopen(&tc.issue, map[string]map[Info]int64{stack: map[Info]int64{tc.info: 1}})
 			if got != tc.want {